Homo sapiens
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PROVIDER: PRJNA255515 | ENA |
REPOSITORIES: ENA
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Project description:The emergence of anti-estrogen resistance in breast cancer is an important clinical phenomenon affecting long-term survival in this disease. Identifying factors that convey cell survival in this setting may guide improvements in treatment. Estrogen (E2) can induce apoptosis in breast cancer cells that have been selected for survival after E2 deprivation for long periods (MCF-7:5C cells), but the mechanisms underlying E2-induced stress in this setting have not been elucidated. Here, we report that the c-Src kinase functions as a key adapter protein for the estrogen receptor (ER, ESR1) in its activation of stress responses induced by E2 in MCF-7:5C cells. E2 elevated phosphorylation of c-Src, which was blocked by 4-hydroxytamoxifen (4-OHT), suggesting that E2 activated c-Src through the ER. We found that E2 activated the sensors of the unfolded protein response (UPR), IRE1? (ERN1) and PERK kinase (EIF2AK3), the latter of which phosphorylates eukaryotic translation initiation factor-2? (eIF2?). E2 also dramatically increased reactive oxygen species production and upregulated expression of heme oxygenase HO-1 (HMOX1), an indicator of oxidative stress, along with the central energy sensor kinase AMPK (PRKAA2). Pharmacologic or RNA interference-mediated inhibition of c-Src abolished the phosphorylation of eIF2? and AMPK, blocked E2-induced ROS production, and inhibited E2-induced apoptosis. Together, our results establish that c-Src kinase mediates stresses generated by E2 in long-term E2-deprived cells that trigger apoptosis. This work offers a mechanistic rationale for a new approach in the treatment of endocrine-resistant breast cancer. MCF-7:5C cells were treated with vehicle (0.1% EtOH) as control, E2 (10-9mol/L), 4-OHT (10-6mol/L), E2 (10-9mol/L) plus 4-OHT (10-6mol/L), PP2 (5x10-6mol/L), and E2 (10-9mol/L) plus PP2 (5x10-6mol/L) respectively for 72 hours.
2014-07-18 | E-GEOD-59535 | biostudies-arrayexpress
Project description:The emergence of anti-estrogen resistance in breast cancer is an important clinical phenomenon affecting long-term survival in this disease. Identifying factors that convey cell survival in this setting may guide improvements in treatment. Estrogen (E2) can induce apoptosis in breast cancer cells that have been selected for survival after E2 deprivation for long periods (MCF-7:5C cells), but the mechanisms underlying E2-induced stress in this setting have not been elucidated. Here, we report that the c-Src kinase functions as a key adapter protein for the estrogen receptor (ER, ESR1) in its activation of stress responses induced by E2 in MCF-7:5C cells. E2 elevated phosphorylation of c-Src, which was blocked by 4-hydroxytamoxifen (4-OHT), suggesting that E2 activated c-Src through the ER. We found that E2 activated the sensors of the unfolded protein response (UPR), IRE1α (ERN1) and PERK kinase (EIF2AK3), the latter of which phosphorylates eukaryotic translation initiation factor-2α (eIF2α). E2 also dramatically increased reactive oxygen species production and upregulated expression of heme oxygenase HO-1 (HMOX1), an indicator of oxidative stress, along with the central energy sensor kinase AMPK (PRKAA2). Pharmacologic or RNA interference-mediated inhibition of c-Src abolished the phosphorylation of eIF2α and AMPK, blocked E2-induced ROS production, and inhibited E2-induced apoptosis. Together, our results establish that c-Src kinase mediates stresses generated by E2 in long-term E2-deprived cells that trigger apoptosis. This work offers a mechanistic rationale for a new approach in the treatment of endocrine-resistant breast cancer.
2014-07-18 | GSE59535 | GEO
Project description:Estrogen deprivation using aromatase inhibitors is currently the standard of care for patients with estrogen-receptor (ER)-positive breast cancer. Unfortunately, prolonged estrogen deprivation leads to drug resistance (i.e. hormone-independent growth). We therefore used DNA microarray analysis to study the gene expression profiles of wild-type MCF-7 cells (which are sensitive to antihormone therapy) and long-term estrogen deprived MCF-7:5C and MCF-7:2A breast cancer cells (which are resistance to estrogen-deprivation; aromatase inhibitor resistant). Transcriptional profiling of wild-type MCF-7 cells and estrogen deprived MCF-7:5C and MCF-7:2A cells was performed using Affymetrix Human Genome U133 Plus 2.0 Array. Keywords: breast cancer cells, estrogen
2008-03-19 | GSE10879 | GEO
Project description:MCF-7:PF is a a new in vitro model of antihormone resistant breast cancer that exhibits the characteristics of acquired tamoxifen resistance in vivo. It is well known that estrogen (E2) induces apoptosis in long-term estrogen-deprived breast cancer cells, MCF-7:5C (PubMed References PMID:15862958, PMID:16333030). MCF-7:PF was derived from MCF-7:5C through inhibition of c-Src, which blocks E2-induced apoptosis, coverts E2 responses from apoptosis to proliferation. MCF-7:PF cell growth is stimulated by E2 and SERMS in an ERα-dependent manner. Abstract: A c-Src inhibitor blocks estrogen (E2)-induced stress and converts E2 responses from inducing apoptosis to stimulating growth in E2-deprived breast cancer cells. A resulting cell line, MCF-7:PF, is reprogrammed with features of functional estrogen receptor (ER) and over-expression of insulin-like growth factor-1 receptor beta (IGF-1Rβ). We addressed the question of whether the antiestrogenic selective ER modulator 4-hydroxytamoxifen (4-OHT) could target ER to prevent E2-stimulated growth in MCF-7:PF cells. Unexpectedly, 4-OHT stimulated cell growth in an ER-dependent manner. However, unlike E2, 4-OHT suppressed classic ER-target genes as does the pure antiestrogen ICI 182,780, even during growth stimulation. Chromatin-immunoprecipitation (ChIP) assay indicated that 4-OHT did not recruit ER or nuclear receptor coactivator 3 (SRC3) to the promoter of ER-target gene, pS2. Paradoxically, 4-OHT reduced total IGF-1Rβ but increased phosphorylation of IGF-1Rβ, which was responsible for the activation of the phosphatidylinositol-3 kinases (PI3K)/Akt signaling pathway. Mechanistic studies revealed that 4-OHT rapidly activated the non-genomic pathway through ER, but other membrane-associated proteins such as IGF-1Rβ and c-Src participated. Furthermore, 4-OHT was more potent than E2 to up-regulate membrane remodeling molecules and activated focal adhesion molecules to promote cell growth. Therefore, disruption of membrane-associated signaling completely abolished 4-OHT-stimulated cell growth, but not E2-stimulated cell growth. Despite continued suppression of classic ER-target genes, 4-OHT activated the complex network of cytoskeleton remodeling and extracellular matrix-related signaling which facilitated 4-OHT-stimulated cell growth. This study is the first to recapitulate a cellular model in vitro of acquired tamoxifen (TAM) resistance developed in athymic mice in vivo.
2014-07-14 | GSE54171 | GEO
Project description:Estrogen deprivation using aromatase inhibitors is currently the standard of care for patients with estrogen-receptor (ER)-positive breast cancer. Unfortunately, prolonged estrogen deprivation leads to drug resistance (i.e. hormone-independent growth). We therefore used DNA microarray analysis to study the gene expression profiles of wild-type MCF-7 cells (which are sensitive to antihormone therapy) and long-term estrogen deprived MCF-7:5C and MCF-7:2A breast cancer cells (which are resistance to estrogen-deprivation; aromatase inhibitor resistant). Transcriptional profiling of wild-type MCF-7 cells and estrogen deprived MCF-7:5C and MCF-7:2A cells was performed using Affymetrix Human Genome U133 Plus 2.0 Array. Experiment Overall Design: We wanted to study the gene expression profiles of the different cell lines in their growth media without any drug treatment. Therefore, MCF-7, MCF-7:5C, and MCF-7:2A cells were grown in estrogen-free media (phenol red-free RPMI medium supplemented with 10% 4X dextran-coated charcoal-treated fetal bovine serum) until they were 70-80% confluent then RNA was extracted, labeled, and hybridized to the Affymetrix Human Genome U133 Plus 2.0 Arrays.
2008-04-05 | E-GEOD-10879 | biostudies-arrayexpress
Project description:A series of MCF-7 variants were previously developed that are either estrogen-dependent for growth (MCF-7:WS8 cells), or resistant to estrogen deprivation and refractory (MCF-7:2A) or sensitive (MCF-7:5C) to E2-induced apoptosis. To identify genes associated with E2-induced apoptosis, estrogen deprivation-resistant/apoptotic-sensitive 5C cells were compared to both estrogen-dependent MCF-7:WS8 and estrogen deprivation/apoptotic-refractory MCF-7:2A cells
2011-11-21 | GSE29917 | GEO
Project description:A series of MCF-7 variants were previously developed that are estrogen-dependent for growth (MCF-7:WS8 cells), or resistant to estrogen deprivation/vulnerable to fast (MCF-7:5C) and delayed (MCF-7:2A) E2-inducible apoptosis. To identify miRNAs associated with aromatase inhibitor (AI)-resistance and vulnerability to E2-induced apoptosis, estrogen deprivation-resistant 5C and 2A cells were compared to estrogen-dependent WS8 cells and among each other.
2017-03-01 | GSE79326 | GEO
Project description:A series of MCF-7 variants were previously developed that are either estrogen-dependent for growth (MCF-7:WS8 cells), or resistant to estrogen deprivation and refractory (MCF-7:2A) or sensitive (MCF-7:5C) to E2-induced apoptosis. To identify genes associated with E2-induced apoptosis, estrogen deprivation-resistant/apoptotic-sensitive 5C cells were compared to both estrogen-dependent MCF-7:WS8 and estrogen deprivation/apoptotic-refractory MCF-7:2A cells Each cell line was treated with 10-9 M E2 or vehicle control over a 96 h time course consisting of 7 time points (2, 6, 12, 24, 48, 72 and 96 h) using 6 biological replicates per condition. cRNA probes from individual E2-treated samples were competitively hybridized against time-matched pooled control probes using 2-color Agilent 4x44k human oligonucleotide microarrays.
2011-11-21 | E-GEOD-29917 | biostudies-arrayexpress
Project description:MCF-7:5C and MCF-7:2A are two in vitro models of Estrogen Receptor alpha positive (ER+) estrogen deprivation-resistant breast cancer. Both cell lines grow robustly in the absence of estrogen [PMID:1301400, PMID:7780972]. MCF-7:PF is an in vitro model of antihormone resistant breast cancer that exhibits the characteristics of acquired tamoxifen resistance [PMID:24183378] The goal of this study was to compare basal levels of gene expression during exponential phase of growth in MCF-7-derived models of endocrine resistance, relative to their isogenic parental cells
2014-11-30 | GSE60079 | GEO
Project description:A c-Src inhibitor blocks estrogen (E2)-induced stress and converts E2 responses from inducing apoptosis to growth stimulation in E2-deprived breast cancer cells. A reprogrammed cell line, MCF-7:PF, results with features of functional estrogen receptor (ER) and over-expression of insulin-like growth factor-1 receptor beta (IGF-1Rβ). We addressed the question of whether the selective ER modulator 4-hydroxytamoxifen (4-OHT) could target ER to prevent E2-stimulated growth in MCF-7:PF cells. Selected expression of mRNA was measured through real-time RT-PCR. Global gene expression was analyzed by microarray and RNA-seq analysis. Unexpectedly, both 4-OHT and E2 stimulated cell growth in a concentration-dependent manner. Global gene expression analysis showed a remarkable overlap in genes regulated in the same direction by E2 and 4-OHT. Pathway enrichment analysis of the 280 genes commonly deregulated by 4-OHT and E2 revealed functions mainly related to membrane, cytoplasm, and metabolic processes. Further analysis of 98 up-regulated genes by both 4-OHT and E2 uncovered a significant enrichment in genes associated with membrane remodeling, cytoskeleton reorganization, cytoplasmic adapter proteins, cytoplasm organelles proteins, and related processes. 4-OHT was more potent than E2 to up-regulate some membrane remodeling molecules, such as EHD2, FHL2, HOMER3 and RHOF. In contrast, 4-OHT acted as an antagonist to inhibit expression of the majority of enriched membrane-associated genes in wild-type MCF-7 cells. Long-term selection pressure has changed the cell population responses to 4-OHT. Membrane-associated signaling is critical for 4-OHT-stimulated cell growth in MCF-7:PF cells. This study provides a rationale for the further investigation of targeted therapy for tamoxifen resistant patients. Wild-type MCF-7 cells were treated with vehicle control (0.1% ethanol), E2 (10-9 mol/L) and 4-OHT (10-6 mol/L) respectively for 24 hours.
2014-07-18 | E-GEOD-59536 | biostudies-arrayexpress