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Find video protocols related to scientific articles indexed in Pubmed.
MicroRNA-23a mediates post-transcriptional regulation of CXCL12 in bone marrow stromal cells.
Haematologica
PUBLISHED: 02-28-2014
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The chemokine CXCL12 regulates the interaction between hematopoietic stem and progenitor cells and bone marrow stromal cells. Although its relevance in the bone marrow niche is well recognized, the regulation of CXCL12 by microRNA is not completely understood. We transfected a library of 486 microRNA in the bone marrow stromal cell line SCP-1 and studied the expression of CXCL12. Twenty-seven microRNA were shown to downregulate expression of CXCL12. Eight microRNA (miR-23a, 130b, 135, 200b, 200c, 216, 222, and 602) interacted directly with the 3'UTR of CXCL12. Next, we determined that only miR-23a is predicted to bind to the 3'UTR and is strongly expressed in primary bone marrow stromal cells. Modulation of miR-23a changes the migratory potential of hematopoietic progenitor cells in co-culture experiments. We discovered that TGFB1 mediates its inhibitory effect on CXCL12 levels by upregulation of miR-23a. This process was partly reversed by miR-23a molecules. Finally, we determined an inverse expression of CXCL12 and miR-23a in stromal cells from patients with myelodys-plastic syndrome indicating that the interaction has a pathophysiological role. Here, we show for the first time that CXCL12-targeting miR23a regulates the functional properties of the hematopoietic niche.
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Obinutuzumab plus chlorambucil in patients with CLL and coexisting conditions.
N. Engl. J. Med.
PUBLISHED: 01-08-2014
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The monoclonal anti-CD20 antibody rituximab, combined with chemotherapeutic agents, has been shown to prolong overall survival in physically fit patients with previously untreated chronic lymphocytic leukemia (CLL) but not in those with coexisting conditions. We investigated the benefit of the type 2, glycoengineered antibody obinutuzumab (also known as GA101) as compared with that of rituximab, each combined with chlorambucil, in patients with previously untreated CLL and coexisting conditions.
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MiR-134-mediated ?1 integrin expression and function in mesenchymal stem cells.
Biochim. Biophys. Acta
PUBLISHED: 05-17-2013
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The composition of the hematopoietic stem cell (HSC) niche within the bone marrow is highly dynamic, tightly regulated, and of importance for various HSC properties. Integrins are important molecules within this niche that influence those properties through the interactions of HSCs and mesenchymal stem cells (MSCs). Here we investigated the function of miR-134 in integrin regulation in MSCs. In MSCs, miR-134 post-transcriptionally regulated ?1 integrin expression. This negative regulation of ?1 integrin was mediated by the binding of miR-134 to its 3 untranslated region, which contains two conserved binding sites for miR-134. The miR-134-mediated silencing of ?1 integrin in MSCs was shown by atomic force microscopy to decrease the adhesion of 32D cells to MSCs transfected with miR-134. Furthermore, the adhesion of MSCs to fibronectin was reduced after transfection with miR-134. MSCs from patients with myelodysplastic syndrome (MDS) revealed highly significant miR-134 overexpression compared with MSCs from healthy bone marrow donors. MSCs from MDS patients showed lower ?1 integrin protein, but not lower mRNA, expression, suggesting post-transcriptional regulation. The present study demonstrates miR-134-mediated negative regulation of ?1 integrin that influences cell adhesion to and of MSCs. These results further contribute to our understanding of the complexity of MDS.
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MicroRNA29a regulates the expression of the nuclear oncogene Ski.
Blood
PUBLISHED: 06-17-2011
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MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate growth and differentiation. miRNAs are frequently located at cancer-specific fragile sites in the human genome, such as chromosome 7q. The nuclear oncogene SKI is up-regulated in acute myeloid leukemia (AML) with -7/del7q. Here we asked whether loss of miRNAs on chromosome 7q may explain this up-regulation. miR-29a expression was found to be down-regulated in AML with -7/del7q. Forced expression of miR-29a down-regulated Ski and its target gene, Nr-CAM, whereas miR-29a inhibition induced Ski expression. Luciferase assays validated a functional binding site for miR-29a in the 3 untranslated region of SKI. Finally, in samples of AML patients, we observed an inverse correlation of Ski and miR-29a expression, respectively. In conclusion, up-regulation of Ski in AML with -7/del7q is caused by loss of miR-29a. miR-29a may therefore function as an important tumor suppressor in AML by restraining expression of the SKI oncogene.
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miR-10a overexpression is associated with NPM1 mutations and MDM4 downregulation in intermediate-risk acute myeloid leukemia.
Exp. Hematol.
PUBLISHED: 02-02-2011
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The study investigated differential microRNA (miRNA) expression patterns in acute myeloid leukemia (AML) patients with intermediate-risk (IR) characteristics. After characterization and validation of miR-10a, which was specifically upregulated in nucleophosmin 1 (NPM1) mutant AML samples, functional consequences of miR-10a overexpression were further delineated in vitro.
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Posaconazole prophylaxis during induction therapy of patients with acute lymphoblastic leukaemia.
Mycoses
PUBLISHED: 03-22-2010
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Novel treatment schedules of induction therapy for acute lympoblastic leukaemia (ALL) use combinations of immunosuppressive and cytotoxic drugs that are associated with neutropenia and acquisition of invasive fungal infections. It has been described that posaconazole, a triazole antifungal drug, is active against a variety of Candida and Aspergillus species in vitro. Moreover, large clinical trials using posaconazole in severely immunosuppressed patients provided data on efficacy against Aspergillus in vivo. As patients with ALL are also affected by difficult-to-treat Aspergillus infections, we conducted a pilot study to prove the safety of posaconazole in patients undergoing intensified induction phase treatment. We report on eight patients receiving prophylactic (200 mg t.i.d.) dose of posaconazole and demonstrate good tolerability of the drug. The most obvious side effect was liver toxicity as defined by abnormal serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase and bilirubin levels (
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Monitoring of donor chimerism in sorted CD34+ peripheral blood cells allows the sensitive detection of imminent relapse after allogeneic stem cell transplantation.
Haematologica
PUBLISHED: 11-03-2009
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Analysis of donor chimerism is an important diagnostic tool to assess the risk of relapse after allogeneic stem cell transplantation, especially in patients lacking a specific marker suitable for monitoring of minimal residual disease. We prospectively investigated the predictive value of donor chimerism analyses in sorted CD34(+) peripheral blood cells in 90 patients with acute leukemia and myelodysplastic syndrome. The cumulative incidence of relapse after four years was significantly increased in cases with decreasing or incomplete CD34(+) donor chimerism (57% vs. 18%, p=0.0001). Multivariate analysis confirmed decreasing CD34(+) donor chimerism as an independent predictor of relapse and inferior survival. The interval between a decrease of CD34(+) chimerism of less than 80% and hematologic relapse was 61 days (range 0-567). Monitoring of CD34(+) donor chimerism in the peripheral blood allows prediction of imminent relapse after allogeneic stem cell transplantation even when a disease-specific marker is lacking.
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Elevated AF1q expression is a poor prognostic marker for adult acute myeloid leukemia patients with normal cytogenetics.
Am. J. Hematol.
PUBLISHED: 04-28-2009
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Nearly half of the patients with newly diagnosed acute myeloid leukemia have normal cytogenetics (NC-AML) and are classified as intermediate risk, but their 5-year overall survival (OS) ranges from 24 to 42%. Therefore, molecular biomarkers to identify poor-risk patients are needed. Elevated AF1q expression in the absence of specific poor cytogenetics is associated with poor outcomes in pediatric patients with AML and adult patients with myelodysplastic syndrome. We examined AF1q expression in 290 patients with NC-AML. We found that patients with low AF1q (n = 73) expression (AF1q(low)) have better OS (P = 0.026), disease-free survival (P = 0.1), and complete remission rate (P = 0.06) when compared with patients with high AF1q expression (AF1q(high) n = 217). The patients with AF1q(high) had significantly greater incidence of concurrent tyrosine kinase3 internal tandem duplication. A subgroup of the patients with AF1q(high) who received allogeneic stem cell transplantation (SCT) had a significant better relapse-free survival when compared with patients who received chemotherapy/autologous SCT (P = 0.04). This study suggests that high AF1q expression is a poor prognostic marker for adult patients with NC-AML.
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Oncogenic RAS enables DNA damage- and p53-dependent differentiation of acute myeloid leukemia cells in response to chemotherapy.
PLoS ONE
PUBLISHED: 04-26-2009
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Acute myeloid leukemia (AML) is a clonal disease originating from myeloid progenitor cells with a heterogeneous genetic background. High-dose cytarabine is used as the standard consolidation chemotherapy. Oncogenic RAS mutations are frequently observed in AML, and are associated with beneficial response to cytarabine. Why AML-patients with oncogenic RAS benefit most from high-dose cytarabine post-remission therapy is not well understood. Here we used bone marrow cells expressing a conditional MLL-ENL-ER oncogene to investigate the interaction of oncogenic RAS and chemotherapeutic agents. We show that oncogenic RAS synergizes with cytotoxic agents such as cytarabine in activation of DNA damage checkpoints, resulting in a p53-dependent genetic program that reduces clonogenicity and increases myeloid differentiation. Our data can explain the beneficial effects observed for AML patients with oncogenic RAS treated with higher dosages of cytarabine and suggest that induction of p53-dependent differentiation, e.g. by interfering with Mdm2-mediated degradation, may be a rational approach to increase cure rate in response to chemotherapy. The data also support the notion that the therapeutic success of cytotoxic drugs may depend on their ability to promote the differentiation of tumor-initiating cells.
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Detection of herpesvirus and adenovirus co-infections with diagnostic DNA-microarrays.
J. Virol. Methods
PUBLISHED: 03-19-2009
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In immunocompromised patients, the diagnosis of infections with herpesviruses and adenoviruses relies mainly on PCR amplification of viral genomic DNA from clinical samples. In the case of co-infections with two or more viruses, single amplification of viral DNA from clinical samples has proven to be time-consuming and expensive, hampering the efficient diagnosis and therapy of viral co-infections. In this study, a diagnostic DNA-microarray allowing simultaneous detection of herpes simplex virus types 1 and 2 (HSV 1/2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus-6 types A and B (HHV-6 A/B), and adenovirus in clinical samples was developed and validated. The assay displays a high analytical sensitivity (10genomeequivalents(GE)/reaction) and specificity, being cost-effective and time-saving. Because the DNA-microarray uses the same analytical conditions as real-time quantitative PCR, it can be used as a screening device for multiple viral infections, followed by selective viral load measurement depending on the clinical context. Those features make the DNA-microarray an attractive device for the management of viral infections in immunocompromised patients.
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HLA-DRneg patients without acute promyelocytic leukemia show distinct immunophenotypic, genetic, molecular, and cytomorphologic characteristics compared to acute promyelocytic leukemia.
Cytometry B Clin Cytom
PUBLISHED: 03-18-2009
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Loss of HLA-DR and CD34 is a well-known characteristic of malignant promyelocytes in acute promyelocytic leukemia (APL). However, this immunophenotype is not specific for APL. The purpose of this study was to investigate whether further biological characterization of the HLA-DR(neg) acute myeloid leukemia patients would allow more clearly define criteria to separate APL from non-APL patients.
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Expression of ABCC-type nucleotide exporters in blasts of adult acute myeloid leukemia: relation to long-term survival.
Clin. Cancer Res.
PUBLISHED: 02-24-2009
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Successful treatment of acute myeloid leukemia (AML) remains a therapeutic challenge, with a high percentage of patients suffering from persistent or relapsed disease. Resistance to drug therapy can develop from increased drug export and/or altered intracellular signaling. Both mechanisms are mediated by the efflux transporters ABCC4 (MRP4), ABCC5 (MRP5), and ABCC11 (MRP8), which are involved in cellular efflux of endogenous signaling molecules (e.g., cyclic adenosine 3, 5-monophosphate and cyclic guanosine 3,5-monophosphate) and nucleoside analogues. The nucleoside analogue cytosine arabinoside (AraC) is administered to all patients with AML.
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The efficacy of arsenic trioxide for the treatment of relapsed and refractory multiple myeloma: a systematic review.
Cancer Treat. Rev.
PUBLISHED: 02-10-2009
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Arsenic trioxide (ATO) has been proposed as an option for the treatment of relapsing or refractory multiple myeloma. In order to critically appraise the published clinical evidence, a systematic search of the databases PubMed, Embase, Web of Science and the Cochrane Library was performed. Studies were selected according to prospectively defined criteria. Eventually 16 articles met the inclusion criteria. Six trials evaluated ATO as a single agent or in combination with ascorbic acid and ten trials added ATO to other cytostatic agents. Apart from one randomized controlled trial (RCT), all other studies were designed as case series. The patient numbers were generally small, treatment regimens differed both regarding the dosage of ATO and combinations with other drugs. Monotherapy with ATO resulted in partial response rates between 0% and 17% and minimal responses of 7-33%, resulting in mean overall response rates of 30%. Overall response rates in combined regimens varied widely between 12% and 100%. Response rates for patients in the three arms of the RCT did not differ significantly. The results demonstrate the potential efficacy of ATO in refractory multiple myeloma, but the validity of these findings is reduced by considerable methodological flaws. RCTs should further investigate the efficacy of ATO or new arsenicals in order to overcome methodological concerns of the studies presented here. With respect to the higher evidence level of new substances such as bortezomib or lenalidomide, at present ATO has no role in routine management of relapsed or refractory myeloma.
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Clonal evolution including partial loss of human leukocyte antigen genes favoring extramedullary acute myeloid leukemia relapse after matched related allogeneic hematopoietic stem cell transplantation.
Transplantation
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Relapse of acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (HSCT) leaves few therapeutic options, and mechanisms of immune escape of recurring leukemic cells remain poorly understood. Recently, acquired loss of mismatched human leukocyte antigen (HLA) was demonstrated in patients with AML undergoing haploidentical allogeneic HSCT and was suggested not to occur in HLA-matched HSCT. We hypothesized that this mechanism applies to extramedullary AML relapse which occurs frequently after allogeneic HSCT and might also not be restricted to haploidentical HSCT.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.