Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA125453 | ENA |
REPOSITORIES: ENA
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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: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: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:We performed ChIP-seq on MCF7 cells in an effort to discern differential binding patterns between wild type MCF7s and MCF7s that have acquired resistance to Tamoxifen and Estrogen deprivation. Furthermore, we also performed an HAtag ChIP on a DOX inducible RUNX2 overexpression MCF7 cell line. We also performed RNA-seq on MCF7 cells to determine transciptional changes after acquisition of Tamoxifen resistance, and also transciptional changes in a DOX inducible RUNX2 overexpression model.
2017-03-01 | GSE86538 | GEO
Project description:Expression data from MCF7 and BT474 cell lines after long term estrogen deprivation culture
| PRJNA219180 | ENA
Project description:Expression data from MCF7 cell line after silencing of Estrogen receptor
| PRJNA138447 | ENA
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
2011-02-19 | GSE20463 | GEO
Project description:Cyclin D1 determines estrogen dependent signaling in human breast cancer cell line MCF7
| PRJNA212533 | ENA
Project description:We report the first discovery of naturally occurring ESR1Y537C and ESR1Y537S mutations in MCF7 and MCF7 ESR1-positive cell-lines after acquisition of resistance to long-term-estrogen-deprivation (LTED) and subsequent resistance to fulvestrant (ICIR).
2018-01-12 | GSE100074 | GEO
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
| S-EPMC2531291 | biostudies-literature