Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Genome-wide activity of unliganded Estrogen Receptor alpha in breast cancer cells [ChIP-Seq]

ABSTRACT: Estrogen Receptor α (ERα) has central role in hormone-dependent breast cancer and its ligand-induced functions have been extensively characterized. However, evidence exists that ERα has functions which are independent of ligands. In the present work, we investigated the binding of ERα to chromatin in absence of ligands, and its function(s) on gene regulation. We demonstrated that in MCF7 breast cancer cells unliganded ERα binds to more than four thousands chromatin sites. Unexpectedly, although almost entirely comprised in the larger group of estrogen-induced binding sites, we found that unliganded-ERα binding is specifically linked to genes with developmental functions, as compared to estrogen-induced binding. Moreover, we found that siRNA-mediated downregulation of ERα in absence of estrogen is accompanied by changes in the expression levels of hundreds of coding and noncoding RNAs. Downregulated mRNAs showed enrichment in genes related to epithelial cell growth and development. Stable ERα downregulation using shRNA, which caused cell-growth arrest, was accompanied by increased H3K27me3 at ERα binding sites. Finally, we found that FOXA1 and AP2γ binding to several sites is decreased upon ERα silencing, suggesting that unliganded ERα participates, together with other factors, to the maintenance of the luminal-specific cistrome in breast cancer cells.

ORGANISM(S): Homo sapiens

PROVIDER: GSE53531 | GEO | 2014/03/03

SECONDARY ACCESSION(S): PRJNA232304

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Genome-wide activity of unliganded Estrogen Receptor alpha in breast cancer cells [RNA-Seq]

Project description:ERα is essential for the anti-proliferative response of breast cancer cells not only to estrogen antagonists, but also to estrogen withdrawal by means of aromatase inhibitors. We explored here one of the simplest explanation for this, consisting in the possibility that ERα may have a wide genomic function in absence of ligands. The genomic binding of ERα in the complete absence of estrogen was then studied using hormone-dependent MCF7 cells, by chromatin immunoprecipitation sequencing. From these data, 4.2K highly significant binding events were identified, which were further confirmed by comparing binding events in cells expressing ERα to cells silenced for ERα. Apo-ERα binding sites were distributed close to genes with functions associated to cell growth and epithelial maintenance and show significant overlap with binding of other transcription factors important for luminal epithelial breast cancer. Interestingly, we found that upon ERα silencing cognate gene transcription in absence of estrogen is downregulated and this is accompanied by increased H27Kme3 at ERα binding sites. RNA-Seq experiments showed that unliganded ERα controls basal transcription widely, including both coding and noncoding transcripts. Genes affected by ERα silencing can be easily functionally related to mammary epithelium differentiation and maintenance, especially when considering downregulated genes. Additional functions related to inflammatory and immune response was observed. Our data unravel unexpected actions of ERα in breast cancer cells and provide a novel framework to understand success and failure of hormone therapy in breast cancer. Examination of unligandend estrogen receptor alpha (aERα) DNA interactions in control and aERα siRNA treated MCF7 cells.

2014-03-03 | E-GEOD-53532 | biostudies-arrayexpress

Genome-wide activity of unliganded Estrogen Receptor alpha in breast cancer cells [ChIP-Seq]

Project description:Estrogen Receptor ? (ER?) has central role in hormone-dependent breast cancer and its ligand-induced functions have been extensively characterized. However, evidence exists that ER? has functions which are independent of ligands. In the present work, we investigated the binding of ER? to chromatin in absence of ligands, and its function(s) on gene regulation. We demonstrated that in MCF7 breast cancer cells unliganded ER? binds to more than four thousands chromatin sites. Unexpectedly, although almost entirely comprised in the larger group of estrogen-induced binding sites, we found that unliganded-ER? binding is specifically linked to genes with developmental functions, as compared to estrogen-induced binding. Moreover, we found that siRNA-mediated downregulation of ER? in absence of estrogen is accompanied by changes in the expression levels of hundreds of coding and noncoding RNAs. Downregulated mRNAs showed enrichment in genes related to epithelial cell growth and development. Stable ER? downregulation using shRNA, which caused cell-growth arrest, was accompanied by increased H3K27me3 at ER? binding sites. Finally, we found that FOXA1 and AP2? binding to several sites is decreased upon ER? silencing, suggesting that unliganded ER? participates, together with other factors, to the maintenance of the luminal-specific cistrome in breast cancer cells. Examination of unligandend estrogen receptor alpha (apoER?) DNA interactions in control and ER? siRNA treated MCF7 cells.

2014-03-03 | E-GEOD-53531 | biostudies-arrayexpress

Genome-wide activity of unliganded Estrogen Receptor alpha in breast cancer cells [RNA-Seq]

2014-03-03 | GSE53532 | GEO

Identification of cytoplasmic proteins interacting with unliganded estrogen receptor α and β- in human breast cancer cells

Project description:Estrogen Receptor subtypes (ERα and ERβ) are transcription factors sharing similar structure, however, they often perform opposite roles in breast cancer’s cell proliferation and tumor progression. Besides the well-characterized genomic actions of ERs upon ligand binding, rapid non-genomic cytoplasmic changes together with the recently discovered ligand-free action of ERs are emerging as key regulators of tumorigenesis. The identification of cytoplasmic interaction partners of unliganded ERα and ERβ may help characterize the molecular basis of the extra-nuclear mechanism of action of these receptors, revealing novel mechanisms to explain their role in breast cancer response or resistance to endocrine therapy. To this aim, in this study, cytoplasmic extracts from stably expressing TAP-ERα and -ERβ MCF-7 cell clones were subjected to interaction proteomics in the absence of estrogen stimulation, leading to the identification of 84 and 142 proteins associated with unliganded ERα and ERβ, respectively. Functional analyses of ER subtype-specific interactomes revealed significant differences in the molecular pathways associated to each receptor in the cytoplasm. This work reports the first identification of the unliganded ERα and ERβ cytoplasmic interactomes in breast cancer cells, providing novel experimental evidence on the non-genomic effects of ERs in the absence of hormonal stimulus.

2015-03-11 | PXD001202 | Pride

Unliganded estrogen receptor alpha regulates vascular cell function and gene expression

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

Nuclear Estrogen Receptor alpha (ERα) interactome following estrogen and antiestrogen treatment.

Project description:The Estrogen Receptor alpha (ERα) controls key cellular functions in hormone responsive breast cancer by assembling in large functional multiprotein complexes. ERα ligands are classified as agonists and antagonist, according to the response they elicit, thus the molecular characterization of the of ERα nuclear iteractome composition following estrogen and antiestrogen stimulation whose is needed to understand their effects on estrogen target tissues, in particular breast cancer. To this aim interaction proteomics coupled to mass spectrometry (MS) was applied to map the ERα nuclear interacting partners in MCF7 breast cancer cell nuclei following estrogen and antiestrogen stimuli.

2020-09-02 | PXD018709 | Pride

Unliganded Estrogen Receptor beta (ERβ) interactome before and after RNAse treatment in human breast cancer cells nuclei.

Project description:The Estrogen Receptor beta (ERβ), is a member of the nuclear receptor superfamily of trancriptional regulators, with oncosuppressive activities, antagonizing hormone-induced carcinogenesis and inhibiting growth and oncogenic functions in breast cancers (BCs). It is able to exert specific biological functions also in the absence of estrogen stimuli. Interaction proteomics coupled to mass spectrometry (MS) was applied to deeply characterize the nuclear interactors cooperating with unliganded ERβ and the role of RNA in mediating these iteractions.

2017-12-19 | PXD006720 | Pride

ERα and PolII ChIP seq from Mouse Uterus

Project description:To advance understanding of mechanisms leading to biological and transcriptional endpoints related to estrogen action in the mouse uterus, we have mapped ERα and RNA polymerase II binding sites using chromatin immunoprecipitation (ChIP) followed by sequencing of enriched chromatin fragments (ChIP-seq). In the absence of hormone, 5184 ERα binding sites were apparent in the vehicle treated ovariectomized uterine chromatin, while 17240 were seen one hour after estrogen (E2) treatment, indicating that some sites are occupied by unliganded ERα, and that ERα binding is increased by E2. Approximately 15% of the uterine ERα binding sites were adjacent to (<10 KB) annotated transcription start sites and many sites are found within genes or are found more than 100 KB distal from mapped genes; however, the density (sites per bp) of ERα binding sites is significantly greater adjacent to promoters. An increase in quantity of sites but no significant positional differences were seen between vehicle and E2 treated samples in the overall locations of ERα binding sites either distal from, adjacent to or within genes. Analysis of the PolII data revealed the presence of poised promoter proximal PolII on some highly upregulated genes. Additionally, co-recruitment of PolII and ERα to some distal enhancer regions was observed. A de novo motif analysis of sequences in the ERα bound chromatin confirmed that estrogen response elements (EREs) were significantly enriched. Interestingly, in areas of ERα binding without predicted ERE motifs, homeodomain transcription factor (Hox) binding motifs were significantly enriched. The integration of the ERα and PolII binding sites from our uterine ChIP-seq data with transcriptional responses revealed in our uterine microarrays has the potential to greatly enhance our understanding of mechanisms governing estrogen response in uterine and other estrogen target tissues.

2012-04-09 | GSE36455 | GEO

Co-regulated gene expression by estrogen receptor-α and liver receptor homolog-1 is a feature of the estrogen response in breast cancer cells

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

Expression microarray screen for genes regulated by the unliganded glucocorticoid receptor

Project description:To further characterize the role of the unliganded glucocorticoid receptor (GR) in breast cells, we used an shRNA vector directed against GR to create EPH-4 mouse mammary cell lines with depleted endogenous levels of this receptor. RNA prepared from normal (EV-50) and GR-depleted (shGR-19) cells was used in an expression microarray screen for targets of unliganded GR. This analysis revealed 260 targets of negaive regulation by unliganded GR, and 343 targets of positive regulation by unliganded GR, several of which were involved in pro-apoptotic networks, and opposed the activity of liganded GR targets. This work presents the first screen for targets of unliganded GR. We propose that the balance between liganded and unliganded GR signaling is responsible for controlling differentiation and apoptosis, respectively, and suggest that gene regulation by unliganded GR may represent a mechanism of reducing the risk of breast tumourigenesis.

2014-05-11 | GSE51408 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data