This SuperSeries is composed of the SubSeries listed below.
Cell-type-specific control of enhancer activity by H3K9 trimethylation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Role of cell-type specific nucleosome positioning in inducible activation of mammalian promoters.
Specimen part, Treatment
View SamplesIn fibroblasts, p65-dependent genes can be sub-divided, depending on whether they are Trap-80-dependent or -independent. To examine the generality of this grouping, we performed a microarray analysis of wild-type and Trap-80 knock-down fibroblasts, before and after stimulation of NF-kappaB activity using TNF-alpha.
Two modes of transcriptional activation at native promoters by NF-kappaB p65.
No sample metadata fields
View SamplesIn dendritic cells, expression of the H3K9me3 demethylase JmjD2d is upregulated by LPS stimulation. To identify genes whose induction by LPS depends on JmjD2d activity, we performed a microarray analysis of wild-type and JmjD2d-knockdown dendritic cells, before and after stimulation with LPS.
Cell-type-specific control of enhancer activity by H3K9 trimethylation.
No sample metadata fields
View SamplesWe used microarrays to asses gene expression in 3T3 fibroblasts, after knock-down of Brg1 and Brm using stable shRNA interference. Cells were treated with 5ng/ml mouse TNF-alpha to stimulate inducible gene activation.
Role of cell-type specific nucleosome positioning in inducible activation of mammalian promoters.
No sample metadata fields
View SamplesAbstract of publicaton: CD4/CD8 double-positive (DP) thymocytes express the transcriptional repressor Histone Deacetylase 7 (HDAC7), a class IIa HDAC that is exported from the cell nucleus after T cell receptor (TCR) engagement. Through signal-dependent nuclear export, class IIa HDACs such as HDAC7 mediate signal-dependent changes in gene expression that are important to developmental fate decisions in multiple tissues. We report that HDAC7 is exported from the cell nucleus during positive selection in thymocytes, and regulates genes mediating the coupling between TCR engagement and downstream events that determine cell survival. Thymocytes lacking HDAC7 are inefficiently positively selected due to a severely shortened lifespan and exhibit a truncated repertoire of TCR Jalpha segments. The expression of multiple important mediators and modulators of the response to TCR engagement is altered in HDAC7-deficient thymocytes, resulting in increased tonic MAP kinase activity that contributes to the observed loss of viability. Remarkably, the activity of Protein Kinase D, the kinase that mediates nuclear export of HDAC7 in response to TCR signaling, is also increased in HDAC7-deficient thymocytes, suggesting that HDAC7 nuclear export governs a self-sustaining auto-excitatory loop. These experiments add to the understanding of the life/death decision in thymic T cell development, define a novel function for class IIa HDACs, and point to a novel feed-forward mechanism whereby these molecules regulate their own state and mediate stable developmental transitions. Title of manuscript: Nuclear Export of Histone Deacetylase 7 During Thymic Selection Mediates Immune Self-tolerance. abstract of manuscript: Histone Deacetylase 7 (HDAC7) is a TCR signal-dependent regulator of differentiation that is highly expressed in CD4/CD8 double-positive (DP) thymocytes. Here we examine the effect of blocking TCR-dependent nuclear export of HDAC7 during thymic selection, through expression of a signal-resistant mutant of HDAC7 (HDAC7-?P) in thymocytes. We find that HDAC7-?P Transgenic thymocytes exhibit a profound block in negative thymic selection, but can still undergo positive selection, resulting in the escape of autoreactive T cells into the periphery. Gene expression profiling reveals a comprehensive suppression of the negative selection-associated gene expression program in DP thymocytes, associated with a defect in the activation of MAP kinase pathways by TCR signals. The consequence of this block in vivo is a lethal autoimmune syndrome involving the exocrine pancreas and other abdominal organs. These experiments establish a novel molecular model of autoimmunity and cast new light on the relationship between thymic selection and immune self-tolerance. Goal of Microarray experiment: We did these experiments to determine how alteration of the function of HDAC7, a site-specific and signal-dependent repressor of transcription, changes gene expression in CD4/CD8 DP thymocytes.
Histone deacetylase 7 regulates cell survival and TCR signaling in CD4/CD8 double-positive thymocytes.
Specimen part, Treatment
View SamplesWe used DNA microarray technology to assess changes in gene expression after treatment of 11 lymphoma cell lines with epigenetic drugs. We identified genes with upregulated expression in treated cell lines and with downregulated expression in B-cell lymphoma patient samples when compared to normal B cells.
Identification of highly methylated genes across various types of B-cell non-hodgkin lymphoma.
Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Enhanced stability of microRNA expression facilitates classification of FFPE tumour samples exhibiting near total mRNA degradation.
Specimen part, Cell line
View SamplesSamples were taken from colorectal cancers in surgically resected specimens in 290 colorectal cancer patients. The expression profiles were determined using Affymetrix Human Genome U133Plus 2.0 arrays. The training set of our prognosis classifier included the stage A and D samples. Validation used our stage B and C samples.
Metastasis-Associated Gene Expression Changes Predict Poor Outcomes in Patients with Dukes Stage B and C Colorectal Cancer.
No sample metadata fields
View SamplesThe analysis of several mammalian genomes has revealed between 20,000 to 30,000 genes in each genome, a number that may seem hard to reconcile with the large number of cell types and complex functions of these organisms. The solution to this paradox partly lies in the large array of transcripts that each gene can potentially generate through usage of alternative promoters and the variable levels of transcripts that each gene produces in different tissues and cell types. Thus, in order to understand the mechanisms that control diverse patterns of gene expression in mammals, it is necessary to accurately define the active promoters and monitor their cell or tissue-dependent activity. Previous high throughput strategies for assaying tissue-specific gene expression have primarily relied on measurements of steady-state transcript levels by microarrays or tag sequencing. Here, we employ a new experimental strategy to identify and characterize tissue specific promoters by integrating genome-wide maps of RNA polymerase II (Pol II) binding, chromatin modifications and gene expression profiles. We applied this strategy to mouse embryonic stem cells (mES), and adult brain, heart, kidney, and liver. Our results delineated 24,363 Pol II binding sites throughout the genome, 91% of which correspond to 5 end annotation based on known transcripts and cap-analysis of gene expression (CAGE) and can be regarded as promoters. A majority of these experimentally defined promoters are active in all tissues, while only 4,396 can be characterized as tissue-specific using a quantitative measure of Pol II occupancy. In general, Pol II occupancy at these tissue specific promoters is correlated with the presence of active histone modification marks. However, a set of mES- specific promoters display persistent levels of H3K4me3 in non-ES tissues despite undetectable Pol II binding and transcript. Broadly, our results expand the knowledge of tissue-specific mammalian genes and provide a resource for understanding the transcriptional programs in mammalian development and differentiation.
Genome-wide mapping and analysis of active promoters in mouse embryonic stem cells and adult organs.
No sample metadata fields
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