Project description:In this study we show that depletion of the cohesin subunit SMC3 or the Mediator subunit MED12 significantly impairs the ERα-regulated transcriptome. Surprisingly, SMC3 depletion appears to elicit this effect indirectly by rapidly decreasing ESR1 transcription and ERα protein levels. Moreover, we provide evidence that both SMC3 and MED12 colocalize on the ESR1 gene and are mutually required for occupancy as well as for transcriptional elongation. Finally, we show that extended proteasome inhibition decreases the mRNA expression of cohesin subunits which accompanies a decrease in ESR1 mRNA and ERα protein levels as well as estrogen-regulated transcription. Conclusions: These results identify the ESR1 gene as a cohesin/Mediator-dependent gene and indicate that this regulation may potentially be exploited for the treatment of estrogen-dependent breast cancer. This set contains 18 microarray samples with triplicates for each condition. 3 control siRNA, 3 control estrogen stimulated, 3 siRNA Med12 knockdown, 3 siRNA Med12 knockdown estrogen stimulated, 3 siRNA Smc3 knockdown, 3 siRNA Smc3 knockdown estrogen stimulated.
Project description:Affymetrix microarray data was generated from MCF7 breast cancer cells treated in vitro with siRNAs against estrogen receptor alpha (ESR1). Gene expresion of estrogen receptor alpha (ESR1) was knocked down in MCF7 breast cancer cells using siRNA. Then the gene expression profiles of these MCF7 cells, along with non-targetting control treated cells were analysed using Affymetrix Human Genome U133 Plus 2.0 microarrays.
Project description:Estrogen signaling in breast cancer cells relies on long-range chromatin interactions connecting distal regulatory elements bound by the estrogen receptor 1 (ESR1) to target gene promoters. This ensures stimulus and subtype-specific transcriptional responses. Expanding on the function of CTCF and the cohesin complex in breast cancer, we demonstrate that the chromatin-looping factor ZNF143 binds the promoter of most early-response estrogen target genes connected to distal regulatory elements in ESR1-positive breast cancer cells. Its chromatin occupancy is unaffected by estrogen stimulation, supporting a stable three-dimensional genomic architecture within the early response to estrogen. Its loss abrogates the estrogen-induced transcriptional response and growth of breast cancer cells. When taking into account CTCF, ZNF143 and cohesin complex subunits, we show that chromatin-looping factors are genetically altered in over 20% of ESR1-positive primary breast tumors. Furthermore, the overexpression of ZNF143, CTCF and RAD21, a cohesin complex subunit, in ESR1-positive breast tumors associates with a worse clinical outcome. Overall, our results suggest that ZNF143 is a new critical effector of the estrogen response and highlights the contribution of the chromatin looping machinery to ESR1-positive breast cancer development. Examination of genome-wide ZNF143 binding in MCF-7 cells
Project description:Estrogen signaling in breast cancer cells relies on long-range chromatin interactions connecting distal regulatory elements bound by the estrogen receptor 1 (ESR1) to target gene promoters. This ensures stimulus and subtype-specific transcriptional responses. Expanding on the function of CTCF and the cohesin complex in breast cancer, we demonstrate that the chromatin-looping factor ZNF143 binds the promoter of most early-response estrogen target genes connected to distal regulatory elements in ESR1-positive breast cancer cells. Its chromatin occupancy is unaffected by estrogen stimulation, supporting a stable three-dimensional genomic architecture within the early response to estrogen. Its loss abrogates the estrogen-induced transcriptional response and growth of breast cancer cells. When taking into account CTCF, ZNF143 and cohesin complex subunits, we show that chromatin-looping factors are genetically altered in over 20% of ESR1-positive primary breast tumors. Furthermore, the overexpression of ZNF143, CTCF and RAD21, a cohesin complex subunit, in ESR1-positive breast tumors associates with a worse clinical outcome. Overall, our results suggest that ZNF143 is a new critical effector of the estrogen response and highlights the contribution of the chromatin looping machinery to ESR1-positive breast cancer development. mRNA profiles of MCF-7 cells (siCtl or siZNF143) under vehicle (EtOH) or E2 (10 uM 17-beta oestradiol) stimulation
Project description:In this study we show that depletion of the cohesin subunit SMC3 or the Mediator subunit MED12 significantly impairs the ERα-regulated transcriptome. Surprisingly, SMC3 depletion appears to elicit this effect indirectly by rapidly decreasing ESR1 transcription and ERα protein levels. Moreover, we provide evidence that both SMC3 and MED12 colocalize on the ESR1 gene and are mutually required for occupancy as well as for transcriptional elongation. Finally, we show that extended proteasome inhibition decreases the mRNA expression of cohesin subunits which accompanies a decrease in ESR1 mRNA and ERα protein levels as well as estrogen-regulated transcription. Conclusions: These results identify the ESR1 gene as a cohesin/Mediator-dependent gene and indicate that this regulation may potentially be exploited for the treatment of estrogen-dependent breast cancer.
Project description:Estrogen protects females from hepatocellular carcinoma (HCC). To determine whether this protection is mediated by classic estrogen receptors, we tested HCC susceptibility in estrogen receptor-deficient mice. In contrast to a previous study, we found that diethylnitrosamine induces hepatocarcinogenesis to a much greater extent when females lack Esr1, which encodes Estrogen Receptor-α. Relative to wild-type littermates, Esr1 knockout females developed 9-fold more tumors. Deficiency of Esr2, which encodes Estrogen Receptor-β, did not affect liver carcinogenesis in females. Using microarrays and QPCR to examine estrogen receptor effects on hepatic gene expression patterns, we found that germline Esr1 deficiency resulted in the masculinization of gene expression in the female liver.
Project description:Estrogen signaling in breast cancer cells relies on long-range chromatin interactions connecting distal regulatory elements bound by the estrogen receptor 1 (ESR1) to target gene promoters. This ensures stimulus and subtype-specific transcriptional responses. Expanding on the function of CTCF and the cohesin complex in breast cancer, we demonstrate that the chromatin-looping factor ZNF143 binds the promoter of most early-response estrogen target genes connected to distal regulatory elements in ESR1-positive breast cancer cells. Its chromatin occupancy is unaffected by estrogen stimulation, supporting a stable three-dimensional genomic architecture within the early response to estrogen. Its loss abrogates the estrogen-induced transcriptional response and growth of breast cancer cells. When taking into account CTCF, ZNF143 and cohesin complex subunits, we show that chromatin-looping factors are genetically altered in over 20% of ESR1-positive primary breast tumors. Furthermore, the overexpression of ZNF143, CTCF and RAD21, a cohesin complex subunit, in ESR1-positive breast tumors associates with a worse clinical outcome. Overall, our results suggest that ZNF143 is a new critical effector of the estrogen response and highlights the contribution of the chromatin looping machinery to ESR1-positive breast cancer development.
Project description:Estrogen signaling in breast cancer cells relies on long-range chromatin interactions connecting distal regulatory elements bound by the estrogen receptor 1 (ESR1) to target gene promoters. This ensures stimulus and subtype-specific transcriptional responses. Expanding on the function of CTCF and the cohesin complex in breast cancer, we demonstrate that the chromatin-looping factor ZNF143 binds the promoter of most early-response estrogen target genes connected to distal regulatory elements in ESR1-positive breast cancer cells. Its chromatin occupancy is unaffected by estrogen stimulation, supporting a stable three-dimensional genomic architecture within the early response to estrogen. Its loss abrogates the estrogen-induced transcriptional response and growth of breast cancer cells. When taking into account CTCF, ZNF143 and cohesin complex subunits, we show that chromatin-looping factors are genetically altered in over 20% of ESR1-positive primary breast tumors. Furthermore, the overexpression of ZNF143, CTCF and RAD21, a cohesin complex subunit, in ESR1-positive breast tumors associates with a worse clinical outcome. Overall, our results suggest that ZNF143 is a new critical effector of the estrogen response and highlights the contribution of the chromatin looping machinery to ESR1-positive breast cancer development.
Project description:Estrogen and progesterone are important regulators of human endometrial differentiation. These steroid hormones act, at least in part, through their nucelar receptors. Role of estrogen receptor alpha (ESR1) during human endometrial differentiation is still unclear. We used microarray analysis to detail the gene expression regulated by ESR1 during differentiation of human endometrial stromal cells.