Imatinib has become the current standard therapy for patients with chronic myelogenous leukaemia (CML). For a better understanding of the Imatinib-related molecular effects in vivo, we assessed gene expression profiles of Philadelphia Chromosome positive (Ph+) CD34+ cells from peripheral blood of 6 patients with de novo CML in chronic phase. After 7 days of treatment with Imatinib the Ph+ CD34+ cells were reassessed to look for changes in the transcriptome. The expression level of 303 genes was significantly different comparing the transcriptome of the Ph+ CD34+ cells before and after 7 days of Imatinib therapy (183 down-regulated, 120 up-regulated, lower bound 1.2-fold). For a substantial number of genes governing cell cycle and DNA replication, the level of expression significantly decreased (CDC2, RRM2, PCNA, MCM4). On the other hand, therapy with Imatinib was associated with an increase of genes related to adhesive interactions, such as L-selectin or CD44. A group of 8 genes with differential expression levels were confirmed using a gene specific quantitative real-time PCR. Thus, during the first week of treatment, Imatinib is preferentially counteracting the bcr-abl induced effects related to a disturbed cell cycle and defective adhesion of leukemic Ph+ CD34+ cells.
Early in vivo changes of the transcriptome in Philadelphia chromosome-positive CD34+ cells from patients with chronic myelogenous leukaemia following imatinib therapy.
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View SamplesFoxp3+ regulatory T (Treg) cells prevent inflammatory disease but the mechanistic basis of suppression is not understood completely . Gene silencing by RNA interference can act in a cell-autonomous and non-cell-autonomous manner, providing mechanisms of inter-cellular regulation. Here, we demonstrate that non-cell-autonomous gene silencing, mediated by miRNA-containing exosomes, is a mechanism employed by Treg cells to suppress T cell-mediated disease. Treg cells transferred microRNAs (miRNA) to various immune cells, including T helper 1 (Th1) cells, suppressing Th1 cell proliferation and cytokine secretion. Use of Dicer-deficient or Rab27a and Rab27b double-deficient Treg cells to disrupt miRNA-biogenesis or the exosomal pathway, respectively, established a requirement for miRNAs and exosomes for Treg cell-mediated suppression. Transcriptional analysis and miRNA inhibitor studies showed that exosome-mediated transfer of Let-7d from Treg cell to Th1 cells contributed to suppression and prevention of systemic disease. These studies reveal a mechanism of Treg cell-mediated suppression mediated by miRNA-containing exosomes.
MicroRNA-containing T-regulatory-cell-derived exosomes suppress pathogenic T helper 1 cells.
Specimen part
View SamplesIt has long been known that leukemic cells disrupt normal patterns of blood cell formation, but little is understood about mechanisms. It has generally been assumed that normal hematopoietic stem and progenitor cells (HSPC) are simply out-competed for space by malignant cells. We designed a strategy to determine if leukemic cells alter intrinsic properties and functions of normal HSPCs. Chimeric mice were generated by transplantation of normal marrow and marrow from an inducible transgenic model of chronic myelogenous leukemia (CML). With induction of CML, the composition of the marrow changed dramatically, and normal HSPCs divided more readily and lost their ability to produce lymphocytes. In contrast, only modest changes were recorded in numbers of normal hematopoietic stem cells (HSCs). However, these stem cells were not unscathed, and had reduced reconstitution and self-renewal potential upon transplantation. Interestingly, the normal bystander cells acquired gene expression patterns resembling their neighboring malignant counterparts. This suggested that much of the leukemia signature is mediated by extrinsic factors in the environment.
Treatment of chronic myelogenous leukemia by blocking cytokine alterations found in normal stem and progenitor cells.
Specimen part
View SamplesGene expression of Treg cells that have lost Foxp3 expression and acquired Il4 expression following adoptive transfer into T-cell deficient mice (HpTR-IL-4gfp+), cmpared to conventional Treg cells isolated from H. polygyrus-infected wild-type mice (HpTR) and Th2 cells generated from nave T cells following adoptive transfer into H. polygyrus-infected T-cell deficient mice (nT-IL-4gfp+).
Interleukin 4 promotes the development of ex-Foxp3 Th2 cells during immunity to intestinal helminths.
Specimen part
View SamplesWe found that composition of cell subsets within the CD34+ cell population is markedly altered in chronic phase (CP) chronic myeloid leukemia (CML). Specifically, proportions and absolute cell counts of common myeloid progenitors (CMP) and megakaryocyte-erythrocyte progenitors (MEP) are significantly greater in comparison to normal bone marrow whereas absolute numbers of hematopoietic stem cells (HSC) are equal. To understand the basis for this, we performed gene expression profiling (Affymetrix HU-133A 2.0) of the distinct CD34+ cell subsets from six patients with CP CML and five healthy donors. Euclidean distance analysis revealed a remarkable transcriptional similarity between the CML patients' HSC and normal progenitors, especially CMP. CP CML HSC were transcriptionally more similar to their progeny than normal HSC to theirs, suggesting a more mature phenotype. Hence, the greatest differences between CP CML patients and normal donors were apparent in HSC including downregulation of genes encoding adhesion molecules, transcription factors, regulators of stem-cell fate and inhibitors of cell proliferation in CP CML. Impaired adhesive and migratory capacities were functionally corroborated by fibronectin detachment analysis and transwell assays, respectively. Based on our findings we propose a loss of quiescence of the CML HSC on detachment from the niche leading to expansion of myeloid progenitors.
The hematopoietic stem cell in chronic phase CML is characterized by a transcriptional profile resembling normal myeloid progenitor cells and reflecting loss of quiescence.
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View SamplesDespite significant advances in our understanding of the biology determining systemic energy homeostasis, the treatment of obesity remains a medical challenge. Activation of AMP-activated protein kinase (AMPK) has been proposed as an attractive strategy for the treatment of obesity and its complications. AMPK is a conserved, ubiquitously expressed, heterotrimeric serine/threonine kinase whose short-term activation has multiple beneficial metabolic effects. Whether these translate into long-term benefits for obesity and its complications is unknown. Here, we observe that mice with chronic AMPK activation, resulting from mutation of the AMPK ?2 subunit, exhibit ghrelin signalling-dependent hyperphagia, obesity and impaired pancreatic islet insulin secretion. Humans bearing the homologous mutation manifest a congruent phenotype. Our studies highlight that long-term AMPK activation can have adverse metabolic consequences with implications for pharmacological strategies seeking to chronically activate AMPK systemically to treat metabolic disease. Overall design: Transcriptomic profiling of the hypothalamic arcuate nucleus from AMPK ?2 R299Q knock-in mice
Chronic Activation of γ2 AMPK Induces Obesity and Reduces β Cell Function.
Specimen part, Cell line, Subject
View SamplesMultiple myeloma (MM) is a clonal plasma cell disorder frequently accompanied by hematopoietic impairment. Genomic profiling of distinct HSPC subsets revealed a consistent deregulation of signaling cascades, including TGF beta signaling, p38MAPK signaling and pathways involved in cytoskeletal organization, migration, adhesion and cell cycle regulation in MM patients.
Multiple myeloma-related deregulation of bone marrow-derived CD34(+) hematopoietic stem and progenitor cells.
Specimen part, Disease, Disease stage
View SamplesThis series includes the four major subtypes of pituitary adenomas and normal post-mortem pituitary tissue
Differential gene expression in pituitary adenomas by oligonucleotide array analysis.
No sample metadata fields
View SamplesProstate tumors contain foci of neuroendocrine transdifferentiation (NETD), resulting in an increase of androgen-independent neuroendocrine-like (NE) tumor cells, whose number significantly correlates with tumor aggressiveness and a lower survival rate. The mechanisms leading to NETD and the exact role of NE-like tumor cells in disease progression are not fully understood yet.
The deregulation of miR-17/CCND1 axis during neuroendocrine transdifferentiation of LNCaP prostate cancer cells.
Cell line, Treatment
View SamplesPrimary RNASeq data for progenitor, resident, and stimulated (C.alb, LPS, injury, APAP+ starved overnight and pIC) mononuclear phagocytes from fourteen organs. Overall design: RNASeq data for over 400 samples comprising of 130 populations submitted by 16 labs (both non-ImmGen and ImmGen labs) from 8 locations around the world for ImmGen OpenSource Mononuclear Project. Samples were sorted in these facilities using ImmGen's stringent ULI protocol and shipped to one location for library preparation and sequencing. Contributor: Immunological Genome Project Consortium
ImmGen report: sexual dimorphism in the immune system transcriptome.
Age, Specimen part, Cell line, Subject
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