Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA296868 | ENA |
REPOSITORIES: ENA
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Project description:The human RNA polymerase II-associated factor complex (hPAFc) and its individual subunits have been implicated in human diseases including cancer. However, its involvement in breast cancer cells awaits investigation. Using data mining and human breast cancer tissue microarrays, we found that Ctr9, the key scaffold subunit in hPAFc, is highly expressed in ERα+ luminal breast cancer and the high expression of Ctr9 correlates with poor prognosis. Knockdown of Ctr9 in ERα+ breast cancer cells almost completely erased estrogen regulated transcriptional response. At the molecular level, Ctr9 enhances ERα protein stability, promotes recruitment of ERα and RNAPII and stimulates transcription elongation and transcription-coupled histone modifications. Knockdown of Ctr9, but not other hPAFc subunits, alters the morphology, proliferative capacity and tamoxifen-sensitivity of ERα+ breast cancer cells. Together, our study reveals that Ctr9, a key subunit of hPAFc, is a central regulator of estrogen signaling that drives ERα+ breast tumorigenesis, rendering it a potential target for the treatment of ERα+ breast cancer.
2015-09-25 | GSE73388 | GEO
Project description:Ctr9, the key scaffold subunit of the human RNA polymerase II (RNAPII) associated factor complex (PAFc), has been demonstrated as a positive regulator of ERα-positive breast cancer progression and ERα-target gene expression. Previously, we found that knockdown of Ctr9 reduces ERα protein stability and decreases the occupancy of ERα and RNAPII at select ERα-target genes. However, the genome-wide regulation of the occupancy of ERα and RNAPII mediated by Ctr9 is still unclear. Here, we determined the genome-wide ERα and RNAPII occupancy in response to estrogen induction and/or Ctr9 knockdown by performing chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq). We found that loss of Ctr9 dramatically decreases the global occupancy of ERα and RNAPII, highlighting the significance of Ctr9 in regulating estrogen signaling in ERα-positive breast cancer cells. Combining this resource with previously published genomic data sets, we identified a unique subset of ERα and Ctr9 target genes, and further delineates the possible independent function of Ctr9 from other subunits in PAFc.
2016-10-10 | GSE80728 | GEO
Project description:The molecular mechanisms underlying estrogen receptor (ER)-positive breast carcinogenesis and endocrine therapy resistance remain incompletely understood. Here, we reported that circPVT1, a circular RNA generated from lncRNA PVT1, is highly expressed in ERalpha-positive breast cancer cell lines and tumor samples, which is functionally important in promoting ERalpha-positive breast tumorigenesis and endocrine therapy resistance. CircPVT1 acts as a competing endogenous RNA (ceRNA) to sponge miR-181a-2-3p, promoting the expression of ESR1 and downstream ERalpha-target genes and breast cancer cell growth. Meanwhile, circPVT1 directly interacts with MAVS to disrupt the RIGI-MAVS complex formation, inhibiting type I interferon (IFN) signaling pathway and anti-tumor immunity. The dual mechanisms both contribute to ERα-positive breast tumorigenesis. Anti-sense oligonucleotides (ASO) targeting circPVT1 was shown to inhibit ERalpha-positive breast cancer cell and tumor growth, and could re-sensitize tamoxifen-resistant ERalpha-positive breast cancer cells to tamoxifen treatment. Taken together, our data demonstrated that circPVT1 can work through both ceRNA and protein scaffold mechanisms to promote cancer, and in particular, circPVT1 may serve as a diagnosis biomarker and therapeutic target for ERalpha-positive breast cancer in the clinic.
2023-02-06 | GSE220776 | GEO
Project description:Despite the role of the estrogen receptor alpha (ERalpha) pathway as a key growth driver for breast cells, the phenotypic consequence of exogenous introduction of ERalpha into ERalpha-negative cells paradoxically has been growth inhibition. We map the binding profiles of ERalpha and its interacting transcription factors (TFs), FOXA1 and GATA3 in MCF-7 breast carcinoma cells. We observe that these three TFs form a functional enhanceosome and cooperatively modulate the transcriptional networks previously ascribed to ERalpha alone. We demonstrate that these enhanceosome occupied sites are associated with optimal enhancer characteristics with highest p300 coactivator recruitment, RNA Pol II occupancy, and chromatin opening. The enhancesome binding sites appear to regulate the genes driving core ERalpha function. Most importantly, we show that the transfection of all three TFs was necessary to reprogramme the ERalpha-negative MDA-MB-231 and BT-459 cells to restore the estrogen responsive growth and to transcriptionally resemble the estrogen treated ERalpha-positive MCF-7 cells. Cumulatively, these results suggest that all the enhanceosome components comprising ERalpha, FOXA1 and GATA3 are necessary for the full repertoire of cancer associated effects of the ERalpha.
2011-09-05 | GSE30574 | GEO
Project description:Despite the role of the estrogen receptor alpha (ERalpha) pathway as a key growth driver for breast cells, the phenotypic consequence of exogenous introduction of ERalpha into ERalpha-negative cells paradoxically has been growth inhibition. We map the binding profiles of ERalpha and its interacting transcription factors (TFs), FOXA1 and GATA3, in MCF-7 breast carcinoma cells. We observe that these three TFs form a functional enhanceosome and cooperatively modulate the transcriptional networks previously ascribed to ERalpha alone. We demonstrate that these enhanceosome-occupied sites are associated with optimal enhancer characteristics with highest p300 coactivator recruitment, RNA Pol II occupancy, and chromatin opening. The enhancesome binding sites appear to regulate the genes driving core ERalpha function. Most importantly, we show that transfection of all three TFs was necessary to reprogram the ERalpha-negative MDA-MB-231 and BT-459 cells to restore the estrogen responsive growth and to transcriptionally resemble the estrogen-treated ERalpha-positive MCF-7 cells. Cumulatively, these results suggest that all of the enhanceosome components comprising ERalpha, FOXA1 and GATA3 are necessary for the full repertoire of the cancer-associated effects of the ERalpha.
2011-09-05 | GSE29073 | GEO
Project description:Estrogen receptor alpha (ERalpha signaling pathway is essential for ERalpha positive breast cancer progression and endocrine therapy resistance. BPTF associated protein of 18kDa (BAP18) has been recognized as a crucial H3K4me3 reader. However, the whole genomic occupation of BAP18 and its biological function in breast cancer are still elusive. Here, we found that higher expression of BAP18 in ERalpha positive breast cancer is positively correlated with poor prognosis. ChIP-seq analysis further demonstrated that the half estrogen response elements (EREs) and the CCCTC binding factor (CTCF) binding sites are the significant enrichment sites found in estrogen-induced BAP18 binding sites. In addition, we provide the evidence to demonstrate that BAP18 as a novel co-activator of ERalpha is required for the recruitment of COMPASS-like core subunits to cis-regulatory element of ERalpha target genes in breast cancer cells. BAP18 is recruited to the promoter regions of estrogen-induced genes, accompanied with the enrichment of the lysine 4-trimethylated histone H3 tail (H3K4me3) in the presence of E2. Furthermore, BAP18 promotes cell growth and confers to ERalpha antagonist tamoxifen resistancein ERalpha positive breast cancer. Our data suggest that BAP18 facilitates the association between ERalpha and COMPASS-like core subunits, which might be an essential epigenetic therapeutic target for breast cancer.
2020-11-09 | GSE144641 | GEO
Project description:Despite the role of the estrogen receptor alpha (ERalpha) pathway as a key growth driver for breast cells, the phenotypic consequence of exogenous introduction of ERalpha into ERalpha-negative cells paradoxically has been growth inhibition. We map the binding profiles of ERalpha and its interacting transcription factors (TFs), FOXA1 and GATA3 in MCF-7 breast carcinoma cells. We observe that these three TFs form a functional enhanceosome and cooperatively modulate the transcriptional networks previously ascribed to ERalpha alone. We demonstrate that these enhanceosome occupied sites are associated with optimal enhancer characteristics with highest p300 coactivator recruitment, RNA Pol II occupancy, and chromatin opening. The enhancesome binding sites appear to regulate the genes driving core ERalpha function. Most importantly, we show that the transfection of all three TFs was necessary to reprogramme the ERalpha-negative MDA-MB-231 and BT-459 cells to restore the estrogen responsive growth and to transcriptionally resemble the estrogen treated ERalpha-positive MCF-7 cells. Cumulatively, these results suggest that all the enhanceosome components comprising ERalpha, FOXA1 and GATA3 are necessary for the full repertoire of cancer associated effects of the ERalpha. Illumina HumanRef-8 v3 Expression BeadChip was used to measure the gene expression levels from ERalpha negative breast cancer cell MDA-MB-231 with different transfections: with vector control, with ERalpha only, or with ERalpha+FOXA1+GATA3 combined.
2011-09-04 | E-GEOD-30574 | biostudies-arrayexpress
Project description:Despite the role of the estrogen receptor alpha (ERalpha) pathway as a key growth driver for breast cells, the phenotypic consequence of exogenous introduction of ERalpha into ERalpha-negative cells paradoxically has been growth inhibition. We map the binding profiles of ERalpha and its interacting transcription factors (TFs), FOXA1 and GATA3, in MCF-7 breast carcinoma cells. We observe that these three TFs form a functional enhanceosome and cooperatively modulate the transcriptional networks previously ascribed to ERalpha alone. We demonstrate that these enhanceosome-occupied sites are associated with optimal enhancer characteristics with highest p300 coactivator recruitment, RNA Pol II occupancy, and chromatin opening. The enhancesome binding sites appear to regulate the genes driving core ERalpha function. Most importantly, we show that transfection of all three TFs was necessary to reprogram the ERalpha-negative MDA-MB-231 and BT-459 cells to restore the estrogen responsive growth and to transcriptionally resemble the estrogen-treated ERalpha-positive MCF-7 cells. Cumulatively, these results suggest that all of the enhanceosome components comprising ERalpha, FOXA1 and GATA3 are necessary for the full repertoire of the cancer-associated effects of the ERalpha. The analysis of ERalpha, FOXA1, and GATA3 in MCF-7 cancer cells was done by ChIP-seq data obtained either with estradiol (E2) stimulation or without stimulation using vehicle as a control. Using the ERalpha bindings defined by ChIP-seq (GSE23893), FOXA1 bindings (GSE26831), and GATA3 bindings (this Series), we analyzed the enhanceosome effect of the overlapped binding sites from ERalpha, FOXA1 and GATA3.
2011-09-05 | E-GEOD-29073 | biostudies-arrayexpress
Project description:Using a chromatin immunoprecipitation-paired end diTag cloning and sequencing strategy, we mapped estrogen receptor alpha (ERalpha) binding sites in MCF-7 breast cancer cells. We identified 1,234 high confidence binding clusters of which 94% are projected to be bona fide ERalpha binding regions. Only 5% of the mapped estrogen receptor binding sites are located within 5 kb upstream of the transcriptional start sites of adjacent genes, regions containing the proximal promoters, whereas vast majority of the sites are mapped to intronic or distal locations (>5 kb from 5' and 3' ends of adjacent transcript), suggesting transcriptional regulatory mechanisms over significant physical distances. Of all the identified sites, 71% harbored putative full estrogen response elements (EREs), 25% bore ERE half sites, and only 4% had no recognizable ERE sequences. Genes in the vicinity of ERalpha binding sites were enriched for regulation by estradiol in MCF-7 cells, and their expression profiles in patient samples segregate ERalpha-positive from ERalpha-negative breast tumors. The expression dynamics of the genes adjacent to ERalpha binding sites suggest a direct induction of gene expression through binding to ERE-like sequences, whereas transcriptional repression by ERalpha appears to be through indirect mechanisms. Our analysis also indicates a number of candidate transcription factor binding sites adjacent to occupied EREs at frequencies much greater than by chance, including the previously reported FOXA1 sites, and demonstrate the potential involvement of one such putative adjacent factor, Sp1, in the global regulation of ERalpha target genes. Unexpectedly, we found that only 22%-24% of the bona fide human ERalpha binding sites were overlapping conserved regions in whole genome vertebrate alignments, which suggest limited conservation of functional binding sites. Taken together, this genome-scale analysis suggests complex but definable rules governing ERalpha binding and gene regulation. Keywords: time course
2008-05-07 | GSE11352 | GEO
Project description:Estrogen receptor alpha (ERalpha) is a ligand-dependent transcription factor that plays an important role in breast cancer. Estrogen-dependent gene regulation by ERalpha can be mediated by interaction with other DNA-binding proteins, such as activator protein-1 (AP-1). The nature of such interactions in mediating the estrogen response in breast cancer cells remains unclear. Here we show that knockdown of c-Fos, a component of the transcription factor AP-1, attenuates the expression of 37% of all estrogen-regulated genes, suggesting that AP-1 is a fundamental factor for ERalpha-mediated transcription. Additionally, knockdown of c-Fos affected the expression of a number of genes that were not regulated by estrogen. Pathway analysis reveals that silencing of c-Fos downregulates an E2F1-dependent pro-proliferative gene network. Thus, modulation of the E2F1 pathway by c-Fos represents a novel mechanism by which c-Fos enhances breast cancer cell proliferation. Furthermore, we show that c-Fos and ERalpha can cooperate in regulating E2F1 gene expression by binding to regulatory elements in the E2F1 promoter. To start to dissect the molecular details of the cross-talk between AP-1 and estrogen signaling, we identify a novel ERalpha/AP-1 target, PKIB (cAMP-dependent protein kinase inhibitor-beta), which is overexpressed in ERalpha-positive breast cancer tissues. Knockdown of PKIB by siRNA results in drastic growth suppression of breast cancer cells. Collectively, our findings support AP-1 as a critical factor that governs estrogen-dependent gene expression and breast cancer proliferation programs.
2012-08-06 | GSE36586 | GEO