Transcription profiling of human MCF-7 breast adenocarcinoma cells were treated with empty dendrimer control, E2, or Estrogen Dendrimer Conjugate (EDC) for 4 hours to investigate nuclear and extranuclear pathway inputs in the regulation of global gene expression by estrogen receptors
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Zeynep Madak Erdogan
PROVIDER: E-GEOD-15717 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Whereas estrogens exert their effects by binding to nuclear estrogen receptors and directly altering target gene transcription, they can also initiate extranuclear signaling through activation of kinase cascades. We have investigated the impact of estrogen-mediated extranuclear initiated pathways on global gene expression by using estrpgen-dendrimer conjugates. Keywords: ligand treatment
2009-04-18 | GSE15717 | GEO
Project description:The nuclear hormone receptor, estrogen receptor-alpha (ERα), and MAP kinases both play key roles in hormone-dependent cancers, yet their interplay and the integration of their signaling inputs remain poorly understood. In these studies, we document that estrogen-occupied ERα activates and interacts with ERK2, a downstream effector in the MAPK pathway, resulting in ERK2 and ERα colocalization at chromatin binding sites across the genome of breast cancer cells. KEYWORDS: siRNA knock-down, ligand treatment MCF-7 human breast adenocarcinoma cells were tranfected with control, ERK1 and ERK2 siRNA for 60 hours and treated with 0.1% EtOH (Vehicle) or 10 nM E2 for 4 hours or 24 hours, and cDNA microarray analyses were carried out using Affymetrix [HG-U133A_2] Affymetrix Human Genome U133A 2.0 Array.
2011-01-10 | E-GEOD-24592 | biostudies-arrayexpress
Project description:Despite the success of the aromatase inhibitors (AIs) in treating estrogen receptor positive breast cancer, 15-20% of patients receiving adjuvant AIs will relapse within 5-10 years of treatment initiation. Long term estrogen deprivation (LTED) of breast cancer cells in culture has been successfully used to mimic AI-induced estrogen depletion to dissect mechanisms of AI resistance. However, we hypothesized that a subset of patients receiving AI therapy may maintain low circulating concentrations of estrogens that influence the development of endocrine resistance. We sought to expand established LTED models to account for these observations. MCF-7 cells were grown in medium with charcoal stripped serum supplemented with defined concentrations of E2 or the estrogenic androgen metabolite 3βAdiol. Cells were selected in the EC10 and EC90 of E2 or 3βAdiol, or estrogen deprived. Estrogen-independence was evaluated during selection by assessing cell growth in the absence or presence of E2 or 3βAdiol. Following >7 months of selection, estrogen-independence developed in estrogen-deprived cells and cells maintained in low concentrations of steroid hormone. Functional analyses demonstrated that estrogen-deprived and low-steroid selected cells developed estrogen-independence via unique mechanisms, independent and dependent of ERα, respectively. Estrogen-independent growth in low-steroid selected cells could be blocked by kinase inhibitors. However, these cells were completely resistant to kinase inhibition in the presence of low steroid hormone concentrations. These data offer a novel perspective on the development of resistance to AI therapy, and may yield novel approaches to treat AI-resistant tumors. MCF-7 cells were selected for >7months in IMEM+10% Charcoal Stripped FBS, supplmented with defined steroid hormone conditions. Following outgrowth of estrogen-independent cells, cell lines were grown in estrogen-free conditions and gene expression analysis was performed to identify drivers of estrogen-independent growth. Cells were assessed in biological triplicates.
2012-03-29 | E-GEOD-33287 | biostudies-arrayexpress
Project description:We report the immediate effects of estrogen signaling on the transcriptome of breast cancer cells using Global Run-On and sequencing (GRO-seq). We found that estrogen signaling directly regulates a strikingly large fraction of the transcriptome in a rapid, robust, and unexpectedly transient manner. In addition to protein-coding genes, estrogen regulates the distribution and activity of all three RNA polymerases, and virtually every class of non-coding RNA that has been described to date. This data submission covers >95% of mapped reads comprising nearly all transcript classes described. Reads mapping to intergenic and enhancer transcripts were removed from this data submission and will be reported separately (manuscripts in preparation). Bed files are tab-separated text files in which columns represent: chrom, chromStart (5' End of the read), chromEnd (chromStart+1), name (unused always 'n'), score (the number of mismatches), and strand. Note that because of the inclusion of reads mapping to the rRNA chromosome, bed files cannot be uploaded to the UCSC genome browser directly. Instead, use the wiggle files (coming soon!) for this purpose. Using GRO-seq over a time course (0, 10, 40, 160 min) of estrogen signaling in ER-alpha positive MCF-7 human breast cancer cells.
2011-05-05 | E-GEOD-27463 | biostudies-arrayexpress
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2015-07-01 | E-GEOD-69118 | biostudies-arrayexpress
Project description:The interplay between mitogenic and proinflammatory signaling pathways play key roles in determining the phenotypes and clinical outcomes of breast cancers. We have used global nuclear run-on coupled with deep sequencing to characterize the immediate transcriptional responses of MCF-7 breast cancer cells treated with estradiol, TNF?, or both. In addition, we have integrated these data with chromatin immunoprecipitation coupled with deep sequencing for estrogen receptor alpha (ER?), the pioneer factor FoxA1 and the p65 subunit of the NF-?B transcription factor. Our results indicate extensive transcriptional interplay between these two signaling pathways, which is observed for a number of classical mitogenic and proinflammatory protein-coding genes. In addition, GRO-seq has allowed us to capture the transcriptional crosstalk at the genomic locations encoding for long non-coding RNAs, a poorly characterized class of RNAs which have been shown to play important roles in cancer outcomes. The synergistic and antagonistic interplay between estrogen and TNF? signaling at the gene level is also evident in the patterns of ER? and NF-?B binding, which relocalize to new binding sites that are not occupied by either treatment alone. Interestingly, the chromatin accessibility of classical ER? binding sites is predetermined prior to estrogen treatment, whereas ER? binding sites gained upon co-treatment with TNF? require NF-?B and FoxA1 to promote chromatin accessibility de novo. Our data suggest that TNF? signaling recruits FoxA1 and NF-?B to latent ER? enhancer locations and directly impact ER? enhancer accessibility. Binding of ER? to latent enhancers upon co-treatment, results in increased enhancer transcription, target gene expression and altered cellular response. This provides a mechanistic framework for understanding the molecular basis for integration of mitogenic and proinflammatory signaling in breast cancer. Using GRO-seq and ChIP-seq (ER, FoxA1 and p65) to assay the molecular crosstalk of MCF-7 cells treated with E2, TNFa or both E2+TNFa.
2015-03-05 | E-GEOD-59530 | biostudies-arrayexpress
Project description:The closely related transcription factors (TFs), estrogen receptors ERα and ERβ, regulate divergent gene expression programs and proliferative outcomes in breast cancer. Utilizing MCF-7 breast cancer cells with ERα, ERβ, or both receptors as a model system to define the basis of differing response specification by related TFs, we show that these TFs and their key coregulators, SRC3 and RIP140, generate overlapping as well as unique chromatin-binding and transcription-regulating modules. Cistrome and transcriptome analyses and use of clustering algorithms delineated 11 clusters representing different chromatin-bound receptor and coregulator assemblies that could be functionally associated through enrichment analysis with distinct patterns of gene regulation and preferential coregulator usage, RIP140 with ERβ and SRC3 with ERα. The receptors modified each other’s transcriptional effect, and ERβ countered the proliferative drive of ERα through several novel mechanisms associated with specific binding site clusters. Our findings delineate distinct TF-coregulator assemblies that function as control nodes specifying precise patterns of gene regulation, proliferation, and metabolism, as exemplified by two of the most important nuclear hormone receptors in human breast cancer. MCF-7 cells expressing endogenous ERalpha were infected with adenovirus carrying either estrogen receptor beta (AdERb) or no insert (Ad) at multiplicity of infection (moi) of 50. ERβ only cells were generated from these cells by knockdown of ERα in parental cells using the following siERα sequences from Dharmacon: forward, 5’-UCAUCGCAUUCCUUGCAAAdTdT-3’, and reverse, 5’-UUUGCAAGGAAUGCGAUGAdTdT-3’. siRNA experiments were performed as previously described, and resulted in knocknown of ERα mRNA and protein by greater than 95% (GSE4006, PMID 16809442). Briefly, cells were transfected with 20 nM siCtrl [GSE4006] or siERα for 48 h after infection. Then cells were treated with 0.1% EtOH (Veh) or 10 nM E2 (Sigma-Aldrich) for 24h. All experiments were conducted with two replicates. key words; Adenovirus infection,siRNA knock-down, ligand treatment
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Project description:Transcriptome analysis of MCF-7 cells exposed for 48 hours to various concentrations of xenoestrogen chemicals. Although biological effects of endocrine disrupting chemicals (EDCs) are often observed at unexpectedly low doses with occasional non-monotonic dose-response characteristics, transcriptome-wide profiles of sensitivities or dose-dependent behaviors of the EDC responsive genes have remained unexplored. Here, we describe expressome analysis for the comprehensive examination of dose-dependent gene responses and its applications to characterize estrogen responsive genes in MCF-7 cells. Transcriptomes of MCF-7 cells exposed to varying concentrations of representative natural and xenobiotic estrogens for 48 hours were determined by microarray and used for computational calculation of interpolated approximations of estimated transcriptomes for 300 doses uniformly distributed in log space for each chemical. The entire collection of these estimated transcriptomes, designated as the expressome, has provided unique opportunities to profile chemical-specific distributions of ligand sensitivities for large numbers of estrogen responsive genes, revealing that at low concentrations estrogens generally tended to suppress rather than to activate transcription. Gene ontology analysis demonstrated distinct functional enrichment between high- and low-sensitivity estrogen responsive genes, supporting the notion that a single EDC chemical can cause qualitatively distinct biological responses at different doses. Expressomal heatmap visualization of dose-dependent induction of Bisphenol A-inducible genes showed a weak gene activation peak at a very low concentration range (ca. 0.1 nM) in addition to the main, strong gene activation peak at and above 100 nM. Thus, expressome analysis is a powerful approach to understanding the EDC dose-dependent dynamic changes in gene expression at the transcriptomal level, providing important information on the overall profiles of ligand sensitivities and non-monotonic responses. Subconfluent density of MCF-7 cells were exposed to various concentrations of xenoestrogen chemicals for 48 hours and then subjected to transcriptomal analysis using Affymetrix U133 version 2 plus microarray.
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Project description:We used Global Run-on and Sequencing (GRO-seq) to measure the rate of transcription elongation by RNA polymerase II (Pol II) following gene activation. We observed that Pol II elongation rates can vary as much as 4-fold at different genomic loci and in response to two distinct cellular signaling pathways (i.e., estrogen and TNFM-NM-1). Elongation rates are slowest near the promoter and increase during the first ~15 kb transcribed into the gene body. Gene body elongation rates correlate with the density of Pol II, consequently resulting in systematically higher rates of transcript production at genes with higher Pol II density. By monitoring Pol II dynamics following short inductions, we found that E2 stimulates gene expression by increasing Pol II initiation, whereas TNFM-NM-1 stimulates the release of Pol II from promoter proximal pause sites. Collectively, our results identify previously uncharacterized variation in the rate of Pol II elongation and highlight elongation as an important, variable, and regulated rate limiting step in the transcription cycle. Using GRO-seq over a time course (0, 10, 25, and 40 min) of estrogen signaling in ER-alpha positive MCF-7 human breast cancer cells.
2013-04-10 | E-GEOD-41324 | biostudies-arrayexpress
Project description:The closely related transcription factors (TFs), estrogen receptors ER? and ER?, regulate divergent gene expression programs and proliferative outcomes in breast cancer. Utilizing MCF-7 breast cancer cells with ER?, ER?, or both receptors as a model system to define the basis of differing response specification by related TFs, we show that these TFs and their key coregulators, SRC3 and RIP140, generate overlapping as well as unique chromatin-binding and transcription-regulating modules. Cistrome and transcriptome analyses and use of clustering algorithms delineated 11 clusters representing different chromatin-bound receptor and coregulator assemblies that could be functionally associated through enrichment analysis with distinct patterns of gene regulation and preferential coregulator usage, RIP140 with ER? and SRC3 with ER?. The receptors modified each other’s transcriptional effect, and ER? countered the proliferative drive of ER? through several novel mechanisms associated with specific binding site clusters. Our findings delineate distinct TF-coregulator assemblies that function as control nodes specifying precise patterns of gene regulation, proliferation, and metabolism, as exemplified by two of the most important nuclear hormone receptors in human breast cancer. Examination of Estrogen Receptors alpha and beta and their coregulators SRC3 and RIP140 in different cell types
2013-07-05 | E-GEOD-42348 | biostudies-arrayexpress