The ability of chromatin to switch back and forth from open euchromatin to closed heterochromatin is vital for transcriptional regulation and genomic stability, and subject to disruption by exposure to environmental agents such as hexavalent chromium. Cr(VI) exposure can cause chromosomal disruption through formation of Cr-DNA adducts, free radical-induced DNA damage, and DNA-Cr-protein and DNA-Cr-DNA cross-links, all of which may disrupt chromatin remodeling mechanisms responsible for maintenance or controlled modification of epigenetic homeostasis. In addition, dose-response analyses have shown that acute exposures to high-concentrations of Cr(VI) and chronic exposures to low-concentrations of the same agent lead to significantly different transcriptomic and genomic stability outcomes. To investigate how transcriptional responses to chromium exposure might correlate to structural changes in chromatin, we have used whole genome Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) analysis coupled with deep sequencing to identify regions of the genome that switch from open to closed chromatin or vice versa in response to exposure to varying Cr(VI) concentrations. We find that the switch affects gene expression levels in the target areas that vary depending on Cr(VI) concentration. At either Cr(VI) concentration, chromatin domains surrounding binding sites for AP-1 transcription factors become significantly open, treatment whereas BACH2 and CTCF binding sites are open solely at the low and high concentrations, respectively. Our results suggest that FAIRE may be a useful technique to map chromatin elements targeted by DNA damaging agents for which there is no prior knowledge of their specificity, and to identify subsequent transcriptomic changes induced by those agents. Overall design: Cr25 treatment and control samples are in duplicate for RNA-seq, and no replicate for FAIRE-seq. Cr0.5 treatment and control samples are in duplicate for RNA-seq, and no replicate for FAIRE-seq.
Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) analysis uncovers broad changes in chromatin structure resulting from hexavalent chromium exposure.
No sample metadata fields
View SamplesAffymetrix Human Genome U133A platform was used to obtain gene expression profiles of 28 pathologically and clinically well characterized adenocarcinomas of the lung. In addition, EGFR status was determined by fluorescent in situ hybridization and immunohistochemistry.
Gene expression profiles of lung adenocarcinoma linked to histopathological grading and survival but not to EGF-R status: a microarray study.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
EZH2 inhibition in multiple myeloma downregulates myeloma associated oncogenes and upregulates microRNAs with potential tumor suppressor functions.
Cell line
View SamplesMultiple Myeloma (MM) is a plasma cell tumor localized to the bone marrow (BM). Despite current progress in improving patient outcome, MM remains largely incurable. Disease clonal and interpatient heterogeneity has hampered identification of a common underlying mechanism for disease establishment and have slowed the development of novel targeted therapies. Epigenetic aberrations are now emerging as increasingly important in tumorigenesis, thus selective targeting of crucial epigenetic enzymes may provide new therapeutic potential in cancer including MM. Recently, we and others suggested the histone methyltransferase enhancer of zeste homolog 2 (EZH2), to be a potential therapeutic target in MM. Now we show that pharmacological inhibition of EZH2 suppresses the MM cell growth through downregulation of MM-associated oncogenes; IRF-4, XBP-1, PRDM1/BLIMP-1and c-MYC. We also show that downregulation of these genes is mediated via reactivated expression of microRNAs with tumor suppressor functions; primarily miR125a-3p and miR320c. Using chromatin immunoprecipitation (ChIP) we demonstrate that miR125a-3p and miR320c are targets of EZH2 and H3K27me3 in MM cell lines and primary MM cells. Our results further highlight the importance of polycomb-mediated silencing in MM to include microRNAs with tumor suppressor activity. This novel role further strengthens the oncogenic features of EZH2 and its potential as a therapeutic target in MM.
EZH2 inhibition in multiple myeloma downregulates myeloma associated oncogenes and upregulates microRNAs with potential tumor suppressor functions.
Cell line
View SamplesBackground:
Loss of Ezh2 promotes a midbrain-to-forebrain identity switch by direct gene derepression and Wnt-dependent regulation.
Specimen part
View SamplesMechanisms controlling the proliferative activity of neural stem/progenitor cells (NSPCs) play a pivotal role to ensure life-long neurogenesis in the mammalian brain. How metabolic programs are coupled with NSPC activity remains unknown. Here we show that fatty acid synthase (FASN), the key enzyme of de novo lipogenesis, is highly active in adult NSPCs and that conditional deletion of FASN in NSPCs impairs adult neurogenesis. The rate of de novo lipid synthesis and subsequent proliferation of NSPCs is regulated by Spot14, a gene we found to be selectively expressed in low proliferating adult NSPCs. Spot14 reduces the availability of malonyl-CoA, which is an essential substrate for FASN to fuel lipogenesis. Thus, we here identified a functional coupling between the regulation of lipid metabolism and adult NSPC proliferation.
Metabolic control of adult neural stem cell activity by Fasn-dependent lipogenesis.
Specimen part
View SamplesThe meningeal space is occupied by a diverse repertoire of innate and adaptive immune cells. CNS injury elicits a rapid immune response that affects neuronal survival and recovery, but the role of meningeal inflammation in CNS injury remains poorly understood. Here we describe group 2 innate lymphoid cells (ILC2s) as a novel cell type resident in the healthy meninges that is activated following CNS injury. ILC2s are present throughout the naïve mouse meninges, though are concentrated around the dural sinuses, and have a unique transcriptional profile relative to lung ILC2s. After spinal cord injury, meningeal ILC2s are activated in an IL-33 dependent manner, producing type 2 cytokines. Using RNAseq, we characterized the gene programs that underlie the ILC2 activation state. Finally, addition of wild type lung-derived ILC2s into the meningeal space of IL-33R-/- animals improves recovery following spinal cord injury. These data characterize ILC2s as a novel meningeal cell type that responds to and functionally affects outcome after spinal cord injury, and could lead to new therapeutic insights for CNS injury or other neuroinflammatory conditions. Overall design: ILC2s were isolated from 10 week C57/Bl6 mice with and without spinal cord injury (1 day post injury). 5 mice were pooled per group, with meninges dissected, digested, and FACs sorted (CD45+/DAPI-/Lin–/St2+/Thy1+) directly into RNA lysis buffer.
Characterization of meningeal type 2 innate lymphocytes and their response to CNS injury.
Age, Specimen part, Cell line, Subject
View SamplesBackground: Genes upregulated by low oxygen have been suggested as endogenous markers for tumor hypoxia. Yet, most of the genes investigated have shown inconsistent results, which have led to concerns about their ability to be true hypoxia markers. Previous studies have demonstrated that expression of hypoxia induced genes can be affected by extracellular pH (pH e ). Methods: Five different human cell lines (SiHa, FaDu DD, UTSCC5, UTSCC14 and UTSCC15) were exposed to different oxygen concentrations and pH (7.5 or 6.3), and gene expression analyzed with microarray (Affymetrix - Human Genome U133 Plus 2.0 Array). Results: An analysis of two of the cell lines using SAM identified 461 probesets that were able to separate the four groups Normal oxygen, normal pH , Low oxygen, normal pH , Normal oxygen, low pH and Low oxygen, low pH . From here it was possible to identify a fraction of probesets induced at low oxygen independent of pH in these two cell lines, this fraction included HIG2, NDRG1, PAI1 and RORA. Further verifi cation by qPCR highlighted the necessity of using more cell lines to obtain a robust gene expression profi les. To specifi cally select pH independent hypoxia regulated genes across more cell lines, data for FaDu DD, UTSCC5, UTSCC14 and UTSCC15 were analyzed to identify genes that were induced by hypoxia in each cell line, where the induction was not affected by low pH, and where the gene was not signifi cantly induced by low pH alone. Each cell line had 65 122 probesets meeting these criteria. For genes to be considered as target genes (hypoxia inducible pH independent), genes had to be present in three of four cell lines. Conclusion: The result is a robust hypoxia profile unaffected by pH across cell lines consisting of 27 genes. This study demonstrates a way to identify hypoxia markers by microarray, where other factors in the tumor microenvironment are taken into account.
Identifying pH independent hypoxia induced genes in human squamous cell carcinomas in vitro.
Cell line
View SamplesAnalysis of gene expression profile in peritoneal macrophage extracted from LPS or PBS challenged DUSP3-/- and WT mice. DUSP3 deletion protects mice from sepsis and endotoxemia. We performed a microarray analysis to get insights into the differentially regulated pathways between WT and KO under inflammatory conditions.
DUSP3 Genetic Deletion Confers M2-like Macrophage-Dependent Tolerance to Septic Shock.
Sex, Age, Specimen part
View SamplesWe examined the effect of ablation of Tet2, an epigenetic regulator of gene transcription, in the global programme of gene expression at baseline, without pro-inflammatory activation, in macrophages.
Clonal hematopoiesis associated with TET2 deficiency accelerates atherosclerosis development in mice.
No sample metadata fields
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