Epigenetic code modifications by histone deacetylase inhibitors (HDACi) have recently been proposed as potential new therapies for hematological malignancies. Chronic Lymphocytic Leukemia (CLL) remains incurable despite the introduction of new treatments. CLL cells are characterized by an apoptosis defect rather than excessive proliferation, but proliferation centers have been found in organs such as bone marrow and lymph nodes.
Antileukemic activity of valproic acid in chronic lymphocytic leukemia B cells defined by microarray analysis.
Sex, Age
View SamplesIt is now well established that bone marrow (BM) constitutes a microenvironment required for differentiation. Bone marrow mesenchymal stromal cells (BM-MSCs) strongly support MM cell growth, by producing a high level of Interleukin-6 (IL-6), a major MM cell growth factor. BM-MSCs also support osteoclastogenesis and angiogenesis. Previous studies have suggested that the direct (VLA-4, VCAM-1, CD44, VLA-5, LFA-1, syndecan-1,) and indirect interactions (soluble factors) between MM plasma cells and BM-MSCs result in constitutive abnormalities in BM-MSCs. In particular, MM BM-MSCs express less CD106 and fibronectin and more DKK1, IL-1 and TNF- as compared with normal BM-MSCs. In order to gain a global view of the differences between BM-MSCs from MM patients and healthy donors, we used gene expression profiling to identify genes associated to the transformation of MM BM-MSCs.
Evidences of early senescence in multiple myeloma bone marrow mesenchymal stromal cells.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesComparison of Chronic Lymphocytic Leukemia patients expressing high or low levels of ZAP70 mRNA: prognostic factors and interaction with the microenvironment.
Gene expression profiling reveals differences in microenvironment interaction between patients with chronic lymphocytic leukemia expressing high versus low ZAP70 mRNA.
Sex, Age
View SamplesReporter genes integrated into the genome are a powerful tool to reveal effects of regulatory elements and local chromatin context on gene expression. However, so far such reporter assays have been of low throughput. Here we describe a multiplexing approach for the parallel monitoring of transcriptional activity of thousands of randomly integrated reporters. More than 27,000 distinct reporter integrations in mouse embryonic stem cells, obtained with two different promoters, show ~1,000-fold variation in expression levels. Data analysis indicates that lamina-associated domains act as attenuators of transcription, likely by reducing access of transcription factors to binding sites. Furthermore, chromatin compaction is predictive of reporter activity. We also found evidence for cross-talk between neighboring genes, and estimate that enhancers can influence gene expression on average over ~20 kb. The multiplexed reporter assay is highly flexible in design and can be modified to query a wide range of aspects of gene regulation. Overall design: mRNA profiles of 11 mouse embryonic cell lines each harboring multiple barcoded reporter constructs with mouse PGK promoter integrated at random positions in the genome, single replicate.
Chromatin position effects assayed by thousands of reporters integrated in parallel.
Specimen part, Cell line, Subject
View SamplesInteractions between Chronic Lymphocytic Leukemia B-cells (CLL B-cells) and the microenvironment (ME) play a major function in the physiopathology of CLL. Extracellular vesicles (EVs) (composed of exosomes and microparticles) have been shown to play an important role in cell communication. EVs, purified by ultracentrifugation from bone marrow mesenchymal stromal cells (BM-MSC) culture, were added to CLL B-cells. Microarray study highlighted 805 differentially expressed genes between CLL-B-cells cultured with and without EVs. Of these, CCL3/4, EGR1/2/3, MYC (involved in BCR pathway) were increased while pro-apoptotic genes like HRK were decreased. We showed for the first time the potential of EVs alone to induce gene expression modifications in CLL B-cell, notably in BCR and apoptosis pathways. We concluded that a substantial part of communication between CLL B-cells and BM-ME is mediated through EV.
Extracellular vesicles of bone marrow stromal cells rescue chronic lymphocytic leukemia B cells from apoptosis, enhance their migration and induce gene expression modifications.
Specimen part, Subject
View SamplesTyrosine phosphorylation is a hallmark for activation of Signal Transducer and Activator of Transcription (STAT) proteins, but their transcriptional activity also depends on other secondary modifications. Type I interferons (IFNs) can activate both the ISGF3 (STAT1:STAT2:IRF9) complex and STAT3, but with cell-specific, selective triggering of only the ISGF3 transcriptional program. Following a genome-wide RNAi screen, we identified the Sin3a complex as an important mediator of this STAT3 transcriptional repression. Sin3a directly interacts with the DNA-binding domain of STAT3 and alters its acetylation status. SIN3A silencing enhances recruitment of STAT3 and enhanceosome components to the SOCS3 promoter, resulting in histone hyperacetylation and enhanced transcription. Conversely, Sin3a is required for ISGF3-dependent gene transcription and for an efficient IFN-mediated antiviral protection against Influenza A and hepatitis C viruses. The Sin3a complex therefore acts as a context-dependent STAT1/3 transcriptional switch.
The Sin3a repressor complex is a master regulator of STAT transcriptional activity.
Cell line, Treatment
View SamplesHuman skin-derived precursor cells (hSKP) are a stem cell population that represents key candidates for cell based-therapy. Inflammation, however, is often present in situations where cellular replacement therapy is required. These inflammatory conditions, and more specifically the presence of the cytokine interferon (IFN)-, might result in an increase of MHC class II antigens in hSKP-derived grafts and facilitate their rejection.
Human skin-derived precursor cells are poorly immunogenic and modulate the allogeneic immune response.
Sex, Age, Specimen part
View SamplesAnalysis of perirenal adipose tissue from healthy kidney donors (age 449 years, BMI 25.83.3 kg/m2, meanSD).
FTO Obesity Variant Circuitry and Adipocyte Browning in Humans.
Specimen part
View SamplesIslets are known to respond to changes in ambient glucose. To quantify the transcriptome-wide changes in ambient glucose, we compared transcriptome of islets exposed to low and high glucose. Overall design: Isolated islets from wild type male mice. Islets from adult males were pooled, cultured overnight in RPMI containing 11 mM glucose. The next day, all islets were starved in RPMI containing 2.8 mM glucose for 2 hours before stimulation with 2.8 mM glucose or 16.8 mM glucose for 12 hours. Islets were lysed in Trizol for RNA isolation and library construction.
The transcriptional landscape of mouse beta cells compared to human beta cells reveals notable species differences in long non-coding RNA and protein-coding gene expression.
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View SamplesRodent models are widely used to study diabetes. Yet, significant gaps remain in our understanding of mouse islet physiology. We generated comprehensive transcriptomes of mouse delta, beta and alpha cells using two separate triple transgenic mouse models generated for this purpose. This enables systematic comparison across thousands of genes between the three major endocrine cell types of the islets of Langerhans whose principal hormones control nutrient homeostasis. Overall design: FACS purified delta or alpha cells and beta cells from the same islets. Islets were isolated from triple transgenic offspring of a cross between mIns1-H2b-mCherry (Jax # 028589) and either Sst-Cre (delta) or Gcg-cre (alpha) cells and a floxed YFP allele to label delta or alpha cells, respectively. Islets from replicate groups of 10 to 12 triple transgenic animals for each group were pooled by sex to obtain sufficient material. Pooled islets were dissociated, sorted and collect in Trizol for RNA isolation and library construction.
Comprehensive alpha, beta and delta cell transcriptomes reveal that ghrelin selectively activates delta cells and promotes somatostatin release from pancreatic islets.
Sex, Specimen part, Subject
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