Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Growth Factor Stimulation Induces a Distinct ERα Cistrome Underlying Breast Cancer Endocrine Resistance

ABSTRACT: Estrogen receptor alpha (ERα) expression in breast cancer is predictive of response to endocrine therapy, however resistance is common in ERα-positive tumors that over-express the growth factor receptor ERBB2. Even in the absence of estrogen, ERα can be activated by growth factors including the epidermal growth factor (EGF). EGF induces a transcriptional program distinct from estrogen, however the mechanism of the stimulus-specific response is unknown. Here we show that the EGF-induced ERα genomic targets, its cistrome, are distinct from those induced by estrogen in a process dependent on the transcription factor AP-1. The EGF-induced ERα cistrome specifically regulates genes found over-expressed in ERBB2-positive human breast cancers. This provides a potential molecular explanation for the endocrine therapy resistance seen in ERα-positive breast cancers that over-express ERBB2. These results suggest a central role for ERα in hormone-refractory breast tumors dependent on growth factor pathway activation and favors the development of therapeutic strategies completely antagonizing ERα as opposed to blocking its estrogen responsiveness alone.

ORGANISM(S): Homo sapiens

PROVIDER: GSE26081 | GEO | 2010/12/29

SECONDARY ACCESSION(S): PRJNA135217

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Transition of breast cancer cells from luminal to basal-like phenotype engages a shift from genomic to non-genomic activities of ERα activity

Project description:Estrogen receptor (ERα) is central in driving the development of hormone-dependent breast cancers. A major challenge in treating these cancers is to understand and struggle endocrine resistance. We have previously shown that the Megakaryoblastic Leukemia 1 (MKL1) protein, a master regulator of actin dynamic and cellular motile functions, directs down-regulation of ERα and hormonal escape of estrogen-responsive breast cancer cell lines. In the present study, we decipher the underlining mechanisms by tracking functional changes in ERα activity. We demonstrate through gene expression microarray analysis that the constitutive activation of MKL1 in ERα-positive MCF7 breast cancer cells induces a transition from a luminal to a basal-like phenotype and suppresses almost all regulations of gene expression by estrogen. Chromatin immunoprecipitation of DNA coupled to high-throughput sequencing (ChIP-Seq) shows a profound reprogramming in ERα cistrome associated with a massive loss of ERα binding sites (ERBSs) generally associated with lower ERα-binding activity. Novel ERBSs appear to be associated with EGF and RAS signaling pathways. ERα dynamic was further impacted by a displacement of its monomer/dimer equilibrium towards its monomer state, associated with a redistribution of the normally nuclear ERα protein to the entire cell volume. We next show that the combination of these remodeled dynamics of ERα alters its interactions with genomic and non-genomic partners. In particular, the formation of ERα/kinase complexes was promoted by the constitutive activation of MKL1. Hence, MKL1-induced transition of ER-positive breast cancer cells from luminal to basal-like phenotype shifts ERα activities from genomic to non-genomic function.

2019-09-11 | GSE107924 | GEO

Transition of breast cancer cells from luminal to basal-like phenotype engages a shift from genomic to non-genomic activities of estrogen receptor-alpha activity

2019-12-31 | GSE107476 | GEO

Heat Shock Factor 1 (HSF1) acquires transcriptional competence under 17b-estradiol in ERa-positive breast cancer cells [ChIP-seq]

Project description:Heat Shock Transcription Factor 1 (HSF1) is a well-known regulator of gene expression during acute environmental stress that enables the cells to survive. Its high level in estrogen receptor-positive breast cancer patients correlated with a worse prognosis. Here, we demonstrated that 17β-estradiol (E2) as well as bisphenol A (BPA) and propyl pyrazole triol (PPT, ERα agonist) led to HSF1 phosphorylation on S326 in ERα positive mammary breast cancer cells, but not in ERα-negative ones. We showed that ERK1/2 signaling was involved in this process and down-regulation of ERα expression abrogated it. E2activated HSF1 was transcriptionally potent. Chip-Seq and RNA-Seq analyses revealed that it could modulate the expression of several genes known to be essential for breast cancer cells growth and/or ERα action, i.e. HSPB8, LHX4, PRKCE, WWC1, and GREB1. Our findings indicate that a positive feedback loop between ERα and HSF1 signaling may exist which support the growth of estrogen-dependent tumors.

2019-10-05 | GSE137558 | GEO

Heat Shock Factor 1 (HSF1) acquires transcriptional competence under 17b-estradiol in ERa-positive breast cancer cells [RNA-seq]

2019-10-05 | GSE137559 | GEO

Genome-wide analysis of PIAS1 on AR gene expression in MDA-MB453

Project description:The majority of breast cancer subtypes express androgen receptor (AR) in addition to estrogen receptor α (ERα). Depending on the breast cancer subtype androgen signaling has either stimulatory or inhibitory roles in breast cancer cell growth. We have mapped AR cistrome in ERα negative human molecular apocrine breast cancer MDA-MB453 cells and analyzed it in relation to the androgen-regulated transcriptome in the same cells. We have also examined the effect of silencing of the coregulator SUMO ligase PIAS1 on the androgen-regulated transcriptome and AR cistrome in MDA-MB453 cells. Our results show that the MDA-MB453 cells share with VCaP prostate cancer cells a core AR cistrome and target gene signature linked to cancer cell growth and that PIAS1 acts as an AR target gene-selective coregulator in MDA-MB453 cells.

2016-07-18 | GSE70162 | GEO

Inhibition of O-GlcNAc transferase activates tumor-suppressor gene expression in tamoxifen-resistant breast cancer cells

Project description:In this study, we probed the importance of OGT activity for the survival of Tamoxifen-sensitive (TamS) and Tamoxifen-resistant (TamR) breast cancer cells. Tamoxifen is an antagonist of estrogen receptor (ERα), a transcription factor expressed in over half of all breast cancers, and the defining characteristic of the ERα-positive disease. ERα-positive breast cancers are successfully treated with Tamoxifen; however, a significant number of patients develops Tamoxifen-resistant disease. We show here that in vitro development of Tamoxifen-resistance results in acquired sensitivity to OGT small molecule inhibitor OSMI-1. Global transcriptome profiling revealed that TamS cells adapt to OSMI-1 treatment by undergoing significant chromatin compaction. In the TamR cells, however, OGT inhibition induces ERRFI1 tumor-suppressor gene expression. ERRFI1 is an endogenous inhibitor of ERBB-signaling, while activation of the ERBB-signaling is one of the best understood mechanism for Tamoxifen-resistance. We show that ERRFI1 is selectively downregulated in ERα-positive breast cancers and breast cancers driven by ERBB2, and provide data to support that this occurs through promoter methylation. Finally, we show that increased ERRFI1 expression is associated with extended survival in patients with ERα-positive tumors (p=9.2e-8). In summary, we show that Tamoxifen-resistance is associated with acquired sensitivity to OSMI-1, and propose that this is explained in part through an epigenetic activation of the tumor-suppressor ERRFI1 in response to OSMI-1 treatment.

2020-10-22 | GSE148186 | GEO

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

Project description: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.

2014-03-03 | GSE53531 | GEO

DNA structure-specific endonuclease FEN1 as a novel drug target in tamoxifen resistant breast cancer.

Project description:Estrogen receptor α (ERα) is a key transcriptional regulator in the majority of breast cancers. ERα-positive patients are frequently treated with tamoxifen, but resistance is common. In this study, we refined a previously identified 111-gene outcome prediction-classifier, revealing FEN1 as the strongest determining factor in ERα-positive patient prognostication. FEN1 levels were predictive of outcome in tamoxifen-treated patients, and FEN1 played a causal role in ERα-driven cell growth. FEN1 impacted the transcriptional-activity of ERα by facilitating coactivator recruitment to the ERα transcriptional complex. FEN1 blockade induced proteasome-mediated degradation of activated ERα, resulting in loss of ERα-driven gene expression and eradicated tumor cell proliferation. Finally, a high-throughput 465,195 compound screen identified a novel FEN1 inhibitor, which effectively blocked ERα-function and inhibited proliferation of tamoxifen-resistant cell lines as well as ex-vivo cultured ERα-positive breast tumors. Collectively, these results provide therapeutic proof-of-principle for FEN1 blockade in tamoxifen-resistant breast cancer.

2020-06-01 | GSE95302 | GEO

A super enhancer-controlled BRD4/ERα-RET-ERα positive feedback loop promotes ERα-positive breast cancer [GRO-seq]

Project description:Dysregulated estrogen and estrogen receptor (ER)-induced gene transcription is tightly associated with estrogen receptor alpha (ERα)-positive breast carcinogenesis. ERα-occupied enhancers, particularly super enhancers, have been suggested to play a vital role in such transcriptional events. However, the landscape of ERα-occupied super enhancers (ERSEs) as well as key super enhancer-associated genes remain to be fully characterized. Here, we defined the landscape of ERSEs in MCF7, a ERα-positive breast cancer cell line, and demonstrated that bromodomain protein BRD4 is a master regulator of the transcriptional activation of ERSE and cognate ERα-target genes. Furthermore, RET, a member of the tyrosine protein kinase family of proteins, was identified to be a key target gene of BRD4-regulated ERSEs, which is vital for estrogen/ ERα-induced gene transcriptional activation and malignant phenotypes through activating the Ras-Raf-MEK-ERK-p90RSK-ERα phosphorylation cascade. Accordingly, combination therapy with BRD4 and RET inhibitors exhibited synergistic effects on suppressing ERα-positive breast cancer both in vitro and in vivo. Taken together, our data uncovered the critical role of a super enhancer-associated BRD4/ERα-RET-ERα positive feedback loop in ERα-positive breast cancer, and targeting components in this loop will provide new therapeutic avenue for treating ERα-positive breast cancer in the clinic.

2022-10-19 | GSE186643 | GEO

A super enhancer-controlled BRD4/ERα-RET-ERα positive feedback loop promotes ERα-positive breast cancer [ChIP-seq]

2022-10-19 | GSE186645 | 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