Expression data from MCF7 and BT474 cell lines after long term estrogen deprivation culture
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE50820 | GEO | 2013/10/02
SECONDARY ACCESSION(S): PRJNA219180
REPOSITORIES: GEO
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Project description:MCF7 and BT474 cell lines were exposed to LTED culture for 0 and 2 days, 6 weeks and 10 months and monitored for changes in gene expression MCF7 0 days vs 2 days, 6 weeks and 10 months, BT474 0 days vs 2 days, 6 weeks and 10 months
2013-10-02 | E-GEOD-50820 | biostudies-arrayexpress
Project description:Endocrine therapies targeting the proliferative effect of 17β-estradiol (17βE2) through estrogen receptor α (ERα) are the most effective systemic treatment of ERα-positive breast cancer. However, most breast tumors initially responsive to these therapies develop resistance through a molecular mechanism that is not yet fully understood. The long-term estrogen-deprived (LTED) MCF7 cell model has been proposed to recapitulate acquired resistance to aromatase inhibitors (AIs) in postmenopausal women. To elucidate this resistance, genomic, transcriptomic and molecular data were integrated into the time course of MCF7-LTED adaptation. Dynamic and widespread genomic changes were observed, including amplification of the ESR1 locus consequently linked to an increase in ERα. Dynamic transcriptomic profiles were also observed that correlated significantly with genomic changes and were influenced by transcription factors known to be involved in acquired resistance or cell proliferation (e.g. IRF1 and E2F1, respectively) but, notably, not by canonical ERα transcriptional function. Consistently, at the molecular level, activation of growth factor signaling pathways by EGFR/ERBB/AKT and a switch from phospho-Ser118 (pS118)- to pS167-ERα were observed during MCF7-LTED adaptation. Evaluation of relevant clinical settings identified significant associations between MCF7-LTED and breast tumor transcriptome profiles that characterize ERα-negative status, early response to letrozole and recurrence after tamoxifen treatment. This study proposes a mechanism for acquired resistance to estrogen deprivation that is coordinated across biological levels and independent of canonical ERα function.
2010-09-01 | GSE20361 | GEO
Project description:Endocrine therapies targeting the proliferative effect of 17β-estradiol (17βE2) through estrogen receptor α (ERα) are the most effective systemic treatment of ERα-positive breast cancer. However, most breast tumors initially responsive to these therapies develop resistance through a molecular mechanism that is not yet fully understood. The long-term estrogen-deprived (LTED) MCF7 cell model has been proposed to recapitulate acquired resistance to aromatase inhibitors (AIs) in postmenopausal women. To elucidate this resistance, genomic, transcriptomic and molecular data were integrated into the time course of MCF7-LTED adaptation. Dynamic and widespread genomic changes were observed, including amplification of the ESR1 locus consequently linked to an increase in ERα. Dynamic transcriptomic profiles were also observed that correlated significantly with genomic changes and were influenced by transcription factors known to be involved in acquired resistance or cell proliferation (e.g. IRF1 and E2F1, respectively) but, notably, not by canonical ERα transcriptional function. Consistently, at the molecular level, activation of growth factor signaling pathways by EGFR/ERBB/AKT and a switch from phospho-Ser118 (pS118)- to pS167-ERα were observed during MCF7-LTED adaptation. Evaluation of relevant clinical settings identified significant associations between MCF7-LTED and breast tumor transcriptome profiles that characterize ERα-negative status, early response to letrozole and recurrence after tamoxifen treatment. This study proposes a mechanism for acquired resistance to estrogen deprivation that is coordinated across biological levels and independent of canonical ERα function. LTED (long term estrogen deprived) cell line was generated from MCF-7 cells by long-term culture under estrogen deprivated conditions. And RNA samples were obtained after 3, 15, 30, 90, 120, 150 and 180 days.
2010-09-01 | E-GEOD-20361 | biostudies-arrayexpress
Project description:Wild type (wt) MCF7 cells, modelling breast cancer at primary diagnosis, were cultured in phenol red-free RPMI supplemented with 10% FBS and 1nM estradiol (E2). Long-term oestrogen deprived (LTED) cell lines, which model resistance to endocrine therapy, were cultured in phenol red-free RPMI in the absence of exogenous E2 and supplemented with 10% dextran charcoal-stripped bovine serum (DCC). Samples were harvested at baseline and at the point of resistance (LTED). In order to do comparative analysis in the ER-interactome of wt-MCF7 and MCF7-LTED cells, ER-RIME (rapid immunoprecipitation mass spectrometry of endogenous proteins) was conducted in these cells.
2020-07-13 | PXD004648 | Pride
Project description:To identify novel therapeutic opportunities for patients with acquired resistance to endocrine treatments in breast cancer, we applied a high-throughput drug screen. The IC50 values were determined for MCF7 and MCF7-LTED cells.
2014-03-17 | GSE38829 | GEO
Project description:The human oestrogen-positive breast cancer cell line MCF7 was cultured in phenol red-free RPMI medium supplemented with 10% fetal bovine serum, 10mg/ml insulin and 1nM estradiol (E2) and was referred to as wild-type MCF7. The wt-MCF7 cells were passaged weekly and medium was replenished every two to three days. To model acquisition of resistance to long term estrogen deprivation (LTED) on an aromatase inhibitor (AI), wt-MCF7 cells were cultured in phenol red-free RPMI medium supplemented with 10% dextran charcoal-stripped bovine serum (DCC) and 10mg/ml insulin. RNA was extracted from the LTED monolayers using RNeasy columns (Qiagen) according to manufacturerﾒs protocol. RNA amplification, labeling and hybridization on HumanWG-6 v3 Expression BeadChips were performed according to the manufacturer's instructions (http://www.illumina.com) to assess changes in gene expression during adaptation to LTED.
2012-05-03 | E-MTAB-922 | biostudies-arrayexpress
Project description:Wild type (wt) MCF7 cells, modelling breast cancer at primary diagnosis, were cultured in phenol red-free RPMI supplemented with 10% FBS and 1nM estradiol (E2). Long-term oestrogen deprived (LTED) cell lines, which model resistance to endocrine therapy, were cultured in phenol red-free RPMI in the absence of exogenous E2 and supplemented with 10% dextran charcoal-stripped bovine serum (DCC). Samples were harvested at baseline and at the point of resistance (LTED). To reveal differential protein abundances between wt-MCF7 and MCF7 LTED, the peptides were labelled with chemical labelling and underwent fractionation using OFFGEL electrophoresis.
2016-06-01 | PXD004085 | Pride
Project description:Therapies targeting estrogenic stimulation in estrogen receptor positive (ER+) breast cancer (BC) reduce mortality, but resistance remains a major clinical problem. Molecular studies have shown few high frequency mutations to be associated with endocrine resistance. In contrast, expression profiling of primary ER+ BC samples has identified several promising signatures/networks for targeting. In this study, the cholesterol biosynthesis pathway was the common upregulated pathway in the ER+ LTED but not ER- LTED cell lines, suggesting a potential mechanism dependent on continued ER expression. Targeting the individual genes of the cholesterol biosynthesis pathway with siRNAs caused a 30-50% drop in proliferation. Further analysis showed increased expression of 25-hydroxycholesterol (HC) in the MCF7 LTED cells. Exogenous 25-HC or 27-HC increased ER mediated-transcription and expression of the endogenous estrogen-regulated gene TFF1 in ER+ LTED cells but not in the ER-negative LTED. Additionally, recruitment of the ER and CREB-binding protein (CBP) to the TFF1 promoter was increased upon treatment with 25-HC and 27-HC. In silico analysis of 704 primary ER+ BC patients treated with adjuvant tamoxifen showed increased expression of MSMO1 (p=0.047), EBP (p=0.043), SQLE (p=0.000009), and IDI1 (p=0.0005), enzymes required for cholesterol synthesis and increased in our in vitro models of endocrine resistance, to be associated with poor relapse-free survival. In contrast, no association was identified in over 700 patients with ER-negative BC. Taken together, these data provide support for the role of cholesterol biosynthesis enzymes and the cholesterol metabolites, 25-HC and 27-HC, in a novel mechanism of resistance to endocrine therapy in ER+ BC that has potential as a therapeutic target.
2016-05-20 | GSE75971 | GEO
Project description:To identify novel therapeutic opportunities for patients with acquired resistance to endocrine treatments in breast cancer, we applied high-throughput screening to explore currently marketed drugs. The Ec50 values were determined for MCF7 and LTED cell lines to identify the compounds showing higher inhibition of LTED cells. The best compound was YC-1 and gene microarray studies were done in vitro for mechanistic exploration. MCF7 and LTED cells were treated with YC-1 for RNA extraction and hybridization on Affymetrix microarrays.
2014-03-17 | E-GEOD-38829 | biostudies-arrayexpress
Project description:Hyperactivation of phosphatidylinositol-3 kinase (PI3K) promotes escape from hormone dependence in estrogen receptor-positive breast cancer. A significant fraction of breast cancers exhibit de novo or acquired resistance to estrogen deprivation. We used gene expression microarrays to identify genes and pathways that are commonly dysregulated in ER+ cell lines with acquired hormone-independent growth. MCF-7, ZR75-1, MDA-361, and HCC-1428 ER+, estrogen-responsive breast cancer cells were cultured under hormone-depleted conditions (10% DCC-FBS) for several months until sustainable hormone-independent cell populations emerged. Parental and long-term estrogen-deprived (LTED) cells were treated with 10% dextran-coated charcoal-treated fetal bovine serum (DCC-FBS) x 24 hrs prior to RNA harvest for array analysis.
2010-06-23 | E-GEOD-19639 | biostudies-arrayexpress