The JAK2V617F mutation has been reported in about 40-60% of Essential Thrombocythemia (ET) patients. However, little is known about specific molecular abnormalities of the hematopoietic stem cell compartment of ET according to JAK2 mutation. Therefore, we compared the gene expression profiles of bone marrow (BM) CD34+ cells from 16 patients with and without the JAK2V617F mutation to identify differentially expressed genes.
Molecular profile of CD34+ stem/progenitor cells according to JAK2V617F mutation status in essential thrombocythemia.
No sample metadata fields
View SamplesPeripheral T-cell lymphoma unspecified (PTCL/U), the most common form of PTCL, displays heterogeneous morphology and phenotype, poor response to treatment, and dismal prognosis. We demonstrate that PTCL/U shows a gene expression profile clearly distinct from that of normal T-cells. Comparison with the profiles of purified T-cell subpopulations [CD4+, CD8+, resting (HLA-DR-), and activated (HLA-DR+)] reveals that PTCLs/U are most closely related to activated peripheral T-lymphocytes, either CD4+ or CD8+. Interestingly, the global gene expression profile cannot be surrogated by routine CD4/CD8 immunohistochemistry. When compared with normal T-cells, PTCLs/U display deregulation of functional programs often involved in tumorigenesis (e.g. apoptosis, proliferation, cell adhesion, and matrix remodeling). Products of deregulated genes can be detected in PTCLs/U by immunohistochemistry with an ectopic, paraphysiologic or stromal location. Among others, PTCLs/U aberrantly express PDGFRA, a tyrosine-kinase receptor, whose deregulation is often related to a malignant phenotype. Notably, both phosphorylation of PDGFRA and sensitivity of cultured PTCL cells to imatinib (as well as to an inhibitor of histone-deacetylase) are found. These results, which might be extended to other rarer PTCL categories, are provided with implications for tumor pathogenesis and clinical management.
Gene expression analysis of peripheral T cell lymphoma, unspecified, reveals distinct profiles and new potential therapeutic targets.
No sample metadata fields
View SamplesBackground: In human malaria, parasites of the genus Plasmodium elicit expansion of atypical memory B cells (atMBCs), which lack the classical markers CD21 and CD27. We have identified a putative population of analogous B cells in a murine model of infection with P. chabaudi, delineated by the marker FCRL5. We performed RNA-Seq on FCRL5+ and FCRL5- B cells sorted from infected mice, so as to characterize the transcriptional profile of these cells and permit comparison to atMBCs in humans. Results: FCRL5+ B cells were found to have distinct transcriptional profiles from FCRL5- B cells, with approximately 400 genes exhibiting significant differences between the two groups. Additionally, about 25% of these differentially expressed genes were also differentially expressed in human atMBCs versus classical MBCs, as previously described by Sullivan et al (PLoS Pathogens 2015). Conclusions: FCRL5+ class-switched B cells are a transcriptionally distinct subset arising in P. chabaudi infection, with transcriptional similarities to human atMBCs that develop in chronic malaria settings. Overall design: Class-switched B cells (IgM- IgD- CD19+) were isolated into FCRL5+ and FCRL5- populations by double-sorting from the blood of C57BL/6 adult female mice 21 days post-infection with Plasmodium chabaudi. Pools of ~1000 cells were isolated and processed for RNA sequencing. 5 biological replicates were analyzed for each sample type.
FCRL5<sup>+</sup> Memory B Cells Exhibit Robust Recall Responses.
Specimen part, Subject
View SamplesIn the present study, we investigated whether, and to what extent, P2Rs and their ligands are involved in the regulation of AML cells. Our findings show that AML blasts express several receptors belonging to the P2X and P2Y family. Although different samples respond differently to ATP and UTP stimulation (reflecting the variability intrinsic to the group of acute myeloid leukemias), all the tested samples appear to be responsive to purinergic signalling, as demonstrated by intracellular calcium mobilization.
Purinergic signaling inhibits human acute myeloblastic leukemia cell proliferation, migration, and engraftment in immunodeficient mice.
Specimen part
View SamplesWe show the molecular and functional characterization of a novel population of lineage-negative CD34-negative (Lin- CD34-) hematopoietic stem cells (HSCs) from chronic myelogenous leukemia (CML) patients at diagnosis. Molecular caryotyping and quantitative analysis of BCR/ABL transcript demonstrated that about one third of CD34- was leukemic. CML CD34- cells showed kinetic quiescence and limited clonogenic capacity. However, stroma-dependent cultures and cytokines induced CD34 expression on some HSCs, cell cycling, acquisition of clonogenic activity and increased expression of BCR/ABL transcript. CML CD34- cells showed an engraftment rate in immunodeficient mice similar to that of CD34+ cells. Gene expression profiling revealed the down-regulation of cell cycle arrest genes together with genes involved in antigen presentation and processing, while the expression of angiogenic factors was strongly up-regulated when compared to normal counterparts. Flow cytometry analysis confirmed the significant down-regulation of HLA class I and II molecules in CML CD34-cells. Increasing doses of imatinib mesilate (IM) did not affect fusion transcript levels, BCR-ABL kinase activity and the clonogenic efficiency of CML CD34- cells as compared to leukemic CD34+cells.
Molecular and functional analysis of the stem cell compartment of chronic myelogenous leukemia reveals the presence of a CD34- cell population with intrinsic resistance to imatinib.
No sample metadata fields
View SamplesAnalysis of mRNA in THP1 (human monocytic leukemia) cell line in order to correlate miRNA activity with target abundance. Overall design: THP1 mRNA profiles were generated in triplicates by deep-sequencing in Illumina HiSeq2000.
High-throughput assessment of microRNA activity and function using microRNA sensor and decoy libraries.
Specimen part, Cell line, Subject
View SamplesGenome instability is a potential limitation to the research and therapeutic application of induced pluripotent stem cells (iPSCs). Observed genomic variations reflect the combined activities of DNA damage, cellular DNA damage response (DDR), and selection pressure in culture. To understand the contribution of DDR on the distribution of copy number variations (CNVs) in iPSCs, we mapped CNVs of iPSCs with mutations in the central DDR gene ATM onto genome organization landscapes defined by genome-wide replication timing profiles. We show that following reprogramming the early and late replicating genome is differentially affected by CNVs in ATM deficient iPSCs relative to wild type iPSCs. Specifically, the early replicating regions had increased CNV losses during retroviral reprogramming. This differential CNV distribution was not present after later passage or after episomal reprogramming. Comparison of different reprogramming methods in the setting of defective DNA damage response reveals unique vulnerability of early replicating open chromatin to retroviral vectors.
Influence of ATM-Mediated DNA Damage Response on Genomic Variation in Human Induced Pluripotent Stem Cells.
Specimen part
View SamplesmicroRNA-126 is a microRNA predominately expressed by endothelial cells and controls angiogenesis. Unexpectedly, we found that mice deficient in miR-126 have a major impairment in their innate response to pathogen-associated nucleic acids, as well as HIV, which results in more widespread cell infection. Further examination revealed that this was due to miR-126 control of plasmacytoid DC (pDC) homeostasis and function, and that miR-126 regulates expression of TLR7, TLR9, NFkB1 and other innate response genes, as well as VEGF-receptor 2 (VEGFR2). Deletion of VEGFR2 on DCs resulted in reduced interferon production, supporting a role for VEGFR2 in miR-126 regulation of pDCs. These studies identify the miR-126/VEGFR2 axis as an important regulator of the innate response that operates through multiscale control of pDCs.
The miR-126-VEGFR2 axis controls the innate response to pathogen-associated nucleic acids.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The distribution of genomic variations in human iPSCs is related to replication-timing reorganization during reprogramming.
Sex, Age, Specimen part, Disease, Disease stage, Subject, Time
View SamplesCell fate change involves significant genome reorganization, including change in replication timing, but how these changes are related to genetic variation has not been examined. To study how change in replication timing that occurs during reprogramming impacts the copy number variation (CNV) landscape, we generated genome-wide replication timing profiles of induced pluripotent stem cells (iPSCs) and their parental fibroblasts. A significant portion of the genome changes replication timing as a result of reprogramming, indicative of overall genome reorganization. We found that early and late replicating domains in iPSCs are differentially affected by copy number gains and losses, and that in particular CNV gains accumulate in regions of the genome that change to earlier replication during the reprogramming process. This differential relationship was present irrespective of reprogramming method. Overall, our findings reveal a functional association between reorganization of replication timing and the CNV landscape that emerges during reprogramming.
The distribution of genomic variations in human iPSCs is related to replication-timing reorganization during reprogramming.
Specimen part, Disease, Disease stage, Subject
View Samples