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Articles by Maher Albitar in JoVE

Other articles by Maher Albitar on PubMed

Prognostic Factors and Scoring Systems in Chronic Myelomonocytic Leukemia: a Retrospective Analysis of 213 Patients

Blood. Feb, 2002  |  Pubmed ID: 11806985

Chronic myelomonocytic leukemia (CMML) is a hematologic malignancy characterized by wide heterogeneity of clinical presentation and course. CMML shares myelodysplastic characteristics with features of myeloproliferative disorders. No treatment has proven effective in modifying the natural course of the disease. To improve the prognostic assessment of clinical outcome, the associations of patient and disease characteristics with survival times of 213 patients with CMML was investigated retrospectively. Median survival was 12 months. Univariate analysis identified low hemoglobin level; low platelet count; high white blood cell, monocyte, and lymphocyte counts; presence of circulating immature myeloid cells, high percentage of marrow blasts, low percentage of marrow erythroid cells, abnormal cytogenetics, and high levels of serum lactate dehydrogenase and beta(2)-microglobulin as characteristics associated with shorter survival. Hemoglobin level below 120 g/L (12 g/dL), presence of circulating immature myeloid cells, absolute lymphocyte count above 2.5 x 10(9)/L, and marrow blasts 10% or more were independently associated with shorter survival by multivariate analysis and were used to generate a prognostic score. The model identified 4 subgroups of patients with median survival of 24, 15, 8, and 5 months for low, intermediate-1, intermediate-2, and high risk, respectively. Researchers could not confer objective evidence suggesting that arbitrary divisions of CMML by white blood cell counts into "dysplastic" and "proliferative" categories reflect clinical entities differing in the risk of acute leukemia development, although a trend of shorter survival in patients with leukocytosis was observed. The prognostic model was compared with 6 previously published scoring systems for myelodysplastic syndrome/CMML. The reported results should provide an improved assessment of prognosis in CMML.

Clinical Significance of Plasma Endostatin in Acute Myeloid Leukemia/myelodysplastic Syndrome

Cancer. Jan, 2002  |  Pubmed ID: 11815955

Endostatin, a C-terminal fragment of collagen XVIII, is an endogenous angiogenesis inhibitor. While endostatin is being investigated for its usefulness in treating solid tumors, its significance in hematologic malignancies is unknown.

Comparison Between Pediatric Acute Myeloid Leukemia (AML) and Adult AML in VEGF and KDR (VEGF-R2) Protein Levels

Leukemia Research. Apr, 2002  |  Pubmed ID: 11839384

We reported previously that high levels of vascular endothelial growth factor (VEGF) were associated with shorter survival in adult acute myeloid leukemia (AML) patients. In this study, cellular VEGF and its receptor, VEGF-R2 (kinase domain receptor (KDR)), were analyzed in 45 pediatric AML patients using Western blot and solid-phase radioimmunoassay (RIA). Cellular VEGF levels were significantly lower in pediatric AML compared to adult AML patients. In contrast, there was no significant difference in VEGF-R2 levels between adult and pediatric AML. Higher VEGF and VEGF-R2 levels in pediatric AML patients correlated with higher white blood cell (WBC). Unlike in adults, VEGF and VEGF-R2 levels in pediatric AML patients did not correlate with survival. This data suggest that the role of VEGF and its receptor VEGF-R2 in pediatrics AML may be different from that in adult AML.

Emerging Information on the Use of Rituximab in Chronic Lymphocytic Leukemia

Seminars in Oncology. Feb, 2002  |  Pubmed ID: 11842391

Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA, and IDEC Pharmaceuticals, San Diego, CA) is a chimeric monoclonal antibody that targets mature B cells in most lymphoid B-cell malignancies. While rituximab was approved by the US Food and Drug Administration for the treatment of recurrent B-cell lymphoma, initial studies suggested that it had less activity in small lymphocytic lymphoma, the nodal counterpart of chronic lymphocytic leukemia (CLL). Two studies have now investigated the activity of higher-dose and more intensive therapy with rituximab in CLL. They have shown a dose-response relationship and a higher response rate than previously seen in the lower-dose studies. This is presumably caused by the overcoming of lower antigen density on CLL cells compared with lymphoma cells, and the shorter half-life of rituximab in small lymphocytic lymphoma. There is now evidence that CD20 is shed into the plasma in patients with CLL, which may explain the shorter half-life of the antibody in small lymphocytic lymphoma/CLL. The higher dose may then be effective in overcoming this so-called "antigen sink." Toxicity was uncommon except in previously untreated patients and those with atypical forms of CLL such as mantle cell lymphoma and prolymphocytic leukemia. There is now evidence in vitro of additive or synergistic activity of rituximab with a variety of chemotherapeutic agents including fludarabine and cyclophosphamide. Combinations of fludarabine with rituximab or these two drugs combined with cyclophosphamide have given very high complete response rates in series of patients with both previously untreated and treated CLL. It is apparent that rituximab is playing a significant role in the management of patients with CLL as salvage therapy and is a potential potentiating agent for combined chemoimmunotherapy strategies for front-line or relapsed patients with CLL.

Prognostic Significance of Cellular Vascular Endothelial Growth Factor Expression in Chronic Phase Chronic Myeloid Leukemia

Blood. Mar, 2002  |  Pubmed ID: 11877311

The impact of elevated vascular endothelial growth factor (VEGF) expression on the course of chronic myeloid leukemia (CML) is unknown. By radioimmunoassay, we measured pretreatment cellular VEGF protein in bone marrow samples from 184 (148 chronic and 36 accelerated/blastic phases) CML patients and found the levels to be 1.6-fold higher than in 31 normal control bone marrow samples (P =.000 01). No significant differences were found in VEGF levels by different phases of CML (P =.1). VEGF levels correlated with older age (P =.01) and higher platelet count (P =.0003), but also with smaller spleen size (P =.004), lower white blood cell count (P =.0006), and lower percentage of peripheral blasts (P =.04). With the use of Cox proportional hazard model and VEGF levels as a continuous variable, high VEGF levels correlated with shorter survival of patients in chronic CML (P =.008). Multivariate analysis showed that VEGF was not independent of the synthesis stage (P =.09). These data suggest that VEGF plays a role in the biology of CML and that VEGF inhibitors should be investigated in CML.

Hepatocytes and Epithelial Cells of Donor Origin in Recipients of Peripheral-blood Stem Cells

The New England Journal of Medicine. Mar, 2002  |  Pubmed ID: 11882729

Bone marrow contains stem cells with the potential to differentiate into mature cells of various organs. We determined whether circulating stem cells have a similar potential.

Polymerase Chain Reaction on Blood for the Diagnosis of Invasive Pulmonary Aspergillosis in Cancer Patients

Cancer. Feb, 2002  |  Pubmed ID: 11920473

The premortem diagnosis of invasive pulmonary aspergillosis (IPA) is difficult to make and often missed. Several retrospective studies have suggested that Aspergillus polymerase chain reaction (PCR) performed on serum or whole blood is useful in diagnosing IPA. Two prospective studies confirmed this finding but included a small number of IPA cases.

Prognostic Significance of Tie-1 Protein Expression in Patients with Early Chronic Phase Chronic Myeloid Leukemia

Cancer. Mar, 2002  |  Pubmed ID: 11920509

The Tie-1 tyrosine kinase receptor and its thus far unidentified ligand appear to play a distinct role in the regulatory pathways of early hematopoiesis and angiogenesis. Because vascularity is increased in the bone marrow of patients with chronic myeloid leukemia (CML), the authors evaluated the clinical significance of Tie-1 expression in such patients.

The Clinical and Diagnostic Relevance of CD23 Expression in the Chronic Lymphoproliferative Disease

Cancer. Mar, 2002  |  Pubmed ID: 11920534

CD23 antigen is a cell surface protein considered important in the differentiation of chronic lymphocytic leukemia (CLL) from other lymphoid leukemias.

Diagnosis of Invasive Pulmonary Aspergillosis Using Polymerase Chain Reaction-based Detection of Aspergillus in BAL

Chest. Apr, 2002  |  Pubmed ID: 11948049

To assess the value of Aspergillus polymerase chain reaction (PCR) test performed on the BAL in diagnosing invasive pulmonary aspergillosis (IPA).

Imatinib Mesylate (STI571) Therapy for Philadelphia Chromosome-positive Chronic Myelogenous Leukemia in Blast Phase

Blood. May, 2002  |  Pubmed ID: 11986206

Molecular abnormalities caused by the hybrid Bcr-Abl gene are causally associated with the development and progression of Philadelphia chromosome-positive (Ph(+)) chronic myelogenous leukemia (CML). Imatinib mesylate (STI571), a specific Bcr-Abl tyrosine-kinase signal-transduction inhibitor, has shown encouraging activity in phase I and II studies of CML. Here, we describe the use of imatinib mesylate to treat 75 patients in blast-phase CML (median age, 53 years; 65 with nonlymphoid and 10 with lymphoid blasts), and compare the results with those of a historical control group treated with standard cytarabine-based therapy. Imatinib mesylate was given as oral doses at 300 to 1000 mg per day and was the first salvage therapy for 47 patients. The objective response rate was 52% (39 of 75 patients: 16 had complete and 3 had partial hematologic response; 12 had hematologic improvement; 7 returned to second chronic phase; and 1 had a complete response in extramedullary blastic disease). Response rates were not different between nonlymphoid and lymphoid groups. The cytogenetic response rate was 16% (12 patients: 5 complete, 3 partial [Ph(+) below 35%], and 4 minor [Ph(+), 34% to 90%]). The estimated median overall survival was 6.5 months; the estimated 1-year survival was 22%. Response to therapy (landmark analysis at 8 weeks) was associated with survival prolongation. Compared with standard cytarabine combinations, imatinib mesylate therapy was less toxic and produced a higher response rate (55% versus 29%, P =.001), longer median survival (7 versus 4 months, P =.04), and lower 4-week induction mortality (4% versus 15%, P =.07). Imatinib mesylate is currently being tested in combination with other drugs to improve the prognosis for blast-phase CML.

Therapeutic Role of Alemtuzumab (Campath-1H) in Patients Who Have Failed Fludarabine: Results of a Large International Study

Blood. May, 2002  |  Pubmed ID: 11986207

This study investigated the efficacy, safety, and clinical benefit of alemtuzumab (Campath-1H) for patients with relapsed or refractory B-cell chronic lymphocytic leukemia exposed to alkylating agents and having failed fludarabine therapy. Ninety-three patients received alemtuzumab in 21 centers worldwide, with the aim to obtain an overall response rate of at least 20%. Dosage was increased gradually (target 30 mg, 3 times weekly, for a maximum of 12 weeks). Infection prophylaxis was mandatory, beginning on day 8, and continuing for a minimum of 2 months after treatment. Responses were assessed at weeks 4, 8, and 12, and patients were followed for 34 months. Overall objective response in the intent-to-treat population (n = 93) was 33% (CR 2%, PR 31%). Median time to response was 1.5 months (range, 0.4-3.7 months). Median time to progression was 4.7 months overall, 9.5 months for responders. At data cut-off, 27 patients (29%) were alive; overall median survival was 16 months (95% CI: 11.8-21.9) and 32 months for responders. Nineteen responders survived more than 21 months. Clinical benefit was observed both in responders and in patients with stable disease. The most common adverse events were related to infusion, generally grade 1 or 2 in severity, occurring mainly in the first week. Grade 3 or 4 infections were reported in 25 patients (26.9%). However, only 3 (9.7%) of 31 patients who responded to alemtuzumab treatment developed grade 3 or 4 infections on the study. Alemtuzumab induced significant responses in these patients with clinical benefit in the majority and with acceptable toxicity in a high-risk group.

Proliferation and Apoptosis in Acute and Chronic Leukemias and Myelodysplastic Syndrome

Leukemia Research. Jun, 2002  |  Pubmed ID: 12007503

Clonal expansion of leukemic cells is thought to be due to proliferation in excess of apoptosis. To define and compare proliferation and apoptosis between various leukemias and myelodysplastic syndrome (MDS), we measured proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU) incorporation as surrogate markers for proliferation and caspase 3 activity and annexin V surface binding as surrogate markers for activation of the apoptotic cascade in patients with MDS, chronic myelomonocytic leukemia (CMML), acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML). We found high proliferation in bone marrow cells from MDS and CMML as measured by PCNA and BrdU incorporation. The lowest level of proliferation was found in CLL. Apoptosis was also highest in MDS and CMML as measured by annexin V and caspase 3 activity. Unexpectedly, we found no significant difference in proliferation in bone marrow CD34+ cells from various leukemias or MDS. Apoptosis was significantly higher in bone marrow CD34+ cells from MDS and CML in chronic phase as compared to CD34+ cells from AML patients. Our results illustrate differences in proliferation and apoptosis between acute and chronic leukemias and MDS. These differences may have diagnostic and therapeutic implications.

Clinical Relevance of Vascular Endothelial Growth Factor Receptors 1 and 2 in Acute Myeloid Leukaemia and Myelodysplastic Syndrome

British Journal of Haematology. Jul, 2002  |  Pubmed ID: 12100142

We have previously reported that high levels of cellular vascular endothelial growth factor (VEGF) protein correlated with short survival of patients with acute myeloid leukaemia (AML). As VEGF exerts its effects via two receptors, VEGF receptor 1 (VEGFR-1) and VEGFR-2, we evaluated the significance of VEGFR-1 and VEGFR-2 protein levels in AML and myelodysplastic syndrome (MDS), and their relationship to VEGF protein levels. Western blot analysis and radioimmunoassay confirmed and quantified specific protein levels in bone marrow samples from 41 MDS and 66 AML previously untreated patients. VEGFR-1 levels were significantly higher in AML than in MDS (P = 0.0004), but no significant difference was found in the VEGFR-2 levels (P = 0.5). No significant correlation between VEGFRs levels and duration of survival was found. VEGF protein levels were significantly higher in MDS than in AML (P < 0.0001). A Cox proportional-hazard regression model showed increasing VEGF levels to significantly correlate with shorter survival of patients with MDS (P = 0.008), a finding similar to our previous report of the inverse relationship between VEGF levels and survival of AML patients. We found a significant correlation between VEGF and VEGFR-2 levels in both AML and MDS (P < 0.0000001 andP < 0.0002 respectively) but not between VEGF and VEGFR-1 levels. These data suggest that VEGF expression, rather than the expression of its receptors, is the determining factor in the biological behaviour of AML and MDS, and that VEGFRs are differentially expressed in AML and MDS.

Imatinib Mesylate for Philadelphia Chromosome-positive, Chronic-phase Myeloid Leukemia After Failure of Interferon-alpha: Follow-up Results

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Jul, 2002  |  Pubmed ID: 12114418

We treated 261 patients with Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML) in chronic phase after failure of IFN-alpha with the Bcr-Abl tyrosine kinase inhibitor imatinib mesylate (400 mg/day given p.o.) and analyzed hematological and cytogenetic responses, long-term prognosis, factors associated with achievement of major cytogenetic response and survival, and comparative survival in similar patients treated with other regimens. Median patient age was 55 years; 34% were 60 years or older, and median chronic-phase duration was 33 months. Overall, 94% achieved a complete hematological response, and 71% had a cytogenetic response [major (Ph+ cells <35%) in 62% and complete in 45%]. At a median follow-up of 17 months, 241 patients (92%) were still taking imatinib mesylate; estimated 18-month freedom from progression and survival rates were 93 and 96%. Multivariate analysis of factors associated with major cytogenetic response identified long chronic phase, marrow basophilia, high percentage of Ph+ cells before therapy, and prior hematological resistance to IFN-alpha as being adverse factors. This model was used to generate good-, intermediate- and poor-risk subgroups who had estimated major cytogenetic response rates of 93, 53, and 34%, respectively. Univariate analysis in terms of survival identified leukocytosis, high percentages of peripheral and marrow blasts, marrow basophilia, and the presence of cytogenetic clonal evolution as being adverse factors. Achieving a cytogenetic response at 3 or 6 months of therapy was associated with prolonged survival. In a subset analysis, survival rates among 161 patients with Ph-positive CML after hematological or cytogenetic failure after IFN-alpha who had been treated with imatinib mesylate were better than those for similar patients treated previously with other regimens. In summary, imatinib mesylate is highly effective in chronic-phase CML after IFN-alpha failure. We identified pretreatment and treatment-associated factors that were associated with higher major cytogenetic response rates and with improved survival.

Myelodysplastic Syndrome is Not Merely "preleukemia"

Blood. Aug, 2002  |  Pubmed ID: 12130488

Myelodysplastic syndrome (MDS) is a disease characterized by ineffective hematopoiesis. There are significant biologic and clinical differences between MDS and acute myeloid leukemia (AML). We studied a cohort of 802 patients, 279 (35%) with newly diagnosed MDS and 523 (65%) with newly diagnosed AML, and compared clinical and biologic characteristics of the 2 groups. Complete clinical and cytogenetic data were available on all patients, and a subgroup of patients was studied for apoptosis, angiogenesis, proliferation, and growth factors. Our results demonstrate that MDS is a discrete entity that is different from AML and is characterized primarily by increased apoptosis in early and mature hematopoietic cells. Using cell sorting and loss of heterozygosity, we demonstrate that the leukemic cells from MDS patients are capable of differentiation into mature myeloid cells and monocytes. We also demonstrate that there is a significant overlap between AML and MDS when MDS is defined on the basis of an arbitrary percentage of blasts of 20% or 30%. These data suggest that despite similarities between AML and MDS in their responses to treatment and outcomes, MDS is biologically and clinically different from AML and should not be considered an early phase of AML. The data indicate that MDS must be better defined on the basis of its biology rather than the percentage of blasts; further, the data suggest that there is a need to develop therapeutic approaches that specifically address the biologic abnormalities of MDS.

The Clinical Significance of Tumor Necrosis Factor-alpha Plasma Level in Patients Having Chronic Lymphocytic Leukemia

Blood. Aug, 2002  |  Pubmed ID: 12149200

Tumor necrosis factor-alpha (TNF-alpha), a cytokine possessing pleiotropic biological activities, is produced by leukemic lymphocytes in patients with chronic lymphocytic leukemia (CLL) and acts as an autocrine and paracrine growth factor in this disease. In this study, TNF-alpha levels were determined in 150 patients with CLL and correlated with disease characteristics, prognostic factors, and survival. The mean TNF-alpha plasma concentration in the patients with CLL was significantly higher than in the healthy control population (16.4 versus 8.7 pg/mL; P <.0001). Patients having an elevated TNF-alpha level had more advanced Rai and Binet stage disease, higher serum beta(2)-microglobulin (beta(2)M) levels, a greater percentage of cells expressing CD38, and lower hemoglobin and platelet levels. Patients having chromosomal abnormalities such as 11q deletion, trisomy 12, and chromosome 17 aberrations had a higher mean TNF-alpha level (27.5 pg/mL) than patients having a diploid karyotype or other miscellaneous cytogenetic abnormalities (14.2 pg/mL; P <.001). The TNF-alpha level was a predictor of survival when the Cox proportional hazards model was used with TNF-alpha entered as a continuous variable (P =.0001). Also, patients having a TNF-alpha level above the mean value of 14 pg/mL had significantly shorter survival duration (P =.00001). The TNF-alpha level remained predictive of survival in Cox multivariate analysis independent of Rai staging and beta(2)M, hemoglobin, prior therapy, white cell count, and platelet level (P =.005). We conclude that the TNF-alpha level serves as a prognostic factor in patients with CLL and that inhibition of TNF-alpha in these patients could have therapeutic importance.

CXCR4 Expression is Associated with Survival in Familial Chronic Lymphocytic Leukemia, but CD38 Expression is Not

Blood. Aug, 2002  |  Pubmed ID: 12150154

Less Apoptosis in Patients with 5q-syndrome Than in Patients with Refractory Anemia

Leukemia Research. Oct, 2002  |  Pubmed ID: 12163050

The WHO classification of hematological malignancies includes 5q-syndrome as a separate category within myelodysplastic syndromes (MDS). Clinically, patients with 5q-syndrome have a milder disease than patients with other MDS. The basis for this difference is not known. Identifying 5q-syndrome can be difficult because some of its morphologic and cytogenetic features are similar to those of other MDS. We compared apoptosis between 5q-syndrome and other refractory anemias. We found lower levels of apoptosis in 5q-syndrome as detected by less disruption of mitochondrial potential (P=0.008) and decreased annexin V positivity (P=0.01). Our results suggest that lower apoptosis in 5q-syndrome may explain the milder clinical course of the disease and distinguish 5q-syndrome from other MDS.

Recombinant Human Soluble Tumor Necrosis Factor (TNF) Receptor (p75) Fusion Protein Enbrel in Patients with Refractory Hematologic Malignancies

Cancer Chemotherapy and Pharmacology. Sep, 2002  |  Pubmed ID: 12203106

Tumor necrosis factor-alpha (TNF-alpha) is an important effector and regulatory cytokine involved in the pathophysiology of hematologic malignancies, including hairy cell leukemia (HCL), chronic lymphocytic leukemia (CLL), agnogenic myeloid metaplasia (AMM) and Philadelphia-negative myeloproliferative disorders (MPD). We conducted a pilot study to assess the safety of the soluble TNF receptor, etanercept (p75 TNFR:Fc; Enbrel) in patients with refractory hematologic malignancies.

Prognostic Value of Plasma Interleukin-6 Levels in Patients with Chronic Lymphocytic Leukemia

Cancer. Sep, 2002  |  Pubmed ID: 12209693

Interleukin 6 (IL-6) is a B-cell growth and differentiation factor, which may promote the growth of B-cell neoplasms. In chronic lymphocytic leukemia (CLL) patients, IL-6 plasma levels increased in a stage-dependent manner, suggesting that IL-6 may be a useful prognostic marker. The purpose of this study is to fully assess the prognostic value of IL-6 in CLL patients.

Epidemiology, Molecular Mycology, and Environmental Sources of Fusarium Infection in Patients with Cancer

Infection Control and Hospital Epidemiology. Sep, 2002  |  Pubmed ID: 12269452

To investigate the epidemiology and environmental sources of Fusarium infections in patients with cancer.

Bone Marrow Cyclooxygenase-2 Levels Are Elevated in Chronic-phase Chronic Myeloid Leukaemia and Are Associated with Reduced Survival

British Journal of Haematology. Oct, 2002  |  Pubmed ID: 12358901

Increased angiogenesis is important in the pathophysiology of haematological malignancies. Cyclooxygenase-2 (Cox-2) converts arachidonic acid to prostaglandins, which induce expression of angiogenic factors, including vascular endothelial growth factor (VEGF), basic-fibroblast growth factor, transforming growth factor-beta and interleukin 6. Cox-2 may also reduce apoptosis and reduce cellular attachment to the extracellular matrix (ECM). Increased bone marrow (BM) vascularity, increased BM cellular and plasma VEGF levels, and decreased progenitor adherence to BM ECM have all been observed in chronic myeloid leukaemia (CML). We investigated the prognostic significance of levels of Cox-2 in BM cells from patients with CML. Western blot and solid-phase radioimmunoassay (RIA) were used to measure Cox-2 BM levels in 149 patients with chronic phase CML (CP CML). Results were compared with those of normal controls. Expression of Cox-2 was significantly higher in CML than in normal controls (P < 0.0001). Increasing levels of Cox-2 were significantly associated with shorter survival (P = 0.0002, Cox proportional hazard model). A multivariate model based on Cox-2 and degree of splenomegaly was developed for survival in patients with early CP CML. Agents that inhibit Cox-2 activity merit investigation in patients with CP CML.

Characteristics and Outcome of Patients with Philadelphia Chromosome Negative, Bcr/abl Negative Chronic Myelogenous Leukemia

Cancer. Oct, 2002  |  Pubmed ID: 12365015

Up to 5% of patients with chronic myelogenous leukemia (CML) do not have the Philadelphia (Ph) translocation t(9;22)(q34;q11) or a bcr/abl molecular rearrangement. Although the diagnostic criteria of this entity are still under debate, there is general agreement that patients with Ph negative, bcr/abl negative CML have a severe clinical course that is not affected significantly by current treatment options.

Differences in CD33 Intensity Between Various Myeloid Neoplasms

American Journal of Clinical Pathology. Oct, 2002  |  Pubmed ID: 12375643

We measured the concentration of CD33 antigen on the surface of cells in 315 bone marrow (BM) samples and 114 corresponding peripheral blood (PB) samples from patients with various leukemias (acute myeloid leukemia [AML], chronic myelogenous leukemia [CML], myeloproliferative disorder [MPD] other than CML, myelodysplastic syndrome [MDS]) and from control subjects. Overall CD33 intensity in total CD33+ cells was significantly higher in BM than in PB. CD33 intensity in total BM CD33+ cells differed significantly with the type of disease. The median number of CD33 molecules per cell was highest in AML, followed by MDS, CML, and control subjects and lowest in MPD. When only CD34+/CD33+ cells were examined, CD33 molecules per cell were highest in CD34+ cells in AML and lowest in MPD (P = .027). Patients with AML or MDS younger than 60 years had significantly higher intensity of CD33 expression on CD34+ cells than patients 60 years or older. Levels of CD33 intensity did not correlate with cytogenetics in patients with AML or MDS. There was no correlation between CD33 intensity and response to therapy or overall survival in 35 patients treated with protocols including Mylotarg. These data demonstrate variation in CD33 intensity between various leukemias.

Plasma Vascular Endothelial Growth Factor Levels Have Prognostic Significance in Patients with Acute Myeloid Leukemia but Not in Patients with Myelodysplastic Syndromes

Cancer. Nov, 2002  |  Pubmed ID: 12404286

Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are positive regulators of angiogenesis. Increased levels in urine, serum, plasma, or malignant tissue have been associated with an adverse prognosis in patients with solid tumors.

Chronic Lymphocytic Leukemia with T(14;18) and Trisomy 12

Archives of Pathology & Laboratory Medicine. Dec, 2002  |  Pubmed ID: 12456221

The chromosomal abnormality t(14;18) is most commonly associated with neoplasms of follicular center cell origin. However, t(14;18) also has been reported in rare cases of chronic lymphocytic leukemia (CLL). In 2215 cases of CLL studied by conventional cytogenetics in our institution, we identified 2 cases of CLL carrying t(14;18). Both patients were men, aged 52 and 71 years at the time of diagnosis. One patient presented with leukemia and the other primarily with nodal disease. In addition to t(14;18), trisomy 12 (+12) was identified in the same clone in both cases. Atypical morphologic features were identified: case 1 contained more than 15% lymphoid cells with cleaved nuclei, whereas case 2 contained more than 15% plasmacytoid lymphoid cells. The immunophenotype of case 2 was also unusual for CLL, showing weak CD23 expression and FMC7 positivity. We identified 6 other t(14;18)-carrying CLL cases in the literature; 2 had t(14;18) as the sole abnormality and 2 contained +12 as the additional abnormality. To conclude, cases of CLL carrying t(14;18) are exceedingly rare, and +12 appears to be the most common cytogenetic abnormality coexisting with t(14;18) in CLL.

Association of Cancer-related Symptoms with Physiological Parameters

Journal of Pain and Symptom Management. Oct, 2002  |  Pubmed ID: 12505202

Emerging Information on the Use of Rituximab in Chronic Lymphocytic Leukemia

Seminars in Oncology. Feb, 2002  |  Pubmed ID: 28140094

Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA, and IDEC Pharmaceuticals, San Diego, CA) is a chimeric monoclonal antibody that targets mature B cells in most lymphoid B-cell malignancies. While rituximab was approved by the US Food and Drug Administration for the treatment of recurrent B-cell lymphoma, initial studies suggested that it had less activity in small lymphocytic lymphoma, the nodal counterpart of chronic lymphocytic leukemia (CLL). Two studies have now investigated the activity of higher-dose and more intensive therapy with rituximab in CLL. They have shown a dose-response relationship and a higher response rate than previously seen in the lower-dose studies. This is presumably caused by the overcoming of lower antigen density on CLL cells compared with lymphoma cells, and the shorter half-life of rituximab in small lymphocytic lymphoma. There is now evidence that CD20 is shed into the plasma in patients with CLL, which may explain the shorter half-life of the antibody in small lymphocytic lymphoma/CLL. The higher dose may then be effective in overcoming this so-called "antigen sink." Toxicity was uncommon except in previously untreated patients and those with atypical forms of CLL such as mantle cell lymphoma and prolymphocytic leukemia. There is now evidence in vitro of additive or synergistic activity of rituximab with a variety of chemotherapeutic agents including fludarabine and cyclophosphamide. Combinations of fludarabine with rituximab or these two drugs combined with cyclophosphamide have given very high complete response rates in series of patients with both previously untreated and treated CLL. It is apparent that rituximab is playing a significant role in the management of patients with CLL as salvage therapy and is a potential potentiating agent for combined chemoimmunotherapy strategies for front-line or relapsed patients with CLL. Semin Oncol 29 (suppl 2):70-74. Copyright © 2002 by W.B. Saunders Company.

Efficacy of the Farnesyl Transferase Inhibitor R115777 in Chronic Myeloid Leukemia and Other Hematologic Malignancies

Blood. Mar, 2003  |  Pubmed ID: 12411300

We investigated the clinical activity of the farnesyl transferase inhibitor R115777 in 22 patients with chronic myelogenous leukemia (CML) in chronic, accelerated, or blastic phase and in 8 patients with myelofibrosis (MF) and 10 patients with multiple myeloma (MM). R115777 was administered at 600 mg orally twice daily for 4 weeks every 6 weeks. Seven patients with CML (6 in chronic phase, 1 in advanced phase) achieved complete or partial hematologic response. Four of them had a minor cytogenetic response. Responses were transient, with a median duration of 9 weeks (range, 3-23 weeks). Two patients discontinued therapy because of toxicity while in complete hematologic response. Two MF patients had a significant decrease in splenomegaly, one had normalization of white blood cell count and differential, and one became transfusion independent. One patient with MM had a reduction in monoclonal protein of 34%. Adverse events included nausea in 22 patients (55%; all grade 2 or lower) and fatigue in 19 (48%; grade 3 or higher in 1). Other grade 3 or 4 toxicities included skin rash (4 patients, 10%), peripheral neuropathy (2 patients, 5%), and liver toxicity (2 patients, 5%). Patients who responded to therapy had significantly higher plasma vascular endothelial growth factor (VEGF) concentrations prior to treatment than nonresponders. Plasma concentrations decreased significantly during therapy among responders. R115777 showed clinical activity in patients with CML and MF. The effect on VEGF needs to be further investigated to determine whether this might be a possible mechanism of action of R115777.

Circulating CD20 is Detectable in the Plasma of Patients with Chronic Lymphocytic Leukemia and is of Prognostic Significance

Blood. Apr, 2003  |  Pubmed ID: 12446458

CD20 is a 33- to 36-kDa transmembrane phosphoprotein involved in the activation, proliferation, and differentiation of B lymphocytes. The predicted amino acid sequence of the CD20 suggests 4 transmembrane-spanning regions with both N- and C-termini located in the cytoplasm. We demonstrate herein that significant levels of circulating CD20 (cCD20) can be detected in the plasma of patients with chronic lymphocytic leukemia (CLL) and that cCD20 interferes with the binding of rituximab, a humanized anti-CD20 monoclonal antibody, to CLL cells. An enzyme-linked immunosorbent assay (ELISA) was developed to measure circulating cCD20 levels in the plasma. We measured cCD20 levels in the plasma of 180 patients with CLL and correlated these levels with clinical characteristics and outcome. Circulating CD20 levels correlated positively with beta(2)-microglobulin level (p =.006) and percentage of CD38(+) cells (p =.03) and negatively with platelet count (p =.004) and hemoglobin level (p =.02). Patients with advanced Rai (III/IV) or Binet (C) stage disease had significantly higher levels of cCD20 than did patients with earlier-stage disease (P =.01 and P =.006, respectively). There was no correlation between cCD20 level and age, lymphocyte count, or white blood cell count. Using a recursive classification method, we found that patients with a cCD20 level more than 1875 nM/L had significantly shorter survival than those with cCD20 1875 nM/L or below (P =.01). The prognostic value of cCD20 was independent of Rai staging or hemoglobin level. Prospective evaluation is indicated to establish whether rituximab dosing should be adjusted according to cCD20 levels.

The Prognostic Significance of Bone Marrow Levels of Neurofibromatosis-1 Protein and Ras Oncogene Mutations in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome

Cancer. Jan, 2003  |  Pubmed ID: 12518368

It has been reported that point mutations of the ras gene occur frequently in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). However, the prognostic significance of ras gene mutations in patients with these disorders has been a controversial issue. Although abnormalities in the neurofibromatosis 1 (NF1) gene, which is a gene involved in the ras pathway, have been observed frequently in patients with juvenile chronic myelogenous leukemia, the role of these abnormalities in adult patients with AML or MDS is not clear.

Presence of Restricted Killer Immunoglobulin-like Receptor Repertoire and Monoclonal T-cell Receptor Gamma Rearrangement As Evidence of Mixed NK/T-cell Differentiation in a Subset of Sinonasal Lymphomas

Laboratory Investigation; a Journal of Technical Methods and Pathology. Jan, 2003  |  Pubmed ID: 12533686

Most sinonasal lymphomas have a restricted killer immunoglobulin-like receptor (KIR) repertoire without a monoclonal T-cell receptor-gamma (TCR-gamma) rearrangement, implying an NK lineage. However, the lineage assignment of sinonasal lymphoma with a monoclonal TCR-gamma rearrangement is unclear because of its mixed NK/T phenotype. The possibility of a mixed NK/T lineage arises with the discovery of T cells with NK features, such as KIR(+) T cells or Valpha24(+) NKT cells. The former might transform into a T-cell lymphoma with both a monoclonal TCR-gamma rearrangement and a restricted KIR repertoire; the latter might give rise to a T-cell lymphoma with a monoclonal Valpha24 rearrangement and possibly a restricted KIR repertoire. To identify such mixed-lineage lymphomas, we undertook a survey of 15 consecutive sinonasal lymphomas and found six with both a restricted KIR repertoire and a monoclonal TCR-gamma rearrangement, consistent with KIR(+) T-cell lymphomas. Among these six cases, four female CD56(-)/CD44(-)/CD8(-)/CD45RO(+)/CD45RA(-) cases constituted a distinct group with a better prognosis than the rest of the male cases of sinonasal lymphomas. None of the six cases had a monoclonal Valpha24 repertoire, thus excluding a derivation from NKT cells. The predominance of KIR(+) T cells that normally function in chronic viral infections over Valpha24(+) NKT cells that typically recognize glycolipid antigens is consistent with the known association of Epstein-Barr virus infection with sinonasal lymphoma. The demonstration of mixed lineage in a mature lymphoid neoplasm is unusual and echoes the World Health Organization classification that placed NK-cell and T-cell lymphomas in a mixed group.

Aberrant DNA Methylation in Pediatric Patients with Acute Lymphocytic Leukemia

Cancer. Feb, 2003  |  Pubmed ID: 12548613

Aberrant methylation of promoter-associated cystosine-guanine (CpG) islands is an epigenetic modification of DNA frequently observed in adult patients with acute lymphocytic leukemia (ALL). This epigenetic modification has been associated with gene silencing, malignant transformation, and aging. It is not known whether there are epigenetic differences between pediatric patients and adult patients with ALL.

Plasma Interleukin 8 Level Predicts for Survival in Chronic Lymphocytic Leukaemia

British Journal of Haematology. Feb, 2003  |  Pubmed ID: 12580959

The malignant B cells of patients with chronic lymphocytic leukaemia (CLL) constitutively express interleukin 8 (IL-8) and IL-8 receptors. Ex vivo culture with exogenous IL-8 enhances IL-8 expression and prolongs leukaemia cell survival, partly through increased bcl-2 expression. IL-8 may function as an autocrine growth and apoptosis resistance factor in CLL. Therefore, we evaluated the prognostic relevance of plasma IL-8 levels in 151 CLL patients [median age 61 years (range, 32-84 years), median plasma IL-8 level 18.9 pg/ml (9.1-89.1 pg/ml)]. All Rai stages were represented; advanced stage was associated with significantly higher plasma IL-8 levels (P < 0.0001, Kruskal-Wallis). Also, plasma IL-8 level was correlated with serum beta2-microglobulin (beta2-M) (R = 0.24, P = 0.0081), haemoglobin (R = -0.39, P < 0.0001) and platelet count (R = -0.23, P = 0.0049) by Spearman's rank correlation. Univariate analysis using Cox proportional hazards models identified elevated IL-8 and beta2-M as significant prognostic factors with relative risks of 7.43 (P = 9.1 x 10(-9)) and 16.40 (P = 5.9 x 10(-10)) respectively. High levels of IL-8 were associated with shorter survival independent of beta2-M level. Using recursive-partitioning procedures, an IL-8 cut-off point of 26.2 pg/ml segregated a group of CLL patients with significantly shorter survival (median 9.3 months) (P < 0.0001). In conclusion, plasma IL-8 level in CLL patients correlates with other prognostic factors, such as Rai stage and beta2-M, and is associated with increased risk of death in CLL patients. The role of IL-8 inhibitors in the treatment of patients with CLL should be explored.

A Randomized Trial of Liposomal Daunorubicin and Cytarabine Versus Liposomal Daunorubicin and Topotecan with or Without Thalidomide As Initial Therapy for Patients with Poor Prognosis Acute Myelogenous Leukemia or Myelodysplastic Syndrome

Cancer. Mar, 2003  |  Pubmed ID: 12599230

Because angiogenesis may play a role in the pathogenesis of acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS), and thalidomide (Th) has shown significant anti-angiogenic activity, this study was designed to investigate the potential role of Th in the treatment of patients with AML and MDS and the possible role of a non-ara-C-containing regimen.

Increased Telomerase Activity is Associated with Shorter Survival in Patients with Chronic Phase Chronic Myeloid Leukemia

Cancer. Mar, 2003  |  Pubmed ID: 12599232

Significantly elevated telomerase activity (TA) has been found in samples from patients with many malignant hematologic diseases. However, the impact of elevated TA on the course of patients with chronic phase chronic myeloid leukemia (CP-CML) is unknown.

Pilot Study of Recombinant Human Soluble Tumor Necrosis Factor (TNF) Receptor (p75) Fusion Protein (TNFR:Fc; Enbrel) in Patients with Refractory Multiple Myeloma: Increase in Plasma TNF Alpha Levels During Treatment

Leukemia Research. May, 2003  |  Pubmed ID: 12620287

Elevated tumor necrosis factor (TNF)-alpha levels are associated with poor prognosis in patients with multiple myeloma (MM). Enbrel is a TNF antagonist fusion protein consisting of the extracellular, ligand-binding domain of the human p75 TNF receptor linked to the Fc portion of human IgG1. Ten patients with refractory MM were treated with Enbrel 25mg s.c twice weekly for a minimum of eight median age was 63 years (range, 43-76). The total number of Enbrel doses was 191 (median 16; range, 3-55). TNF alpha plasma levels increased significantly during treatment with Enbrel. No objective response occurred. Acceleration of disease occurred in four patients. While well-tolerated, Enbrel did not have anti-myeloma activity as administered on this study.

Gemtuzumab, Fludarabine, Cytarabine, and Cyclosporine in Patients with Newly Diagnosed Acute Myelogenous Leukemia or High-risk Myelodysplastic Syndromes

Cancer. Mar, 2003  |  Pubmed ID: 12627513

Gemtuzumab is used to treat patients with previously untreated or recurrent acute myelogenous leukemia (AML). The fludarabine and cytarabine (ara-C) regimen is active in these patients. Resistance to gemtuzumab is associated with blast multidrug resistance (MDR). The objectives of this study were to evaluate the efficacy and toxicity of a combination regimen of gemtuzumab, fludarabine, ara-C, and the MDR modifier (cyclosporine [CyA]) in patients with previously untreated AML, refractory anemia with excess blasts (RAEB), or RAEB in transformation (RAEBT).

SU5416, a Small Molecule Tyrosine Kinase Receptor Inhibitor, Has Biologic Activity in Patients with Refractory Acute Myeloid Leukemia or Myelodysplastic Syndromes

Blood. Aug, 2003  |  Pubmed ID: 12649163

Increased bone marrow angiogenesis and vascular endothelial growth factor (VEGF) levels are adverse prognostic features in patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDSs). VEGF is a soluble circulating angiogenic molecule that stimulates signaling via receptor tyrosine kinases (RTKs), including VEGF receptor 2 (VEGFR-2). AML blasts may express VEGFR-2, c-kit, and FLT3. SU5416 is a small molecule RTK inhibitor (RTKI) of VEGFR-2, c-kit, and both wild-type and mutant FLT3. A multicenter phase 2 study of SU5416 was conducted in patients with refractory AML or MDS. For a median of 9 weeks (range, 1-55 weeks), 55 patients (33 AML: 10 [30%] primary refractory, 23 [70%] relapsed; 22 MDS: 15 [68%] relapsed) received 145 mg/m2 SU5416 twice weekly intravenously. Grade 3 or 4 drug-related toxicities included headaches (14%), infusion-related reactions (11%), dyspnea (14%), fatigue (7%), thrombotic episodes (7%), bone pain (5%), and gastrointestinal disturbance (4%). There were 11 patients (20%) who did not complete 4 weeks of therapy (10 progressive disease, 1 adverse event); 3 patients (5%) who achieved partial responses; and 1 (2%) who achieved hematologic improvement. Single agent SU5416 had biologic and modest clinical activity in refractory AML/MDS. Overall median survival was 12 weeks in AML patients (range, 4-41 weeks) and not reached in MDS patients. Most observed toxicities were attributable to drug formulation (polyoxyl 35 castor oil or hyperosmolarity of the SU5416 preparation). Studies of other RTKI and/or other antiangiogenic approaches, with correlative studies to examine biologic effects, may be warranted in patients with AML/MDS.

Fractionated Cyclophosphamide, Vincristine, Liposomal Daunorubicin, and Dexamethasone Plus Rituximab and Granulocyte-macrophage-colony Stimulating Factor (GM-CSF) Alternating with Methotrexate and Cytarabine Plus Rituximab and GM-CSF in Patients with Richter Syndrome or Fludarabine-refractory Chronic Lymphocytic Leukemia

Cancer. Apr, 2003  |  Pubmed ID: 12655528

Therapy for patients with Richter syndrome (RS) or fludarabine-refractory chronic lymphocytic leukemia (CLL) is unsatisfactory. A Phase II study was conducted to evaluate an alternating combination cytotoxic regimen given with rituximab and granulocyte-macrophage-colony stimulating factor (GM-CSF) in these patients.

Clinical Relevance of the Expression of the CD31 Ligand for CD38 in Patients with B-cell Chronic Lymphocytic Leukemia

Cancer. Apr, 2003  |  Pubmed ID: 12673718

CD31 (platelet endothelial cell adhesion molecule-1 [PECAM-1]) is the ligand for CD38, a transmembrane glycoprotein that is expressed on the surface of leukemic cells in many patients with B-cell chronic lymphocytic leukemia (B-CLL). In a previous study, the authors showed that CD38 expression was correlated with a poor prognosis in patients with B-CLL. In the current study, blood samples from patients with B-CLL were examined to identify CD31 surface marker expression, and CD31 expression was correlated with several other known prognostic variables, including CD38.

Phase II Study of SU5416--a Small-molecule, Vascular Endothelial Growth Factor Tyrosine-kinase Receptor Inhibitor--in Patients with Refractory Myeloproliferative Diseases

Cancer. Apr, 2003  |  Pubmed ID: 12673719

Increased bone marrow angiogenesis and vascular endothelial growth factor (VEGF) levels are of adverse prognostic significance in patients with myeloproliferative disorders (MPD), including agnogenic myeloid metaplasia (AMM), chronic myeloid leukemia in blastic phase (CML-BP), and chronic myelomonocytic leukemia (CMML). VEGF is a soluble, circulating, angiogenic molecule that acts through receptor tyrosine kinases (RTK), including VEGF receptor 2 (VEGFR-2). SU5416 is a small-molecule RTK inhibitor (RTKI) that targets VEGFR-2, c-kit, and fms-related tyrosine kinase Flk2.

Clinical Relevance of VEGF Receptors 1 and 2 in Patients with Chronic Myelogenous Leukemia

Leukemia Research. Jul, 2003  |  Pubmed ID: 12681367

Vascularity is increased in the bone marrow of patients with chronic myeloid leukemia (CML) and high vascular endothelial growth factor (VEGF) levels correlate with worse survival. We analyzed the significance of VEGF-receptor 1 (VEGF-R1) and VEGF-R2 levels in bone marrow samples from 170 CML patients (137 chronic, 24 accelerated, and 9 blastic phase). Median VEGF-R1 and VEGF-R2 levels were 4.66 and 2-fold, respectively, that in normal control samples. Receptor levels did not correlate with disease phase or other host and disease features examined. Chronic phase CML patients with increased VEGF-R2 levels had significantly inferior survival than patients without receptor up-regulation (P=0.009). Patients in accelerated/blastic phase CML with elevated VEGF-R2 expression had marginally worse survival (P=0.05). In contrast, high VEGF-R1 levels did not correlate with a specific CML phase, characteristic, or outcome. Our findings support VEGF-R2 over-expression as an independent prognostic indicator for shortened survival in patients with CML.

Vascularity, Angiogenesis and Angiogenic Factors in Leukemias and Myelodysplastic Syndromes

Leukemia & Lymphoma. Feb, 2003  |  Pubmed ID: 12688336

Bone marrow microenvironment plays a crucial role inthe leukemogenic process. New studies suggest that the bone marrow vascularity changes significantly in the leukemic process and that angiogenic factors play a major role in leukemia and myelodysplasia. However, hematologic malignancies appear to be particularly vulnerable to the effects of angiogenic factors because most of these factors appear to be secreted by hematopoietic cells, and they may have autocrine and paracrine regulatory effects on the hematopoietic system. The use of angiogenesis inhibitors for the treatment of hematologic malignancies is particularly attractive because it may target not only the environment but also the malignant cells.

Telomerase Activity is Prognostic in Pediatric Patients with Acute Myeloid Leukemia: Comparison with Adult Acute Myeloid Leukemia

Cancer. May, 2003  |  Pubmed ID: 12712473

Significantly elevated telomerase activity (TA) has been found in samples from patients with almost all malignant hematologic diseases. The impact of elevated TA on the course of pediatric patients with acute myeloid leukemia (P-AML) is unknown.

Increased Apoptosis in Bone Marrow B Lymphocytes but Not T Lymphocytes in Myelodysplastic Syndrome

Blood. Sep, 2003  |  Pubmed ID: 12730116

The hallmark of myelodysplastic syndrome (MDS) is enhanced apoptosis in myeloid, erythroid, and megakaryocytic cells in the bone marrow leading to ineffective hematopoiesis. Recent studies suggested that immunological and microenvironmental factors play a role in the pathophysiology of this disease. We report a significant increase in apoptosis in bone marrow B lymphocytes in MDS as compared to that found in acute myeloid leukemia and healthy controls. Furthermore, we demonstrate that patients with refractory anemia with excess blasts in transformation (RAEB-T) had apoptosis levels in lymphocytes similar to those seen in other subtypes of MDS. Our findings suggest that the alterations in B lymphocytes in the form of increased apoptosis can be seen in MDS and support the concept that immune modulation plays a role in the pathophysiology of MDS.

In Vitro Activity of Dimethylarsinic Acid Against Human Leukemia and Multiple Myeloma Cell Lines

Cancer Chemotherapy and Pharmacology. May, 2003  |  Pubmed ID: 12736761

Arsenic trioxide (As(2)O(3)), an inorganic arsenic compound, has recently been approved for the treatment of relapsed or refractory acute promyelocytic leukemia. However, systemic toxicity associated with As(2)O(3) treatment remains a problem. Inorganic arsenic is detoxified in vivo by methylation reactions into organic arsenic compounds that are less toxic.

A Prognostic Model for Survival in Chronic Lymphocytic Leukaemia Based on P53 Expression

British Journal of Haematology. May, 2003  |  Pubmed ID: 12752098

As the abnormal expression of p53 protein is prognostically significant in some human cancers, its significance in patients with B-cell chronic lymphocytic leukaemia (CLL) was assessed. Two investigators evaluated the percentage of bone marrow mononuclear cells that stained for p53, using biopsies stained with anti-p53 monoclonal antibody (DO-7), and graded the degree of staining (0, +, ++, +++). Samples from a cohort of 90 patients with CLL were studied (median age 60 years, range 30-89 years; 57 patients were (63%) previously untreated, 22 patients (24%) had received one or two prior regimens, 11 patients had received (12%) three to seven regimens. The overall percentage of cells positive for p53 staining was a median of 43 (range 1-88). No investigator effect was detected either in overall percentage cells rated p53 positive or on the degree of staining (Pearson's correlation coefficient 0.980, P-value < 0.001). A Cox proportional hazards model showed that the percentage of ++ and +++ p53-positive cells correlated with various prognostic factors in CLL (P < 0.0001). A multivariate model incorporating prior therapy, Rai stage, beta2 microglobulin (beta2M) and p53 expression showed that only the percentage of p53-positive cells and beta2M were predictive of survival, and enabled the development of a highly predictive model of survival based on these two parameters.

Results of Imatinib Mesylate Therapy in Patients with Refractory or Recurrent Acute Myeloid Leukemia, High-risk Myelodysplastic Syndrome, and Myeloproliferative Disorders

Cancer. Jun, 2003  |  Pubmed ID: 12767088

Imatinib mesylate is a selective tyrosine kinase inhibitor of c-abl, bcr/abl, c-kit, and platelet-derived growth factor-receptor (PDGF-R). c-kit is expressed in most patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) and PDGF has been implicated in the pathogenesis of myeloproliferative disorders (MPD).

Anagrelide and Imatinib Mesylate Combination Therapy in Patients with Chronic Myeloproliferative Disorders

Cancer Chemotherapy and Pharmacology. Sep, 2003  |  Pubmed ID: 12783207

The tyrosine kinase inhibitor imatinib mesylate inhibits the function of the Bcr-Abl oncoprotein associated with Philadelphia-positive chronic myelogenous leukemia (CML). Anagrelide suppresses megakaryocyte proliferation and differentiation. The objectives of this study were to investigate the feasibility and safety of imatinib mesylate and anagrelide combination therapy in patients with Ph-positive CML or chronic myeloproliferative disorders (MPD) with persistent thrombocythemia.

Gemtuzumab Ozogamicin, Fludarabine, Cytarabine and Cyclosporine Combination Regimen in Patients with CD33+ Primary Resistant or Relapsed Acute Myeloid Leukemia

Leukemia Research. Oct, 2003  |  Pubmed ID: 12860008

Clinical resistance to gemtuzumab ozogamicin (Mylotarg) in acute myeloid leukemia (AML) is associated with blast multidrug resistance (MDR) phenotype. A Phase II study of Mylotarg, fludarabine, ara-C and the MDR-modifier, cyclosporine (CSA) (MFAC) was conducted in 32 patients with primary resistant (11, 34%) or relapsed (21, 66%) AML. Nine (28%) patients obtained complete remission (CR), two (6%) CR with incomplete platelet recovery. Overall median survival was 5.3 months, 12-month survival rate 19%. Fourteen patients (44%) developed grade 3/4 hyperbilirubinemia; six (18%) grade 3/4 hepatic transaminitis; three (9%) hepatic veno-occlusive disease (VOD). CSA inclusion in gemtuzumab ozogamicin-based regimens is feasible. MFAC is an effective regimen for refractory AML.

ATM Mutations and Protein Expression Are Not Associated with Familial B-CLL Cases

Leukemia Research. Oct, 2003  |  Pubmed ID: 12860021

Transient Down-modulation of CD20 by Rituximab in Patients with Chronic Lymphocytic Leukemia

Blood. Nov, 2003  |  Pubmed ID: 12893761

Lymphoid cells in most patients with chronic lymphocytic leukemia (CLL), when treated with rituximab, become CD20-. This is thought to be due to masking of CD20 by rituximab. We used specific antimouse immunoglobulin antibodies to detect rituximab on the surface of CLL lymphocytes and we demonstrate that rituximab is rarely detectable after therapy. Only 3 of 65 patients with CLL had rituximab detectable on their lymphocytes after rituximab therapy despite the fact that most had no detectable CD20 expression. In vitro mixing of CLL or Raji cells with rituximab demonstrated that rituximab was detectable on the surface of cells due to its binding to CD20. However, the addition of plasma led to the down-modulation of CD20 expression, and the rituximab became undetectable. This down-modulation of CD20 protein expression was associated with a down-modulation of CD20 mRNA. CLL cells that lost their CD20 expression regained CD20 expression after 24 hours in culture. These data suggest that rituximab therapy leads to a substantial but transient down-modulation of CD20 expression and that negativity for CD20 in cells from patients treated with rituximab is not necessarily due to CD20 masking. The importance of this down-modulation in the efficacy of current therapy with rituximab needs further investigation.

Phase II Study of Troxacitabine, a Novel Dioxolane Nucleoside Analog, in Patients with Untreated or Imatinib Mesylate-resistant Chronic Myelogenous Leukemia in Blastic Phase

Leukemia Research. Dec, 2003  |  Pubmed ID: 12921945

A phase II study of troxacitabine, a non-natural dioxolane nucleoside L-enantiomer, was conducted in patients with chronic myelogenous leukemia in blastic phase (CML-BP). Patients were untreated for BP, or treated with imatinib mesylate (IM) as sole prior therapy for BP. Troxacitabine was given as an intravenous infusion over 30 min daily for 5 days at a dose of 8.0 mg/m(2) per day. Thirty-one patients, 29 (93%) of whom had failed prior IM therapy, received 51 courses of therapy. Grade 3 or 4 toxicities included stomatitis (4%), hand-foot syndrome (18%), and skin rash (12%). Four patients (13%) responded. Troxacitabine-based combinations merit study in IM-resistant CML.

Use of Plasma DNA in Detection of Loss of Heterozygosity in Patients with Multiple Myeloma

European Journal of Haematology. Sep, 2003  |  Pubmed ID: 12930317

Deletions or structural abnormalities in chromosomes 11 and 13 have been shown to be important in predicting clinical behavior in patients with multiple myeloma (MM). However, cytogenetic analysis in MM is frequently difficult because of poor yield of informative metaphases and the disease is frequently patchy, which complicates fluorescent in situ hybridization studies.

Molecular Differences Between Small and Large Cells in Patients with Chronic Lymphocytic Leukemia

European Journal of Haematology. Oct, 2003  |  Pubmed ID: 12950231

The genetic events involved in the transformation of chronic lymphocytic leukemia (CLL) to Richter's syndrome (RS) are poorly understood. Frequently large cells are seen in the bone marrows of patients with CLL and evidence of RS. Using a laser-capture microdissection we analyzed small and large leukemic bone marrow cells from 19 patients with RS for loss of heterozygosity (LOH) on chromosome 11 (D11S2179 at the ATM gene), 17 (D17S938 and D17S1852 at the TP53 site), and 20 (Plc1, D20S96, D20S110, and D20S119). Megakaryocytes were also isolated and used as a control for normal cells. Four of 15 (27.7%) informative cases showed LOH in small cells in the ATM gene while seven (46.7%) showed LOH in large cells. Six of 15 (40%) informative cases had LOH in chromosome 17 in small cells, and eight (53%) showed LOH in large cells. Eleven of 19 informative cases (61.1%) showed LOH in chromosome 20 in large cells, and eight (42.1%) showed LOH in small cells. RS cases with LOH at chromosome 20 were associated with marginally shorter survival rates (P = 0.08). Our data suggest that there are significant molecular differences between large and small cells in patients with CLL. Further analysis of the genes on these chromosomes may provide new insight into our understanding of the transformation of small CLL cells to large (Richter) cells.

The Clinical Significance of Soluble CD86 Levels in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome

Cancer. Oct, 2003  |  Pubmed ID: 14534885

Levels of the soluble form of CD86 (sCD86) are elevated in a proportion of patients with leukemia. Although it is a potential modulator of antitumor responses, the significance of sCD86 in patients with hematologic malignancies is unknown.

Single Agent Thalidomide in Patients with Relapsed or Refractory Acute Myeloid Leukaemia

British Journal of Haematology. Nov, 2003  |  Pubmed ID: 14617002

Thalidomide is a putative anti-angiogenesis agent that has significant anti-tumour activity in haematological malignancies with increased bone marrow angiogenesis, including multiple myeloma (MM) and myelodysplastic syndromes (MDS). Increased levels of the mitogen for angiogenesis, vascular endothelial growth factor (VEGF), correlate with worse survival in acute myeloid leukaemia (AML). A phase II trial of thalidomide was conducted in patients with relapsed- or refractory-AML previously treated with cytarabine-containing regimens. A total of 16 patients with refractory- or relapsed-AML were treated with thalidomide 200-800 mg orally daily (median dose 400 mg daily) for a median of 27 d (range, 3-94 d). Overall, one patient (6%) achieved complete remission (CR) lasting for 36 months, and two patients had a transient reduction in marrow blasts from 8% and 7% to less than 5% in both cases. There was no correlation between reduction in levels of angiogenesis markers and response. Toxicities related to thalidomide were significant, and precluded dose escalation beyond 400 mg orally daily in most patients. Although there appears to be some evidence of biological activity, single agent thalidomide is not an optimal choice of therapy for salvaging patients with relapsed- or refractory-AML. Thalidomide analogues with more potent immunomodulatory activities and more favourable toxicity profiles may offer more promise as anti-AML therapy.

Circulating CD20 and CD52 in Patients with Non-Hodgkin's Lymphoma or Hodgkin's Disease

British Journal of Haematology. Dec, 2003  |  Pubmed ID: 14632776

The cell surface proteins CD20 and CD52 differ significantly in their structures and are expressed on the majority of B cells. Both circulating CD20 (cCD20) and circulating CD52 (cCD52) have been recently documented in patients with chronic lymphocytic leukaemia. A retrospective study to establish whether cCD20 and/or cCD52 were detectable in patients with lymphoma, and the clinical associations of these soluble antigens if detected, was conducted. cCD20 and cCD52 levels were analysed in a cohort of 65 patients with non-Hodgkin's lymphoma (NHL) and 37 with Hodgkin's disease (HD). Patients with NHL had elevated pretherapy levels of cCD20 and cCD52 compared with normal individuals. Patients with HD had significantly lower than normal pretherapy levels of both cCD20 and cCD52. cCD20 levels were marginally elevated post-therapy in NHL patients while in patients with HD, cCD20 levels remained significantly lower than normal after therapy. Serum cCD52 levels became significantly lower than normal post-therapy in NHL patients, and remained significantly lower than normal in HD patients. No predictive effects were found for pretherapy or post-therapy levels of cCD52 on survival for either cohort of patients. Post-therapy cCD20 levels independently highly correlated with survival in patients with NHL. Prospective evaluation will be required to establish if cCD20 and cCD52 may be used as biomarkers in the diagnosis, prognostic categorization, and monitoring of the clinical course in patients with lymphoma. The clinical significance of circulating antigen in patients receiving monoclonal antibody therapy directed against CD20 and/or CD52 warrants study.

Alemtuzumab As Treatment for Residual Disease After Chemotherapy in Patients with Chronic Lymphocytic Leukemia

Cancer. Dec, 2003  |  Pubmed ID: 14669286

The objective of this study was to investigate the efficacy and safety of alemtuzumab, the humanized anti-CD52 monoclonal antibody, in patients with B-cell chronic lymphocytic leukemia and residual disease after chemotherapy.

Relative Increase in Leukemia-specific DNA in Peripheral Blood Plasma from Patients with Acute Myeloid Leukemia and Myelodysplasia

Blood. Apr, 2004  |  Pubmed ID: 14576069

Using loss of heterozygosity (LOH) and X-chromosome inactivation, we compared peripheral blood (PB) plasma with bone marrow (BM) cells in detecting genomic abnormalities in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We detected LOH in the PB plasma of all 45 patients who had cytogenetically documented chromosomal abnormalities (5q-, 7-, +8, 17-, or 20-). BM cells from the same patients showed LOH in 89% of patients with MDS and 70% of patients with AML. Posttherapy samples from 16 of these patients demonstrated complete concordance between LOH and cytogenetics in detecting residual disease in 15 samples. Of the 16 samples, 4 showed LOH in plasma with normal BM morphology. Using X-chromosome inactivation, clonality was detectable in 19 (73%) of 26 BM samples, whereas all PB plasma samples showed clonality. These data support the conclusion that PB plasma is enriched by tumor-specific DNA and can replace BM cells for studying genomic abnormalities.

Intrinsic Oxidative Stress in Cancer Cells: a Biochemical Basis for Therapeutic Selectivity

Cancer Chemotherapy and Pharmacology. Mar, 2004  |  Pubmed ID: 14610616

Therapeutic selectivity is one of the most important considerations in cancer chemotherapy. The design of therapeutic strategies to preferentially kill malignant cells while minimizing harmful effects to normal cells depends on our understanding of the biological differences between cancer and normal cells. We have previously demonstrated that certain agents generating reactive oxygen species (ROS) such as 2-methoxyestradiol (2-ME) preferentially kill human leukemia cells without exhibiting significant cytotoxicity in normal lymphocytes. The purpose of the current study was to investigate the biochemical basis for such selective anticancer activity.

Bovine Serum Albumin in the Preparation of Peripheral Blood Smears

Cytometry. Part B, Clinical Cytometry. Jan, 2004  |  Pubmed ID: 14696064

Phase II Study of SU5416, a Small Molecule Vascular Endothelial Growth Factor Tyrosine Kinase Receptor Inhibitor, in Patients with Refractory Multiple Myeloma

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Jan, 2004  |  Pubmed ID: 14734456

Increased bone marrow angiogenesis and vascular endothelial growth factor (VEGF) levels are of adverse prognostic significance in patients with multiple myeloma (MM). VEGF, a soluble circulating angiogenic molecule, acts via receptor tyrosine kinases, including VEGF receptor 2. SU5416 is a small molecule VEGF receptor 2 inhibitor.

Imatinib Mesylate Resistance Through BCR-ABL Independence in Chronic Myelogenous Leukemia

Cancer Research. Jan, 2004  |  Pubmed ID: 14744784

Imatinib mesylate (IM) binds to the BCR-ABL protein, inhibiting its kinase activity and effectively controlling diseases driven by this kinase. IM resistance has been associated with kinase mutations or increased BCR-ABL expression. However, disease progression may be mediated by other mechanisms that render tumor cells independent of BCR-ABL. To demonstrate this potential, IM-resistant cells were found in chronic myelogenous leukemia patients with continuous BCR-ABL gene expression but undetectable BCR-ABL protein expression. These cells were unresponsive to IM and acquired BCR-ABL-independent signaling characteristics. IM resistance in some patients may be mediated through loss of kinase target dependence.

Thalidomide for Patients with Recurrent Lymphoma

Cancer. Mar, 2004  |  Pubmed ID: 15022285

Thalidomide has significant clinical activity in patients with multiple myeloma. However, its activity against other lymphoid tumors is unknown. The authors reported their experience with thalidomide in patients with recurrent/refractory non-Hodgkin lymphoma and in patients with Hodgkin disease.

Phase I and Pharmacokinetic Study of a Low-clearance, Unilamellar Liposomal Formulation of Lurtotecan, a Topoisomerase 1 Inhibitor, in Patients with Advanced Leukemia

Cancer. Apr, 2004  |  Pubmed ID: 15042679

OSI-211 is a low-clearance, unilamellar liposomal formulation of a water-soluble camptothecin analogue, lurtotecan. OSI-211 has significant activity in severe combined immunodeficient mouse models of human leukemia.

Phase II Study of R115777, a Farnesyl Transferase Inhibitor, in Myelodysplastic Syndrome

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Apr, 2004  |  Pubmed ID: 15051776

To perform a phase II study of the farnesyl transferase inhibitor R115777 (Zarnestra; Johnson and Johnson Pharmaceutical Research and Development, Raritan, NJ) in patients with myelodysplastic syndrome (MDS), using doses recommended in a phase I study in relapsed/refractory leukemia.

Myelodysplastic Syndrome: from Morphology to Biology

Current Hematology Reports. May, 2004  |  Pubmed ID: 15087062

Myelodysplastic syndrome is characterized by ineffective hematopoiesis manifesting as peripheral cytopenia, despite adequate or increased cellularity in bone marrow. Increased intramedullary apoptosis is thought to be the mechanism underlying this phenomenon. However, the mechanisms leading to this increased apoptosis remain largely unknown. Although less apoptosis is seen in more advanced disease with increased blasts, apoptosis remains the major characteristic feature of this disease and data suggest that all cases are biologically similar, irrespective of the blast count. Myelodysplastic syndrome is a highly aggressive disease that carries a poor prognosis, especially in symptomatic patients. New therapeutic agents that target histone deacetylation, DNA methylation, or angiogenesis show promise, but focused biologic and therapeutic studies are needed to improve the outcome of this disease.

C-kit Receptor Expression in Acute Leukemias-association with Patient and Disease Characteristics and with Outcome

Leukemia Research. Apr, 2004  |  Pubmed ID: 15109537

We hypothesize that c-kit expression may be associated with disease-specific features and have prognostic value in acute leukemias. In acute lymphocytic leukemia (ALL), higher levels of c-kit expression predicted lower complete response (CR) rates, suggesting that these patients may benefit from acute myelogenous leukemia (AML) therapy. Despite a negative association with the Philadelphia-chromosome, there was no correlation with disease-free survival (DFS) in CR. In AML, c-kit was associated with older age and cytogenetic abnormality t(-5, -7). Consequently higher levels of c-kit predicted lower CR rates. However, after accounting for these covariates, multivariate analysis indicates that higher c-kit expression predicts higher CR rates, although there was no effect on DFS in CR.

Soluble Vascular Endothelial Growth Factor Receptor 1, and Not Receptor 2, is an Independent Prognostic Factor in Acute Myeloid Leukemia and Myelodysplastic Syndromes

Cancer. May, 2004  |  Pubmed ID: 15112269

Vascular endothelial growth factor (VEGF) and its receptors (VEGFRs) are major regulators of angiogenesis, which plays a key role in the growth and dissemination of solid tumors and hematologic neoplasms.

Clinical Relevance of Circulating Angiogenic Factors in Patients with Non-Hodgkin's Lymphoma or Hodgkin's Lymphoma

Leukemia Research. Jun, 2004  |  Pubmed ID: 15120936

Vascular endothelial growth factor (VEGF), basic-fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), and angiogenin are important angiogenic factors. In 65 patients with non-Hodgkin's lymphoma (NHL), pre-treatment VEGF, bFGF, and HGF levels were significantly elevated compared to normal individuals, while angiogenin levels were significantly subnormal. In 37 patients with Hodgkin's disease, pre-treatment levels of VEGF and HGF were significantly elevated, bFGF levels were normal, and angiogenin levels were significantly subnormal. In patients with NHL, post-therapy levels of angiogenin were independently predictive of survival. Both pre-therapy and post-therapy VEGF levels were independently predictive of survival in patients with HD.

The Clinical Significance of Large Cells in Bone Marrow in Patients with Chronic Lymphocytic Leukemia

Cancer. May, 2004  |  Pubmed ID: 15139060

Patients with chronic lymphocytic leukemia (CLL) that transforms to Richter syndrome (RS) frequently show atypical lymphocytes in bone marrow; however, a diagnosis of RS requires confirmation of the presence of sheets of large cells in bone marrow or lymph nodes.

Effects of SU5416, a Small Molecule Tyrosine Kinase Receptor Inhibitor, on FLT3 Expression and Phosphorylation in Patients with Refractory Acute Myeloid Leukemia

Leukemia Research. Jul, 2004  |  Pubmed ID: 15158089

Acute myeloid leukemia (AML) is associated with dysregulated hematopoietic cell proliferation and increased bone marrow angiogenesis, each regulated by signaling through receptor tyrosine kinases (RTKs). SU5416 is a small molecule inhibitor of VEGF receptors, c-kit and FLT3 and therefore provides a novel opportunity to target both angiogenesis and proliferation in AML. SU5416 was assessed in a phase II hematological malignancy trial in the US, where partial responses were observed in two of 33 patients. Since AML provides a unique platform to evaluate mechanism of action of small molecule inhibitors, investigation of the effect of SU5416 on FLT3 expression and phosphorylation in blood and bone marrow was an additional focus of this trial. Phosphorylated FLT3 was detected by immunoprecipitation/Western analysis in peripheral blood samples from 17 of 22 patients, and seven exhibited strong inhibition of phosphorylation immediately following a 1h SU5416 infusion, demonstrating that SU5416 can modulate RTK phosphorylation in humans. Although no clear correlation with clinical response was observed, analysis of patient plasma drug levels suggested that a threshold SU5416 concentration of 15 microM was associated with FLT3 inhibition. This observation was supported by data from an ex vivo model where AML cells were spiked into human blood, established to mimic the clinical setting and enable more rigorous analysis of effect of SU5416. In addition, FLT3 protein levels were downregulated in patient bone marrow samples, analyzed by an RIA assay. To identify putative predictors of response, patient plasma was analyzed for levels of secreted ligands of SU5416 targets; SCF and FLT3 ligand. Baseline levels of SCF in patients with stable or progressive disease were significantly higher than those in normal donors, whereas FLT3 ligand levels in patients who exhibited progressive disease were significantly lower than those in normal donors. The translational and clinical analyses described in this report provide some insights into the mechanism and duration of action of SU5416.

Telomerase Activity is Not a Prognostic Factor in Chronic Lymphocytic Leukemia

Leukemia Research. Jul, 2004  |  Pubmed ID: 15158092

We measured telomerase activity (TA) in bone marrow samples from 214 patients with CLL and correlated it with patients' characteristics and survival. In >50% of cases (126/214; 59%) no detectable TA was found. There was no difference in TA between previously treated (n = 153) and untreated (n = 61) patients (P = 0.4), or patients with various Rai (0-IV) stages (P = 0.85). TA correlated significantly with white blood cell and lymphocyte count (P = 0.02 and 0.01, respectively) but not with bone marrow cellularity, beta2-microglobulin (beta2M), or other patient characteristics. Patients who had no TA had slightly lower beta2M and lower lymphocyte counts (P = 0.5 and 0.04, respectively) as compared with patients with detectable TA. However, there was no correlation between TA and survival. This data suggests that TA may not play a significant role in the clinical behavior of CLL.

Free Circulating Soluble CD52 As a Tumor Marker in Chronic Lymphocytic Leukemia and Its Implication in Therapy with Anti-CD52 Antibodies

Cancer. Sep, 2004  |  Pubmed ID: 15329909

The CD52 antigen is a glycoprotein anchored on the cell membrane of mature B and T lymphocytes, monocytes, and eosinophils. Alemtuzumab (CAMPATH-1H; anti-CD52) is currently approved for the treatment of patients with refractory chronic lymphocytic leukemia (CLL). The authors investigated the possibility that CD52 may be shed from cells and, once soluble, may bind to injected alemtuzumab, forming immune complexes.

Alemtuzumab: Validation of a Sensitive and Simple Enzyme-linked Immunosorbent Assay

Leukemia Research. Dec, 2004  |  Pubmed ID: 15475065

Alemtuzumab (MabCampath) is a humanized rat monoclonal antibody that targets the CD52 antigen. It has been approved for the treatment of patients with resistant chronic lymphocytic leukaemia (CLL). Measuring plasma/serum levels of alemtuzumab is important for optimizing the dosing and scheduling of therapy; however, current assays in serum or plasma, based on the capture of alemtuzumab using CD52, are complicated and difficult to adapt for high throughput testing. We developed a simple sandwich enzyme-linked immunosorbent assay (ELISA) to measure alemtuzumab that takes advantage of the remaining rat sequence in alemtuzumab. Using specific anti-rat immunoglobulin (Ig) antibodies (absorbed against human Ig), alemtuzumab levels were measured in the serum and plasma of patients treated with alemtuzumab. Levels were similar between plasma and serum samples, in fresh samples and samples stored at 4 degrees C for 24 h, but were significantly lower in samples stored at room temperature for 24h. The assay was successfully used to determine serum alemtuzumab pre- and post-treatment. This assay is simple and adaptable for high throughput testing, with a limit of detection of 0.05 microg/ml and a coefficient of variation of +/-12.5%. No false positivity was observed in >200 samples tested. This validated assay should help optimize the dosing and scheduling of alemtuzumab therapy. The underlying principles are also applicable to the measurement of other humanized antibodies using an appropriate anti-Ig.

Chemoimmunotherapy with Fludarabine, Cyclophosphamide, and Rituximab for Relapsed and Refractory Chronic Lymphocytic Leukemia

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Jun, 2005  |  Pubmed ID: 15767647

The efficacy, toxicity, and tolerability of chemoimmunotherapy with the combination of fludarabine, cyclophosphamide, and rituximab (FCR) were evaluated in previously treated patients with chronic lymphocytic leukemia (CLL). The purpose of this study was to improve the complete remission (CR) rate for previously treated patients and evaluate the quality of bone marrow response.

Early Results of a Chemoimmunotherapy Regimen of Fludarabine, Cyclophosphamide, and Rituximab As Initial Therapy for Chronic Lymphocytic Leukemia

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Jun, 2005  |  Pubmed ID: 15767648

Fludarabine and cyclophosphamide (FC), which are active in treatment of chronic lymphocytic leukemia (CLL), are synergistic with the monoclonal antibody rituximab in vitro in lymphoma cell lines. A chemoimmunotherapy program consisting of fludarabine, cyclophosphamide, and rituximab (FCR) was developed with the goal of increasing the complete remission (CR) rate in previously untreated CLL patients to >/= 50%.

Adaptive Randomized Study of Idarubicin and Cytarabine Alone or with Interleukin-11 As Induction Therapy in Patients Aged 50 or Above with Acute Myeloid Leukemia or High-risk Myelodysplastic Syndromes

Leukemia Research. Jun, 2005  |  Pubmed ID: 15863204

A higher complete remission (CR) rate was observed in patients with acute myeloid leukemia (AML) who, on a prior randomized study of induction therapy, received gemtuzumab ozogamicin (GO) plus interleukin-11 (IL-11) rather than GO alone. An adaptive randomized phase III study of the addition of IL-11 to idarubicin and cytarabine (IA) induction in 100 patients >/=50 years of age with AML or high-risk myelodysplastic syndrome (MDS) was conducted. Median patient age was 67 years (range 50-82). Twenty-four of the 45 (53%) patients randomized to IA plus IL-11 achieved CR. Eight (33%) subsequently relapsed, 4 (17%) died in CR; median time to treatment failure (TTF) was 37 weeks. Twenty-nine of the 55 (53%) patients treated without IL-11 achieved CR. Eight (28%) subsequently relapsed, 2 (7%) died in CR; median TTF was 46 weeks. Median overall survivals were 21 and 59 weeks for the IA plus IL-11 and IA cohorts, respectively (p=0.271, log rank test; 0.435, Gehan-Breslow test). Ten episodes of the following grade 3 or 4 cardiopulmonary toxicities were observed in patients receiving IA plus IL-11, 12 such episodes in those receiving IA alone: atrial fibrillation, pleural effusions, myocardial infarction, bradycardia or hypotension. Two patients in each arm experienced grade 3 peripheral edema. There was no significant difference in incidence of any grade 3 or 4 adverse event, including thrombocytopenia, between treatment arms. There was no significant impact on CR rates, TTF, survival, or toxicity of adding an IL-11 regimen to IA induction in patients >/=50 years of age with AML.

Cognitive Impairment, Fatigue, and Cytokine Levels in Patients with Acute Myelogenous Leukemia or Myelodysplastic Syndrome

Cancer. Aug, 2005  |  Pubmed ID: 15973668

The objective of the current study was to assess the correlations between cognitive function, fatigue, quality of life, and circulating cytokine levels in patients with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS).

Angiogenic Factors May Have a Different Prognostic Role in Adult Acute Lymphoblastic Leukemia

Blood. Dec, 2005  |  Pubmed ID: 16123221

Angiogenesis plays an important role in solid tumors and hematologic malignancies. The prognostic significance of angiogenic factors in adult acute lymphoblastic leukemia (ALL) remains ambiguous. We therefore analyzed the impact of angiogenic factor levels on overall survival of newly diagnosed adult ALL patients. Plasma levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), interleukin-1 receptor alpha (IL-1Ralpha), IL-6, IL-8, VEGF receptors VEGFR1 and VEGFR2, and thrombopoietin (TPO) were measured in plasma samples of 95 patients by enzyme-linked immunosorbent assay (ELISA). In a univariate Cox proportional hazards model, higher levels of IL-1Ralpha, IL-8, VEGFR1, and VEGFR2 were predictive of poor survival. In contrast, higher levels of VEGF were predictive of longer survival, and higher levels of bFGF suggested a similar trend (P = .09). The multivariate model simultaneously included VEGF (relative risk [RR] for death, 8.01; P = .001 for levels less than or equal to 19.5 pg/mL), IL-1Ralpha (RR, 5.12; P = .007 for levels greater than 373 pg/mL), and VEGFR2 (RR, 4.01; P = .04 for levels greater than 8222 pg/mL) as independent factors for survival. Of interest is the association of high levels of VEGF with good prognosis and higher levels of VEGF receptors with poor outcome. These data reflect the complexity by which angiogenic factors may affect the clinical behavior of patients with ALL, and this complexity should be considered in any therapeutic strategy incorporating antiangiogenic agents.

Phase 1 Study of ABT-751, a Novel Microtubule Inhibitor, in Patients with Refractory Hematologic Malignancies

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Sep, 2005  |  Pubmed ID: 16166440

ABT-751 is an oral antimitotic agent that binds to the colchicine site on beta-tubulin. A phase 1 study was conducted to determine the maximum tolerated dose and toxicities of ABT-751 in patients with advanced myelodysplastic syndrome and relapsed or refractory acute leukemias.

Phase I Study of Cloretazine (VNP40101M), a Novel Sulfonylhydrazine Alkylating Agent, Combined with Cytarabine in Patients with Refractory Leukemia

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Nov, 2005  |  Pubmed ID: 16278404

Cloretazine (VNP40101M) is a novel sulfonylhydrazine alkylating agent with significant antileukemia activity. A phase I study of cloretazine combined with cytarabine (1-beta-d-arabinofuranosylcytosine, ara-C) was conducted in patients with refractory disease.

Mammalian Target of Rapamycin As a Therapeutic Target in Leukemia

Current Molecular Medicine. Nov, 2005  |  Pubmed ID: 16305491

Reflecting its critical role in integrating cell growth and division with the cellular nutritional environment, the mammalian target of rapamycin *(mTOR) is a highly conserved downstream effector of the phosphatidylinositol 3-kinase (PI3K)/Akt (protein kinase B) signaling pathway. mTOR activates both the 40S ribosomal protein S6 kinase (p70s6k) and the eukaryotic initiation factor 4E-binding protein-1. As a consequence of inhibiting its downstream messengers, mTOR inhibitors prevent cyclin-dependent kinase (CDK) activation, inhibit retinoblastoma protein phosphorylation, and accelerate the turnover of cyclin D1, leading to a deficiency of active CDK4/cyclin D1 complexes, all of which may help cause GI phase arrest. Constitutive activation of the PI3K/Akt kinases occur in human leukemias. FLT3, VEGF, and BCR-ABL mediate their activities via mTOR. New rapamycin analogs including CCI-779, RAD001, and AP23573, are entering clinical studies for patients with hematologic malignancies.

Monoclonal Antibodies in the Treatment of Leukemia

Current Molecular Medicine. Nov, 2005  |  Pubmed ID: 16305492

MoAb-based therapies are evolving into the first broad-spectrum class of targeted anti-leukemic therapy. Developments in many areas, including computer modeling of receptors and ligands, and increasing sophistication in recombinant technologies may result in a rapid increase in the number and complexity of MoAb's available. We can anticipate an increase in the number of safer conjugates being delivered to leukemia cells. Further understanding of the in vitro mechanisms involved in tumor cell killing by MoAb will be important in maximizing the efficacy of this approach.

Proteomic-based Prediction of Clinical Behavior in Adult Acute Lymphoblastic Leukemia

Cancer. Apr, 2006  |  Pubmed ID: 16518825

Response in adult acute lymphoblastic leukemia (ALL) can be achieved in a majority of patients. However, unlike pediatric ALL, recurrence is common in adult ALL, and the ability to predict at an early stage which patients are most likely to experience recurrence may help in devising new therapeutic approaches to prevent recurrence.

Decitabine Improves Patient Outcomes in Myelodysplastic Syndromes: Results of a Phase III Randomized Study

Cancer. Apr, 2006  |  Pubmed ID: 16532500

Aberrant DNA methylation, which results in leukemogenesis, is frequent in patients with myelodysplastic syndromes (MDS) and is a potential target for pharmacologic therapy. Decitabine indirectly depletes methylcytosine and causes hypomethylation of target gene promoters.

Plasma Thrombopoietin Compared with Immunoglobulin Heavy-chain Mutation Status As a Predictor of Survival in Chronic Lymphocytic Leukemia

Blood. Aug, 2006  |  Pubmed ID: 16551975

We investigated the association of plasma thrombopoietin (TPO) and overall survival in 127 patients with previously treated and previously untreated chronic lymphocytic leukemia (CLL). Higher levels of TPO were associated with advanced Rai stage (P < .001), higher levels of beta(2)-microglobulin (beta2-M) (P < .001), and the absence of mutation in the immunoglobulin heavy chain variable region (IgV(H)) (P < .001), and were inversely correlated with platelet count (P = .002). We found that TPO correlated strongly in a continuous manner with overall survival in both previously treated and untreated patients. The univariate Cox proportional hazard model demonstrated that high TPO levels were associated with shorter survival (P < .001), and multiple variable Cox proportional hazards regression analysis demonstrated that this was independent of the IgV(H) mutation status, beta2-M, and Rai stage. Recursive partitioning showed that a cutoff point of 639 pg/mL separated the CLL patients into 2 major survival groups (P < .001). The effects of beta2-M were masked by the effects of TPO in the patients with TPO levels higher than 639 pg/mL, but in the remainder, patients with beta2-M level higher than 4.95 mg/L had significantly shorter survival than those with lower values. Plasma TPO and beta2-M may be useful for the prediction of clinical behavior in CLL and may replace the need for the determination of IgV(H) mutation status.

A Phase II Study of Cloretazine (VNP40101M), a Novel Sulfonylhydrazine Alkylating Agent, in Patients with Very High Risk Relapsed Acute Myeloid Leukemia

Leukemia Research. Dec, 2006  |  Pubmed ID: 16574225

Cloretazine (VNP40101M) is a sulfonylhydrazine alkylating agent with significant anti-leukemia activity. A multicenter phase II study of cloretazine was conducted in patients with first relapse of acute myeloid leukemia (AML) following an initial complete remission (CR) of less than 12 months. Cloretazine was given as a single intravenous infusion at a dose of 600 mg/m(2). Fifty-three patients (median age 62 years (18-84), 41 of 44 (93%) evaluable with intermediate or high risk cytogenetics, 32 (60%) with initial CR durations < or =6 months) were treated on study. Two patients (4%) achieved a second CR. Five (9%) patients died within 30 days of receiving cloretazine therapy. Median overall survival (2.3 months) in the study cohort was directly comparable to that of 233 matched patients treated with other single agents. The study cloretazine regimen had minimal activity in a very high risk subset of patients with relapsed AML.

Thalidomide Therapy for Myelofibrosis with Myeloid Metaplasia

Cancer. May, 2006  |  Pubmed ID: 16583431

Thalidomide is a putative antiangiogenesis agent with activity in several hematologic malignancies.

Circulating Levels and Clinical Significance of Soluble CD40 in Patients with Hematologic Malignancies

Cancer. May, 2006  |  Pubmed ID: 16598754

CD40 plays a critical role in immunoregulation, and CD40 ligation is being investigated as a therapy for hematologic malignancies. Although soluble CD40 (sCD40) is a potential modulator of both antitumor responses and CD40-based therapies, the levels and significance of sCD40 in patients with hematologic malignancies are unknown.

Nilotinib in Imatinib-resistant CML and Philadelphia Chromosome-positive ALL

The New England Journal of Medicine. Jun, 2006  |  Pubmed ID: 16775235

Resistance to imatinib mesylate can occur in chronic myelogenous leukemia (CML). Preclinical in vitro studies have shown that nilotinib (AMN107), a new BCR-ABL tyrosine kinase inhibitor, is more potent than imatinib against CML cells by a factor of 20 to 50.

Validation of the European Prognostic Index for Younger Adult Patients with Acute Myeloid Leukaemia in First Relapse

British Journal of Haematology. Jul, 2006  |  Pubmed ID: 16803568

In order to validate the European Prognostic Index (EPI) for patients

A Phase I Study of Intravenous LBH589, a Novel Cinnamic Hydroxamic Acid Analogue Histone Deacetylase Inhibitor, in Patients with Refractory Hematologic Malignancies

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Aug, 2006  |  Pubmed ID: 16899611

LBH589 is a novel histone deacetylase inhibitor that inhibits proliferation and induces apoptosis in tumor cell lines. In this phase I study, LBH589 was administered i.v. as a 30-minute infusion on days 1 to 7 of a 21-day cycle.

Phase I/II Study of the Mammalian Target of Rapamycin Inhibitor Everolimus (RAD001) in Patients with Relapsed or Refractory Hematologic Malignancies

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Sep, 2006  |  Pubmed ID: 16951235

Everolimus (RAD001, Novartis), an oral derivative of rapamycin, inhibits the mammalian target of rapamycin (mTOR), which regulates many aspects of cell growth and division. A phase I/II study was done to determine safety and efficacy of everolimus in patients with relapsed or refractory hematologic malignancies.

Clinical Relevance of Soluble HLA-I and Beta2-microglobulin Levels in Non-Hodgkin's Lymphoma and Hodgkin's Disease

Leukemia Research. Feb, 2007  |  Pubmed ID: 16545870

Plasma levels of beta-2 microglobulin (beta2M), a subunit of the human leukocyte antigen-class I (HLA-I) molecule, correlate negatively with outcome in non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). We examined the clinical relevance of soluble HLA-I (sHLA-I) levels in NHL and HD. Sera from consecutive NHL (n=65) and HD (n=37) patients were analyzed in a blinded manner. NHL and HD patients had significantly higher levels of sHLA-1 and beta2M than control subjects. In NHL patients, sHLA-I levels correlated with clinical behavior in a fashion similar to that of beta2M. However, multivariate analysis incorporating beta2M, sHLA-I, and international prognostic index (IPI) indicated that NHL patients with elevated (>312.6mug/100mL) sHLA-I levels had significantly shorter survival, independent of IPI score as well as beta2M. In HD patients, beta2M but not sHLA-I levels were associated with clinical behavior. These findings not only establish the role of sHLA-I as an independent tumor marker in NHL that can be used to stratify patients, but also suggest that beta2M and sHLA-I may reflect different biological processes in HD and NHL. Further studies are needed to assess whether the immunomodulatory properties of sHLA-I may be responsible for its divergence from beta2M as an indicator of clinical behavior in HD.

Cloretazine (VNP40101M), a Novel Sulfonylhydrazine Alkylating Agent, in Patients Age 60 Years or Older with Previously Untreated Acute Myeloid Leukemia

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Jan, 2007  |  Pubmed ID: 17146105

Cloretazine (VNP40101M) is a sulfonylhydrazine alkylating agent with significant antileukemia activity. A multicenter phase II study of cloretazine was conducted in patients 60 years of age or older with previously untreated acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS).

The Haematopoietic Cell Transplantation Comorbidity Index Score is Predictive of Early Death and Survival in Patients over 60 Years of Age Receiving Induction Therapy for Acute Myeloid Leukaemia

British Journal of Haematology. Feb, 2007  |  Pubmed ID: 17223919

The haematopoietic cell transplantation comorbidity index (HCTCI) predicts nonrelapse mortality and overall survival (OS) post-stem cell transplantation. HCTCI scores were assessed in 177 patients over 60 years of age receiving acute myeloid leukaemia (AML) induction therapy. HCTCI score was 0 in 22% of patients, 1-2 in 30%, and > or =3 in 48%. In patients with scores of 0, 1-2, or > or =3, early death rates were 3%, 11% and 29% (P < 0.001) respectively; median OS was 45, 31 and 19 weeks (P = 0.04) respectively. The HCTCI score is predictive of early death rates and OS in older patients receiving AML induction therapy.

Plasma RNA As an Alternative to Cells for Monitoring Molecular Response in Patients with Chronic Myeloid Leukemia

Haematologica. Feb, 2007  |  Pubmed ID: 17296565

Quantitation of BCR-ABL mRNA is emerging as the standard of care to monitor the status of chronic myeloid leukemia (CML). Peripheral blood plasma was analyzed in this study because of previous detection of nucleic acids and proteins from tumor cells in plasma samples.

PTK787/ZK 222584, a Small Molecule Tyrosine Kinase Receptor Inhibitor of Vascular Endothelial Growth Factor (VEGF), Has Modest Activity in Myelofibrosis with Myeloid Metaplasia

Leukemia Research. Jul, 2007  |  Pubmed ID: 17560285

Angiogenesis is part of the pathophysiology of myelofibrosis with myeloid metaplasia (MMM). PTK787/ZK 222584 (PTK/ZK) is a novel inhibitor of vascular endothelial growth factor receptors. Twenty-nine patients with MMM received a continuous dosing schedule of PTK/ZK doses of 500 or 750 mg twice daily (BID). Transient potentially PTK/ZK related mild nausea, vomiting, dizziness, fatigue, thrombocytopenia, or anorexia occurred in 15% of patients. Dose limiting toxicities of dyspepsia, proteinurea, and/or mucositis were observed in patients treated with 750 mg BID. One (3%) and five (17%) patients achieved complete remission and clinical improvement, respectively. PTK/ZK has modest activity in patients with MMM.

Bi-clonal Disease in Patients with Chronic Lymphocytic Leukaemia As Detected by Analysing IGHV Mutation Status

British Journal of Haematology. Nov, 2007  |  Pubmed ID: 17868045

Plasma-based Testing As a New Paradigm for Clinical Testing in Hematologic Diseases

Expert Review of Molecular Diagnostics. Sep, 2007  |  Pubmed ID: 17892367

Recent advances in molecular biology have paved the way for the detection of minute quantities of cellular components with robust assays that are amenable for use in clinical laboratories. This review discusses the recently developed series of plasma-based assays that are changing the testing paradigm for hematologic diseases. These tests are based on the concept that a high turnover of neoplastic hematologic cells, relative to normal cells, enriches plasma with tumor-specific DNA, RNA and protein. Plasma-based testing promises to reduce the need for bone marrow biopsy, allow for more frequent and accurate monitoring of changes in bone marrow, allow the detection of more aggressive subclones of the malignant cells and provide a more quantitative means to measure the load of the malignant clone. We present data demonstrating that plasma, in some situations, allows even more sensitive detection than bone marrow cells. Moreover, the lessened impact of dilution by normal cells in plasma permits a distinction between homozygous and hemizygous abnormalities. Unlike solid tumors, currently available data suggest that in hematologic diseases, plasma is superior to cells in detecting molecular abnormalities.

A Potential Role for HSP90 Inhibitors in the Treatment of JAK2 Mutant-positive Diseases As Demonstrated Using Quantitative Flow Cytometry

Leukemia & Lymphoma. Nov, 2007  |  Pubmed ID: 17926180

The V617F mutation of the JAK2 tyrosine kinase is found in a majority of patients with myeloproliferative disorders. Flow cytometry assays for quantitation of phosphorylated and total protein for JAK2, STAT5, and heat shock proteins (HSPs) were developed to facilitate the study of the JAK/STAT pathway. A cell line homozygous for V617F (HEL) was treated with inhibitors of JAK2 tyrosine kinase activity and the HSP90 inhibitor 17-AAG. 17-AAG reduced HSP90 levels, but increased HSP70 levels. Phospho-STAT5, total STAT5, and total AKT levels were also reduced by 17-AAG treatment. Further, phospho-JAK2, total JAK2, and cell viability were reduced to a greater extent by 17-AAG than by the pan-JAK kinase family inhibitor JKII or the JAK2-specific inhibitor AG490, and these inhibitors failed to synergize with 17-AAG. Flow-cytometry-based assays for JAK/STAT signaling pathway and HSPs are likely to have broad clinical utility for monitoring patients with abnormalities in the JAK2 pathway.

He Use of the Antibodies in the Diagnosis of Leukemia and Lymphoma by Flow Cytometry

Methods in Molecular Biology (Clifton, N.J.). 2007  |  Pubmed ID: 18605077

Flow cytometry is an automated analysis of cells passing in the fluid suspension through a laser light beam, which react with monoclonal antibodies specific for a variety of cell surface antigens. A specimen of peripheral blood, bone marrow, or other cell suspension is incubated with fluorescent-labeled antibodies, which bind to target antigens on cell surfaces or--following cell permeabilization--to cytoplasmic and nuclear antigens. The analysis of surface antigens is performed on cells selected (gated) based on light-scatter properties. The expression of specific marker or confirmation of markers defines a specific cell population or the original of these cells. This in turn helps in diagnosis and classification of various hematological diseases and leads to choosing a specific therapy. Here, we describe a methodology for using flow cytometry with six colors for the analysis of various tissues for hematological diseases.

Quantification of Surface Antigens and Quantitative Flow Cytometry

Methods in Molecular Biology (Clifton, N.J.). 2007  |  Pubmed ID: 18605078

Measuring expression levels of cell surface antigens is important for the diagnosis of diseases such as B-cell chronic lymphocytic leukemia and the monitoring of targeted therapy, particularly antibody-based therapy. In some cases, the number of antigens that the therapeutic antibodies bind on the cell surface may reflect the efficacy of therapy. Thus, quantitating the number of molecules on the surface of cells before, during, and after therapy would provide important information for monitoring antibody-based therapy and potentially can be used to adjust dosing. We describe a quantitative flow cytometry approach to measuring levels of the CD20 surface antigen, the molecular target of rituximab.

Monitoring Cell Signaling Pathways by Quantitative Flow Cytometry

Methods in Molecular Biology (Clifton, N.J.). 2007  |  Pubmed ID: 18605080

As the signaling pathways involved in leukemogenesis are being elucidated, several proteins have emerged as potential targets for therapy. Downstream from those targets are numerous intracellular factors that are constantly modulated. Monitoring those factors could provide insight into the potential efficacy of therapies by predicting which patients will respond to them and by determining the optimal dosage that will inhibit the target protein. We describe a flow cytometry method for quantitation of total and phosphorylated intracellular proteins. Compared with Western blot analysis, this technique dramatically decreases time and labor while providing multiparameter information on specific cell populations. As an example, total and phosphorylated CRKL is quantitated. The methodology has the potential for widespread application in the monitoring of targeted therapy.

Cell-free Bead-based Detection of Total and Phosphorylated Proteins in Plasma and Cell Lysates: Detection of FLT3

Methods in Molecular Biology (Clifton, N.J.). 2007  |  Pubmed ID: 18605083

Frequently direct measurement of proteins or their phosphorylation in intact cells is not possible, for instance, when cells are too few, frozen, or subject to degradation. We have demonstrated that tumor cells pour their DNA, RNA, and protein content into circulation because of turnover and breakdown of cell structures. Proteins in solution most likely circulate as complexes, which protects them from degradation. We describe a cell-free, bead-based method that takes advantage of this phenomenon. Our approach is based on immunoprecipitation of the protein of interest on the surface of beads, followed by detection of the protein or its modification (phosphorylation) using a secondary antibody labeled with phycoerythrin at a 1:1 ratio. Fms-like tyrosine kinase-3, which is mutated in majority of cases of acute myeloid leukemia, is used as an example. This method could be applied to the quantitation of several other proteins without the need for intact cells.

Measuring Humanized Antibodies in Plasma of Patients Treated with Antibody-based Therapy Using Bead-based Flow Cytometry: the Story of Alemtuzumab

Methods in Molecular Biology (Clifton, N.J.). 2007  |  Pubmed ID: 18605084

Alemtuzumab (Campath), the humanized rat monoclonal antibody that targets the CD52 surface antigen, is currently used for treatment of patients with resistant chronic lymphocytic leukemia. Monitoring levels of the antibody in plasma/serum could provide insight into the optimal dosing and scheduling of therapy. Current methods of detecting alemtuzumab in serum or plasma are complicated and difficult to adapt to high-throughput testing. We describe a novel bead-based assay that measures circulating alemtuzumab by taking advantage of remnant rat sequence in the antibody. Levels of total alemtuzumab complexed with CD52, and free alemtuzumab are quantitated in the serum or plasma by flow cytometry. This approach is applicable to the measurement of other humanized antibodies that contain an appropriate remnant animal sequence.

Detection of Chromosome Translocations by Bead-based Flow Cytometry

Methods in Molecular Biology (Clifton, N.J.). 2007  |  Pubmed ID: 18605085

Chromosome translocations resulting in fusion genes have been implicated in leukemogenesis. The paradigm involves the fusion of the genes encoding BCR and ABL, leading to a constitutively active tyrosine kinase. The detection of BCR-ABL has been limited to fluorescence in situ hybridization analysis, reverse transcription-polymerase chain reaction, of mRNA, and Western blot of analysis downstream effectors in the BCR-ABL activated pathway. Here, we describe a novel immunoassay that directly measures levels of BCR-ABL fusion protein and its phosphorylation in peripheral blood plasma and cell lysates. This approach has the potential for widespread application in the detection and quantitation of other fusion genes involved in hematological malignancies.

Phosphorylation Levels of BCR-ABL, CrkL, AKT and STAT5 in Imatinib-resistant Chronic Myeloid Leukemia Cells Implicate Alternative Pathway Usage As a Survival Strategy

Leukemia Research. Apr, 2008  |  Pubmed ID: 17900686

Ex-vivo studies have suggested that imatinib-resistance in chronic myeloid leukemia (CML) patients occurs despite adequate suppression of BCR-ABL activity. Whether BCR-ABL phosphorylation levels differ between imatinib-sensitive and -resistant patients is not known. We compared the phosphorylation of BCR-ABL in 54 previously untreated CML patients and 62 imatinib-resistant CML patients with progressive disease. Resistant patients had significantly lower levels of BCR-ABL, CrkL and AKT phosphorylation than previously untreated patients, but STAT5 phosphorylation showed no difference. These observations suggest that imatinib- resistance is not necessarily dependent on higher activity in BCR-ABL-dependent pathways, but is likely due to the activation of other pathways.

An Immunological Method for the Detection of BCR-ABL Fusion Protein and Monitoring Its Activation

Leukemia Research. Jun, 2008  |  Pubmed ID: 18155764

We have developed a simplified sandwich immunoassay to measure free circulating total and phosphorylated fusion BCR-ABL protein in patients with the t(9;22)(q34;q11) chromosomal translocation. The assay is based on immunoprecipitating BCR-ABL protein using beads coated with anti-BCR antibody and detecting the fusion protein with anti-ABL antibody and flow cytometry. We show that this method allows the quantification of this protein in the plasma and may allow the measurement of tumor load. This method also allows the measurement of the level of phosphorylation of the immunoprecipitated BCR-ABL using antibodies against phosphorylated ABL protein, which can be used for monitoring of therapy with kinase inhibitors. The sensitivity of this immunoassay was comparable to the sensitivity of reverse transcription-polymerase chain reaction (RT-PCR) assay. This technique is useful in monitoring patients with chronic myeloid leukemia (CML) or acute lymphoblastic leukemia (ALL), but the same approach can be used in other translocations and has the potential of multiplexing.

Enzymatic Activity of Circulating Proteasomes Correlates with Clinical Behavior in Patients with Chronic Lymphocytic Leukemia

Cancer. Mar, 2008  |  Pubmed ID: 18224667

The ubiquitin-proteasome pathway has been implicated in the pathogenesis of many hematologic malignancies.

Molecular Basis Explanation for Imatinib Resistance of BCR-ABL Due to T315I and P-loop Mutations from Molecular Dynamics Simulations

Cancer. Apr, 2008  |  Pubmed ID: 18338744

Computational simulations have become powerful tools for understanding detailed interactions in biologic systems. To the authors' knowledge to date, the mechanism of imatinib resistance in BCR-ABL has not been clarified at the atomic level, and computational studies are required.

Higher Detection Rate of JAK2 Mutation Using Plasma

Blood. Apr, 2008  |  Pubmed ID: 18362222

A Phase 2 Clinical Trial of Deforolimus (AP23573, MK-8669), a Novel Mammalian Target of Rapamycin Inhibitor, in Patients with Relapsed or Refractory Hematologic Malignancies

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. May, 2008  |  Pubmed ID: 18451242

Deforolimus (AP23573), a novel non-prodrug rapamycin analogue, inhibits the mammalian target of rapamycin, a downstream effector of the phosphatidylinositol 3-kinase/Akt and nutrient-sensing pathways. A phase 2 trial was conducted to determine the efficacy and safety of single-agent deforolimus in patients with relapsed or refractory hematologic malignancies.

The Prognostic Significance of Cytokine Levels in Newly Diagnosed Acute Myeloid Leukemia and High-risk Myelodysplastic Syndromes

Cancer. Oct, 2008  |  Pubmed ID: 18683214

Tumor necrosis factor (TNF)-alpha and other cytokines are involved in the pathogenesis of acute myeloid leukemia (AML) and high-risk myelodysplastic syndromes (MDS), but their prognostic significance in these diseases is unknown. In the current study, the authors assessed the association between serum levels of various cytokines and clinical outcomes in patients with untreated AML or high-risk MDS.

Toward the Identification of Mesenchymal Stem Cells in Bone Marrow and Peripheral Blood for Bone Regeneration

Implant Dentistry. Sep, 2008  |  Pubmed ID: 18784524

The advent of monoclonal antibody stem cell marker technology has made it possible to identify a variety of human stem cells and their progeny. Specific markers exist for cells related to bone healing and bone regeneration. These include but are not limited to hematopoietic, mesenchymal, endothelial, angiogenic, and vasculargenic precursor cells.

Liquid-based Fluorescence in Situ Hybridization Assay for Detection of ERBB2 Gene Amplification in Patients with Breast Cancer

Clinical Chemistry. Nov, 2008  |  Pubmed ID: 18787015

Current reference methods for evaluating gene amplification and expression of ERBB2 (also known as HER-2)--cell-based fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC)--are subjective and influenced by methods of tissue preparation and fixation. We developed and evaluated a novel, quantitative liquid-based FISH (L-FISH) assay that uses flow cytometry to detect ERBB2 gene amplification in breast cancer patients.

BCR-ABL Alternative Splicing As a Common Mechanism for Imatinib Resistance: Evidence from Molecular Dynamics Simulations

Molecular Cancer Therapeutics. Dec, 2008  |  Pubmed ID: 19056677

Rare cases of chronic myelogenous leukemia (CML) express high levels of alternatively spliced BCR-ABL mRNA with a 35-bp insertion (35INS) between ABL kinase domain exons 8 and 9. This insertion results in a frameshift leading to the addition of 10 residues and truncation of 653 residues due to early termination. Sensitive PCR-based testing showed that 32 of 52 (62%) imatinib-resistant CML patients in chronic phase and 8 of 38 (21%) in accelerated or blast crisis expressed varying levels of the alternatively spliced BCR-ABL mRNA. A three-dimensional structural model of the 35INS ABL kinase domain complexed with imatinib was built using homology modeling, followed by molecular dynamics simulations. Simulation results showed that the new residues cause a significant global conformational change, altering imatinib binding in a way similar to that of the T315I mutation and, therefore, providing resistance to imatinib that depends on the level of expression.

Circulating Heat Shock Protein 70 and Progression in Patients with Chronic Myeloid Leukemia

Leukemia Research. Feb, 2009  |  Pubmed ID: 18715642

We evaluated the association of circulating levels of heat shock protein 70 (Hsp70) in plasma with clinical behavior and progression in 139 chronic myeloid leukemia (CML) patients. Circulating Hsp70 levels did not differ significantly between CML patients in the chronic phase (n=93; median 33.24 ng/mL, range 3.89-128.2 ng/mL) and those in the accelerated/blast phase (n=46; median 26.57 ng/mL, range 4.5-114.7 ng/mL). However, overall CML patients had significantly higher levels of Hsp70 than healthy subjects (n=95, median 4.17 ng/mL, range 1.75-24.7 ng/mL) (P<0.001). In chronic phase CML patients, Hsp70 levels above the median were associated with a higher rate of progression to the accelerated/blast phase and a tendency toward shorter survival. Plasma Hsp70 thus could be a potential marker for predicting disease progression in patients with chronic phase CML.

Mutation Profile of JAK2 Transcripts in Patients with Chronic Myeloproliferative Neoplasias

The Journal of Molecular Diagnostics : JMD. Jan, 2009  |  Pubmed ID: 19074595

Here, we describe the JAK2 mutation profile in a series of approximately 20,000 blood samples from patients with clinically suspected myeloproliferative neoplasias. Using a sensitive reverse transcription-PCR and direct sequencing approach on RNA rather than DNA, we detected JAK2 mutations in exons 12-15 in approximately 20% of these patients. We identified new mutations in addition to the known V617F and exon 12 mutations, which were the most common. Most of the novel mutations are located in the pseudokinase domain and therefore are expected to relieve the autoinhibitory function of this domain on JAK2 kinase activity. Our data suggest that molecular testing of JAK2 mutations should not be restricted to the V617F and exon 12 mutations, but perhaps should extend to most of the pseudokinase domain coding region as well. Furthermore, mutation screening using RNA is highly sensitive and could replace DNA-based testing because of the relative abundance of target transcripts and the ease in detecting deletion of the entire exon.

Plasma-based Detection of Clonality in Lymphoid Malignancies

European Journal of Haematology. Jun, 2009  |  Pubmed ID: 19187275

Plasma has been found to be enriched with tumor-specific DNA, RNA, and protein in patients with hematologic disease. We assessed the utility of plasma as a DNA source for detection of genetic abnormalities in patients with suspected B- or T-cell lymphoproliferative disorders.

Mechanisms of Constitutive Activation of Janus Kinase 2-V617F Revealed at the Atomic Level Through Molecular Dynamics Simulations

Cancer. Apr, 2009  |  Pubmed ID: 19195039

The tyrosine kinase Janus kinase 2 (JAK2) is important in triggering nuclear translocation and regulation of target genes expression through signal transducer and activator of transcription pathways. The valine-to-phenylalanine mutation at amino acid 617 (V617F), which results in the deregulation of JAK2, has been implicated in the oncogenesis of chronic myeloproliferative disease. However, both the mechanism of JAK2 autoinhibition and the mechanism of V617F constitutive activation remain unclear.

B-cell Clones As Early Markers for Chronic Lymphocytic Leukemia

The New England Journal of Medicine. Feb, 2009  |  Pubmed ID: 19213679

Otherwise healthy persons with a small number of B-cell clones circulating in the peripheral blood have been designated as having monoclonal B-cell lymphocytosis (MBL). Hospital-based series indicate an excess risk of progression from MBL to chronic lymphocytic leukemia (CLL). In this prospective cohort study, we tested the hypothesis that CLL is always preceded by MBL.

K-ras Mutations and Cetuximab in Colorectal Cancer

The New England Journal of Medicine. Feb, 2009  |  Pubmed ID: 19238675

Detection of Nucleophosmin Gene Mutations in Plasma from Patients with Acute Myeloid Leukemia: Clinical Significance and Implications

Cancer Biomarkers : Section A of Disease Markers. 2009  |  Pubmed ID: 19242062

Roughly one-third of acute myeloid leukemia (AML) patients exhibit mutations in the nucleophosmin (NPM1) gene, and multiple studies have linked these mutations with a more favorable clinical outcome. We developed an assay for the detection of NPM1 mutations in peripheral blood plasma, and compared the results with clinical outcomes from a single institution. Analyzing plasma from previously untreated AML patients revealed NPM1 insertion mutations in 24 of 98 (24%) patients, with greater sensitivity than existing peripheral blood cell-based tests which showed positivity in only 22 of the 24 patients. Plasma testing allowed the detection of a novel 4 bp deletion in NPM1 in one patient. Analysis of clinical data corroborated previous data linking NPM1 mutations with better clinical outcome. These data underline the significance of NPM1 in the biology and clinical behavior of AML, and demonstrate the reliability and efficacy of plasma-based testing for NPM1 mutations.

BCR-ABL Truncation Due to Premature Translation Termination As a Mechanism of Resistance to Kinase Inhibitors

Acta Haematologica. 2009  |  Pubmed ID: 19332983

Kit Inhibitor APcK110 Induces Apoptosis and Inhibits Proliferation of Acute Myeloid Leukemia Cells

Cancer Research. May, 2009  |  Pubmed ID: 19383925

Kit is a membrane-bound tyrosine kinase and receptor for stem cell factor (SCF) with a crucial role in hematopoiesis. Mutations of KIT occur in almost half of patients with core-binding factor leukemias, in which they have been associated with worse outcome. Development of new compounds targeting Kit may therefore hold promise for therapy. We investigated the activity and mechanism of action of APcK110, a novel Kit inhibitor, in the mastocytosis cell line HMC1.2 (KITV560G and KITD816V), acute myeloid leukemia (AML) lines OCIM2 and OCI/AML3 (both wild-type), and primary samples from patients with AML. We show that (a) APcK110 inhibits proliferation of the mastocytosis cell line HMC1.2 and the SCF-responsive cell line OCI/AML3 in a dose-dependent manner; (b) APcK110 is a more potent inhibitor of OCI/AML3 proliferation than the clinically used Kit inhibitors imatinib and dasatinib and at least as potent as cytarabine; (c) APcK110 inhibits the phosphorylation of Kit, Stat3, Stat5, and Akt in a dose-dependent fashion, showing activity of APcK110 on Kit and its downstream signaling pathways; (d) APcK110 induces apoptosis by cleavage of caspase-3 and poly(ADP-ribose) polymerase; and (e) APcK110 inhibits proliferation of primary AML blasts in a clonogenic assay but does not affect proliferation of normal colony-forming cells. Although APcK110 activity may partly depend on cytokine responsiveness (e.g., SCF) and not exclusively KIT mutation status, it remains a potent inhibitor of AML and mastocytosis cell lines and primary AML samples. APcK110 and similar compounds should be evaluated in clinical trials of patients with AML.

Proteomics-based Prediction of Clinical Response in Acute Myeloid Leukemia

Experimental Hematology. Jul, 2009  |  Pubmed ID: 19422784

Response to chemotherapy is achieved in 60% to 70% of patients with acute myeloid leukemia. The ability to predict responders may help in stratifying patients and exploring different therapeutic approaches for nonresponders. Proteomics methods were used to search for predictive factors or combinations of factors.

Proteasome Enzymatic Activities in Plasma As Risk Stratification of Patients with Acute Myeloid Leukemia and Advanced-stage Myelodysplastic Syndrome

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Jun, 2009  |  Pubmed ID: 19458051

Cytogenetic abnormalities are currently the most important predictors of response and clinical outcome for patients with acute myeloid leukemia (AML) or advanced-stage myelodysplastic syndrome (MDS). Because clinical outcomes vary markedly within cytogenetic subgroups, additional biological markers are needed for risk stratification.

Basis for Resistance to Imatinib in 16 BCR-ABL Mutants As Determined Using Molecular Dynamics

Recent Patents on Anti-cancer Drug Discovery. Jun, 2009  |  Pubmed ID: 19519539

Large-scale (approximately 36,000 atoms) long-time (30 ns each) molecular dynamics (MD) simulations on the complex of imatinib and 16 common mutants of the ABL tyrosine kinase domain have been performed to study the imatinib resistance mechanisms at the atomic level. MD simulations show that long time computational simulations could offer insight information that static models, simple homology modeling methods, or short-time simulations cannot provide for the BCR-ABL imatinib resistance problem. Three possible types of mutational effects from those mutants are found: the direct effect on the contact interaction with imatinib (e.g. some P-loop mutations), the effect on the conformation of a remote region contacting with imatinib (e.g. T315I), and the effect on interaction between two regions within the BCR-ABL domain (e.g. H396P). Insights of possible imatinib resistance mechanisms, not consistent with current consensus, are revealed from various analyses and our findings suggest that drugs with different binding modes may be necessary to overcome the drug resistance due to T315I and other mutations. The relevant patents are discussed.

Multicenter Study of Decitabine Administered Daily for 5 Days Every 4 Weeks to Adults with Myelodysplastic Syndromes: the Alternative Dosing for Outpatient Treatment (ADOPT) Trial

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Aug, 2009  |  Pubmed ID: 19528372

Decitabine, a DNA-targeted hypomethylating agent, is approved by the United States Food and Drug Administration for treatment of patients with myelodysplastic syndromes (MDS) on a schedule of 15 mg/m(2) administered via intravenous (IV) infusion every 8 hours for 3 days. This study assessed the efficacy and safety of an alternative dosing regimen administered on an outpatient basis in academic and community-based practices.

Acute Lymphoblastic Leukemia with Burkitt-like Morphologic Features and High Myeloperoxidase Activity

American Journal of Clinical Pathology. Aug, 2009  |  Pubmed ID: 19605811

Expression of a high level of myeloperoxidase (MPO) as a sole myeloid marker in acute leukemias that express typical lymphoblastic markers is unusual. Herein we report 5 cases of MPO+, otherwise typical acute lymphoblastic leukemia (ALL) without the expression of other myeloid markers. In most cases, MPO positivity was detected in more than 20% of blasts by immunologic (flow cytometric) and enzymatic testing. The striking feature of most of these cases is a morphologic picture reminiscent of that seen in Burkitt-like B-cell ALL with basophilic cytoplasm and vacuoles but no expression of surface immunoglobulin. All cases responded to ALL therapy and should be distinguished from myeloid leukemia and from Burkitt leukemia/lymphoma.

Phase 3 Randomized, Placebo-controlled, Double-blind Study of High-dose Continuous Infusion Cytarabine Alone or with Laromustine (VNP40101M) in Patients with Acute Myeloid Leukemia in First Relapse

Blood. Nov, 2009  |  Pubmed ID: 19710500

Laromustine is a sulfonylhdrazine alkylator with significant antileukemia activity. An international, randomized (2:1), double-blind, placebo-controlled study was conducted to compare complete remission (CR) rates and overall survival (OS) in patients with first relapse acute myeloid leukemia (AML) treated with laromustine and high-dose cytarabine (HDAC) versus HDAC/placebo. Patients received 1.5 g/m(2) per day cytarabine continuous infusion for 3 days and laromustine 600 mg/m(2) (n = 177) or placebo (n = 86) on day 2. Patients in CR received consolidation with laromustine/HDAC or HDAC/placebo as per initial randomization. After interim analysis at 50% enrollment, the Data Safety Monitoring Board (DSMB) expressed concern that any advantage in CR would be compromised by the observed on-study mortality, and enrollment was held. The CR rate was significantly higher for the laromustine/HDAC group (35% vs 19%, P = .005). However, the 30-day mortality rate and median progression-free survival were significantly worse in this group compared with HDAC/placebo (11% vs 2%; P = .016; 54 days vs 34; P = .002). OS and median response durations were similar in both groups. Laromustine/HDAC induced significantly more CR than HDAC/placebo, but OS was not improved due to mortality associated with myelosuppression and its sequelae. The DSMB subsequently approved a revised protocol with laromustine dose reduction and recombinant growth factor support. The study was registered as NCT00112554 at

High-dose Imatinib in Newly Diagnosed Chronic-phase Chronic Myeloid Leukemia: High Rates of Rapid Cytogenetic and Molecular Responses

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Oct, 2009  |  Pubmed ID: 19720924

Long-term clinical outcome data have established imatinib 400 mg/d as standard front-line treatment for newly diagnosed patients with chronic myeloid leukemia (CML).

Structural Effects of Clinically Observed Mutations in JAK2 Exons 13-15: Comparison with V617F and Exon 12 Mutations

BMC Structural Biology. Sep, 2009  |  Pubmed ID: 19744331

The functional relevance of many of the recently detected JAK2 mutations, except V617F and exon 12 mutants, in patients with chronic myeloproliferative neoplasia (MPN) has been significantly overlooked. To explore atomic-level explanations of the possible mutational effects from those overlooked mutants, we performed a set of molecular dynamics simulations on clinically observed mutants, including newly discovered mutations (K539L, R564L, L579F, H587N, S591L, H606Q, V617I, V617F, C618R, L624P, whole exon 14-deletion) and control mutants (V617C, V617Y, K603Q/N667K).

Evidence of Serum Immunoglobulin Abnormalities Up to 9.8 Years Before Diagnosis of Chronic Lymphocytic Leukemia: a Prospective Study

Blood. Dec, 2009  |  Pubmed ID: 19828698

Immune-related deficiencies are well-known complications of chronic lymphocytic leukemia (CLL). Although recent data indicate that almost all CLL patients are preceded by a monoclonal B-cell lymphocytosis precursor state, patterns of immune defects preceding CLL diagnosis are unclear. We identified 109 persons who developed CLL from the prospective and nationwide Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial with 77 469 participants, with serially collected prediagnostic serum samples. We assayed monoclonal (M)-proteins, kappa/lambda free light chains (FLCs) in prediagnostic obtained up to 9.8 years before CLL diagnosis. The prevalence of an abnormal FLC ratio, M-protein, and hypogamma-globulinemia before CLL diagnosis was 38% (95% confidence interval, 29%-47%), 13% (7%-21%), and 3% (1%-8%), respectively. M-proteins and abnormal FLC ratios were detected up to 9.8 years before CLL diagnosis in a total of 48 persons (44%). Hypogammaglobulinemia was not present until 3 years before the diagnosis of CLL. Among 37 patients with information on tumor cell immunophenotype, an association between immunophenotype and involved FLC (P = .024, Fisher exact test) was observed. Among 61 persons with a normal FLC ratio and without an M-protein, 17 had elevated kappa and/or lambda FLC levels, indicating polyclonal B-cell activation in 17 of 109 (16%) patients. These findings support a role for chronic immune stimulation in CLL genesis.

Circulating Ki-67 Protein in Plasma As a Biomarker and Prognostic Indicator of Acute Lymphoblastic Leukemia

Leukemia Research. Feb, 2010  |  Pubmed ID: 19679351

Tissue-based determination of Ki-67, a marker of cellular proliferation, has shown prognostic value in solid tumors and hematological malignancies. We developed and validated an electrochemiluminescence-based method for sensitive measurement of circulating Ki-67 in plasma (cKi-67). This assay demonstrated significantly higher levels of cKi-67 in patients with newly diagnosed acute lymphoblastic leukemia (ALL) (n=27; median, 762; range, 0-4574U/100 microL) than in healthy control subjects (n=114; median, 399; range, 36-2830U/100 microL). Moreover, elevated plasma cKi-67 was associated with significantly shorter survival in ALL patients (P=0.05). These findings suggest that Ki-67 can be detected in circulation and has potential for use as a biomarker for predicting clinical behavior in ALL.

Clinical Correlation of Circulating Heat Shock Protein 70 in Acute Leukemia

Leukemia Research. May, 2010  |  Pubmed ID: 19800118

The heat shock protein 70 (HSP70) is one of the molecular chaperone family involved in the protection of cells upon exposure to various types of stresses. Plasma circulating HSP70 (cHSP70) is believed to play a role in the anti-tumor immune responses and its levels may reflect the levels of severity or the disease condition. Using electrochemiluminescence protein detection immunoassay, we measured the cHSP70 levels in the plasma of patients with acute myeloid leukemia (AML) (n=96), myelodysplastic syndrome (MDS) (n=28), and acute lymphoblastic leukemia (ALL) (n=40) and compared with those in normal individuals (n=99). cHSP70 levels were significantly higher in AML (median: 10.71 ng/mL, range: 1.93-79.0 ng/mL) and ALL (median: 27.59 ng/mL, range: 5.09-129.6 ng/mL) as compared to those in MDS (median: 4.54 ng/mL, range: 1.35-58.3 ng/mL) or healthy controls (median: 4.13 ng/mL, range: 1.75-13.6 ng/mL). Levels of cHSP70 showed significant positive correlation with lactate dehydrogenase (LDH) and white blood cells (WBC) in AML and ALL patients, which may reflect overall tumor load. Furthermore, patients with higher levels of cHSP70 had significantly shorter survival in AML (P=0.04) and ALL (P=0.05), suggesting that in these two acute diseases, cHSP70 is an indicator for poor prognosis. Our data support the potential of using free cHSP70 as a biomarker in leukemias and potentially other types of cancers.

Circulating CD52 and CD20 Levels at End of Treatment Predict for Progression and Survival in Patients with Chronic Lymphocytic Leukaemia Treated with Fludarabine, Cyclophosphamide and Rituximab (FCR)

British Journal of Haematology. Feb, 2010  |  Pubmed ID: 19895616

CD52 and CD20 antigens are important therapeutic targets for the monoclonal antibodies (mAbs) alemtuzumab and rituximab respectively. Circulating CD52 (cCD52) and CD20 (cCD20) have prognostic utility in lymphoid malignancies. The efficacy of mAb therapy in patients with chronic lymphocytic leukaemia (CLL) may be adversely affected by cCD52 or cCD20. In this report, blood and bone marrow (BM) cCD52 and cCD20 were measured at response assessment in previously treated (N = 235) patients with CLL who received fludarabine, cyclophosphamide, and rituximab (FCR). Univariate and multivariate statistical models evaluated correlations of pre- and response variables with progression-free (PFS) and overall survival (OS). Response variables included 1996 National Cancer Institute-Working Group (NCI-WG) response, polymerase chain reaction (PCR) for immunoglobulin heavy chain (IGHV) in BM, and cCD52 and cCD20 levels (blood and BM) at response assessment. Using multivariate analysis, response blood and BM cCD52, blood cCD20, and NCI-WG response were significant independent predictors of PFS. At the time of response assessment, BM cCD52 correlated with OS in univariate analysis. cCD52 and cCD20, therefore appear useful in predicting survival and may be important for monitoring patients following salvage FCR (fludarabine, cyclophosphamide, rituximab) therapy. These data further indicate that plasma may be a good target to evaluate for minimal residual disease using cCD52/cCD20 levels.

Single-agent Laromustine, a Novel Alkylating Agent, Has Significant Activity in Older Patients with Previously Untreated Poor-risk Acute Myeloid Leukemia

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Feb, 2010  |  Pubmed ID: 20026800

PURPOSE An international phase II study of laromustine (VNP40101M), a sulfonylhydrazine alkylating agent, was conducted in patients age 60 years or older with previously untreated poor-risk acute myeloid leukemia (AML). PATIENTS AND METHODS Laromustine 600 mg/m(2) was administered as a single 60-minute intravenous infusion. Patients were age 70 years or older or 60 years or older with at least one additional risk factor-unfavorable AML karyotype, Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2, and/or cardiac, pulmonary, or hepatic comorbidities. Results Eighty-five patients (median age, 72 years; range, 60 to 87 years) were treated. Poor-risk features included age 70 years or older, 78%; adverse karyotype, 47%; PS of 2, 41%; pulmonary disease, 77%; cardiac disease, 73%; and hepatic disease, 3%. Ninety-six percent of patients had at least two risk factors, and 39% had at least four risk factors. The overall response rate (ORR) was 32%, with 20 patients (23%) achieving complete response (CR) and seven (8%) achieving CR with incomplete platelet recovery (CRp). ORR was 20% in patients with adverse cytogenetics; 32% in those age 70 years or older; 32% in those with PS of 2; 32% in patients with baseline pulmonary dysfunction; 34% in patients with baseline cardiac dysfunction; and 27% in 33 patients with at least four risk factors. Twelve (14%) patients died within 30 days of receiving laromustine therapy. Median overall survival was 3.2 months, with a 1-year survival of 21%; the median duration of survival for those who achieved CR/CRp was 12.4 months, with a 1-year survival of 52%. CONCLUSION Laromustine has significant single-agent activity in elderly patients with poor-risk AML. Adverse events are predominantly myelosuppressive or respiratory. Response rates are consistent across a spectrum of poor-risk features.

Circulating Ki-67 Index in Plasma As a Biomarker and Prognostic Indicator in Chronic Lymphocytic Leukemia

Leukemia Research. Oct, 2010  |  Pubmed ID: 20362333

Ki-67 is a nuclear antigen that is expressed in all stages of the cell cycle, except G(0), and is widely used as a marker of cellular proliferation in human tumors. We recently showed that elevated levels of Ki-67 circulating in plasma (cKi-67) are associated with shorter survival in patients with acute lymphoblastic leukemia. The current study included 194 patients with CLL and 96 healthy control subjects. cKi-67 levels in plasma were determined using an electrochemiluminescent immunoassay. We normalized the cKi-67 level to the absolute number of lymphocytes in the patient's peripheral blood to establish the plasma cKi-67 index. The cKi-67 index showed significant correlation with lymph node involvement and Rai stage (P=0.05). Higher cKi-67 index values were significantly associated with shorter survival. Multivariate Cox proportional hazards regression analysis demonstrated that the association of the cKi-67 index with shorter survival was independent of IgV(H) mutation status. In a multivariate model incorporating the cKi-67 index with B2M and IgV(H), only cKi-67 index and B2M levels remained as independent predictors of survival. The results of this study suggest that the plasma cKi-67 index, along with B2M level, is a strong predictor of clinical behavior in CLL.

Circulating CD33 and Its Clinical Value in Acute Leukemia

Experimental Hematology. Jun, 2010  |  Pubmed ID: 20362641

CD33 is a cell surface antigen for committed myelomonocytic lineage. We explored the potential of detecting CD33 as cell-free circulating protein in patients with leukemia.

Quantification of Intracellular Proteins and Monitoring Therapy Using Flow Cytometry

Current Drug Targets. Aug, 2010  |  Pubmed ID: 20426764

Here we review phospho-specific, quantitative flow cytometry approach as a rapid and reliable tool for measuring intracellular signaling proteins with potential applications in monitoring efficacy of targeted therapy. The single cell, multiparameter nature of flow cytometry allows simultaneous investigation of specific cell type and the corresponding intracellular markers. Peripheral blood can be directly stained with surface markers to delineate cell populations of interest, followed by fixation, permeabilization, and immunostaining with specific antibodies to the cellular targets. By using calibrated standardized phycoerythrin (PE)-conjugated beads for signal quantification, an informative Index value can be generated for each sample by multiplication of percentages of positive cells with fluorescence intensity per cell. This technique can yield both qualitative and quantitative information on effects of cellular markers upon targeted therapy, thereby providing another layer of advantages over the conventional flow cytometry analysis. Advances in this technology: high-throughput capability and automation, making it a valuable platform in modern drug discovery.

Tanespimycin Monotherapy in Relapsed Multiple Myeloma: Results of a Phase 1 Dose-escalation Study

British Journal of Haematology. Aug, 2010  |  Pubmed ID: 20618337

Tanespimycin, a heat shock protein 90 (HSP90) inhibitor, induces apoptosis in drug-sensitive and -resistant MM cell lines and in tumour cells from patients with relapsed MM. In this phase 1 dose-escalation study, the safety, plasma pharmacokinetics, and biological/antitumour activity of tanespimycin were evaluated in heavily pretreated patients with relapsed/refractory MM. Tanespimycin (150-525 mg/m(2)) was given on days 1, 4, 8, and 11 of each 3-week cycle for up to 8 cycles. Non-haematological AEs included diarrhoea (59%), back pain (35%), fatigue (38%), and nausea (35%); haematological AEs included anaemia (24%) and thrombocytopenia (21%). One patient (3%) achieved minimal response (MR), with a progression-free survival (PFS) of 3 months, a 41% decrease from baseline in urine M protein, and a 33% decrease from baseline in serum M protein. Fifteen patients (52%) achieved SD with a median PFS of 2.1 months; 5/15 had reductions in serum M protein ranging from 7% to 38% and in urine M protein ranging from 6% to 91%. Mean HSP70 levels increased from day 1 h 0 to day 1 h 4 with further increases on day 11 h 0 and day 11 h 4, consistent with a therapeutic treatment effect. Tanespimycin monotherapy was well tolerated and demonstrated activity across all doses tested.

Tanespimycin with Bortezomib: Activity in Relapsed/refractory Patients with Multiple Myeloma

British Journal of Haematology. Aug, 2010  |  Pubmed ID: 20618338

Tanespimycin (17-allylamino-17-demethoxygeldanamycin, 17-AAG) disrupts heat shock protein 90 (HSP90), a key molecular chaperone for signal transduction proteins critical to myeloma growth, survival and drug resistance. In previous studies, tanespimycin monotherapy was well tolerated and active in heavily pretreated patients with relapsed/refractory multiple myeloma (MM). Preclinical data have shown antitumour synergy between tanespimycin and bortezomib, with more pronounced intracellular accumulation of ubiquitinated proteins than either drug alone, an effect attributed to the synergistic suppression of chymotryptic activity in the 20S proteasome. HSP70 induction has been observed in all Phase 1 tanespimycin studies in which it has been measured, with several separate reports of HSP70 overexpression protecting against peripheral nerve injury. In this Phase 2, open-label multicentre study, we compared 1.3 mg/m2 bortezomib + three doses of tanespimycin: 50, 175 and 340 mg/m2 in heavily pretreated patients with relapsed and refractory MM and measured HSP70 expression and proteasome activity levels in plasma of treated patients. The study was closed prematurely for resource-based reasons, precluding dose comparison. Nonetheless, antitumour activity was observed, with promising response rates and promising severity of peripheral neuropathy.

JAK2 Exon 14 Deletion in Patients with Chronic Myeloproliferative Neoplasms

PloS One. Aug, 2010  |  Pubmed ID: 20730051

The JAK2 V617F mutation in exon 14 is the most common mutation in chronic myeloproliferative neoplasms (MPNs); deletion of the entire exon 14 is rarely detected. In our previous study of >10,000 samples from patients with suspected MPNs tested for JAK2 mutations by reverse transcription-PCR (RT-PCR) with direct sequencing, complete deletion of exon 14 (Deltaexon14) constituted <1% of JAK2 mutations. This appears to be an alternative splicing mutation, not detectable with DNA-based testing.

Long-term Follow-up of Monoclonal B-cell Lymphocytosis Detected in Environmental Health Studies

Cytometry. Part B, Clinical Cytometry. 2010  |  Pubmed ID: 20839341

Four individuals in whom Monoclonal B cell Lymphocytosis (MBL) had been previously detected were evaluated for the fourth time after 15-18 years since initial testing. All four were environmental health study participants without hematologic malignancies who had elevated absolute B cell counts at initial testing.

Somatic Mutations of Signaling Genes in Non-small-cell Lung Cancer

Cancer Genetics and Cytogenetics. Nov, 2010  |  Pubmed ID: 20951313

Lung cancer is the leading cause of cancer-related deaths, with non-small-cell lung cancer (NSCLC) accounting for approximately 85% of cases. A significant proportion of NSCLC cases are not diagnosed until a late stage, when aggressive treatments are required but often prolong survival only modestly. Recent advances in molecular characterization of NSCLC have enabled identification of numerous cell growth and proliferation pathways that are disrupted in these tumors. This knowledge has provided insight into the mechanisms of tumor development in various histologic subtypes of NSCLC and has pointed the way toward targeted treatment strategies. In this review, we highlight literature findings of somatic mutations in genes involved in cell growth and proliferation that are commonly found in the various subtypes of NSCLC, and we discuss how these findings may relate to treatment strategies.

Significant Association Between Polymorphism of the Erythropoietin Gene Promoter and Myelodysplastic Syndrome

BMC Medical Genetics. Nov, 2010  |  Pubmed ID: 21078205

Myelodysplastic syndrome (MDS) may be induced by certain mutagenic environmental or chemotherapeutic toxins; however, the role of susceptibility genes remains unclear. The G/G genotype of the single-nucleotide polymorphism (SNP) rs1617640 in the erythropoietin (EPO) promoter has been shown to be associated with decreased EPO expression. We examined the association of rs1617640 genotype with MDS.

Ubiquitin-proteasome System Profiling in Acute Leukemias and Its Clinical Relevance

Leukemia Research. Apr, 2011  |  Pubmed ID: 20951430

The ubiquitin-proteasome system (UPS) plays a major role in the homeostasis of cellular protein. We demonstrate that each of the major hematologic diseases (AML, ALL, and MDS) has a specific and different plasma profile of UPS protein and enzymatic activities. While high levels of proteasome and ubiquitin proteins and enzymatic activities are detected in the plasma samples from patients, normalizing enzymatic activities, show that each proteasome has lower enzymatic activities in these diseases as compared with normal controls. Proteasome protein levels in AML are strong predictor of survival independently of cytogenetics, performance status and age. The Ch-L activity when normalized to the level of proteasome protein show significant negative correlation with survival in ALL.

Circulating MicroRNAs As Biomarkers for Hepatocellular Carcinoma

Journal of Clinical Gastroenterology. Apr, 2011  |  Pubmed ID: 21278583

We investigated whether measurement of serum levels of the microRNAs (miRNAs) miR-16, miR-195, and miR-199a, alone or in combination with conventional serum markers, can help to differentiate hepatocellular carcinoma (HCC) from chronic liver diseases (CLDs).

MPL Mutation Profile in JAK2 Mutation-negative Patients with Myeloproliferative Disorders

Diagnostic Molecular Pathology : the American Journal of Surgical Pathology, Part B. Mar, 2011  |  Pubmed ID: 21326037

Mutations in the thrombopoietin receptor gene (myeloproliferative leukemia, MPL) have been reported in patients with JAK2 V617F-negative chronic myeloproliferative disorders (MPDs). We evaluated the prevalence of MPL mutations relative to JAK2 mutations in patients with suspected MPDs. A total of 2790 patient samples submitted for JAK2 mutation analysis were tested using real-time polymerase chain reaction and bidirectional sequencing of plasma RNA. JAK2 V617F-negative samples were tested for JAK2 exons 12 to 14 mutations, and those with negative results were then tested for mutations in MPL exons 10 and 11. Of the 2790 patients, 529 (18.96%) had V617F, 12 (0.43%) had small insertions or deletions in exon 12, and 7 (0.25%) had other JAK2 mutations in exons 12 to 14. Of the 2242 JAK2 mutation-negative patients, 68 (3.03%) had MPL mutations. W515L was the predominant MPL mutation (n=46; 68%), and 10 (15%) patients had other W515 variants. The remaining MPL mutations (n=12, 17%) were detected at other locations in exons 10 and 11 and included 3 insertion/deletion mutations. The S505N mutation, associated with familial MPD, was detected in 3 patients. Overall, for every 100 V617F mutations in patients with suspected MPDs, there were 12.9 MPL mutations, 2.3 JAK2 exon 12 mutations, and 1.3 JAK2 exons 13 to 14 mutations. These findings suggest that MPL mutation screening should be performed before JAK2 exons 12 to 14 testing in JAK2 V617F-negative patients with suspected MPDs.

Exon Scanning by Reverse Transcriptase-polymerase Chain Reaction for Detection of Known and Novel EML4-ALK Fusion Variants in Non-small Cell Lung Cancer

Cancer Genetics. Jan, 2011  |  Pubmed ID: 21356191

Chromosomal inversions within chromosome 2p, resulting in fusions between the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) genes, are a recent focus of treatment options for non-small cell lung cancer. Thirteen EML4-ALK fusion variants have been identified, affecting eight EML4 exons. We have developed an exon scanning approach using multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify known and potential variants involving the first 22 EML4 exons. A total of 55 formalin-fixed, paraffin-embedded lung cancer tumors were screened, of which 5 (9%) were positive for EML4-ALK fusions. Four positive cases harbored known fusion variants: variant 3a, 3b, or both in three cases and variant 1 in one case. The fifth positive specimen harbored two novel variants, designated 8a and 8b, involving exon 17 of EML4. Fluorescence in situ hybridization confirmed the presence of EML4-ALK fusions in three of the four RT-PCR-positive specimens with sufficient tissue for examination, and also confirmed absence of fusions in all 19 RT-PCR-negative specimens tested. Immunohistochemistry analysis confirmed ALK protein expression in the sample containing the novel 8a and 8b variants. This RT-PCR-based exon scanning approach avoids the limitations of screening only for previously identified EML4-ALK fusions and provides a simple molecular assay for fusion detection in a clinical diagnostics setting.

Ubiquitin-proteasome Profiling for Enhanced Detection of Hepatocellular Carcinoma in Patients with Chronic Liver Disease

Journal of Gastroenterology and Hepatology. Apr, 2011  |  Pubmed ID: 21418304

A reliable test for the detection of hepatocellular carcinoma (HCC) could improve disease management. Recent reports suggested a link between abnormalities in the ubiquitin-proteasome system (UPS) and HCC. We investigated the potential of using UPS markers, along with HCC markers, to differentiate HCC from chronic liver disease (CLD).

Reading Immunohistochemical Slides on a Computer Monitor--a Multisite Performance Study Using 180 HER2-stained Breast Carcinomas

Applied Immunohistochemistry & Molecular Morphology : AIMM. May, 2011  |  Pubmed ID: 21475038

With the adoption of digital pathology, image analysis (IA) of immunohistochemistry (IHC) slides can be integrated seamlessly into the digital pathology workflow. A pathologist can now use IA efficiently while reading the digital IHC slides on a computer monitor. Thus, the clinical acceptance of a digital pathology system for IHC quantitation depends both on the performance of the IHC IA, and the ability to manually read digital IHC slides on the monitor. A multisite study was conducted to compare the manual reading of IHC Human Epidermal Growth Factor Receptor 2 (HER2) slides on a monitor, using Aperio Technologies, Inc. ScanScope XT instrument and the Spectrum digital pathology information management system to conventional manual microscopy (MM).

Tanespimycin and Bortezomib Combination Treatment in Patients with Relapsed or Relapsed and Refractory Multiple Myeloma: Results of a Phase 1/2 Study

British Journal of Haematology. Jun, 2011  |  Pubmed ID: 21534941

This open-label, dose escalation, multicentre phase 1/2 trial was undertaken to determine the safety and tolerability of the heat shock protein 90 (HSP90) inhibitor tanespimycin (100-340 mg/m(2) )+ bortezomib (0·7-1·3 mg/m(2) ) given on days 1, 4, 8 and 11 in each 21-d cycle. Phase 2 expansion occurred at the highest tested dose of tanespimycin at 340 mg/m(2) and bortezomib at 1·3 mg/m(2) . Seventy-two patients (median age, 60 years) with relapsed or relapsed and refractory multiple myeloma (MM) were enrolled; 63 patients (89%) completed the study. Tanespimycin in combination with bortezomib was well tolerated; few patients experienced significant neutropenia, constipation and anorexia (<10%), and no patients developed severe peripheral neuropathy. Among 67 efficacy-evaluable patients, there were 2 (3%) complete responses and 8 (12%) partial responses, for an objective response rate (ORR) of 27%, including 8 (12%) minimal responses. Response rates were highest among bortezomib-naive patients and proved durable in all patient subgroups, including those with bortezomib-refractory disease. Pharmacodynamic analyses indicated that tanespimycin plus bortezomib effectively inhibited the proteasome, as evidenced by decreased 20S proteasome activity, and inhibited HSP90, as reflected by increased HSP70 expression. The results of this study support additional studies of this combination approach in MM.

Fluorescence in Situ Hybridization and K-ras Analyses Improve Diagnostic Yield of Endoscopic Ultrasound-guided Fine-needle Aspiration of Solid Pancreatic Masses

Pancreas. Oct, 2011  |  Pubmed ID: 21705950

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is the main diagnostic modality for pancreatic mass lesions. However, cytology is often indeterminate, leading to repeat FNAs and delay in care. Here, we evaluate whether combining routine cytology with fluorescence in situ hybridization (FISH) and K-ras/p53 analyses improves diagnostic yield of pancreatic EUS-FNA.

Trainable Immunohistochemical HER2/neu Image Analysis: a Multisite Performance Study Using 260 Breast Tissue Specimens

Archives of Pathology & Laboratory Medicine. Jul, 2011  |  Pubmed ID: 21732780

Aperio Technologies, Inc (Vista, California) provides a new immunohistochemistry (IHC) HER2 Image Analysis (IA) system that allows tuning of the intensity thresholds of the HER2/ neu scoring scheme to adapt to the staining characteristics of different reagents.

Effects of Clinically Relevant MPL Mutations in the Transmembrane Domain Revealed at the Atomic Level Through Computational Modeling

PloS One. 2011  |  Pubmed ID: 21858098

Mutations in the thrombopoietin receptor (MPL) may activate relevant pathways and lead to chronic myeloproliferative neoplasms (MPNs). The mechanisms of MPL activation remain elusive because of a lack of experimental structures. Modern computational biology techniques were utilized to explore the mechanisms of MPL protein activation due to various mutations.

Plasma Ubiquitin-proteasome System Profile in Patients with Multiple Sclerosis: Correlation with Clinical Features, Neuroimaging, and Treatment with Interferon-beta-1b

Neurological Research. Jul, 2012  |  Pubmed ID: 22709658

Interferon-beta-1b (IFN-beta-1b) reduces relapses in multiple sclerosis (MS) and improves magnetic resonance imaging (MRI) outcomes. Mechanism of action of IFN-beta-1b is only marginally understood. The roles and plasma levels of factors within the ubiquitin-proteasome system (UPS) and the plasma proteasome enzymatic activity of MS patients have not been explored. We hypothesized that pharmacologic double inhibition of the UPS by IFN-beta-1b occurs in MS patients and contributes to improvement of clinical course and reduction in MRI activity.

The T(9;11) Confers Good Prognosis in AML Patients Treated with Stem Cell Transplantation As Compared to Non-t(9;11) and Other Adverse-risk Abnormalities

Hematology/oncology and Stem Cell Therapy. 2012  |  Pubmed ID: 23095795

Dysregulation of Ubiquitin-proteasome Pathway and Apolipoprotein A Metabolism in Sickle Cell Disease-related Pulmonary Arterial Hypertension

Pulmonary Circulation. Dec, 2013  |  Pubmed ID: 25006400

Pulmonary arterial hypertension (PAH) is a major complication of sickle cell disease (SCD). Low levels of apolipoprotein A1 (Apo-A1) have been implicated in the development of PAH in SCD. We speculate that lower levels of Apo-A1 are related to dysregulation of the ubiquitin-proteasome pathway (UPP). Of 36 recruited patients with SCD, 14 were found to have PAH on the basis of right heart catheterization. Levels of Apo-A1 and Apo-B, polyubiquitin, total protease, and specific and normalized activity of chymotrypsin-like, trypsin-like, and caspase-like proteases in plasma were measured. Levels of Apo-A1 were found to be lower and polyubiquitin levels were found to be significantly higher in the PAH group ([Formula: see text]) in SCD. Apo-A levels were inversely correlated with polyubiquitin levels ([Formula: see text], [Formula: see text]). These results indicate that lower levels of Apo-A1 in SCD patients with PAH are likely related to enhance degradation by UPP, potentially contributing to pulmonary vascular pathology. These findings may provide significant insight in identifying suitable therapeutic targets in these patients.

Correlations Between Cytogenetic and Molecular Monitoring Among Patients with Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase: Post Hoc Analyses of the Rationale and Insight for Gleevec High-Dose Therapy Study

Archives of Pathology & Laboratory Medicine. Sep, 2014  |  Pubmed ID: 24308645

Although bone marrow (BM) karyotyping has been the standard in monitoring patients with chronic myeloid leukemia, peripheral blood (PB) monitoring methods may be more convenient.

Diagnostic and Prognostic Scoring System for Prostate Cancer Using Urine and Plasma Biomarkers

Genetic Testing and Molecular Biomarkers. Mar, 2014  |  Pubmed ID: 24512523

To avoid relying solely on serum prostate-specific antigen (sPSA) in screening for prostate cancer (PCa), we developed a scoring system for detecting PCa and the prediction of aggressiveness. We analyzed urine and plasma specimens from 121 patients with PCa or benign prostatic hyperplasia (BPH) for the levels of UAP1, PDLIM5, IMPDH2, HSPD1, PCA3, PSA, TMPRSS2, ERG, GAPDH, and B2M genes. Patient age, sPSA level, and polymerase chain reaction data were entered through multiple algorithms to determine models most useful for the detection of cancer and predicting aggressiveness.

Synonymous Polymorphisms in HOXB13 As a Protective Factor for Prostate Cancer

Journal of Cancer. 2015  |  Pubmed ID: 25874003

Genomic association and linkage studies, as well as epidemiological data have implicated both the HOXB13 gene and single nucleotide polymorphisms (SNPs) in the development of prostate cancer (PCa). The recent association between the G84E polymorphism in the HOXB13 gene and PCa has been shown to result in a more aggressive cancer with an earlier onset of the disease. We examined the frequency of this mutation and other recurrent HOXB13 SNPs in patients with PCa and those with benign prostatic hyperplasia (BPH) or no cancer.

Predicting Prostate Biopsy Results Using a Panel of Plasma and Urine Biomarkers Combined in a Scoring System

Journal of Cancer. 2016  |  Pubmed ID: 26918043

Determining the need for prostate biopsy is frequently difficult and more objective criteria are needed to predict the presence of high grade prostate cancer (PCa). To reduce the rate of unnecessary biopsies, we explored the potential of using biomarkers in urine and plasma to develop a scoring system to predict prostate biopsy results and the presence of high grade PCa.

Chimerism Analysis of Cell-Free DNA in Patients Treated with Hematopoietic Stem Cell Transplantation May Predict Early Relapse in Patients with Hematologic Malignancies

Biotechnology Research International. 2016  |  Pubmed ID: 27006832

Background. We studied DNA chimerism in cell-free DNA (cfDNA) in patients treated with HSCT. Methods. Chimerism analysis was performed on CD3+ cells, polymorphonuclear (PMN) cells, and cfDNA using 16 small tandem repeat loci. The resulting labeled PCR-products were size-fractionated and quantified. Results. Analyzing samples from 191 patients treated with HSCT for nonneoplastic hematologic disorders demonstrated that the cfDNA chimerism is comparable to that seen in PMN cells. Analyzing leukemia patients (N = 126) showed that, of 84 patients with 100% donor DNA in PMN, 16 (19%) had evidence of clinical relapse and >10% recipient DNA in the plasma. Additional 16 patients of the 84 (19%) showed >10% recipient DNA in plasma, but without evidence of relapse. Eight patients had mixed chimerism in granulocytes, lymphocytes, and plasma, but three of these patients had >10% recipient DNA in plasma compared to PMN cells and these three patients had clinical evidence of relapse. The remaining 34 patients showed 100% donor DNA in both PMN and lymphocytes, but cfDNA showed various levels of chimerism. Of these patients 14 (41%) showed laboratory or clinical evidence of relapse and all had >10% recipient DNA in cfDNA. Conclusion. Monitoring patients after HSCT using cfDNA might be more reliable than cellular DNA in predicting early relapse.

Deep Sequencing of Cell-Free Peripheral Blood DNA As a Reliable Method for Confirming the Diagnosis of Myelodysplastic Syndrome

Genetic Testing and Molecular Biomarkers. Jul, 2016  |  Pubmed ID: 27248906

Demonstrating the presence of myelodysplastic syndrome (MDS)-specific molecular abnormalities can aid in diagnosis and patient management. We explored the potential of using peripheral blood (PB) cell-free DNA (cf-DNA) and next-generation sequencing (NGS).

Resistance to Imatinib in Patients with Chronic Myelogenous Leukemia and the Splice Variant BCR-ABL1(35INS)

Leukemia Research. Oct, 2016  |  Pubmed ID: 27658269

In patients with chronic myelogenous leukemia (CML), point mutations in the BCR-ABL1 kinase domain are the most common cause of treatment failure with a tyrosine kinase inhibitor (TKI). It is not clear whether the splice variant BCR-ABL1(35INS) is also associated with treatment failure.

Prevalence and Relative Proportions of CLL and Non-CLL Monoclonal B-cell Lymphocytosis Phenotypes in the Middle Eastern Population

Hematology/oncology and Stem Cell Therapy. Mar, 2017  |  Pubmed ID: 27842210

Clonal Evolution Leading to Ibrutinib Resistance in Chronic Lymphocytic Leukemia

Blood. Mar, 2017  |  Pubmed ID: 28049639

Disease progression in patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib has been attributed to histologic transformation or acquired mutations in BTK and PLCG2. The rate of resistance and clonal composition of PD are incompletely characterized. We report on CLL patients treated with single-agent ibrutinib on an investigator-initiated phase 2 trial. With median follow-up of 34 months, 15 of 84 evaluable patients (17.9%) progressed. Relapsed/refractory disease at study entry, TP53 aberration, advanced Rai stage, and high β-2 microglobulin were independently associated with inferior progression-free survival (P < .05 for all tests). Histologic transformation occurred in 5 patients (6.0%) and was limited to the first 15 months on ibrutinib. In contrast, progression due to CLL in 10 patients (11.9%) occurred later, diagnosed at a median 38 months on study. At progression, mutations in BTK (Cys481) and/or PLCG2 (within the autoinhibitory domain) were found in 9 patients (10.7%), in 8 of 10 patients with progressive CLL, and in 1 patient with prolymphocytic transformation. Applying high-sensitivity testing (detection limit ∼1 in 1000 cells) to stored samples, we detected mutations up to 15 months before manifestation of clinical progression (range, 2.9-15.4 months). In 5 patients (6.0%), multiple subclones carrying different mutations arose independently, leading to subclonal heterogeneity of resistant disease. For a seamless transition to alternative targeted agents, patients progressing with CLL were continued on ibrutinib for up to 3 months, with 19.8 months median survival from the time of progression. This trial was registered at as #NCT01500733.

Using High-sensitivity Sequencing for the Detection of Mutations in BTK and PLCγ2 Genes in Cellular and Cell-free DNA and Correlation with Progression in Patients Treated with BTK Inhibitors

Oncotarget. Feb, 2017  |  Pubmed ID: 28212557

Patients with chronic lymphocytic leukemia (CLL) that develop resistance to Bruton tyrosine kinase (BTK) inhibitors are typically positive for mutations in BTK or phospholipase c gamma 2 (PLCγ2). We developed a high sensitivity (HS) assay utilizing wild-type blocking polymerase chain reaction achieved via bridged and locked nucleic acids. We used this high sensitivity assay in combination with Sanger sequencing and next generation sequencing (NGS) and tested cellular DNA and cell-free DNA (cfDNA) from patients with CLL treated with the BTK inhibitor, ibrutinib. We also tested ibrutinib-naïve patients with CLL. HS testing achieved 100x greater sensitivity than Sanger. HS Sanger sequencing was capable of detecting < 1 mutant allele in background of 1000 wild-type alleles (1:1000). Similar sensitivity was achieved with HS NGS. No BTK or PLCγ2 mutations were detected in any of the 44 ibrutinib-naïve CLL patients. We demonstrate that without the HS testing 56% of positive samples would have been missed for BTK and 85% of PLCγ2 would have been missed. With the use of HS, we were able to detect multiple mutant clones in the same sample in 37.5% of patients; most would have been missed without HS testing. We also demonstrate that with HS sequencing, plasma cfDNA is more reliable than cellular DNA in detecting mutations. Our studies indicate that wild-type blocking and HS sequencing is necessary for proper and early detection of BTK or PLCγ2 mutations in monitoring patients treated with BTK inhibitors. Furthermore, cfDNA from plasma is very reliable sample-type for testing.

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