Project description:Estrogen receptors (ERs), which mediate the proliferative action of estrogens in breast cancer cells, are ligand-dependent transcription factors that regulate expression of their primary target genes through several mechanisms. In addition to direct binding to cognate DNA sequences, ERs can be recruited to DNA through other transcription factors (tethering), or affect gene transcription through modulation of signaling cascades by non-genomic mechanisms of action. To better characterize the mechanisms of gene regulation by estrogens, we have identified more than 700 putative primary and more than 1500 putative secondary target genes of estradiol in MCF7 cells through microarray analysis performed in the presence or absence of the translation inhibitor cycloheximide. Experiment Overall Design: RNA samples were collected 24 h after treatment of MCF7 cells with vehicle or 17{beta}-estradiol (25 nM). Cells were pre-treated 1 h before E2 stimulation with cycloheximide (CHX, 10 microg/ml). Microarray analysis was performed with four replicates for each condition.
Project description:Analysis of MCF7 breast cancer cells treated with estadiol for 6 h in presence or absence of the specific PLK1 inhibitor BI2536. Together with CHIP and global phosphoproteome data, the results demonstrate a key role of PLK1 in the estrogen receptor-mediated gene response. Hormone-deprived MCF7 cells were pretreated with BI2536 or vehicle (DMSO) followed by induction with estradiol (E2) or vehicle (ethanol). RNA of each condition was analysed in triplicate on an Agilent Human genome 4x44k v2 microarray [note: MCF7_DMSO_E2_rep3 sample was a clear technical outlier (poor hybridization), and was therefore excluded from the further analysis/this record].
Project description:Analysis of MCF7 breast cancer cells treated with estadiol for 6 h in presence or absence of the specific PLK1 inhibitor BI2536. Together with CHIP and global phosphoproteome data, the results demonstrate a key role of PLK1 in the estrogen receptor-mediated gene response.
Project description:Estrogen receptors (ERs), which mediate the proliferative action of estrogens in breast cancer cells, are ligand-dependent transcription factors that regulate expression of their primary target genes through several mechanisms. In addition to direct binding to cognate DNA sequences, ERs can be recruited to DNA through other transcription factors (tethering), or affect gene transcription through modulation of signaling cascades by non-genomic mechanisms of action. To better characterize the mechanisms of gene regulation by estrogens, we have identified more than 700 putative primary and more than 1500 putative secondary target genes of estradiol in MCF7 cells through microarray analysis performed in the presence or absence of the translation inhibitor cycloheximide. Keywords: drug treatment
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 MCF7 Luc or Y537S cells were treated with 10nM E2 or ethanol, as vehicle control, for 8 hours, with 3 replicates (2 replicates for Y537S + E2). RNA-seq was carried out using Illumina Hiseq 2500.
Project description:We mapped the location of RNA-DNA hybrids in hormone-starved MCF7 breast cancer cells treated with the hormone estradiol (E2.) E2 is a potent transcriptional activator, and causes proliferation in hormone starved cells. We find a significant induction of hybrids at genes known to be regulated by the estrogen receptor.
Project description:Since the thyroid hormone receptor β (TRβ) appears to suppress breast tumor growth and metastasis, we have analyzed the possibility that this receptor could affect cancer stem cell biology using TRβ-expressing MCF-7 cells (MCF7-TRβ cells) treated with the thyroid hormone T3.
Project description:Since the thyroid hormone receptor β (TRβ) appears to suppress breast tumor growth and metastasis, we have analyzed the possibility that this receptor could affect cancer stem cell biology using mammospheres from TRβ-expressing MCF-7 cells (MCF7-TRβ cells) treated with the thyroid hormone T3.
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.
Project description:This experiment is designed to assess the role of RIP140 in estrogen receptor-dependent gene expression in MCF7 luminal breast cancer cells. Hormone deprived MCF7 cells were treated for 3 hours with E2 or DMSO control, after which samples were processed for ChIp-seq for RIp140.