Project description:We have previously demonstrated that endoxifen is the most important tamoxifen metabolite responsible for eliciting the anti-estrogenic effects of this drug in breast cancer cells expressing estrogen receptor-alpha. However, the relevance of estrogen receptor-beta in mediating endoxifen action has yet to be explored. Therefore, the goals of this study were to determine the differences in the global gene expression profiles elicited by estradiol treatment and endoxifen between parental MCF7 breast cancer cells (expressing estrogen receptor alpha only) and MCF7 cells stably expressing estrogen receptor beta. Total RNA was isolated from parental or estrogen-receptor beta expressing MCF7 cells following 24 hour treatments with either ethanol vehicle, 1nM 17-beta-estradiol or 1nM estradiol plus 40nM endoxifen. All studies were conducted in biological replicates of 2.
Project description:We have previously demonstrated that endoxifen is the most important tamoxifen metabolite responsible for eliciting the anti-estrogenic effects of this drug in breast cancer cells expressing estrogen receptor-alpha. However, the relevance of estrogen receptor-beta in mediating endoxifen action has yet to be explored. Therefore, the goals of this study were to determine the differences in the global gene expression profiles elicited by estradiol treatment and endoxifen between parental MCF7 breast cancer cells (expressing estrogen receptor alpha only) and MCF7 cells stably expressing estrogen receptor beta.
Project description:Estrogen receptorï? beta (ER beta) has potent anti-proliferative and anti-inflammatory properties, suggesting that ER beta-selective agonists might be a new class of therapeutic and chemopreventative agents. To understand how ER beta regulates genes, we identified genes regulated by the unliganded and liganded forms of ER alpha and ER beta in U2OS cells. Microarray data demonstrated that virtually no gene regulation occurred with unliganded ER alpha, whereas many genes were regulated by estradiol (E2). These results demonstrate ER alpha requires a ligand to regulate a single class of genes. In contrast, ER beta regulated three classes of genes. Class I genes were regulated primarily by unliganded ER beta. Class II genes were regulated only with E2, whereas Class III genes were regulated by both unliganded ER beta and E2. There were 453 Class I genes, 258 Class II genes and 83 Class III genes. To explore the mechanism whereby ER beta regulates different classes of genes ChIP-seq was performed to identify ER beta binding sites and adjacent transcription factor motifs in regulated genes. AP1 binding sites were more enriched in Class I genes, whereas ERE, NFKB1 and SP1 sites were more enriched in class II genes. ER beta bound to all three classes of genes demonstrating that ER beta binding is not responsible for differential regulation of genes by unliganded and liganded ER beta. The coactivator, NCOA2 was differentially recruited to several target genes. Our findings indicate that the unliganded and liganded forms of ER beta regulate three classes of genes by interacting with different transcription factors and coactivators. U2OS cell lines are stably transfected with a doxycycline-inducible ER alpha or beta. 18 samples are analyzed with triplicate for each of the 6 conditions. The 6 conditions include ER alpha transfected without doxycycline added, ER alpha transfected with doxycycline added, ER alpha transfected with doxycycline added and E2 treatment, ER beta transfected without doxycycline added, ER beta transfected with doxycycline added, and ER beta transfected with doxycycline added and E2 treatment.
Project description:T-47D breast cancer cells were stably transfected with a tet-off inducible construct encoding estrogen receptor beta. Microarray experiments were carried out at multiple time points 1-30 hours following treatment with estradiol and under induction and non-induction conditions. Keywords: Inducible expression of ERbeta
Project description:Gene expression analyses were carried out to identify genes regulated by 17-beta estradiol (E2) and Hydroxytamoxifen (OHT) through GPR30 in SKBR3 cells, a breast cancer cell-line which expresses GPR30 but lacks Estrogen Receptor alpha or beta. Keywords: Gene expression analysis, Non-genomic signaling in breast cancer cells. Gene expression analyses were done for control transfected SKBR3 cells: 1) Uninduced, 2) Induced with 10 microM OHT, 3) Induced with 1 microM E2 and 4) GPR30-antisense transfected cells induced with 10 microM OHT. The cells were induced for 1h and all the samples were collected in triplicates.
Project description:Estrogen receptor alpha (ERa) is required for the protective effects of 17-beta-estradiol (E2, the active, endogenous form of estrogen) after vascular injury or in atherosclerosis. E2-bound ERa can function as a transcription factor which binds directly to chromatin (the genomic pathway). Some ERa is also associated with the plasma membrane and, when bound by E2, activates cellular kinases, including PI3K, Akt and ERK (the rapid signaling pathway). Rapid signaling is mediated by interaction between ERa and the adaptor molecule striatin. Here we identify a triple point mutation (AA 231,233 & 234 KRR->AAA) of full length ERa that blocks its association with striatin and eliminates its ability to perform rapid signaling (without affecting its ability to perform genomic signaling). We have created stably-transfected human vascular endothelial cell lines expressing either WT ERa (WT ECs) or KRR mutant ERa (KRR ECs), and use these cells to show that rapid signaling through ERa is required for the proper regulation of most E2-regulated genes (the data presented in this record), and also for the ability of E2 to stimulate EC migration and proliferation and to inhibit inflammatory monocyte adhesion to ECs. Human Eahy 926 stable cell lines carrying a full length wild-type human estrogen receptor alpha (ERa) expression vector (WT ECs) or a full length KRR mutant ERa expression vector (KRR ECs, where the KRR mutant ERa is deficient in rapid signaling) were treated with or without 17-b-estradiol (E2) for 16 hrs. RNA from 3 bioligical replicates per condition was harvested and used to probe Illumina bead arrays.
Project description:Estrogens exert many important effects in bone, a tissue that contains both estrogen receptors alpha and beta (ERalpha and ERbeta). To compare the actions of these receptors, we generated U2OS human osteosarcoma cells stably expressing ERalpha or ERbeta, at levels comparable to those in osteoblasts, and we characterized their response to estradiol (E2) over time using Affymetrix GeneChip microarrays to determine the expression of approximately 12,000 genes, followed by quantitative PCR verification of the regulation of selected genes. Of the ca. 100 regulated genes we identified, some were stimulated by E2 equally through ERalpha and ERbeta, whereas others were selectively stimulated via ERalpha or ERbeta. The E2-regulated genes showed three distinct temporal patterns of expression over the 48 h time course studied. Of the functional categories of the E2-regulated genes, most numerous were those encoding cytokines and factors associated with immune response, signal transduction, and cell migration and cytoskeleton regulation, indicating that E2 can exert effects on multiple pathways in these osteoblast-like cell lines. Of note, E2 up-regulated several genes associated with cell motility selectively via ERbeta, in keeping with the selective E2 enhancement of the motility of ERbeta-containing cells. On genes regulated equally by E2 via ERalpha or ERbeta, the phytoestrogen genistein preferentially stimulated gene expression via ERbeta. These studies indicate both common as well as distinct target genes for these two ERs, and identify many novel genes not previously known to be under estrogen regulation.
Project description:Estrogen receptor alpha (ERa) is required for the protective effects of 17-beta-estradiol (E2, the active, endogenous form of estrogen) after vascular injury or in atherosclerosis. E2-bound ERa can function as a transcription factor which binds directly to chromatin (the genomic pathway). Some ERa is also associated with the plasma membrane and, when bound by E2, activates cellular kinases, including PI3K, Akt and ERK (the rapid signaling pathway). Rapid signaling is mediated by interaction between ERa and the adaptor molecule striatin. Here we identify a triple point mutation (AA 231,233 & 234 KRR->AAA) of full length ERa that blocks its association with striatin and eliminates its ability to perform rapid signaling (without affecting its ability to perform genomic signaling). We have created stably-transfected human vascular endothelial cell lines expressing either WT ERa (WT ECs) or KRR mutant ERa (KRR ECs), and use these cells to show that rapid signaling through ERa is required for the proper regulation of most E2-regulated genes (the data presented in this record), and also for the ability of E2 to stimulate EC migration and proliferation and to inhibit inflammatory monocyte adhesion to ECs.
Project description:Gene expression analyses were carried out to identify genes regulated by 17-beta estradiol (E2) and Hydroxytamoxifen (OHT) through GPR30 in SKBR3 cells, a breast cancer cell-line which expresses GPR30 but lacks Estrogen Receptor alpha or beta. Keywords: Gene expression analysis, Non-genomic signaling in breast cancer cells.
Project description:This experiment investigates the functional roles of estrogen receptor alpha and beta in peripheral blood leukocytes by using selective estrogen receptor agonists. The agonists that are used are estradiol (E2), the selective ER-alpha agonist PPT (4,4',4''-(4-Propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol) and the selective ER-beta agonist DPN (2,3-bis(4-hydroxyphenyl)-propionitrile).