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Find video protocols related to scientific articles indexed in Pubmed.
Validation of cytogenetic risk groups according to International Prognostic Scoring Systems by peripheral blood CD34+FISH: results from a German diagnostic study in comparison with an international control group.
Haematologica
PUBLISHED: 10-26-2014
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International Prognostic Scoring Systems are used to determine the individual risk profile of myelodysplastic syndrome patients. For the assessment of International Prognostic Scoring Systems, an adequate chromosome banding analysis of the bone marrow is essential. Cytogenetic information is not available for a substantial number of patients (5-20%) with dry marrow or an insufficient number of metaphase cells. For these patients, a valid risk classification is impossible. In the study presented here, the International Prognostic Scoring Systems were validated based on Fluorescence-in-situ-hybridization analyses using extended probe panels applied to cluster of differentiation 34 positive (CD34+) peripheral blood cells of 328 MDS patients of our prospective multicenter German diagnostic study and compared to chromosome banding results of 2902 previously published patients with myelodysplastic syndromes: For cytogenetic risk classification by Fluorescence-in-situ-hybridization analyses of CD34+ peripheral blood cells the groups differed significantly for overall and leukemia-free survival by uni- and multivariate analyses without discrepancies between treated and untreated patients. Including cytogenetic data of Fluorescence-in-situ-hybridization analyses of peripheral CD34+ blood cells (instead of bone marrow banding analysis) into the complete International Prognostic Scoring System assessment, the prognostic risk groups separated significantly for overall and leukemia-free survival. Our data show that a reliable stratification to the risk groups of the International Prognostic Scoring Systems is possible from peripheral blood in patients with missing chromosome banding analysis by using a comprehensive probe panel. This trial was registered at www.clinicaltrials.gov as #NCT01355913.
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Limited duration of complete remission on ruxolitinib in myeloid neoplasms with PCM1-JAK2 and BCR-JAK2 fusion genes.
Ann. Hematol.
PUBLISHED: 09-11-2014
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Rearrangements of chromosome band 9p24 are known to be associated with JAK2 fusion genes, e.g., t(8;9)(p22;p24) with a PCM1-JAK2 and t(9;22)(p24;q11) with a BCR-JAK2 fusion gene, respectively. In association with myeloid neoplasms, the clinical course is aggressive, and in absence of effective conventional treatment options, long-term remission is usually only observed after allogeneic stem cell transplantation (ASCT). With the discovery of inhibitors of the JAK2 tyrosine kinase and based on encouraging in vitro and in vivo data, we treated two male patients with myeloid neoplasms and a PCM1-JAK2 or a BCR-JAK2 fusion gene, respectively, with the JAK1/JAK2 inhibitor ruxolitinib. After 12 months of treatment, both patients achieved a complete clinical, hematologic, and cytogenetic response. Non-hematologic toxicity was only grade 1 while no hematologic toxicity was observed. However, remission in both patients was only short-term, with relapse occurring after 18 and 24 months, respectively, making ASCT indispensable in both cases. This data highlight (1) the ongoing importance of cytogenetic analysis for the diagnostic work-up of myeloid neoplasms as it may guide targeted therapy and (2) remission under ruxolitinib may only be short-termed in JAK2 fusion genes but it may be an important bridging therapy prior to ASCT.
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The risk of infections in hematologic patients treated with rituximab is not influenced by cumulative rituximab dosage - a single center experience.
BMC Infect. Dis.
PUBLISHED: 06-18-2014
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Rituximab, a monoclonal antibody directed against CD20, is approved for the treatment of CD20-positive B-cell Non-Hodgkin's lymphoma and rheumatologic disorders. Due to its potent activity in depleting CD20-positive lymphocytes, the influence on opportunistic infections is still under discussion. Thus, we analyzed the impact of rituximab either as monotherapy or in combination with other chemotherapeutic regimens to elucidate its role in contributing to infectious complications.
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Distinct characteristics of e13a2 versus e14a2 BCR-ABL1 driven chronic myeloid leukemia under first-line therapy with imatinib.
Haematologica
PUBLISHED: 05-16-2014
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The vast majority of chronic myeloid leukemia patients express a BCR-ABL1 fusion gene mRNA encoding a 210 kDa tyrosine kinase which promotes leukemic transformation. A possible differential impact of the corresponding BCR-ABL1 transcript variants e13a2 ("b2a2") and e14a2 ("b3a2") on disease phenotype and outcome is still a subject of debate. A total of 1105 newly diagnosed imatinib-treated patients were analyzed according to transcript type at diagnosis (e13a2, n=451; e14a2, n=496; e13a2+e14a2, n=158). No differences regarding age, sex, or Euro risk score were observed. A significant difference was found between e13a2 and e14a2 when comparing white blood cells (88 vs. 65 × 10(9)/L, respectively; P<0.001) and platelets (296 vs. 430 × 10(9)/L, respectively; P<0.001) at diagnosis, indicating a distinct disease phenotype. No significant difference was observed regarding other hematologic features, including spleen size and hematologic adverse events, during imatinib-based therapies. Cumulative molecular response was inferior in e13a2 patients (P=0.002 for major molecular response; P<0.001 for MR4). No difference was observed with regard to cytogenetic response and overall survival. In conclusion, e13a2 and e14a2 chronic myeloid leukemia seem to represent distinct biological entities. However, clinical outcome under imatinib treatment was comparable and no risk prediction can be made according to e13a2 versus e14a2 BCR-ABL1 transcript type at diagnosis. (clinicaltrials.gov identifier:00055874).
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Identification and functional characterization of imatinib-sensitive DTD1-PDGFRB and CCDC88C-PDGFRB fusion genes in eosinophilia-associated myeloid/lymphoid neoplasms.
Genes Chromosomes Cancer
PUBLISHED: 04-29-2014
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Eosinophilia-associated myeloid neoplasms with rearrangement of chromosome bands 5q31-33 are frequently associated with PDGFRB fusion genes, which are exquisitely sensitive to treatment with imatinib. In search for novel fusion partners of PDGFRB, we analyzed three cases with translocation t(5;20)(q33;p11), t(5;14)(q33;q32), and t(5;17;14)(q33;q11;q32) by 5?-rapid amplification of cDNA ends polymerase chain reaction (5?-RACE-PCR) and DNA-based long-distance inverse PCR (LDI-PCR) with primers derived from PDGFRB. LDI-PCR revealed a fusion between CCDC88C exon 25 and PDGFRB exon 11 in the case with t(5;17;14)(q33;q11;q32) while 5?-RACE-PCR identified fusions between CCDC88C exon 10 and PDGFRB exon 12 and between DTD1 exon 4 and PDGFRB exon 12 in the cases with t(5;14)(q33;q32) and t(5;20)(q33;p11), respectively. The PDGFRB tyrosine-kinase domain is predicted to be retained in all three fusion proteins. The partner proteins contained coiled-coil domains or other domains, which putatively lead to constitutive activation of the PDGFRB fusion protein. In vitro functional analyses confirmed transforming activity and imatinib-sensitivity of the fusion proteins. All three patients achieved rapid and durable complete hematologic remissions on imatinib.
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Efficacy and pharmacologic data of second-generation tyrosine kinase inhibitor nilotinib in BCR-ABL-positive leukemia patients with central nervous system relapse after allogeneic stem cell transplantation.
Biomed Res Int
PUBLISHED: 03-09-2014
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Central nervous system (CNS) involvement is a severe complication of BCR-ABL-positive leukemia after allogenic stem cell transplantation (alloSCT) associated with fatal outcome. Although second-generation tyrosine-kinase inhibitors (TKI) such as nilotinib have shown activity in systemic BCR-ABL(+) disease, little data exists on their penetration and efficacy within the CNS. Four patients (3 male, 1 female; age 15-49) with meningeal relapse after alloSCT and subsequent treatment with nilotinib were identified. A total of 17 cerebrospinal fluid (csf) and serum samples were assessed for nilotinib concentration and patient outcome was recorded. Nilotinib concentrations showed a low median csf/plasma ratio of 0.53% (range 0.23-1.5%), yet pronounced clinical efficacy was observed with long-lasting responses (>1 year) in three patients. Comparison with historical data showed a trend towards superior efficacy of nilotinib versus imatinib. Despite poor csf penetration, nilotinib showed significant clinical activity in CNS relapse of BCR-ABL(+) leukemias. As nilotinib has a high protein-binding affinity, the low-protein concentration in csf could translate into a relatively higher amount of free and therefore active nilotinib in csf as compared to blood, possibly explaining the observed efficacy. Thus, treatment with a 2nd generation TKI warrants further investigation and should be considered in cases of CNS relapse of BCR-ABL-positive leukemia after alloSCT.
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Myelodysplastic cells in patients reprogram mesenchymal stromal cells to establish a transplantable stem cell niche disease unit.
Cell Stem Cell
PUBLISHED: 02-26-2014
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Myelodysplastic syndromes (MDSs) are a heterogeneous group of myeloid neoplasms with defects in hematopoietic stem and progenitor cells (HSPCs) and possibly the HSPC niche. Here, we show that patient-derived mesenchymal stromal cells (MDS MSCs) display a disturbed differentiation program and are essential for the propagation of MDS-initiating Lin(-)CD34(+)CD38(-) stem cells in orthotopic xenografts. Overproduction of niche factors such as CDH2 (N-Cadherin), IGFBP2, VEGFA, and LIF is associated with the ability of MDS MSCs to enhance MDS expansion. These factors represent putative therapeutic targets in order to disrupt critical hematopoietic-stromal interactions in MDS. Finally, healthy MSCs adopt MDS MSC-like molecular features when exposed to hematopoietic MDS cells, indicative of an instructive remodeling of the microenvironment. Therefore, this patient-derived xenograft model provides functional and molecular evidence that MDS is a complex disease that involves both the hematopoietic and stromal compartments. The resulting deregulated expression of niche factors may well also be a feature of other hematopoietic malignancies.
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Older patients with chronic myeloid leukemia (?65 years) profit more from higher imatinib doses than younger patients: a subanalysis of the randomized CML-Study IV.
Ann. Hematol.
PUBLISHED: 02-14-2014
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The impact of imatinib dose on response rates and survival in older patients with chronic myeloid leukemia in chronic phase has not been studied well. We analyzed data from the German CML-Study IV, a randomized five-arm treatment optimization study in newly diagnosed BCR-ABL-positive chronic myeloid leukemia in chronic phase. Patients randomized to imatinib 400 mg/day (IM400) or imatinib 800 mg/day (IM800) and stratified according to age (?65 years vs. <65 years) were compared regarding dose, response, adverse events, rates of progression, and survival. The full 800 mg dose was given after a 6-week run-in period with imatinib 400 mg/day. The dose could then be reduced according to tolerability. A total of 828 patients were randomized to IM400 or IM800. Seven hundred eighty-four patients were evaluable (IM400, 382; IM800, 402). One hundred ten patients (29 %) on IM400 and 83 (21 %) on IM800 were ?65 years. The median dose per day was lower for patients ?65 years on IM800, with the highest median dose in the first year (466 mg/day for patients ?65 years vs. 630 mg/day for patients <65 years). Older patients on IM800 achieved major molecular remission and deep molecular remission as fast as younger patients, in contrast to standard dose imatinib with which older patients achieved remissions much later than younger patients. Grades 3 and 4 adverse events were similar in both age groups. Five-year relative survival for older patients was comparable to that of younger patients. We suggest that the optimal dose for older patients is higher than 400 mg/day. ClinicalTrials.gov identifier: NCT00055874
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ERG induces a mesenchymal-like state associated with chemoresistance in leukemia cells.
Oncotarget
PUBLISHED: 02-08-2014
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Overexpression of the oncogene ERG (ETS-related gene) is an adverse prognostic factor in acute myeloid and T-cell lymphoblastic leukemia (AML and T-ALL). We hypothesize that ERG overexpression is associated with primary drug resistance thereby influencing the outcome in leukemia. We previously reported a cell-line based model of ERG overexpression which induced a potentially chemo-resistant spindle shape cell type. Herein, we report a specific transcriptional gene signature for the observed spindle shaped morphology. Genes significantly over-expressed after ERG induction strongly resembled adhesive mesenchymal-like genes that included integrins (ITGA10, ITGB5, ITGB3, ITGA2B), CD44, and CD24. Interestingly, the mesenchymal-like signature was accompanied by the repression of DNA chromatin remodeling and DNA repair genes, such as CHEK1, EZH2, SUZ12, and DNMT3a. The ERG-induced mesenchymal-like signature positively correlated with TMPRSS2-ERG prostate tissues and invasive breast cancer mRNA expression datasets reflecting a general ERG-driven pattern of malignancy. Furthermore, inhibitors modulating ERG druggable pathways WNT, PKC, and AKT, and chemotherapeutic agent cytarabine revealed ERG-induced drug resistance. In particular, PKC412 treatment enhanced proliferative rates and promoted spindle shape formation in ERG-induced cells. Nilotinib and dasatinib were effective at abolishing ERG-induced cells. Moreover, ERG overexpression also led to an increase in double strand breaks. This report provides mechanistic clues into ERG-driven drug resistance in the poor prognostic group of high ERG expressers, provides insight to improved drug targeted therapies, and provides novel markers for a mesenchymal-like state in acute leukemia.
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Takotsubo cardiomyopathy after systemic consolidation therapy with high-dose intravenous cytarabine in a patient with acute myeloid leukemia.
Oncol Res Treat
PUBLISHED: 01-16-2014
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Takotsubo cardiomyopathy (TC) is characterized by the abrupt onset of cardiac dysfunction, with transient apical and midventricular hypo-/akinesia with a compensatory hypercontractility of the remaining segments. The clinical presentation appears to be similar to acute myocardial infarction (AMI). However, the myocardial dysfunction is reversible.
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Assessment of acute intestinal graft versus host disease by abdominal magnetic resonance imaging at 3 Tesla.
Eur Radiol
PUBLISHED: 01-14-2014
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After allogeneic stem cell transplantation (SCT), a reliable diagnosis of acute graft versus host disease (aGvHD) is essential for an early and successful treatment. It is the aim of this analysis to assess intestinal aGvHD by magnetic resonance imaging (MRI).
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Incidence of Cyp51 A key mutations in Aspergillus fumigatus-a study on primary clinical samples of immunocompromised patients in the period of 1995-2013.
PLoS ONE
PUBLISHED: 01-01-2014
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As the incidence of azole resistance in Aspergillus fumigatus is rising and the diagnosis of invasive aspergillosis (IA) in immunocompromised patients is rarely based on positive culture yield, we screened our Aspergillus DNA sample collection for the occurrence of azole resistance mediating cyp51 A key mutations. Using two established, a modified and a novel polymerase chain reaction (PCR) assays followed by DNA sequence analysis to detect the most frequent mutations in the A. fumigatus cyp51 A gene conferring azole resistance (TR34 (tandem repeat), L98H and M220 alterations). We analyzed two itraconazole and voriconazole and two multi-azole resistant clinical isolates and screened 181 DNA aliquots derived from clinical samples (blood, bronchoalveolar lavage (BAL), biopsies, cerebrospinal fluid (CSF)) of 155 immunocompromised patients of our Aspergillus DNA sample collection, previously tested positive for Aspergillus DNA and collected between 1995 and 2013. Using a novel PCR assay for the detection of the cyp51 A 46 bp tandem repeat (TR46) directly from clinical samples, we found the alteration in a TR46/Y121F/T289A positive clinical isolate. Fifty stored DNA aliquots from clinical samples were TR46 negative. DNA sequence analysis revealed a single L98H mutation in 2010, two times the L98H alteration combined with TR34 in 2011 and 2012 and a so far unknown N90K mutation in 1998. In addition, four clinical isolates were tested positive for the TR34/L98H combination in the year 2012. We consider our assay of epidemiological relevance to detect A. fumigatus azole resistance in culture-negative clinical samples of immunocompromised patients; a prospective study is ongoing.
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Characteristics, treatment and prognostic factors of patients with gynaecological malignancies treated in a palliative care unit at a university hospital.
Onkologie
PUBLISHED: 10-18-2013
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Limited clinical data have been published on patients suffering from advanced gynaecological malignancies treated in palliative care units, and little is known about prognostic factors.
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The KIT D816V expressed allele burden for diagnosis and disease monitoring of systemic mastocytosis.
Ann. Hematol.
PUBLISHED: 10-15-2013
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The activating KIT D816V mutation plays a central role in the pathogenesis, diagnosis, and targeted treatment of systemic mastocytosis (SM). For improved and reliable identification of KIT D816V, we have developed an allele-specific quantitative real-time PCR (RQ-PCR) with an enhanced sensitivity of 0.01-0.1 %, which was superior to denaturing high-performance liquid chromatography (0.5-1 %) or conventional sequencing (10-20 %). Overall, KIT D816 mutations were identified in 146/147 (99 %) of patients (D816V, n?=?142; D816H, n?=?2; D816Y, n?=?2) with SM, including indolent SM (ISM, n?=?63, 43 %), smoldering SM (n?=?8, 5 %), SM with associated hematological non-mast cell lineage disease (SM-AHNMD, n?=?16, 11 %), and aggressive SM/mast cell leukemia?±?AHNMD (ASM/MCL, n?=?60, 41 %). If positive in BM, the KIT D816V mutation was found in PB of all patients with advanced SM (SM-AHNMD, ASM, and MCL) and in 46 % (23/50) of patients with ISM. There was a strong correlation between the KIT D816V expressed allele burden (KIT D816V EAB) with results obtained from DNA by genomic allele-specific PCR and also with disease activity (e.g., serum tryptase level), disease subtype (e.g., indolent vs. advanced SM) and survival. In terms of monitoring of residual disease, qualitative and quantitative assessment of KIT D816V and KIT D816V EAB was successfully used for sequential analysis after chemotherapy or allogeneic stem cell transplantation. We therefore conclude that RQ-PCR assays for KIT D816V are useful complimentary tools for diagnosis, disease monitoring, and evaluation of prognosis in patients with SM.
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Treatment of acute promyelocytic leukemia with arsenic trioxide: clinical results and open questions.
Expert Rev Anticancer Ther
PUBLISHED: 09-24-2013
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Acute promyelocytic leukemia (APL) is a rare form of acute myeloid leukemia. The specific translocation t(15;17), which results in the fusion gene PML-RARA is the diagnostic and pathomechanistic hallmark of APL. By combination, treatment consisting of the differentiating agent all-trans retinoic acid (ATRA), which targets this molecular lesion, and cytotoxic chemotherapy, cure can be achieved in over 70% of patients. Recently, arsenic trioxide (ATO) has emerged to be the most active single agent in the treatment of APL. Previous studies employing ATO in relapse settings reported average complete remission rates of 85% and a mean overall survival of over 60%. In recent approaches installing ATO in first-line treatment, ATO-induced response rates comparable to previous combination regimen. The results of these newer studies indicate that the backbone of chemotherapy can be dramatically reduced or completely replaced by ATO and ATRA with similar or even better outcome.
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Coinfection of Pneumocystis jirovecii and invasive pulmonary aspergillosis in an immunocompromised patient: a diagnostic challenge.
Onkologie
PUBLISHED: 09-16-2013
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Invasive infections caused by Aspergillus fumigatus as well as Pneumocystis pneumonia are serious and often lethal diseases in severely immunocompromised patients.
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Validation of the revised International Prognostic Scoring System (IPSS-R) in patients with myelodysplastic syndrome: A multicenter study.
Leuk. Res.
PUBLISHED: 09-10-2013
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The revised IPSS (IPSS-R) was developed aiming at a better prognostication, taking into account patients treated with best supportive care. We herein validated this model on the basis of data from 1314 patients who received BSC only as well as patients who underwent induction chemotherapy (n=214) or allogeneic transplantation (n=167). We could demonstrate a clear distinction of the IPSS-R risk categories with regard to survival and risk of AML evolution in all patient cohorts. When comparing IPSS-R, IPSS, WHO prognostic scoring system (WPSS) and Duesseldorf score, the best results regarding the ability to predict survival were obtained by the IPSS-R.
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Comprehensive mutational profiling in advanced systemic mastocytosis.
Blood
PUBLISHED: 08-19-2013
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To explore mechanisms contributing to the clinical heterogeneity of systemic mastocytosis (SM) and to suboptimal responses to diverse therapies, we analyzed 39 KIT D816V mutated patients with indolent SM (n = 10), smoldering SM (n = 2), SM with associated clonal hematologic nonmast cell lineage disorder (SM-AHNMD, n = 5), and aggressive SM (n = 15) or mast cell leukemia (n = 7) with (n = 18) or without (n = 4) AHNMD for additional molecular aberrations. We applied next-generation sequencing to investigate ASXL1, CBL, IDH1/2, JAK2, KRAS, MLL-PTD, NPM1, NRAS, TP53, SRSF2, SF3B1, SETBP1, U2AF1 at mutational hotspot regions, and analyzed complete coding regions of EZH2, ETV6, RUNX1, and TET2. We identified additional molecular aberrations in 24/27 (89%) patients with advanced SM (SM-AHNMD, 5/5; aggressive SM/mast cell leukemia, 19/22) whereas only 3/12 (25%) indolent SM/smoldering SM patients carried one additional mutation each (U2AF1, SETBP1, CBL) (P < .001). Most frequently affected genes were TET2, SRSF2, ASXL1, CBL, and RUNX1. In advanced SM, 21/27 patients (78%) carried ?3 mutations, and 11/27 patients (41%) exhibited ?5 mutations. Overall survival was significantly shorter in patients with additional aberrations as compared to those with KIT D816V only (P = .019). We conclude that biology and prognosis in SM are related to the pattern of mutated genes that are acquired during disease evolution.
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Long-term results of a prospective randomized trial evaluating G-CSF priming in intensive induction chemotherapy followed by autologous stem cell transplantation in elderly patients with acute myeloid leukemia.
Ann. Hematol.
PUBLISHED: 07-22-2013
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Few studies have evaluated granulocyte colony-stimulating factor (G-CSF) priming in elderly patients with intensively treated acute myeloid leukemia (AML), and no data are available for genetically defined AML subgroups. We provide long-term results (median follow-up 7.6 years) of a randomized trial in which 183 patients (median age 67 years) received G-CSF prior to (G-CSF priming) or after two cycles of induction chemotherapy. CR rates with G-CSF priming and G-CSF post-chemotherapy were comparable (57 vs. 67 %, p?=?0.153), with overall survival (OS) probabilities of 14 vs. 17 % at 10 years. Induction mortality was significantly higher with G-CSF priming (23 vs. 10 %, p?=?0.015), primarily in normal karyotype (NK) AML. In this subgroup, a trend for better relapse-free survival (RFS) was observed with G-CSF priming (44 vs. 22 % at 10 years, p?=?0.074) but did not translate into an OS benefit. G-CSF priming had no impact on AML with FLT3-ITD and NPM mutations and did not improve outcome in patients with adverse cytogenetics. In a landmark analysis, late consolidation with autologous stem cell transplantation or a second consolidation cycle significantly improved RFS compared with one consolidation cycle (21.0 vs. 12.8 months, p?=?0.046). Future studies on G-CSF priming should be restricted to NK AML and used only in post-remission therapy.
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Cancer patients and advance directives: a survey of patients in a hematology and oncology outpatient clinic.
Onkologie
PUBLISHED: 07-08-2013
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In 2009, Germany enacted a new law supporting advance directives that led to heated discussions in the media and the public. 3 years after the law passed, we surveyed patients with malignant diseases with regards to their views on advance directives.
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Management of elderly patients with acute promyelocytic leukemia: progress and problems.
Ann. Hematol.
PUBLISHED: 04-22-2013
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Despite substantial progress in the management and outcome of acute promyelocytic leukemia (APL) during the last decades, older age remains a prominent negative prognostic factor. The improvement of long-term stabilization and cure of older APL patients is therefore a particular challenge. Data of unselected population-based studies suggest a high rate of exclusion from clinical trials in older age. The comparison of registry and study data indicates that study patients represent a positive selection. Older APL patients seem as sensitive to therapy as younger patients. With conventional therapy, based on all-trans retinoic acid (ATRA) and chemotherapy, over 50 % of older APL patients can probably be cured. Special problems of advanced age are the high rate of early death before or during induction therapy and the high frequency of death in remission with negative influence on the outcome. Both may be related in part to a higher vulnerability against the common treatment with ATRA and chemotherapy. Alternative less toxic approaches including arsenic trioxide (ATO) with or without ATRA and combinations with gemtuzumab ozogamicin or with reduced chemotherapy can induce long-lasting remission in all stages of APL. Considering the high curative potential and the excellent tolerance of ATO in newly diagnosed and relapsed APL, older patients are probably a particular target group for a chemotherapy-free approach with ATO.
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Whole-exome sequencing in adult ETP-ALL reveals a high rate of DNMT3A mutations.
Blood
PUBLISHED: 04-19-2013
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Early T-cell precursor (ETP) acute lymphoblastic leukemia (ALL) is a high-risk subgroup of T-lineage ALL characterized by specific stem cell and myeloid features. In adult ETP-ALL, no comprehensive studies on the genetic background have been performed to elucidate molecular lesions of this distinct subgroup. We performed whole-exome sequencing of 5 paired ETP-ALL samples. In addition to mutations in genes known to be involved in leukemogenesis (ETV6, NOTCH1, JAK1, and NF1), we identified novel recurrent mutations in FAT1 (25%), FAT3 (20%), DNM2 (35%), and genes associated with epigenetic regulation (MLL2, BMI1, and DNMT3A). Importantly, we verified the high rate of DNMT3A mutations (16%) in a larger cohort of adult patients with ETP-ALL (10/68). Mutations in epigenetic regulators support clinical trials, including epigenetic-orientated therapies, for this high-risk subgroup. Interestingly, more than 60% of adult patients with ETP-ALL harbor at least a single genetic lesion in DNMT3A, FLT3, or NOTCH1 that may allow use of targeted therapies.
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Investigation of viral escape mutations within HCV p7 during treatment with amantadine in patients with chronic hepatitis C.
Antivir. Ther. (Lond.)
PUBLISHED: 04-04-2013
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Combination of several direct-acting antiviral agents will be necessary to overcome viral resistance in interferon-free treatment regimens for chronic HCV infection. HCV p7 inhibitors may be part of such combination regimens. Understanding why amantadine, despite showing inhibition of HCV p7 in vitro, appears ineffective in clinical trials, may help in the design of novel HCV p7 inhibitors. So far it is unknown whether viral escape mutations within HCV p7 explain the ineffectiveness of amantadine in vivo.
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Recurrent mutations in multiple components of the cohesin complex in myeloid neoplasms.
Nat. Genet.
PUBLISHED: 02-15-2013
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Cohesin is a multimeric protein complex that is involved in the cohesion of sister chromatids, post-replicative DNA repair and transcriptional regulation. Here we report recurrent mutations and deletions involving multiple components of the cohesin complex, including STAG2, RAD21, SMC1A and SMC3, in different myeloid neoplasms. These mutations and deletions were mostly mutually exclusive and occurred in 12.1% (19/157) of acute myeloid leukemia, 8.0% (18/224) of myelodysplastic syndromes, 10.2% (9/88) of chronic myelomonocytic leukemia, 6.3% (4/64) of chronic myelogenous leukemia and 1.3% (1/77) of classical myeloproliferative neoplasms. Cohesin-mutated leukemic cells showed reduced amounts of chromatin-bound cohesin components, suggesting a substantial loss of cohesin binding sites on chromatin. The growth of leukemic cell lines harboring a mutation in RAD21 (Kasumi-1 cells) or having severely reduced expression of RAD21 and STAG2 (MOLM-13 cells) was suppressed by forced expression of wild-type RAD21 and wild-type RAD21 and STAG2, respectively. These findings suggest a role for compromised cohesin functions in myeloid leukemogenesis.
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Long-term follow-up of endoscopic therapy for stenosis of the biliobiliary anastomosis associated with orthotopic liver transplantation.
Liver Transpl.
PUBLISHED: 02-14-2013
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Endoscopic treatment for stenosis of an anastomotic biliary stricture (ABS) after orthotopic liver transplantation (OLT) has been proven to be effective and safe, but the long-term outcomes and the risk factors for recurrence are unknown. All 374 patients who underwent OLT at Frankfurt University Hospital were screened for the occurrence of ABSs. ABSs were treated via the endoscopic insertion of a plastic endoprosthesis (29.8%), balloon dilation (12.8%), or a combination of the two (57.4%). The mean follow-up time was 151 weeks, and the mean survival time was 3.4 years. ABSs were observed in 47 patients (12.6%). The mean time from OLT to an ABS was 16.25 months (median?=?3.25 months). The cumulative incidence rates for ABSs were 0.09 after 12 months, 0.10/24 m. and 0.11/36 m. In 12 cases (25.5%), ABSs were observed more than 12 months after OLT. ABSs recurred in 16 of the 47 patients (34%). The occurrence of an ABS 6 weeks or more after OLT was a significant predictor of ABS recurrence [P?=?0.04, hazard ratio (HR)?=?0.235]. There was a trend of hepatitis C virus (HCV) infections being predominant in patients experiencing ABS recurrence (30% for HCV etiology versus 4% for non-HCV etiology) in comparison with patients not experiencing recurrence (36% for HCV etiology versus 30% for non-HCV etiology, P?>?0.05). The severity of the initial stricture predicted ABS recurrence (P?=?0.046, HR?=?2.78), but it did not influence overall survival. The long-term resolution of ABSs was observed in 45 of the 47 patients (95.7%), and ABS recurrence was treated with another attempt (n?=?16 or 34%) or 2 more attempts (n?=?1) at endoscopic treatment. In conclusion, the long-term success of the endoscopic treatment of ABSs is highly probable if recurrent strictures are again treated endoscopically. ABSs might occur late (>36 months) after OLT, and lifelong follow-up is essential for identifying OLT patients with ABSs.
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Molecular cytogenetic monitoring from CD34+ peripheral blood cells in myelodysplastic syndromes: first results from a prospective multicenter German diagnostic study.
Leuk. Res.
PUBLISHED: 02-13-2013
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The gold standard of cytogenetic analysis in myelodysplastic syndromes (MDS) is conventional chromosome banding (CCB) analysis of bone marrow (BM) metaphases. Most aberrations can also be detected by fluorescence-in situ-hybridization (FISH). For this prospective multicenter German diagnostic study (www.clinicaltrials.gov: #NCT01355913) 360 patients, as yet, were followed up to 3 years by sequential FISH analyses of immunomagnetically enriched CD34+ peripheral blood (PB) cells using comprehensive FISH probe panels, resulting in a total number of 19,516 FISH analyses. We demonstrate that CD34+ PB FISH correlates significantly with CCB analysis and represents a feasible method for a reliable non-invasive cytogenetic monitoring from PB.
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PP2A regulatory subunit B? controls endothelial contractility and vessel lumen integrity via regulation of HDAC7.
EMBO J.
PUBLISHED: 02-08-2013
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To supply tissues with nutrients and oxygen, the cardiovascular system forms a seamless, hierarchically branched, network of lumenized tubes. Here, we show that maintenance of patent vessel lumens requires the B? regulatory subunit of protein phosphatase 2A (PP2A). Deficiency of B? in zebrafish precludes vascular lumen stabilization resulting in perfusion defects. Similarly, inactivation of PP2A-B? in cultured ECs induces tubulogenesis failure due to alteration of cytoskeleton dynamics, actomyosin contractility and maturation of cell-extracellular matrix (ECM) contacts. Mechanistically, we show that PP2A-B? controls the activity of HDAC7, an essential transcriptional regulator of vascular stability. In the absence of PP2A-B?, transcriptional repression by HDAC7 is abrogated leading to enhanced expression of the cytoskeleton adaptor protein ArgBP2. ArgBP2 hyperactivates RhoA causing inadequate rearrangements of the EC actomyosin cytoskeleton. This study unravels the first specific role for a PP2A holoenzyme in development: the PP2A-B?/HDAC7/ArgBP2 axis maintains vascular lumens by balancing endothelial cytoskeletal dynamics and cell-matrix adhesion.
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Long-term follow-up of endoscopic therapy in stenosis of the bilio-biliary anastomosis associated with orthotopic liver transplantation.
Liver Transpl.
PUBLISHED: 02-07-2013
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BACKGROUND: Endoscopic treatment of stenosis of the anastomotic biliary stricture (ABS) after orthotopic liver transplantation (OLT) has been proven to be effective and safe, but long term outcome and risk factors for recurrence are unknown. METHODS: All 374 patients who underwent OLT at Frankfurt University hospital were screened for occurrence of ABS. ABS was treated by endoscopic insertion of plastic endoprosthesis (29.8%), balloon dilation (12.8%), or a combination of both (57.4%). Long-term outcome and risk factors for occurrence and recurrence of ABS was determined through competing risk analysis. Mean follow-up time was 151 weeks and mean survival was 3.4 years. RESULTS: ABS was observed in 47 patients (12.6%). Mean (median) time from OLT to ABS was 16.3 months (3.3 months). Cumulative incidence rates of ABS were 0.09 after 12 months, 0.10 after 24 months and 0.11 after 36 months. In 12 cases (25.5%), ABS was observed later than 12 months after OLT. ABS recurred in 14 of 47 (29%). Ocurrence of ABS more than six weeks after OLT was a significant predictor of ABS recurrence (p=0.04, H.R. 0.235). There was a trend of HCV infection to be predominant in patients with recurrence of ABS (30% HCV vs. 4% non-HCV) in comparison to patients with non-recurrence (HCV 36%, non-HCV 30%); p > 0.05. Severity of initial stricture predicted recurrence of ABS (p = 0.046, HR=2.78), but did not influence overall survival. Long-term resolution of ABS was observed in 45 of 47 patients (95.7%), recurrence of ABS was treated with a second (n= 16, 34%), or a third endoscopic treatment attempt (1). CONCLUSION: Long-term success of endoscopic treatment of ABS is highly probable if recurrent strictures are again treated endoscopically. ABS might occur late (>36 months) after OLT and life-long follow-up is essential in OLT patients to identify patients with ABS. © 2013 American Association for the Study of Liver Diseases.
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Acute leukemias of ambiguous lineage in adults: molecular and clinical characterization.
Ann. Hematol.
PUBLISHED: 01-30-2013
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Acute leukemias of ambiguous lineage represent a heterogeneous group of rare, poorly characterized leukemias with adverse outcome. No larger studies have yet performed a combined approach of molecular and clinical characterization of acute undifferentiated leukemia (AUL) and biphenotypic acute leukemia (BAL) in adults. Here we describe 16 adults with AUL and 26 with BAL and performed mutational as well as expression studies of genes with prognostic impact in acute leukemia (BAALC, ERG, MN1, WT1, and IGFBP7). AUL showed overexpression of these genes compared to T-lymphoblastic leukemia (T-ALL), B-precursor ALL, and to acute myeloid leukemia (AML). Genotype alterations were not detectable in AUL. BAL samples were characterized by frequent WT1 mutations (18 %) and BCR-ABL translocations (30 %). ALL-based treatment protocols induced complete remissions in 40 % and AML-like therapies in 22 % of AUL/BAL patients. The outcome in both groups was very poor; a long-term survival was only observed in patients undergoing allogeneic stem cell transplantation (SCT). Our findings indicate that AUL and BAL share important molecular and high-risk features of both myeloid and lymphoid leukemias. BAL patients exhibited genetic alterations, which can be targeted therapeutically. Importantly, ALL therapy might be more effective than AML protocols and AUL/BAL patients should be considered for allogeneic SCT.
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FLT3 mutations in early T-cell precursor ALL characterize a stem cell like leukemia and imply the clinical use of tyrosine kinase inhibitors.
PLoS ONE
PUBLISHED: 01-24-2013
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Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) has been identified as high-risk subgroup of acute T-lymphoblastic leukemia (T-ALL) with a high rate of FLT3-mutations in adults. To unravel the underlying pathomechanisms and the clinical course we assessed molecular alterations and clinical characteristics in a large cohort of ETP-ALL (n = 68) in comparison to non-ETP T-ALL adult patients. Interestingly, we found a high rate of FLT3-mutations in ETP-ALL samples (n = 24, 35%). Furthermore, FLT3 mutated ETP-ALL was characterized by a specific immunophenotype (CD2+/CD5-/CD13+/CD33-), a distinct gene expression pattern (aberrant expression of IGFBP7, WT1, GATA3) and mutational status (absence of NOTCH1 mutations and a low frequency, 21%, of clonal TCR rearrangements). The observed low GATA3 expression and high WT1 expression in combination with lack of NOTCH1 mutations and a low rate of TCR rearrangements point to a leukemic transformation at the pluripotent prothymocyte stage in FLT3 mutated ETP-ALL. The clinical outcome in ETP-ALL patients was poor, but encouraging in those patients with allogeneic stem cell transplantation (3-year OS: 74%). To further explore the efficacy of targeted therapies, we demonstrate that T-ALL cell lines transfected with FLT3 expression constructs were particularly sensitive to tyrosine kinase inhibitors. In conclusion, FLT3 mutated ETP-ALL defines a molecular distinct stem cell like leukemic subtype. These data warrant clinical studies with the implementation of FLT3 inhibitors in addition to early allogeneic stem cell transplantation for this high risk subgroup.
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Centrosome aberrations in bone marrow cells from patients with myelodysplastic syndromes correlate with chromosomal instability.
Ann. Hematol.
PUBLISHED: 01-23-2013
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Centrosomes play important roles in the maintenance of genetic stability and centrosomal aberrations are a hallmark of cancer. Deregulation of centriole duplication leads to supernumerary centrosomes, sister chromatid missegregation and could result in chromosomal instability (CIN) and aneuploidy. CIN is a common feature in at least 45% of patients with myelodysplastic syndromes (MDS). Therefore, we sought to investigate the centrosomal status and its role for development of CIN in bone marrow (BM) cells of MDS patients. BM cells of 34 MDS patients were examined cytogenetically. Furthermore, cells were immunostained with a centrosome-specific antibody to pericentrin to analyze the centrosomal status. Umbilical cord blood specimens and BM cells of healthy persons (n = 11 and n = 4) served as controls. In addition, the protein expression of the protease separase responsible for genetic stability was examined by western blot analysis. Centrosome abnormalities were detected in 10% (range, 4-17%) of cells of MDS samples, but in only 2% (range, 0-4%) of cells of healthy controls. Normal karyotypes were found in control cells and in BM cells of 16/34 MDS patients. The incidence of centrosomal alterations was higher in BM cells of patients with cytogenetic alterations (mean, 12%) compared to BM cells of patients without cytogenetic changes (mean, 7%). Our results indicate that centrosome alterations are a common and early detectable feature in MDS patients and may contribute to the acquisition of chromosomal aberrations. We assume that centrosome defects could be involved in disease progression and may serve as a future prognostic marker.
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Skewed X-inactivation patterns in ageing healthy and myelodysplastic haematopoiesis determined by a pyrosequencing based transcriptional clonality assay.
J. Med. Genet.
PUBLISHED: 01-23-2013
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Investigation of X-chromosome inactivation patterns (XCIP) by determination of differential CpG-methylation has been widely applied for investigation of female cell clonality. Using this approach the clonal origin of various tumours has been corroborated. Controversially, strong age-related increase of peripheral blood (PB) cell clonality in haematologically healthy female subjects was reported. Recently, transcriptional XCIP ratio analysis challenged these results and questioned the suitability of methylation based clonality assays.
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Effects of imatinib mesylate in patients with polycythemia vera: results of a phase II study.
Ann. Hematol.
PUBLISHED: 01-22-2013
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The antiproliferative effects of the tyrosine kinase inhibitor imatinib mesylate were reported in single cases with polycythemia vera (PV). We, therefore, conducted a clinical phase II study to assess the rate and quality of response in patients with PV. Thirty-one patients, with a median age of 64 years (range, 45-84 years), were included. All but one patient were on phlebotomy; 14 (45%) had previously received cytoreductive therapy. Imatinib was started with 400 mg/day. In 26% of patients, dose escalation up to 800 mg was performed. After a median treatment duration of 8.3 months (range, 0.1-62.1 months), the overall response rate was 55%. No complete remission (normalization of all parameters: hematocrit, white blood cell (WBC) count, platelet count, and spleen size determined by ultrasound examination) was reached because the spleen remained enlarged in all patients. Thirteen patients (42%) achieved partial remission (?25% reduction of at least one of the previously mentioned parameters); in 10 of these, the respective reduction was ?50%. In four patients (13%) with minor response, the reduction was <25%. No change or progressive disease was seen in 14 patients (45%). The nonresponders had a longer previous disease duration and had received more antecedent cytoreductive therapy (p?=?0.009). Compared to baseline characteristics, imatinib induced the reduction of phlebotomies (p?=?0.003), of WBC count (p?=?0.002), and of platelet count (p?=?0.04). Three patients became free from phlebotomies. In six investigated patients, no significant reduction of the JAK2V617F burden was observed despite clinical improvement. The results show that imatinib has moderate cytoreductive effects in PV.
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Diagnostic performance of an Aspergillus-specific nested PCR assay in cerebrospinal fluid samples of immunocompromised patients for detection of central nervous system aspergillosis.
PLoS ONE
PUBLISHED: 01-14-2013
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Central nervous system (CNS) invasive aspergillosis (IA) is a fatal complication in immunocompromised patients. Confirming the diagnosis is rarely accomplished as invasive procedures are impaired by neutropenia and low platelet count. Cerebrospinal fluid (CSF) cultures or galactomannan (GM) regularly yield negative results thus suggesting the need for improving diagnostic procedures. Therefore the performance of an established Aspergillus-specific nested polymerase chain reaction assay (PCR) in CSF samples of immunocompromised patients with suspicion of CNS IA was evaluated. We identified 113 CSF samples from 55 immunocompromised patients for whom CNS aspergillosis was suspected. Of these patients 8/55 were identified as having proven/probable CNS IA while the remaining 47 patients were classified as having either possible (n?=?22) or no CNS IA (n?=?25). PCR positivity in CSF was observed for 8/8 proven/probable, in 4/22 possible CNS IA patients and in 2/25 NoIA patients yielding sensitivity and specificity values of 1.0 (95% CI 0.68-1) and 0.93 (95% CI 0.77-0.98) and a positive likelihood ratio of 14 and negative likelihood ratio of 0.0, respectively, thus resulting in a diagnostic odds ratio of ?. The retrospective analysis of CSF samples from patients with suspected CNS IA yielded a high sensitivity of the nested PCR assay. PCR testing of CSF samples is recommended for patients for whom CNS IA is suspected, especially for those whose clinical condition does not allow invasive procedures as a positive PCR result makes the presence of CNS IA in that patient population highly likely.
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Integrin alpha4 blockade sensitizes drug resistant pre-B acute lymphoblastic leukemia to chemotherapy.
Blood
PUBLISHED: 01-14-2013
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Bone marrow (BM) provides chemoprotection for acute lymphoblastic leukemia (ALL) cells, contributing to lack of efficacy of current therapies. Integrin alpha4 (alpha4) mediates stromal adhesion of normal and malignant B-cell precursors, and according to gene expression analyses from 207 children with minimal residual disease, is highly associated with poorest outcome. We tested whether interference with alpha4-mediated stromal adhesion might be a new ALL treatment. Two models of leukemia were used, one genetic (conditional alpha4 ablation of BCR-ABL1 [p210(+)] leukemia) and one pharmacological (anti-functional alpha4 antibody treatment of primary ALL). Conditional deletion of alpha4 sensitized leukemia cell to nilotinib. Adhesion of primary pre-B ALL cells was alpha4-dependent; alpha4 blockade sensitized primary ALL cells toward chemotherapy. Chemotherapy combined with Natalizumab prolonged survival of NOD/SCID recipients of primary ALL, suggesting adjuvant alpha4 inhibition as a novel strategy for pre-B ALL.
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Autotaxin is expressed in FLT3-ITD positive acute myeloid leukemia and hematopoietic stem cells and promotes cell migration and proliferation.
Exp. Hematol.
PUBLISHED: 01-07-2013
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Autotaxin (ATX) has been reported to act as a motility and growth factor in a variety of cancer cells. The ATX protein acts as a secreted lysophospholipase D by converting lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), which signals via G-protein-coupled receptors and has important functions in cell migration and proliferation. This study demonstrates that ATX expression is specifically upregulated and functionally active in acute myeloid leukemia (AML) harboring an internal tandem duplication (ITD) mutation of the FLT3 receptor gene. Moreover, ATX expression was also found in normal human CD34+ progenitor cells and selected myeloid and lymphoid subpopulations. Enforced expression of mutant FLT3-ITD by retroviral vector transduction increased ATX mRNA in selected cell lines, whereas inhibition of FLT3-ITD signaling by sublethal doses of PKC412 or SU5614 led to a significant downregulation of ATX mRNA and protein levels. In the presence of LPC, ATX expression significantly increased proliferation. LPA induced proliferation, regardless of ATX expression, and induced chemotaxis in all tested human leukemic cell lines and human CD34(+) progenitors. LPC increased chemotaxis only in cells with high expression of endogenous ATX by at least 80%, demonstrating the autocrine action of ATX. Inhibition of ATX using a small molecule inhibitor selectively induced killing of ATX-expressing cell lines and reduced motility in these cells. Our data suggest that the production of bioactive LPA through ATX is involved in controlling proliferation and migration during hematopoiesis and that deregulation of ATX contributes to the pathogenesis of AML.
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In acute promyelocytic leukemia (APL) low BAALC gene expression identifies a patient group with favorable overall survival and improved relapse free survival.
Leuk. Res.
PUBLISHED: 01-05-2013
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We evaluated the prognostic value of BAALC expression in 86 patients with acute promyelocytic leukemia (APL). At 10 years, the overall survival (OS) was 66% in all patients and 75% in patients who achieved a complete remission (CR). Patients in the BAALC(low) group showed an OS of 87% as compared to 60% in the BAALC(high) group (p=0.019). This difference was more pronounced in treatment responders (92% vs. 70%; p=0.035). In multivariate analyses low BAALC expression retained its prognostic relevance. In conclusion, BAALC expression analysis might be useful in further risk stratification in APL patients.
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Baseline MELD score predicts hepatic decompensation during antiviral therapy in patients with chronic hepatitis C and advanced cirrhosis.
PLoS ONE
PUBLISHED: 01-01-2013
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In patients with advanced liver cirrhosis due to chronic hepatitis C virus (HCV) infection antiviral therapy with peginterferon and ribavirin is feasible in selected cases only due to potentially life-threatening side effects. However, predictive factors associated with hepatic decompensation during antiviral therapy are poorly defined.
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Single and combined IL28B, ITPA and SLC28A3 host genetic markers modulating response to anti-hepatitis C therapy.
Pharmacogenomics
PUBLISHED: 11-29-2011
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Advances in hepatitis C pharmacogenomics identified modulations of a sustained virologic response (SVR) by frequent IL28B gene variants and of ribavirin-induced hemolysis by frequent ITPA gene variants. These associations have been widely reproduced in various ethnicities, clinical settings and hepatitis C viral genotypes. The IL28B minor alleles rs8099917G, rs12979860T and rs12980275G have been associated with non-SVR whereas the ITPA minor alleles rs1127354A and rs7270101C were associated with less hemolytic side effects, an effect also attributed to a nucleoside transporter gene SLC28A3 rs10868138G/rs56350726T haplotype. The significance levels of these associations, especially in genome-wide studies, were very high. We nevertheless tested how good clinical outcomes of peginterferon ?/ribavirin therapy, such as SVR or hemolytic side effects, were predicted by these variants. An analysis in an example dataset of 115 patients revealed that the prediction of non-SVR or hemolysis by single variants was often only slightly better than guessing. Using combinations of IL28B variants provided a higher accuracy (64.5%) of predicting non-SVR than with single IL28B variants (accuracy 60-63%). Similarly, a decline in blood hemoglobin by ?3 g/dl could be better predicted at an accuracy of 70% (10% better than guessing) with a combination of an ITPA variant with a nucleoside transporter gene (SLC28A3) haplotype. Thus, genotyping information about single IL28B or ITPA variants is reproducibly and statistically significantly associated with hepatitis C therapy outcomes; however, the clinical predictive utility of single variants can be increased by combinations of genotypes.
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Epigenetic dysregulation of GATA1 is involved in myelodysplastic syndromes dyserythropoiesis.
Eur. J. Haematol.
PUBLISHED: 11-22-2011
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Myelodysplastic syndromes (MDS) are characterized by dyserythropoiesis resulting in anemia. This pathological hallmark is incompletely understood. Notch signaling has been linked to impaired erythropoietic and megakaryopoietic development of CD34+ progenitor cells, but its role in MDS is unclear. We have analyzed the transcriptional activity of Notch pathway elements and its association with the key erythroid factor globin transcription factor 1 (GATA1) and the apoptosis regulatory gene B-cell lymphoma-xl (BCLxl) in MDS. The methylation of GATA1 erythroid promoter CpG dinucleotides flanking cis-regulatory elements, including an N-box suppressor binding site for HES1 and a GATA-box binding site, was examined in normal and MDS erythropoiesis. We have generated a kinetic in vitro model of MDS erythropoiesis using CD34+ bone marrow cells from healthy donors (n = 7) and patients with MDS (low risk: RA/n = 6, RARS/n = 3; high risk: RAEB/n = 4, RAEB-T/n = 2). RNA expression of GATA1, BCLxl, DLK1, Notch1, HES1, and HERP2 was measured by real-time RT-PCR (qPCR). DNA methylation at seven CpG dinucleotides of the GATA1 gene promoter was quantitatively analyzed by pyrosequencing of bisulfite-treated genomic DNA at any specific time point. For the Notch pathway elements, no conclusive expression differences were found between MDS and normal erythropoiesis. But we found steadily up-regulated RNA expression of GATA1 and of BCLxl during late normal erythropoietic differentiation. In contrast, during MDS, erythropoiesis a loss of typical up-regulation of GATA1 and BCLxl was observed. Hypermethylation of CpG dinucleotides flanking the repressor HES1 binding site within the 5 region of GATA1 was detected particularly during late MDS erythropoiesis. Interestingly, decremental GATA1 promotor methylation values were seen during normal erythropoiesis matching GATA1 RNA up-regulation. Our data show that the critical erythropoietic transcription factor GATA1 as well as the antiapoptotic molecule BCLxl fails to be normally up-regulated during MDS erythropoiesis. The higher residual 5-GATA1 methylation values in MDS erythropoiesis but decremental loss thereof in normal erythropoiesis suggest a gene dose effect for GATA1 during erythropoiesis being finely tuned by CpG methylation. Its dysregulation may contribute to the ineffective erythropoiesis observed in MDS.
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Impact of additional cytogenetic aberrations at diagnosis on prognosis of CML: long-term observation of 1151 patients from the randomized CML Study IV.
Blood
PUBLISHED: 10-28-2011
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The prognostic relevance of additional cytogenetic findings at diagnosis of chronic myeloid leukemia (CML) is unclear. The impact of additional cytogenetic findings at diagnosis on time to complete cytogenetic (CCR) and major molecular remission (MMR) and progression-free (PFS) and overall survival (OS) was analyzed using data from 1151 Philadelphia chromosome-positive (Ph(+)) CML patients randomized to the German CML Study IV. At diagnosis, 1003 of 1151 patients (87%) had standard t(9;22)(q34;q11) only, 69 patients (6.0%) had variant t(v;22), and 79 (6.9%) additional cytogenetic aberrations (ACAs). Of these, 38 patients (3.3%) lacked the Y chromosome (-Y) and 41 patients (3.6%) had ACAs except -Y; 16 of these (1.4%) were major route (second Philadelphia [Ph] chromosome, trisomy 8, isochromosome 17q, or trisomy 19) and 25 minor route (all other) ACAs. After a median observation time of 5.3 years for patients with t(9;22), t(v;22), -Y, minor- and major-route ACAs, the 5-year PFS was 90%, 81%, 88%, 96%, and 50%, and the 5-year OS was 92%, 87%, 91%, 96%, and 53%, respectively. In patients with major-route ACAs, the times to CCR and MMR were longer and PFS and OS were shorter (P < .001) than in patients with standard t(9;22). We conclude that major-route ACAs at diagnosis are associated with a negative impact on survival and signify progression to the accelerated phase and blast crisis.
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Overexpression of LEF1 predicts unfavorable outcome in adult patients with B-precursor acute lymphoblastic leukemia.
Blood
PUBLISHED: 10-18-2011
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Aberrant activation of the Wnt pathway plays a pathogenetic role in various tumors and has been associated with adverse outcome in acute lymphoblastic leukemia (ALL). LEF1, a key mediator of Wnt signaling, has been linked to leukemic transformation, and recurrent mutations of LEF1 have been identified in pediatric T-ALL. Here we evaluated the prognostic significance of LEF1 expression in B-precursor ALL patients. LEF1 expression was determined by quantitative real-time RT-PCR in 282 adult B-precursor ALL patients treated on 06/99 and 07/03 GMALL trials. Patients were grouped into quartiles (Q1-Q4) according to LEF1 expression levels (LEF1 high, Q4; n = 71; LEF1 low, Q1-Q3; n = 211). Patients with high LEF1 expression had a significantly shorter relapse-free survival (RFS) compared with low LEF1 expressers (5-year RFS: LEF1 high, 27%; LEF1 low, 47%; P = .05). Importantly, high LEF1 expression was also associated with inferior RFS in standard-risk patients and was independently predictive for RFS (P = .02) in multivariate analyses for this subgroup. Thus, high LEF1 expression identifies B-precursor ALL patients with inferior RFS, supporting a pathogenetic role of Wnt signaling in ALL. Standard-risk patients with high LEF1 expression might benefit from early treatment modifications and new molecular therapies, including agents targeting the Wnt pathway.
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Mesenchymal stromal cells of myelodysplastic syndrome and acute myeloid leukemia patients have distinct genetic abnormalities compared with leukemic blasts.
Blood
PUBLISHED: 09-23-2011
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Mesenchymal stromal cells (MSCs) are an essential cell type of the hematopoietic microenvironment. Concerns have been raised about the possibility that MSCs undergo malignant transformation. Several studies, including one from our own group, have shown the presence of cytogenetic abnormalities in MSCs from leukemia patients. The aim of the present study was to compare genetic aberrations in hematopoietic cells (HCs) and MSCs of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) patients. Cytogenetic aberrations were detected in HCs from 25 of 51 AML patients (49%) and 16 of 43 MDS patients (37%). Mutations of the FLT3 and NPM1 genes were detected in leukemic blasts in 12 (23%) and 8 (16%) AML patients, respectively. Chromosomal aberrations in MSCs were detected in 15 of 94 MDS/AML patients (16%). No chromosomal abnormalities were identified in MSCs of 36 healthy subjects. We demonstrate herein that MSCs have distinct genetic abnormalities compared with leukemic blasts. We also analyzed the main characteristics of patients with MSCs carrying chromosomal aberrations. In view of these data, the genetic alterations in MSCs may constitute a particular mechanism of leukemogenesis.
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BCL6-mediated repression of p53 is critical for leukemia stem cell survival in chronic myeloid leukemia.
J. Exp. Med.
PUBLISHED: 09-12-2011
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Chronic myeloid leukemia (CML) is induced by the oncogenic BCR-ABL1 tyrosine kinase and can be effectively treated for many years with tyrosine kinase inhibitors (TKIs). However, unless CML patients receive life-long TKI treatment, leukemia will eventually recur; this is attributed to the failure of TKI treatment to eradicate leukemia-initiating cells (LICs). Recent work demonstrated that FoxO factors are critical for maintenance of CML-initiating cells; however, the mechanism of FoxO-dependent leukemia initiation remained elusive. Here, we identified the BCL6 protooncogene as a critical effector downstream of FoxO in self-renewal signaling of CML-initiating cells. BCL6 represses Arf and p53 in CML cells and is required for colony formation and initiation of leukemia. Importantly, peptide inhibition of BCL6 in human CML cells compromises colony formation and leukemia initiation in transplant recipients and selectively eradicates CD34(+) CD38(-) LICs in patient-derived CML samples. These findings suggest that pharmacological inhibition of BCL6 may represent a novel strategy to eradicate LICs in CML. Clinical validation of this concept could limit the duration of TKI treatment in CML patients, which is currently life-long, and substantially decrease the risk of blast crisis transformation.
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Impact of ribavirin on HCV replicon RNA decline during treatment with interferon-? and the protease inhibitors boceprevir or telaprevir.
Antivir. Ther. (Lond.)
PUBLISHED: 08-06-2011
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Ribavirin increases early and sustained virological response rates in patients chronically infected with HCV who receive pegylated interferon-? and novel HCV protease inhibitors.
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Hepatitis D virus-specific cytokine responses in patients with chronic hepatitis delta before and during interferon alfa-treatment.
Liver Int.
PUBLISHED: 07-15-2011
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Hepatitis delta is caused by infection with the hepatitis D virus (HDV) and is considered the most severe form of viral hepatitis. Treatment options for hepatitis delta are limited, with only 25% of patients responding to interferon (IFN)-alfa-based therapies. The role of the adaptive immune system in controlling HDV infection during spontaneous or treatment-induced viral clearance is not well understood.
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The effect of the CCR5-delta32 deletion on global gene expression considering immune response and inflammation.
J Inflamm (Lond)
PUBLISHED: 06-30-2011
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The natural function of the C-C chemokine receptor type 5 (CCR5) is poorly understood. A 32 base pair deletion in the CCR5 gene (CCR5-delta32) located on chromosome 3 results in a non-functional protein. It is supposed that this deletion causes an alteration in T-cell response to inflammation. For example, the presence of the CCR5-delta32 allele in recipients of allografts constitutes as an independent and protective factor associated with a decreased risk of graft-versus-host disease (GVHD) and graft rejection. However, the mechanism of this beneficial effect of the deletion regarding GVHD is unknown. In this survey we searched for a CCR5-delta32 associated regulation of critical genes involved in the immune response and the development of GVHD.
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Targeting survivin overcomes drug resistance in acute lymphoblastic leukemia.
Blood
PUBLISHED: 06-28-2011
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Relapse of drug-resistant acute lymphoblastic leukemia (ALL) has been associated with increased expression of survivin/BIRC5, an inhibitor of apoptosis protein, suggesting a survival advantage for ALL cells. In the present study, we report that inhibition of survivin in patient-derived ALL can eradicate leukemia. Targeting survivin with shRNA in combination with chemotherapy resulted in no detectable minimal residual disease in a xenograft model of primary ALL. Similarly, pharmacologic knock-down of survivin using EZN-3042, a novel locked nucleic acid antisense oligonucleotide, in combination with chemotherapy eliminated drug-resistant ALL cells. These findings show the importance of survivin expression in drug resistance and demonstrate that survivin inhibition may represent a powerful approach to overcoming drug resistance and preventing relapse in patients with ALL.
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Response of ETV6-FLT3-positive myeloid/lymphoid neoplasm with eosinophilia to inhibitors of FMS-like tyrosine kinase 3.
Blood
PUBLISHED: 06-24-2011
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Imatinib-resistant tyrosine kinase (TK) fusions involving FGFR1, JAK2, or FLT3 are rare but recurrent in patients with eosinophilia-associated neoplasms. We report here 2 male patients with ETV6-FLT3(+) myeloid/lymphoid neoplasms with eosinophilia who were treated with the multitargeted TK inhibitors sunitinib and sorafenib. Patient 1 achieved rapid complete hematologic response and complete cytogenetic response after 3 months of taking sunitinib. A secondary blast phase caused by clonal evolution was diagnosed after 6 months. He achieved a second complete hematologic response after taking sorafenib but relapsed 2 months later. An N841K point mutation within the TK domain of FLT3, previously reported in acute myeloid leukemia and potentially conferring resistance to sorafenib, was subsequently identified. Patient 2 was heavily pretreated according to the initial diagnosis of T-lymphoblastic lymphoma and died in sunitinib-induced pancytopenia. This report highlights the importance of a careful diagnostic workup for eosinophilia-associated neoplasms to evaluate the possibility of TK inhibitor therapy.
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Frequent pathway mutations of splicing machinery in myelodysplasia.
Nature
PUBLISHED: 06-07-2011
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Myelodysplastic syndromes and related disorders (myelodysplasia) are a heterogeneous group of myeloid neoplasms showing deregulated blood cell production with evidence of myeloid dysplasia and a predisposition to acute myeloid leukaemia, whose pathogenesis is only incompletely understood. Here we report whole-exome sequencing of 29 myelodysplasia specimens, which unexpectedly revealed novel pathway mutations involving multiple components of the RNA splicing machinery, including U2AF35, ZRSR2, SRSF2 and SF3B1. In a large series analysis, these splicing pathway mutations were frequent (?45 to ?85%) in, and highly specific to, myeloid neoplasms showing features of myelodysplasia. Conspicuously, most of the mutations, which occurred in a mutually exclusive manner, affected genes involved in the 3-splice site recognition during pre-mRNA processing, inducing abnormal RNA splicing and compromised haematopoiesis. Our results provide the first evidence indicating that genetic alterations of the major splicing components could be involved in human pathogenesis, also implicating a novel therapeutic possibility for myelodysplasia.
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Clinical management of gastrointestinal disturbances in patients with myelodysplastic syndromes receiving iron chelation treatment with deferasirox.
Leuk. Res.
PUBLISHED: 05-31-2011
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Myelodysplastic syndromes are characterized by ineffective hematopoiesis resulting in peripheral cytopenias. The majority of patients is dependent on regular transfusions of packed red blood cells leading to a secondary iron overload which might result in organ damage. Therefore, sufficient iron chelation therapy in selected patients is mandatory. Deferasirox (DFX) is an orally administered iron chelator which has been highly efficient in the treatment of secondary iron overload. Most frequent side effects of DFX are gastrointestinal disturbances, which leads in some patients to low adherence to the therapy. An expert panel met in Lisbon in July 2010 to develop recommendations on prevention and management of GI disturbances based on existing data and personal experiences.
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CD81 expression for discrimination between sustained virologic response and relapse in patients with chronic hepatitis C.
Scand. J. Gastroenterol.
PUBLISHED: 05-26-2011
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The hepatitis C virus (HCV) receptor CD81 is overexpressed on peripheral blood mononuclear cells (PBMC) in patients chronically infected with HCV compared with healthy controls, and expression declines during antiviral therapy. The aim of this study was to prospectively investigate CD81 expression on PBMC for early discrimination between sustained virologic response (SVR) and relapse (REL) to pegylated interferon alfa-2b and ribavirin treatment.
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Prognostic significance of ASXL1 mutations in patients with myelodysplastic syndromes.
J. Clin. Oncol.
PUBLISHED: 05-16-2011
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To study the incidence and prognostic impact of mutations in Additional sex comb-like 1 (ASXL1) in a large cohort of patients with myelodysplastic syndrome (MDS).
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Entecavir treatment for chronic hepatitis B: adaptation is not needed for the majority of naïve patients with a partial virological response.
Hepatology
PUBLISHED: 05-13-2011
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Entecavir (ETV) is a potent inhibitor of viral replication in nucleos(t)ide analogue (NA)-naïve chronic hepatitis B (CHB) patients. The aim of this study was to investigate the long term efficacy and safety of ETV in NA-naïve CHB patients, particularly in those with detectable hepatitis B virus (HBV) DNA after 48 weeks, in whom treatment adaptation is suggested by current guidelines. In a multicenter cohort study, we investigated 333 CHB patients treated with entecavir monotherapy. The NA-naïve population consisted of 243 patients, whereas 90 were NA-experienced. Virological response (VR) (HBV DNA<80 IU/mL) was achieved in 48%, 76%, and 90% of hepatitis B e antigen (HBeAg)-positive and in 89%, 98%, and 99% of HBeAg-negative NA-naïve patients at weeks 48, 96, and 144, respectively. Thirty-six of 175 (21%) NA-naïve patients with at least 48 weeks of follow-up had a detectable load at week 48 (partial virological response [PVR]). Twenty-nine (81%) patients with PVR reached VR during prolonged ETV monotherapy, and none of them developed ETV-resistance. Among 22 patients with HBV DNA<1,000 IU/mL at week 48, VR was achieved in 21 (95%) patients, compared with eight of 14 (57%) patients with HBV DNA?1,000 IU/mL. Continuous HBV DNA decline was observed in most patients without VR during follow-up, and in three patients adherence was suboptimal according to the treating physician. ETV was safe and did not affect renal function or cause lactic acidosis.
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Comparison of acoustic radiation force impulse imaging with transient elastography for the detection of complications in patients with cirrhosis.
Liver Int.
PUBLISHED: 04-15-2011
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Acoustic radiation force impulse (ARFI) imaging is a new non-invasive, ultrasound-based method for the evaluation of liver fibrosis and cirrhosis.
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High expression of IGFBP2 is associated with chemoresistance in adult acute myeloid leukemia.
Leuk. Res.
PUBLISHED: 04-09-2011
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Insulin-like growth factor (IGF) signaling plays an important role in many tumors and overexpression of IGF Binding Protein (IGFBP) 2 has been associated with adverse outcome in childhood leukemia. Here, we evaluated IGFBP2 mRNA expression and its prognostic implications in 99 adult acute myeloid leukemia (AML) patients by quantitative real-time RT-PCR. High IGFBP2 was associated with a high incidence of primary resistant disease (IGFBP2 high 65%, IGFBP2 low 32%; P=0.02) and was independently predictive for therapy resistance [OR 3.6 (95% CI 1.2-11); P=0.02] in multivariate analyses. Gene-expression profiling revealed an up-regulation of genes implicated in leukemogenesis (MYB, MEIS1, HOXB3, HOXA9) and genes associated with adverse outcome (ERG, WT1) in patients with high IGFBP2 expression. Thus, our data suggest a role of IGFBP2 and IGF signaling in chemoresistance of AML. Patients with high IGFBP2 expression might benefit from molecular therapies targeting the IGF pathway.
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A new standard of care for the treatment of chronic HCV infection.
Nat Rev Gastroenterol Hepatol
PUBLISHED: 04-05-2011
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The introduction of direct acting antiviral agents (DAAs) will markedly change treatment options for individuals who have a chronic HCV infection. Within the next few months, licensing of two HCV protease inhibitors (boceprevir and telaprevir) for the treatment of patients with chronic hepatitis C as part of a triple therapy with PEG-IFN-? and ribavirin is anticipated in the USA, Europe and many other countries. Final results of pivotal phase III clinical trials in previously untreated and treatment-experienced patients with HCV genotype 1 infection were presented at the Annual Meeting of the American Association for the Study of the Liver 2010 held in Boston, MA, USA, and at the Annual Conference of the Asian Pacific Association for the Study of the Liver 2011, held in Bangkok, Thailand. This article summarizes the results of these phase III trials in consideration of accumulating data on important baseline and on-treatment predictive factors for treatment response, such as the host IL28B genotype and the rapid virologic response; the introduction of these new therapies into clinical practice is also covered. Furthermore, preliminary data on the combination of different classes of DAAs, such as HCV protease inhibitors and HCV polymerase inhibitors, without interferon ? are discussed.
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Expression of Transketolase like gene 1 (TKTL1) predicts disease-free survival in patients with locally advanced rectal cancer receiving neoadjuvant chemoradiotherapy.
BMC Cancer
PUBLISHED: 03-22-2011
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For patients with locally advanced rectal cancer (LARC) neoadjuvant chemoradiotherapy is recommended as standard therapy. So far, no predictive or prognostic molecular factors for patients undergoing multimodal treatment are established. Increased angiogenesis and altered tumour metabolism as adaption to hypoxic conditions in cancers play an important role in tumour progression and metastasis. Enhanced expression of Vascular-endothelial-growth-factor-receptor (VEGF-R) and Transketolase-like-1 (TKTL1) are related to hypoxic conditions in tumours. In search for potential prognostic molecular markers we investigated the expression of VEGFR-1, VEGFR-2 and TKTL1 in patients with LARC treated with neoadjuvant chemoradiotherapy and cetuximab.
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Role of nucleoside transporters SLC28A2/3 and SLC29A1/2 genetics in ribavirin therapy: protection against anemia in patients with chronic hepatitis C.
Pharmacogenet. Genomics
PUBLISHED: 02-25-2011
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The standard of hepatitis C antiviral therapy combines pegylated interferon-? with ribavirin. This polar guanosine analog improves the sustained virological response (SVR) rates, but may induce hemolytic anemia. As its pharmacokinetics depend on facilitated transmembrane transport, we assessed whether variants in genes that code for concentrative (concentrative nucleoside transporters 2 and 3 coded by SLC28A2 and SLC28A3, respectively) and equilibrative nucleoside transporters (equilibrative nucleoside transporters 1 and 2 coded by SLC29A1 and SLC29A2, respectively) are associated with the therapy response and side effects.
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Nucleos(t)ide analogue treatment reduces apoptotic activity in patients with chronic hepatitis B.
J. Clin. Virol.
PUBLISHED: 02-10-2011
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Reduction of necroinflammatory activity is a major goal of antiviral therapy of patients with chronic hepatitis B. Serum ALT does not detect all forms of cell death.
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BCL6 enables Ph+ acute lymphoblastic leukaemia cells to survive BCR-ABL1 kinase inhibition.
Nature
PUBLISHED: 01-31-2011
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Tyrosine kinase inhibitors (TKIs) are widely used to treat patients with leukaemia driven by BCR-ABL1 (ref. 1) and other oncogenic tyrosine kinases. Recent efforts have focused on developing more potent TKIs that also inhibit mutant tyrosine kinases. However, even effective TKIs typically fail to eradicate leukaemia-initiating cells (LICs), which often cause recurrence of leukaemia after initially successful treatment. Here we report the discovery of a novel mechanism of drug resistance, which is based on protective feedback signalling of leukaemia cells in response to treatment with TKI. We identify BCL6 as a central component of this drug-resistance pathway and demonstrate that targeted inhibition of BCL6 leads to eradication of drug-resistant and leukaemia-initiating subclones.
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Portal vein thrombosis as complication of romiplostim treatment in a cirrhotic patient with hepatitis C-associated immune thrombocytopenic purpura.
J. Hepatol.
PUBLISHED: 01-17-2011
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Thrombopoietin receptor agonists are a new class of compounds licenced for the treatment of immune thrombocytopenic purpura. They are currently being studied for patients with thrombopenia in advanced liver disease or under therapy for hepatitis C. There are indications that the risk for development of portal vein thrombosis in patients with advanced liver cirrhosis might be increased under therapy with thrombopoietin receptor agonists. We report a case of a patient with Child class B liver cirrhosis with concurrent immune thrombocytopenic purpura that developed portal vein thrombosis under therapy with the thrombopoietin receptor agonist romiplostim.
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Novel imatinib-sensitive PDGFRA-activating point mutations in hypereosinophilic syndrome induce growth factor independence and leukemia-like disease.
Blood
PUBLISHED: 01-11-2011
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The FIP1L1-PDGFRA fusion is seen in a fraction of cases with a presumptive diagnosis of hypereosinophilic syndrome (HES). However, because most HES patients lack FIP1L1-PDGFRA, we studied whether they harbor activating mutations of the PDGFRA gene. Sequencing of 87 FIP1L1-PDGFRA-negative HES patients revealed several novel PDGFRA point mutations (R481G, L507P, I562M, H570R, H650Q, N659S, L705P, R748G, and Y849S). When cloned into 32D cells, N659S and Y849S and-on selection for high expressors-also H650Q and R748G mutants induced growth factor-independent proliferation, clonogenic growth, and constitutive phosphorylation of PDGFRA and Stat5. Imatinib antagonized Stat5 phosphorylation. Mutations involving positions 659 and 849 had been shown previously to possess transforming potential in gastrointestinal stromal tumors. Because H650Q and R748G mutants possessed only weak transforming activity, we injected 32D cells harboring these mutants or FIP1L1-PDGFRA into mice and found that they induced a leukemia-like disease. Oral imatinib treatment significantly decreased leukemic growth in vivo and prolonged survival. In conclusion, our data provide evidence that imatinib-sensitive PDGFRA point mutations play an important role in the pathogenesis of HES and we propose that more research should be performed to further define the frequency and treatment response of PDGFRA mutations in FIP1L1-PDGFRA-negative HES patients.
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Screening for IL28B gene variants identifies predictors of hepatitis C therapy success.
Antivir. Ther. (Lond.)
PUBLISHED: 12-15-2010
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Recent research has shown that genetic variation in the IL28B gene predicts both chronicity of HCV infection and sustained virological response (SVR) to antiviral standard therapy. Because HCV affects 170 million people worldwide and is a leading cause of cirrhosis and hepatocellular carcinoma, screening for prognostic factors in routine clinical practice requires rapid and reliable assays.
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Immunosuppressive therapy for patients with myelodysplastic syndrome: a prospective randomized multicenter phase III trial comparing antithymocyte globulin plus cyclosporine with best supportive care--SAKK 33/99.
J. Clin. Oncol.
PUBLISHED: 12-13-2010
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Immunosuppressive treatment is reported to improve cytopenia in some patients with myelodysplastic syndrome (MDS). Combined antithymocyte globulin (ATG) and cyclosporine (CSA) is most effective in patients with immune-mediated marrow failure.
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Expression of IGFBP7 in acute leukemia is regulated by DNA methylation.
Cancer Sci.
PUBLISHED: 10-29-2010
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The important role of insulin-like growth factor binding protein 7 (IGFBP7) as a tumor suppressor in solid tumors has been revealed in several studies. Interestingly, in a recent study IGFBP7 was also shown to be aberrantly expressed in acute leukemia. Moreover, in acute T-lymphoblastic leukemia (T-ALL), high IGFBP7 expression predicts primary therapy resistance. In order to elucidate the mechanisms underlying aberrant IGFBP7 expression, we used pyrosequencing technology to investigate the DNA methylation of IGFBP7 in 109 T-ALL patient samples. Aberrant methylation was shown and hypomethylation was associated with an early immunophenotype and co-expression of the stem cell markers CD117 (P < 0.001) and CD34 (P < 0.001). In concordance, gene expression profiles of 86 T-ALL patients revealed upregulation of stem cell markers (CD34 and CD133) as well as genes associated with poor outcome and pathogenesis of leukemia (MN1, BAALC, FLT3) in the high IGFBP7 expression group. In conclusion, aberrant IGFBP7 expression is regulated by DNA methylation in acute leukemia. Hypomethylation of the gene is likely to characterize an immature and a more malignant subtype of the disease.
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Impact of donor and recipient IL28B rs12979860 genotypes on hepatitis C virus liver graft reinfection.
J. Hepatol.
PUBLISHED: 07-30-2010
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Recent studies have described a major impact of genetic variations near the IL28B gene on the natural course and outcome of antiviral therapy in chronic hepatitis C. We therefore, aimed to explore the impact of donor and recipient genotypes of these polymorphisms on hepatitis C virus (HCV) liver graft reinfection.
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The role of zinc protoporphyrin measurement in the differentiation between primary myelofibrosis and essential thrombocythaemia.
Ann. Hematol.
PUBLISHED: 07-07-2010
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The differentiation between primary myelofibrosis (PMF) and essential thrombocythaemia (ET) may be difficult especially in early-stage disease. In PMF, increased levels of inflammatory cytokines induce impaired iron utilisation and disturbed erythropoiesis. In conditions with impaired iron support to erythropoiesis, zinc protoporphyrin (ZPP) is produced instead of heme. Here, we investigate whether ZPP concentration can be useful in the differentiation between PMF and ET. Seventy newly diagnosed patients (PMF, n=24; ET, n=46) were analysed. Intraerythrocytic ZPP concentration (normal?40 ?mol/mol heme) was measured by an Aviv front-face haematofluorometer. In PMF, ZPP concentrations were significantly increased when compared to ET (99±37 ?mol/mol heme vs. 36±13 ?mol/mol heme, p<0.0001). There was also a significant difference between early-stage PMF and advanced disease (77±30 ?mol/mol heme vs. 122±31 ?mol/mol heme, p=0.003). ZPP>76 ?mol/mol heme as observed in 71% of PMF patients were not seen in ET. In PMF patients responding to immunosuppressive treatment (n=4), the increase in haemoglobin was accompanied by declining ZPP. In summary, by detecting the disturbed iron metabolism common in PMF, ZPP may assist in the differentiation between PMF and ET. Concentrations>60 ?mol/mol heme are unlikely in ET if iron deficiency is excluded. ZPP determination is also useful for monitoring the effect of therapy in PMF.
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Epigenetic regulation of PAX5 expression in acute T-cell lymphoblastic leukemia.
Leuk. Res.
PUBLISHED: 07-02-2010
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The analysis of genomic alterations in acute lymphoblastic leukemia (ALL) has provided new insights for prognosis and possible targets of novel therapies. In T-ALL the role of molecular abnormalities has still to be determined. Deregulated promoter hypermethylation of critical genes like PAX5 may have a significant impact on the course of ALL. Samples derived from 75 patients with ALL (B-ALL = 24, T-ALL = 51) and from healthy volunteers were analyzed. PAX5 expression was assessed by micro-array analysis (HG-U133plus 2.0) and correlated with promoter CpG island methylation of PAX5 using a pyrosequencing approach. The analyzed CpG marks in the promoter region of PAX5 were completely and uniformly unmethylated in the control group of healthy individuals. The T-ALL cases featured even higher methylation levels (median: 20%) with a strong variation of values of up to 85% methylation. Analysis of the association of altered methylation levels with gene expression data indicated a differential epigenetic regulation of PAX5 through promoter methylation which may contribute to the pathogenesis of this disease.
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