Project description:This SuperSeries is composed of the following subset Series: GSE22533: Breast cancer cells resistant to hormone deprivation maintain an estrogen receptor alpha-dependent, E2F-directed transcriptional program GSE27300: Estrogen-independent genomic ER binding analysis Refer to individual Series
Project description:We performed ChIP seq experiment in MDA-MB-134 cell line in order to map the estrogen receptor alpha (ER) binding sites following the estrogen treatment in an ILC model. We have characterized the genome wide recruit of ER and scaned the binding sites for the presence of cofactor motifs. The binding peaks were also correlated to E2 regulated genes in this ILC model. Four samples were subjected to high throughput sequencing: E-ER (estrogen treated followed by ER IP), E-IgG (estrogen treated followed by IgG), V-ER (EtOH treated followed by ER IP) and Input (MCF7 genomic DNA)
Project description:Transcriptomic changes and estrogen and progesterone receptor binding in multiple ER+/PR+ models (eight ER+/PR+ patient tumors, various T47Ds, ZR75) and multiple ER+/PR-negative models (four ER+/PR- patient tuumors, PR-deficient T47D and MCF7 cells) treated with various hormone combinations. Results: In isolation, estrogen and progestin act as genomic agonists by regulating the expression of common target genes in similar directions, but at different levels. Similarly, in isolation, progestin is also a weak phenotypic agonist of estrogen action. However, in the presence of both hormones, progestin behaves as a phenotypic estrogen antagonist. PR remodels nucleosomes to noncompetitively redirect ER genomic binding to distal enhancers enriched for BRCA1 binding motifs and sites that link PR and ER/PR complexes. Importantly, when both hormones are present, progestin modulates estrogen action such that responsive transcriptomes, cellular processes and ER/PR recruitment to genomic sites correlate with those observed with PR alone, but not ER alone. Conclusions: Genomic Agonism and Phenotypic Antagonism between Estrogen and Progesterone Receptors in Breast Cancer. Individual and concerted actions of ER and PR highlight the prognostic and therapeutic value of PR in ER+/PR+ breast cancers.
Project description:Estrogen signaling through estrogen receptor alpha (ER) plays a major role in endometrial cancer risk and progression; however, the molecular mechanisms underlying ER’s regulatory role in endometrial cancer are poorly understood. In breast cancer cells, ER genomic binding is enabled by FOXA1 and GATA3, but the transcription factors that control ER genomic binding in endometrial cancer cells remain unknown. We previously identified ETV4 as a candidate factor controlling ER genomic binding in endometrial cancer cells and here we explore the functional importance of ETV4. Homozygous deletion of ETV4, using CRISPR/Cas9, led to greatly reduced ER binding at the majority of loci normally bound by ER. Consistent with the dramatic loss of ER binding, the gene expression response to estradiol was dampened for most genes. ETV4 contributes to estrogen signaling in two distinct ways; ETV4 loss impacts chromatin accessibility at some ER bound loci and impairs ER nuclear translocation. The diminished estrogen signaling upon ETV4 deletion led to decreased growth, particularly in 3D culture where hollow organoids were formed. Our results show that ETV4 plays a necessary role in estrogen signaling in endometrial cancer cells.
Project description:Estrogen signaling through estrogen receptor alpha (ER) plays a major role in endometrial cancer risk and progression; however, the molecular mechanisms underlying ER’s regulatory role in endometrial cancer are poorly understood. In breast cancer cells, ER genomic binding is enabled by FOXA1 and GATA3, but the transcription factors that control ER genomic binding in endometrial cancer cells remain unknown. We previously identified ETV4 as a candidate factor controlling ER genomic binding in endometrial cancer cells and here we explore the functional importance of ETV4. Homozygous deletion of ETV4, using CRISPR/Cas9, led to greatly reduced ER binding at the majority of loci normally bound by ER. Consistent with the dramatic loss of ER binding, the gene expression response to estradiol was dampened for most genes. ETV4 contributes to estrogen signaling in two distinct ways; ETV4 loss impacts chromatin accessibility at some ER bound loci and impairs ER nuclear translocation. The diminished estrogen signaling upon ETV4 deletion led to decreased growth, particularly in 3D culture where hollow organoids were formed. Our results show that ETV4 plays a necessary role in estrogen signaling in endometrial cancer cells.
Project description:Transcriptomic changes and estrogen and progesterone receptor binding in multiple ER+/PR+ models (eight ER+/PR+ patient tumors, various T47Ds, ZR75) and multiple ER+/PR-negative models (four ER+/PR- patient tuumors, PR-deficient T47D and MCF7 cells) treated with various hormone combinations. Results: In isolation, estrogen and progestin act as genomic agonists by regulating the expression of common target genes in similar directions, but at different levels. Similarly, in isolation, progestin is also a weak phenotypic agonist of estrogen action. However, in the presence of both hormones, progestin behaves as a phenotypic estrogen antagonist. PR remodels nucleosomes to noncompetitively redirect ER genomic binding to distal enhancers enriched for BRCA1 binding motifs and sites that link PR and ER/PR complexes. Importantly, when both hormones are present, progestin modulates estrogen action such that responsive transcriptomes, cellular processes and ER/PR recruitment to genomic sites correlate with those observed with PR alone, but not ER alone. Conclusions: Genomic Agonism and Phenotypic Antagonism between Estrogen and Progesterone Receptors in Breast Cancer. Individual and concerted actions of ER and PR highlight the prognostic and therapeutic value of PR in ER+/PR+ breast cancers. ER+/PR+ and ER+/PR-deficient model systems were deprived of steroids by culturing them in phenol red free RPMI 1640 media that is supplemented with 10% charcoal-stripped fetal bovine serum and 1% penicillin/streptomycin. Subsequently, these steroid-deprived models were treated with either vehicle, 10 nM estradiol, 10 nM progestin R5020 or 10 nM of both the hormones and genomics (ChIP-seq and RNA-seq) was performed. ChIP-seq was done after 45 minutes of hormone treatments. For cell models, RNA-seq was done after 12 hours of hormone treatments. Tumor explants were treated with either 24 or 48 hours.
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.
Project description:Estrogen receptor-α (ERα) is an important driver of breast cancer and is the target for hormonal therapies, anti-estrogens and drugs that limit estrogen biosynthesis (aromatase inhibitors). Mutations in the ESR1 gene identified in metastatic breast cancer provide a potential mechanism for acquired resistance to hormone therapies. We have used CRISPR-Cas9 mediated genome editing in the MCF-7 breast cancer cell line, generating MCF-7-Y537S. MCF-7-Y537S cells encode a wild-type (tyrosine 537) and a mutant (serine 537) allele. Growth of the line is estrogen-independent and expression of ERα target genes is elevated in the absence of estrogen. ER ChIP-seq was carried out to map global ERα binding sites in the presence and absence of estrogen. RNA-seq following estrogen treatment was used for gene expression analysis. We show that expression of ER target genes and ER recruitment to ER binding regions is similar in MCF-7 and MCF-7-Y537S cells, except that ER recruitment to DNA and expression of ER target genes is frequently elevated in the absence of estrogen Hormone depleted MCF-7 LUC /Y537S mutant cells were treated with estrogen (10nM) or ETOH as vehicle control for 45 mins. Erα Chip-seq was performed using Illumnia methodology
Project description:Estrogen receptor-α (ERα) is an important driver of breast cancer and is the target for hormonal therapies, anti-estrogens and drugs that limit estrogen biosynthesis (aromatase inhibitors). Mutations in the ESR1 gene identified in metastatic breast cancer provide a potential mechanism for acquired resistance to hormone therapies. We have used CRISPR-Cas9 mediated genome editing in the MCF-7 breast cancer cell line, generating MCF-7-Y537S. MCF-7-Y537S cells encode a wild-type (tyrosine 537) and a mutant (serine 537) allele. Growth of the line is estrogen-independent and expression of ERα target genes is elevated in the absence of estrogen. ER ChIP-seq was carried out to map global ERα binding sites in the presence and absence of estrogen. RNA-seq following estrogen treatment was used for gene expression analysis. We show that expression of ER target genes and ER recruitment to ER binding regions is similar in MCF-7 and MCF-7-Y537S cells, except that ER recruitment to DNA and expression of ER target genes is frequently elevated in the absence of estrogen
Project description:Transcriptomic changes and estrogen and progesterone receptor binding in multiple ER+/PR+ models (eight ER+/PR+ patient tumors, various T47Ds, ZR75) and multiple ER+/PR-negative models (four ER+/PR- patient tuumors, PR-deficient T47D and MCF7 cells) treated with various hormone combinations. Results: In isolation, estrogen and progestin act as genomic agonists by regulating the expression of common target genes in similar directions, but at different levels. Similarly, in isolation, progestin is also a weak phenotypic agonist of estrogen action. However, in the presence of both hormones, progestin behaves as a phenotypic estrogen antagonist. PR remodels nucleosomes to noncompetitively redirect ER genomic binding to distal enhancers enriched for BRCA1 binding motifs and sites that link PR and ER/PR complexes. Importantly, when both hormones are present, progestin modulates estrogen action such that responsive transcriptomes, cellular processes and ER/PR recruitment to genomic sites correlate with those observed with PR alone, but not ER alone. Conclusions: Genomic Agonism and Phenotypic Antagonism between Estrogen and Progesterone Receptors in Breast Cancer. Individual and concerted actions of ER and PR highlight the prognostic and therapeutic value of PR in ER+/PR+ breast cancers.