RNA-seq in MCF-7 cells which had been exposed to arsenic
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Illumina NovaSeq 6000
ORGANISM(S): Homo sapiens
SUBMITTER: Angela Mathison
PROVIDER: E-MTAB-9498 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Analysis of MCF-7 cells treated for 4h with Ethanol, Estradiol (E2), Dexamethasone (Dex), or Estradiol + Dexamethasone (E2 + Dex) In estrogen receptor (ER)-negative breast cancer (BC), high tumor glucocorticoid receptor (GR) expression has been associated with a relatively poor outcome. In contrast, using a meta-analysis of several genomic datasets, here we find that tumor GR mRNA expression is associated with improved ER+ relapse-free survival (RFS) (independently of progesterone receptor (PR) expression). To understand the mechanism by which GR expression is associated with a better ER+ BC outcome, the global effect of GR-mediated transcriptional activation in ER+ BC cells was studied. Analysis of GR chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) in ER+/GR+ MCF-7 cells revealed that upon co-activation of GR and ER, GR chromatin association became enriched at proximal promoter regions. Furthermore, following ER activation, increased association of GR was observed at ER, FOXO, and AP1 response elements. In addition, it was determined that ER associated with GR response elements, suggesting that ER and GR interact in a complex. Co-activation of GR and ER resulted in increased expression (relative to ER activation alone) of transcripts that encode proteins promoting cellular differentiation (e.g. KDM4B, VDR) and inhibiting Wnt-signaling (IGFBP4). Finally, expression of these individual pro-differentiation genes was associated with significantly improved RFS in ER+ BC patients. Together, these data demonstrate that the co-expression and subsequent activity of tumor cell GR and ER contribute to the less aggressive natural history of early-stage BC by coordinating the altered expression of genes favoring differentiation. Four treatment samples (Vehicle V, Dex D, E2, or Dex+E2). Three biological replicate experiments per sample. Vehicle sample is Ethanol control.
2016-04-01 | E-GEOD-79761 | biostudies-arrayexpress
Project description:Estrogens are steroid hormones that play critical roles in the initiation, development, and metastasis of breast and uterine cancers. The estrogen (E2) response in breast cancer cells is predominantly mediated by the estrogen receptor-alpha (ER alpha), a ligand-activated transcription factor. ER alpha regulates transcription of target genes through direct binding to its cognate recognition sites, known as estrogen response elements (EREs), or by modulating the activity of other DNA-bound transcription factors at alternative DNA sequences. The proto-oncogene c-myc is upregulated by ER¦à in response to E2 and encodes a transcription factor, c-MYC, which regulates a cascade of gene targets whose products mediate cellular transformation. This study aims at mapping the binding sites of these two transcription factors (ER alpha and c-MYC) in one ER alpha positive breast cancer cell line (MCF7 cell line). Keywords: ChIP-Chip Analysis This series contains ChIP-on-Chip data sets for two transcription factors (ER alpha and c-MYC) and control samples (INPUT). All the experiments are done in triplicates. MCF7 Cells were E2-deprived for 3 days and then were treated with 10 nM E2 (45 minutes and 2 hours for mapping ER alpha and c-MYC binding sites, respectively) at 80% confluence.
2010-05-26 | E-GEOD-10800 | biostudies-arrayexpress
Project description:Altered expression of microRNAs (miRNAs), an abundant class of small non-protein-coding RNAs that mostly function as negative regulators of protein-coding gene expression, is common in cancer. Here we analyze the regulation of miRNA expression in response to estrogen, a steroid hormone that is involved in the development and progression of breast carcinomas and that is acting via the estrogen receptors (ER) transcription factors. We set out to thoroughly describe miRNA expression, by using miRNA microarrays and real time RTPCR experiments, in various breast tumor cell lines in which estrogen signaling has been induced by 17β-estradiol (E2). We show that the expression of a broad set of miRNAs decreases following E2 treatment in an ER-dependent manner. We further show that enforced expression of several of the repressed miRNAs reduces E2-dependent cell growth, thus linking expression of specific miRNAs with estrogen-dependent cellular response. In addition, a transcriptome analysis revealed that the E2-repressed miR-26a and miR-181a regulate many genes associated with cell growth and proliferation, including the progesterone receptor gene, a key actor in estrogen signaling. Strikingly, miRNA expression is also regulated in breast cancers of women who had received antiestrogen neoadjuvant therapy thereby showing an estrogen-dependent in vivo regulation of miRNA expression. Overall, our data indicates that the extensive alterations in miRNA regulation upon estrogen signalling pathway plays a key role in estrogen-dependent functions and highlights the utility of considering miRNA expression in the understanding of antiestrogen resistance of breast cancer. 9 samples analyzed. Triplicates were done. MCF-7+miR26a+E2 (n=1 to 3) ; MCF7+miRctrl+E2 (n=1 to 3) ; MCF7+miRctrl+vehicle (n=1 to 3). We generated pairwise comparisons using EASANA from GenoSplice technology: MCF-7+miR26a+E2 versus MCF7+miRctrl+E2 and MCF-7+miRctrl+E2 versus MCF7+miRctrl+vehicle. Fold change ≥1.5 were selected.
2009-08-04 | E-GEOD-17460 | biostudies-arrayexpress
Project description:There is great medical need for estrogens having favorable pharmacological profiles, supporting desirable activities for menopausal women such as metabolic and vascular protection but lacking stimulatory activities on the breast or uterus. Here, we report the development of structurally novel estrogens with favorable target tissue-selective estrogenic activity. Through a process of structural alteration of the hormone estradiol that preserves essential chemical and physical features of estradiol but greatly moderates its binding affinity for the estrogen receptors (ERs), we obtained Pathway Preferential Estrogens (PaPEs) capable of having interaction with ER that is sufficient to activate the extranuclear-initiated signaling pathway preferentially over the direct nuclear-initiated pathway. PaPE modulate a pattern of gene regulation and cellular and biological processes that result in essentially no stimulation of reproductive and mammary tissues and breast cancer cells, but have a favorable pattern of activity on metabolic tissues and the vasculature. The structural permutation process represents a novel approach to govern the balance in utilization of extranuclear vs. nuclear pathways of ER action to obtain tissue-selective/non-nuclear pathway-preferential estrogens, which should prove to be beneficial for postmenopausal hormone replacement. The approach may also have broad applicability for other members of the nuclear hormone receptor superfamily. 24 samples; inhibitor and time course experiments
2016-07-20 | E-GEOD-73663 | biostudies-arrayexpress
Project description:The precise mechanisms by which hormone receptors bind to DNA in the context of chromatin remain unclear. Here we report that the genomic distributions of estrogen receptor (ER) and H3R26 deimination (H3R26Cit) in breast cancer cells are strikingly coincident, linearly correlated, and observed as early as 2 minutes following estradiol treatment. Paired-end MNase ChIP-seq indicates that the charge-neutral H3R26Cit modification facilitates ER binding to DNA by altering the fine structure of the nucleosome. Clinically, we find that PAD2 and H3R26Cit levels correlate with ER expression in breast tumors and that high PAD2 expression is associated with increased survival in ER+ breast cancer patients. Our study suggests that PAD2-mediated histone deimination is fundamental to ER signaling in breast cancer. We performed replicate H3R26Cit ChIP-seq experiments prior to estrogen treatment and 2min, 5min, 10min, 40min, and 160min after E2 treatment. Additionally, we performed H3R26Cit and H3K27ac ChIP on MNase digested chromatin.
2014-08-04 | E-GEOD-58177 | biostudies-arrayexpress
Project description:Estrogen receptor-{alpha} (ER{alpha}) and its ligand estradiol play critical roles in breast cancer growth and are important therapeutic targets for this disease. Using chromatin immunoprecipitation (ChIP)-on-chip, ligand-bound ER{alpha} was recently found to function as a master transcriptional regulator via binding to many cis-acting sites genome-wide. Here, we used an alternative technology (ChIP cloning) and identified 94 ER{alpha} target loci in breast cancer cells. The ER{alpha}-binding sites contained both classic estrogen response elements and nonclassic binding sequences, showed specific transcriptional activity in reporter gene assay, and interacted with the key transcriptional regulators, including RNA polymerase II and nuclear receptor coactivator-3. The great majority of the binding sites were located in either introns or far distant to coding regions of genes. Forty-three percent of the genes that lie within 50 kb to an ER{alpha}-binding site were regulated by estradiol. Most of these genes are novel estradiol targets encoding receptors, signaling messengers, and ion binders/transporters. mRNA profiling in estradiol-treated breast cancer cell lines and tissues revealed that these genes are highly ER{alpha} responsive both in vitro and in vivo. Among estradiol-induced genes, Wnt11 was found to increase cell survival by significantly reducing apoptosis in breast cancer cells. Taken together, we showed novel genomic binding sites of ER{alpha} that regulate a novel set of genes in response to estradiol in breast cancer. Our findings suggest that at least a subset of these genes, including Wnt11, may play important in vivo and in vitro biological roles in breast cancer. Experiment Overall Design: This Series currently contains the gene expression data accompanying Zhihong Lin et al. Cancer Research 67,5017-5024(2007). MCF7 cells were treated with vehicle or E2 at a concentration of 10E-9 mol/L for 3 and 6 h. All experiments were performed in triplicate.
2008-06-20 | E-GEOD-11506 | biostudies-arrayexpress
Project description:We performed microarray experiment on zebrafish exposed to estrogen (17β-estradiol; a classified carcinogen) and an anti-estrogen (ICI 182,780). Our transcriptome analysis captured multiple estrogen-responsive genes and signaling pathways that increased cell proliferation, promoted DNA damage and genome instability, and decreased tumor suppressing effects, suggesting a common mechanism for estrogen-induced carcinogenesis. Comparative analysis with human E2 responsive genes revealed a core set of conserved estrogen-responsive genes that demonstrate enrichment of ER binding sites and cell cycle signaling pathways. Knowledge-based and network analysis led us to propose that the mechanism involving estrogen-activated ER mediated down-regulation certain genes followed by up-regulation cell cycle-related genes is highly conserved. Our study provides first evidence of molecular conservation of estrogen-responsiveness between zebrafish and human cancer cell lines, hence demonstrating the potential of zebrafish for estrogen-related cancer research. 10 samples were analyzed in total. Three samples in control, 3 samples treated with estrogen and 3 samples treated with estrogen in combination with ICI.
2011-03-08 | E-GEOD-27707 | biostudies-arrayexpress
Project description:Estrogen receptor M-NM-1 (ER), a member of the nuclear hormone receptor superfamily, regulates transcriptional activity by ligand-dependent recruitment of cofactors which, in turn, locally alter chromatin structure. It is generally believed that co-factor activity at target promoters leads to a more open, transcriptionally permissive chromatin structure, however, these mechanisms remain to be fully established. Peptidylarginine deiminases (PADIs) catalyze the conversion of positively charged arginine and methylarginine residues to neutrally charged citrulline and this activity has been linked to the gene regulation. Here, we found that PADI2 citrullinate H3 Arginine 26 (H3R26) in vitro and, using a specific H3R26 citrulline (H3Cit26) antibody, we demonstrate that H3Cit26 occurs in vivo following 17M-NM-2-estradiol (E2) stimulation and this unique and pronounced global activation of H3Cit26 is ER-dependent. Using a mammalian-based promoter chromosomal array system, we observed that citrullination at H3R26 is robust and co-localizes with ER at decondensed chromatin loci. Additionally, this histone modification is specifically enriched at ER bound regions of target promoters, forming a permissive chromatin environment for gene transactivation. Interestingly, we have shown in a reciprocal way, that either depletion of PADI2 or inhibition of ER not only dramatically abolished E2-induced activation of H3Cit26 on gene promoters but also affect ER recruitment. Collectively, our results demonstrate that citrullination of H3R26 by PADI2 following estrogen stimulation plays a role in ER target gene activation, likely via decondensation of the local chromatin architecture. Two H3Cit26 ChIP-chip biological replicates under vehicle treatment and two H3Cit26 ChIP-chip biological replicates under E2 stimulation from MCF-7 human breast cancer cells are included.
2012-09-04 | E-GEOD-32599 | biostudies-arrayexpress
Project description:Estrogen signaling in breast cancer cells relies on long-range chromatin interactions connecting distal regulatory elements bound by the estrogen receptor 1 (ESR1) to target gene promoters. This ensures stimulus and subtype-specific transcriptional responses. Expanding on the function of CTCF and the cohesin complex in breast cancer, we demonstrate that the chromatin-looping factor ZNF143 binds the promoter of most early-response estrogen target genes connected to distal regulatory elements in ESR1-positive breast cancer cells. Its chromatin occupancy is unaffected by estrogen stimulation, supporting a stable three-dimensional genomic architecture within the early response to estrogen. Its loss abrogates the estrogen-induced transcriptional response and growth of breast cancer cells. When taking into account CTCF, ZNF143 and cohesin complex subunits, we show that chromatin-looping factors are genetically altered in over 20% of ESR1-positive primary breast tumors. Furthermore, the overexpression of ZNF143, CTCF and RAD21, a cohesin complex subunit, in ESR1-positive breast tumors associates with a worse clinical outcome. Overall, our results suggest that ZNF143 is a new critical effector of the estrogen response and highlights the contribution of the chromatin looping machinery to ESR1-positive breast cancer development. Examination of genome-wide ZNF143 binding in MCF-7 cells
2016-08-09 | E-GEOD-76454 | biostudies-arrayexpress
Project description:Estrogens are an important regulator of breast cancer disease progression, and they function by binding the estrogen receptor--alpha (ER-alpha) to regulate changes in gene expression. ER-alpha is able to both activate and inhibit gene transcription in a gene-specific manner and do so by binding target DNA sequences and recruiting coactivators and corepressors which can modulate the chromatin environment. Silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) is known to act as coactivator and corepressor of ER-alpha in a gene-specific manner. We used a microarray analysis to examine the gene expression changes that occur when the coregulator SMRT is depleted from the ER-alpha positive MCF-7 breast cancer cell line. We sought to determine the genes that are regulated by depletion of the coregulator SMRT using Affymetrix Human Gene 1.0 ST Array. To this end, we transfected MCF-7 cells with control siRNA or SMRT-targeting siRNA for 48 h and treated for an additional 4 or 24 h with vehicle (0.1% EtOH) or 1 nM estradiol (E2). A total of 24 samples were analyzed, separated into eight groups each with three experimental replicates in each group, siControl-Veh 4 h, siControl -E2 4 h, siSMRT-Veh 4 h, siSMRT-E2 4 h, siControl-Veh 24 h, siControl-E2 24 h, siSMRT-Veh 24 h, siSMRT-E2 24 h.
2014-06-21 | E-GEOD-57935 | biostudies-arrayexpress