Microarray: Discovery of a glucocorticoid receptor (GR) activity signature using selective GR antagonism in ER-negative breast cancer
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PROVIDER: PRJNA453420 | ENA |
REPOSITORIES: ENA
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Project description:HGU133+2.0 Microarray on TNBC cells (MDA-MB-231) treated for 4, 8, or 12h with vehicle, 100nM dexamethasone, 100nM Dex/100nM Mifepristone, or 100nM Dex/100nM CORT108297 Purpose: Although high glucocorticoid receptor (GR) expression in early-stage estrogen receptor (ER)-negative breast cancer (BC) is associated with shortened relapse-free survival (RFS), how associated GR transcriptional activity contributes to aggressive BC behavior is not well understood. Using potent GR antagonists and primary tumor gene expression data, we sought to identify a tumor-relevant gene signature based on GR activity that would be more predictive than GR expression alone. Design: Global gene expression and GR ChIP-sequencing were performed to identify GR-regulated genes inhibited by two chemically distinct GR antagonists, mifepristone and CORT108297. Differentially expressed genes from MDA-MB-231 cells were cross-evaluated with significantly expressed genes in GR-high versus GR-low ER-negative primary BCs. The resulting subset of GR targeted genes was analyzed in two independent ER-negative BC cohorts to derive and then validate the GR activity signature (GRsig). Results: Gene expression pathway analysis of glucocorticoid-regulated genes (inhibited by GR antagonism) revealed cell survival and invasion functions. GR ChIP-seq analysis demonstrated that GR antagonists decreased GR chromatin association for a subset of genes. A GRsig comprised of n=74 GR activation-associated genes (also reversed by GR antagonists) was derived from an adjuvant chemotherapy-treated Discovery cohort and found to predicted probability of relapse in a separate Validation cohort (HR=1.9; p= 0.012). Conclusions: The GRsig discovered herein identifies high-risk ER-negative/GR-positive BCs most likely to relapse despite administration of adjuvant chemotherapy. Because GR antagonism can reverse expression of these genes, we propose that addition of a GR antagonist to chemotherapy may improve outcome of these high-risk patients.
2018-04-25 | GSE113571 | GEO
Project description:Purpose: Although high glucocorticoid receptor (GR) expression in early-stage estrogen receptor (ER)-negative breast cancer is associated with shortened relapse-free survival (RFS), how associated GR transcriptional activity contributes to aggressive breast cancer behavior is not well understood. Using potent GR antagonists and primary tumor gene expression data, we sought to identify a tumor-relevant gene signature based on GR activity that would be more predictive than GR expression alone.Experimental Design: Global gene expression and GR ChIP-sequencing were performed to identify GR-regulated genes inhibited by two chemically distinct GR antagonists, mifepristone and CORT108297. Differentially expressed genes from MDA-MB-231 cells were cross-evaluated with significantly expressed genes in GR-high versus GR-low ER-negative primary breast cancers. The resulting subset of GR-targeted genes was analyzed in two independent ER-negative breast cancer cohorts to derive and then validate the GR activity signature (GRsig).Results: Gene expression pathway analysis of glucocorticoid-regulated genes (inhibited by GR antagonism) revealed cell survival and invasion functions. GR ChIP-seq analysis demonstrated that GR antagonists decreased GR chromatin association for a subset of genes. A GRsig that comprised n = 74 GR activation-associated genes (also reversed by GR antagonists) was derived from an adjuvant chemotherapy-treated Discovery cohort and found to predict probability of relapse in a separate Validation cohort (HR = 1.9; P = 0.012).Conclusions: The GRsig discovered herein identifies high-risk ER-negative/GR-positive breast cancers most likely to relapse despite administration of adjuvant chemotherapy. Because GR antagonism can reverse expression of these genes, we propose that addition of a GR antagonist to chemotherapy may improve outcome for these high-risk patients. Clin Cancer Res; 24(14); 3433-46. ©2018 AACR.
| S-EPMC6530562 | biostudies-literature
Project description:Analysis of MCF-7 cells treated for 4h with Ethanol, Estradiol (E2), Dexamethasone (Dex), or Estradiol + Dexamethasone (E2 + Dex) In estrogen receptor (ER)-negative breast cancer (BC), high tumor glucocorticoid receptor (GR) expression has been associated with a relatively poor outcome. In contrast, using a meta-analysis of several genomic datasets, here we find that tumor GR mRNA expression is associated with improved ER+ relapse-free survival (RFS) (independently of progesterone receptor (PR) expression). To understand the mechanism by which GR expression is associated with a better ER+ BC outcome, the global effect of GR-mediated transcriptional activation in ER+ BC cells was studied. Analysis of GR chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) in ER+/GR+ MCF-7 cells revealed that upon co-activation of GR and ER, GR chromatin association became enriched at proximal promoter regions. Furthermore, following ER activation, increased association of GR was observed at ER, FOXO, and AP1 response elements. In addition, it was determined that ER associated with GR response elements, suggesting that ER and GR interact in a complex. Co-activation of GR and ER resulted in increased expression (relative to ER activation alone) of transcripts that encode proteins promoting cellular differentiation (e.g. KDM4B, VDR) and inhibiting Wnt-signaling (IGFBP4). Finally, expression of these individual pro-differentiation genes was associated with significantly improved RFS in ER+ BC patients. Together, these data demonstrate that the co-expression and subsequent activity of tumor cell GR and ER contribute to the less aggressive natural history of early-stage BC by coordinating the altered expression of genes favoring differentiation. Four treatment samples (Vehicle V, Dex D, E2, or Dex+E2). Three biological replicate experiments per sample. Vehicle sample is Ethanol control.
2016-04-01 | E-GEOD-79761 | biostudies-arrayexpress
Project description:Analysis of MCF-7 cells treated for 4h with Ethanol, Estradiol (E2), Dexamethasone (Dex), or Estradiol + Dexamethasone (E2 + Dex) In estrogen receptor (ER)-negative breast cancer (BC), high tumor glucocorticoid receptor (GR) expression has been associated with a relatively poor outcome. In contrast, using a meta-analysis of several genomic datasets, here we find that tumor GR mRNA expression is associated with improved ER+ relapse-free survival (RFS) (independently of progesterone receptor (PR) expression). To understand the mechanism by which GR expression is associated with a better ER+ BC outcome, the global effect of GR-mediated transcriptional activation in ER+ BC cells was studied. Analysis of GR chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) in ER+/GR+ MCF-7 cells revealed that upon co-activation of GR and ER, GR chromatin association became enriched at proximal promoter regions. Furthermore, following ER activation, increased association of GR was observed at ER, FOXO, and AP1 response elements. In addition, it was determined that ER associated with GR response elements, suggesting that ER and GR interact in a complex. Co-activation of GR and ER resulted in increased expression (relative to ER activation alone) of transcripts that encode proteins promoting cellular differentiation (e.g. KDM4B, VDR) and inhibiting Wnt-signaling (IGFBP4). Finally, expression of these individual pro-differentiation genes was associated with significantly improved RFS in ER+ BC patients. Together, these data demonstrate that the co-expression and subsequent activity of tumor cell GR and ER contribute to the less aggressive natural history of early-stage BC by coordinating the altered expression of genes favoring differentiation.
2016-04-01 | GSE79761 | GEO
Project description:The estrogen receptor (ER), glucocorticoid receptor (GR), and forkhead box protein 1 (FoxA1) are significant factors in breast cancer progression. FoxA1 is well-established as a pioneer factor for steroid receptor recruitment to chromatin. Here we show that ER and GR have the ability to alter the genomic response of FoxA1 to specific binding sites within the genome. These findings alter the classical understood mechanism of FoxA1 establishing a dynamic transcription factor that can be regulated by hormones.
2016-04-08 | GSE72249 | GEO
Project description:Glucocorticoids are primary stress hormones and their synthetic derivatives are widely used clinically. The therapeutic efficacy of these steroids is limited by severe side effects and glucocorticoid resistance. Multiple glucocorticoid receptor (GR) isoforms are produced by alternative translation initiation; however, the role individual isoforms play in controlling tissue-specific responses to glucocorticoids in vivo is unknown. We have generated knockin mice that exclusively express the most active receptor isoform, GR-C3. The GR-C3 knockin mice die at birth due to respiratory distress but can be completely rescued by antenatal glucocorticoid administration. To evaluate the GR-C3 transcriptome, we prepared mouse embryonic fibroblasts (MEFs) from E12.5 wild-type (WT) and GR-C3 knockin embryos and treated the cells with vehicle or the synthetic glucocorticoid Dexamethasone (Dex) for 6 hours. The GR-C3 isoform was found to have a markedly different gene-regulatory profile than GR in WT MEFs.
2018-04-23 | GSE103675 | GEO
Project description:Muscle fibers have the capacity to modulate their size in response to hormones, including glucocorticoids. Their effects are mediated by the ubiquitously expressed glucocorticoid receptor (GR). However, GR-mediated transcriptional regulation in skeletal muscle at physiological glucocorticoid levels remains elusive. Our study reveals an increased expression of numerous anabolic factors in GR-deficient myofibers, and a reduced expression of antianabolic factors, leading to fiber hypertrophy. Genome-wide analyses demonstrate that myofiber GR controls broad gene networks by binding to glucocorticoid response elements (GREs) at enhancers. Moreover, we provide topological and molecular insights into the chromatin landscape of GR-controlled genes in myofibers. We demonstrate that cooperative binding of GR with the transcription factors Myod1 and Foxf2 in enhancer regions, in collaboration with Nrf1 at promoters, plays a key role in the negative regulation of muscle mass. Thus, these results open new perspectives to counteract muscle weakness in various diseases.
2021-04-10 | GSE144228 | GEO
Project description:Glucocorticoid (GC) response elements (GREs) are genomic segments that confer GC-regulated transcription by recruiting hormone-bound glucocorticoid receptor (GR) and nucleating assembly of transcriptional regulatory complexes (TRCs). The locations of GR binding, the functionality of those GR occupied regions (GORs) as GREs, and the molecular features and spatial organization that characterize active GREs are gene-, cell- and physiological-context specific, and poorly understood. Moreover, identification of the gene(s) targeted for regulation by a given GRE has been inferred by proximity, or examined outside the normal chromosomal context, rather than rigorously validated. We approached these issues in two human cell lines with distinct tissue origins, treated or not with a hormonal ligand that activates GR.
2020-12-18 | GSE163398 | GEO
Project description:In response to environmental stressors and a variety of inflammatory cytokines, p38 MAPKs become directly activated. Here we report the human glucocorticoid receptor (GR) Serine 134 as a novel target for p38 MAPK. Unlike most other phosphorylation events that occur on the GR, phosphorylation of Ser134 was found to be hormone-independent in several human and rat cell types. Instead we found phosphorylation of Ser134 was induced by a variety of stress-activating stimuli, including: glucose starvation, ultraviolet irradiation, osmotic shock, and oxidative stress. Pharmacological inhibitors and shRNA-mediated knockdown experiments correlate this phosphorylation with the activation of p38 MAPK. Compared to wild-type GR, cells expressing a mutant receptor incapable of phosphorylation at Ser134 (S134A GR) had a significantly altered hormone-dependent genome-wide transcriptional response to glucocorticoids. Moreover, we show that although WT GR regulated roughly half as many genes as S134A GR, WT receptor selectively activated significantly more genes associated with endocrine and inflammatory disease than the mutant receptor, suggesting that the phosphorylation status of Ser134 is critical for modulating GR function. Phosphorylation of Ser134 did not alter either nuclear translocation or the stability of the GR protein in the absence or presence of ligand. However, phosphorylation of Ser134 significantly increased the association of the GR with the zeta isoform the 14-3-3 class of signaling proteins, resulting in a blunted hormone-dependent transcriptional response of LAD1 and IGFBP1 but not GILZ. Together these data suggest that the phosphorylation of Ser134 acts as a molecular sensor on the GR, monitoring the level of cellular stress to allow for altered 14-3-3zeta cofactor association, ultimately modifying glucocorticoid signaling in a gene-dependent manner. Our results reveal one mechanism that may allow cellular stress to dictate the transcriptional response of cells to hormone. U2OS cells, a human osteosarcoma cell line, were transfected with either WT GR or S134A GR and put under antibiotic selection to produce a stable mixed population of cells expressing comparable levels of GR. 10^6 cells were treated with 100nM Dexamethasone (DEX) or vehicle control for 6 hours. Three biological and one hybridization replicate are included for each sample.
2011-10-04 | E-GEOD-28912 | biostudies-arrayexpress
Project description:Estrogen receptor-positive (ER+) invasive lobular breast cancer (ILC) comprises about ~15% of breast cancer. ILC’s unique genotypic (loss of wild type E-cadherin expression) and phenotypic (small individual round cancer cells that grow in discontinuous nests) are thought to contribute to a distinctive pattern of metastases to serosal membranes. Unlike invasive ductal carcinoma (IDC), ILC metastases often intercalate into the mesothelial layer of the peritoneum and other serosal surfaces. While ER activity is a known driver of ILC proliferation, very little is known about how additional nuclear receptors contribute to ILC’s distinctive biology. In ER+ IDC, we showed previously that glucocorticoid receptor (GR) activity inhibits pro-proliferative gene expression and cell proliferation. Here we examined ER+ ILC models and find that GR activation similarly reduces S-phase entry gene expression and ILC proliferation. While slowing tumor growth rate, our data also suggest that GR activation results in an enhanced metastatic phenotype through increasing integrin-encoding gene expression, extracellular matrix protein adhesion, and mesothelial cell clearance. Moreover, in an intraductal mouse mammary gland model of ILC, we found that GR expression is associated with increased metastases despite slowed primary mammary tumor growth. Taken together, our findings suggest GR-mediated gene expression may contribute to the unusual characteristics of ILC biology.
2023-09-04 | GSE241992 | GEO