Arsenic contamination of drinking water occurs globally and is associated with numerous diseases including skin, lung, and bladder cancers, and cardiovascular disease. The mechanisms behind arsenic's effects remain unclear, but recent research indicates that aresnic acts along sex-specific lines and may be an endocrine disruptor. The objective of this study was to evaluate the nature of gene expression chagnes among males and females exposed to arsenic contaminated water in Bangladesh at high and low dose exposures.The median wAs concentration for the low exposure group was 103 g/L for males and 117 g/L for females (range 50200 g/L). For the high exposure group, the median wAs concentration was 355 g /L for males (range 250-500 g /L) and 434 g/L for females (range 2321000 g /L). The PBMCs of males with high exposure compared to those with low exposure there were 534 differentially expressed genes (p <0.05); and for females with high exposure relative to low exposure there were 645 differentially expressed genes (p <0.05) in PBMCs of females.
Sex-specific patterns and deregulation of endocrine pathways in the gene expression profiles of Bangladeshi adults exposed to arsenic contaminated drinking water.
Sex, Specimen part
View SamplesThe histone variant macroH2A1 and the poly(ADP-ribose) polymerase PARP-1 both regulate gene transcription by modulating chromatin structure and function. Of the two macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, the former is often suppressed in cancer and has the unique ability to interact with poly(ADP-ribose). Using ChIP-seq in primary lung fibroblasts, we demonstrate that macroH2A1 is incorporated into either of two spatially and functionally distinct types of chromatin; the first is marked by H3 K27 trimethylation, while the second contains a set of nine histone acetylations. MacroH2A1-regulated genes are involved in cancer progression are specifically found in macroH2A1-containing acetylated chromatin. Through the recruitment of PARP-1, macroH2A1.1 promotes the acetylation of H2B K12 and K120 which plays a key role in the regulation of macroH2A1 target genes in primary cells. The macroH2A1/PARP-1 pathway regulating H2B K12 and K120 acetylation is disrupted in cancer cells, in part, explaining macroH2A1’s role in cancer suppression. Overall design: Three biological replicates of RNA-seq from cells expressing shRNA directed against macroH2A1 or luciferase as a control
MacroH2A1.1 and PARP-1 cooperate to regulate transcription by promoting CBP-mediated H2B acetylation.
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View SamplesAffymetrix expression arrays were used to compare expression patterns upon knockdown of PARP-1, PARG, SIRT1, or macroH2A in comparison to Luciferase control.
Global analysis of transcriptional regulation by poly(ADP-ribose) polymerase-1 and poly(ADP-ribose) glycohydrolase in MCF-7 human breast cancer cells.
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View SamplesPoly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG) are enzymes that modify target proteins in the nucleus by the addition and removal, respectively, of ADP-ribose polymers. Although a role for PARP-1 in gene regulation has been well established, the role of PARG is less clear. To investigate how PARP-1 and PARG coordinately regulate global patterns of gene expression, we used short hairpin RNAs (shRNAs) to stably knockdown PARP-1 or PARG in MCF-7 cells, followed by expression microarray analyses.
Global analysis of transcriptional regulation by poly(ADP-ribose) polymerase-1 and poly(ADP-ribose) glycohydrolase in MCF-7 human breast cancer cells.
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View SamplesIn mammals, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase 1 (NMNAT-1) constitute a nuclear NAD+ salvage pathway, regulating cellular functions of the NAD+-dependent deacetylase SIRT1. However, little is known about the molecular mechanisms by which NAD+ biosynthesis controls gene transcription in the nucleus. In this study, we show that stable knockdown of NAMPT or NMNAT-1 in MCF-7 breast cancer cells significantly reduced total cellular NAD+ levels. Expression microarray analyses demonstrate that both enzymes have broad and overlapping functions in gene regulation. SIRT1 is a key mediator of NAMPT- and NMNAT-1-dependent gene regulation, and is found at promoters of many of the target genes. Furthermore, SIRT1 deacetylase activity at these promoters is regulated by NAMPT and NMNAT-1. Most significantly, NMNAT-1 interacts with SIRT1 and is recruited to target gene promoters by SIRT1. Our results reveal an unexpected mechanism for the direct control of SIRT1 deacetylase activity at target gene promoters by NMNAT-1. Interactions between NMNAT-1 and SIRT1 at gene promoters may provide a platform for integration of multiple signaling pathways that regulate transcription.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
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View SamplesNMNAT1 is a nuclear enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NMNAT1 knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
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View SamplesSIRT1 is a nuclear NAD+-dependent protein deacetylase. Expression microarray analysis was used to study the effect of SIRT1 knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
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View SamplesNAMPT is an enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NAMPT knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
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View SamplesWe analyed the gene expression profiles after knocking down MYCN or TFAP4. Results showed that transcription factor MYCN and TFAP4 commonly regulats a subset of genes that may contribute to neuroblastoma cells proliferation and migration.
MYCN promotes neuroblastoma malignancy by establishing a regulatory circuit with transcription factor AP4.
Specimen part
View SamplesNonsense-mediated mRNA decay (NMD) surveillance pathways are best known to be involved in the degradation of mRNA with premature termination codons (PTCs). More recent studies demonstrate that the role of NMD pathways goes well beyond the degradation of PTC containing mRNA, into the regulation of cell function and thus normal development.
Transcriptome profiling of UPF3B/NMD-deficient lymphoblastoid cells from patients with various forms of intellectual disability.
Specimen part, Disease, Disease stage, Cell line, Subject
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