Co-regulated gene expression by estrogen receptor-a and liver receptor homolog-1 is a feature of the estrogen response in breast cancer cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE49390 | GEO | 2013/08/01
SECONDARY ACCESSION(S): PRJNA213858
REPOSITORIES: GEO
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Project description:Our findings establish a key role for LRH-1 in the regulation of ERa target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERa at estrogen response elements controls the expression of estrogen responsive g Examination of ERα, with or without LRH-1 knockdown, and HA-LRH-1 in MCF-7 cells
2013-08-01 | E-GEOD-49390 | biostudies-arrayexpress
Project description:Estrogen receptor α (ERα) is a nuclear receptor that is the driving transcription factor expressed in the majority of breast cancers. Recent studies have demonstrated that the liver receptor homolog-1 (LRH-1), another nuclear receptor, is ERα-regulated in breast cancer cells. Further, LRH-1 stimulates proliferation and promotes motility and invasion of breast cancer cells. To determine the mechanisms of LRH-1 action in breast cancer cells, we carried out gene expression microarray analysis following siRNA-mediated LRH-1 knockdown. Interestingly, gene ontology (GO) category enrichment analysis of the genes differentially regulated in the presence or absence of LRH-1 identified estrogen responsive genes as the most highly enriched GO categories. To further define LRH-1 target genes, we performed chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) to identify genomic targets of LRH-1. Remarkably, ChIP-seq showed LRH-1 binding at many ERα binding sites. Analysis of select binding sites confirmed regulation of ERα-regulated genes by LRH-1 through binding to estrogen response elements, as exemplified by the TFF1/pS2 gene. Finally, LRH-1 over-expression stimulated ERα recruitment, whilst LRH-1 knockdown reduced ERα recruitment to ERα binding sites. Taken together, our findings establish a key role for LRH-1 in the regulation of ERα target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERα at estrogen response elements controls the expression of estrogen-responsive genes.
2013-09-01 | GSE47803 | GEO
Project description:Estrogen receptor M-NM-1 (ERM-NM-1) is a nuclear receptor that is the driving transcription factor expressed in the majority of breast cancers. Recent studies have demonstrated that the liver receptor homolog-1 (LRH-1), another nuclear receptor, is ERM-NM-1-regulated in breast cancer cells. Further, LRH-1 stimulates proliferation and promotes motility and invasion of breast cancer cells. To determine the mechanisms of LRH-1 action in breast cancer cells, we carried out gene expression microarray analysis following siRNA-mediated LRH-1 knockdown. Interestingly, gene ontology (GO) category enrichment analysis of the genes differentially regulated in the presence or absence of LRH-1 identified estrogen responsive genes as the most highly enriched GO categories. To further define LRH-1 target genes, we performed chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) to identify genomic targets of LRH-1. Remarkably, ChIP-seq showed LRH-1 binding at many ERM-NM-1 binding sites. Analysis of select binding sites confirmed regulation of ERM-NM-1-regulated genes by LRH-1 through binding to estrogen response elements, as exemplified by the TFF1/pS2 gene. Finally, LRH-1 over-expression stimulated ERM-NM-1 recruitment, whilst LRH-1 knockdown reduced ERM-NM-1 recruitment to ERM-NM-1 binding sites. Taken together, our findings establish a key role for LRH-1 in the regulation of ERM-NM-1 target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERM-NM-1 at estrogen response elements controls the expression of estrogen-responsive genes. MCF-7 cells were transfected with LRH-1 siRNA #2, #3, or with a non-targeting siRNA (siControl) for 72 hours. Following assessment of RNA integrity, four biological replicates for each siRNA treatment were used for microarray analysis.
2013-09-01 | E-GEOD-47803 | biostudies-arrayexpress
Project description:Estrogen clearly prevents osteoporotic bone loss by attenuating bone resorption. The molecular basis of how this is accomplished, however, remains elusive. Here we report a critical role of osteoclastic ERa in mediating estrogen action on bone in females. We selectively ablated ERa in differentiated osteoclasts (ERa dOc/dOc). ERa dOc/dOc females, but not males, exhibited clear trabecular bone loss, similar to the osteoporotic bone phenotype in post-menopausal women. Recovery of bone loss by estrogen treatment of the ovariectomized ERa dOc/dOc females was ineffective in the trabecular areas of the long bones and lumbar vertebral bodies. Osteoclastic apoptosis, induced by estrogen, occurred simultaneously with up-regulation of Fas ligand (FasL) expression in intact trabecular bones of ERa +/+mice, but not in ERa dOc/dOc mice. ERa was also required for similar effects of estrogen and tamoxifen in cultured osteoclasts. These findings suggest that the osteoprotective actions of estrogen and SERMS are mediated at least in part through osteoclastic ERa in trabecular bone; and the life span of mature osteoclasts is regulated through activation of the Fas/FasL system. Keywords: Study about estrogen response of osteoclast-specific estrogen receptor alpha mice
2007-06-01 | GSE7798 | GEO
Project description: Not available
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Project description:Estrogen receptor alpha (ERa) has generally been thought to be transcriptionally inactive until it binds estrogen. Here we show that unliganded ERa, far from being transcriptionally inert, regulates a large number of genes both in vascular endothelial cells (ECs) and in mouse aorta. The genes regulated by unliganded ERa in the aorta (largely composed of smooth muscle cells) differ from those in ECs, and aorta- and EC-regulated promoters show enrichment in binding sites for distinct sets of transcription factors. In vitro, the presence of unliganded ERa decreases the migration and proliferation of ECs, and also increases proliferation of SMCs. Consistent with these effects on individual cells in vitro, mice lacking ERa, in the absence of estrogen, show significantly less SMC proliferation and medial thickening after carotid artery wire injury than ER intact mice. The effects of unliganded ERa on vascular gene expression, cell function in vitro and vascular injury responses in vivo are all reversed by the addition of estrogen. Taken together, these results indicate that unliganded ERa regulates vascular gene expression, vascular cell function, and vascular injury responses, and that the cardiovascular protective effects of estrogen may largely be due to the reversal of these effects of unliganded ERa. These results have important implications for the vascular health of men and post-menopausal women with vascular ERa and low circulating levels of estrogen. This study also raises the possibility that the steroid receptor family could have substantial hormone-independent functions in the vasculature and in other tissues.
2016-11-22 | GSE51535 | GEO
Project description:Identification of Estrogen Receptor alpha (ERa) binding sites by ChIP-seq in MCF-7 breast cancer cells following an estrogen treatment. This study describes molecular effects of estradiol treatment and subsequent regulation by ER for a single gene/locus. A public ER chipseq (available in SRA as ERR011973), in addition to our own data, guided us to regulatory regions were ER was binding that were then analyzed in detail using "manual" ChIP. MCF-7 cells were treated for 1 h either 10 nm estradiol (E2) or vehicle (ethanol) and subjected to ChIP using antibodies against ERa or IgG.
2012-12-17 | E-GEOD-34759 | biostudies-arrayexpress
Project description:The estrogen receptor a (ERa) is a ligand-regulated transcription factor. However, a wide variety of other extracellular signals can activate ERa in the absence of estrogen. The impact of these alternate modes of activation on gene expression profiles has not been characterized. We show that estrogen, growth factors and cAMP elicit surprisingly distinct ERa-dependent transcriptional responses in human MCF7 breast cancer cells. In response to growth factors and cAMP, ERa primarily activates and represses genes, respectively. The combined treatments with the antiestrogen tamoxifen and cAMP or growth factors regulate yet other sets of genes. In many cases, tamoxifen is perverted to an agonist, potentially mimicking what is happening in certain tamoxifen-resistant breast tumors and emphasizing the importance of the cellular signaling environment. Using a computational analysis, we predicted that a Hox protein might be involved in mediating such combinatorial effects, and then confirmed it experimentally. Although both tamoxifen and cAMP block the proliferation of MCF7 cells, their combined application stimulates it, and this can be blocked with a dominant-negative Hox mutant. Thus, the activating signal dictates both target gene selection and regulation by ERa, and this has consequences on global gene expression patterns that may be relevant to understanding the progression of ERa-dependent carcinomas. Keywords: treatment response
2008-05-22 | GSE10466 | GEO
Project description:The estrogen receptor a (ERa) is a ligand-regulated transcription factor. However, a wide variety of other extracellular signals can activate ERa in the absence of estrogen. The impact of these alternate modes of activation on gene expression profiles has not been characterized. We show that estrogen, growth factors and cAMP elicit surprisingly distinct ERa-dependent transcriptional responses in human MCF7 breast cancer cells. In response to growth factors and cAMP, ERa primarily activates and represses genes, respectively. The combined treatments with the antiestrogen tamoxifen and cAMP or growth factors regulate yet other sets of genes. In many cases, tamoxifen is perverted to an agonist, potentially mimicking what is happening in certain tamoxifen-resistant breast tumors and emphasizing the importance of the cellular signaling environment. Using a computational analysis, we predicted that a Hox protein might be involved in mediating such combinatorial effects, and then confirmed it experimentally. Although both tamoxifen and cAMP block the proliferation of MCF7 cells, their combined application stimulates it, and this can be blocked with a dominant-negative Hox mutant. Thus, the activating signal dictates both target gene selection and regulation by ERa, and this has consequences on global gene expression patterns that may be relevant to understanding the progression of ERa-dependent carcinomas. Keywords: treatment response 10 treatment conditions (3 biological replicates for each, totalling 30 individual samples), of which 3 were untreated controls. Each replicate was hybridized to a separate chip, totalling 27 cDNA slides representing 9 unique conditions.
2008-05-22 | E-GEOD-10466 | biostudies-arrayexpress
Project description:Assess the full impact of estrogen receptor beta on transcription by a full transcriptome analysis of ERa and ERb-mediated gene regulation in T47D breast cancer cell line with TET-OFF regulated ERb expression.
2007-12-17 | E-MEXP-969 | biostudies-arrayexpress