MiRNA expression data from MCF-7, LCC2 and LCC9 cells
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ABSTRACT:
ORGANISM(S): synthetic construct Homo sapiens
PROVIDER: GSE159979 | GEO | 2020/11/18
REPOSITORIES: GEO
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Project description:Acquired resistance to tamoxifen and fulvestrant is a challenging clinical problem in the treatment of hormone receptor-positive breast cancer patients. Non-coding RNAs (ncRNAs) could contribute to endocrine resistance but their specific roles in tamoxifen and fulvestrant resistance are not fully understood.
2020-11-18 | GSE159980 | GEO
Project description:Acquired resistance to tamoxifen and fulvestrant is a challenging clinical problem in the treatment of hormone receptor-positive breast cancer patients. Non-coding RNAs (ncRNAs) could contribute to endocrine resistance but their specific roles in tamoxifen and fulvestrant resistance are not fully understood.
2020-11-18 | GSE159968 | GEO
Project description:Emergence of antiestrogen-resistant cells in MCF-7 cells during suppression of estrogen signaling is a widely accepted model of acquired breast cancer resistance to endocrine therapy. To obtain insight into the genomic basis of endocrine therapy resistance, we characterized MCF-7 monoclonal sublines that survived 21-day exposure to tamoxifen (T-series sublines) or fulvestrant (F-series sublines) and sublines unselected by drugs (U-series). All T/F-sublines were resistant to the cytocidal effects of both tamoxifen and fulvestrant. However, their responses to the cytostatic effects of fulvestrant varied greatly, and their remarkably diversified morphology showed no correlation with drug resistance. mRNA expression profiles of the U-sublines differed significantly from those of the T/F-sublines, whose transcriptomal responsiveness to fulvestrant was largely lost. A set of genes strongly expressed in the U-sublines successfully predicted metastasis-free survival of breast cancer patients. Most T/F-sublines shared highly homogeneous genomic DNA aberration patterns that were distinct from those of the U-sublines. Genomic DNA of the U-sublines harbored many aberrations that were not found in the T/F-sublines. These results suggest that the T/F-sublines are derived from a common monoclonal progenitor that lost transcriptomal responsiveness to antiestrogens as a consequence of genetic abnormalities many population doublings ago, not from the antiestrogen-sensitive cells in the same culture during the exposure to antiestrogens. Thus, the apparent acquisition of antiestrogen resistance by MCF-7 cells reflects selection of preexisting drug-resistant subpopulations without involving changes in individual cells. Our results suggest the importance of clonal selection in endocrine therapy resistance of breast cancer.
2009-08-27 | GSE14986 | GEO
Project description:Endocrine therapy resistance remains a critical problem in the treatment of estrogen receptor alpha (ERα) breast cancer. Endocrine therapies target ERα via different modes of action. Drug resistance involves drug specific remodeling of the transcriptional and regulatory landscape. Using epigenomics and transcriptomics, we demonstrate that resistance to aromatase inhibitors (AI) induces phenotypical changes through epigenetic activation of cholesterol biosynthesis (CB) and keratin 80. Epigenetic activation is stable and involves both large topological domains and punctuated activation of single enhancers and super-enhancers. Specialized cancer cells expressing high levels of keratin 80 lead invasion through the extracellular matrix. Strikingly, we demonstrate that anti-cholesterol strategies can effectively arrest breast cancer invasion. Our work identifies a robust strategy to target resistant invasive breast cancer. All cell lines were grown in their respective media until they reached 70% confluency. Specifically, MCF7 were grown in DMEM+10% FBS and 1% Pen-Sprep-Glutamine. MCF7T as MCF7 with the addition of 100nM Tamoxifen. MCF7F as MCF7 with the addition of 100nM Fulvestrant. LTED were grown in DMEM without phenol + 10% DCS-FBS and1% Pen-Sprep-Glutamine. LTEDT as LTED with the addition of 100nM Tamoxifen. LTEDF as LTED with the addition of 100nM of Fulvestrant. All chemicals are purchased from Sigma. ChIP-seq was performed using Illumina methodology.
2015-12-31 | E-GEOD-60517 | biostudies-arrayexpress
Project description:Phosphoinositide-3-kinase/protein-kinaseB/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling plays an important role in breast cancer (BC). Its interaction with estrogen receptor (ER) signalling becomes more complex and inter-dependent with acquired endocrine resistance. Targeting mTOR combined with endocrine therapy has shown clinical utility, however, a negative feedback-loop exists downstream of PI3K/AKT/mTOR. Direct blockade of AKT together with endocrine therapy may improve BC treatment. AZD5363, a novel pan-AKT kinase catalytic inhibitor, was examined in a panel of ER+ BC cell lines (MCF7, HCC1428, T47D, ZR75.1) adapted to long-term-estrogen-deprivation (LTED) or tamoxifen (TamR). AZD5363 caused a dose-dependent decrease in proliferation in all cell lines tested (GI50<500nM) except HCC1428 and HCC1428-LTED. T47D-LTED and ZR75-LTED were the most sensitive of the lines (GI50~100nM). AZD5363 re-sensitised TamR cells to tamoxifen and acted synergistically with fulvestrant. AZD5363 decreased p-AKT/mTOR targets leading to a reduction in ERα-mediated transcription in a context specific manner and concomitant decrease in recruitment of ER and CREB-binding protein (CBP) to estrogen-response-elements located on the TFF1, PGR and GREB1 promoters. Furthermore, AZD5363 reduced expression of cell-cycle-regulatory proteins. Global gene expression highlighted ERBB2-ERBB3, ERK5 and IGF1 signaling pathways driven by MYC as potential feedback-loops. Combined treatment with AZD5363 and fulvestrant showed synergy in an ER+ patient derived xenograft and delayed tumour progression post-cessation of therapy. These data support the combination of AZD5363 with fulvestrant as a potential therapy for BC that is sensitive or resistant to E-deprivation or tamoxifen and that activated AKT is a determinant of response, supporting the need for clinical evaluation. Cell lines were treated in biological triplicates in the absence of estrogen with or without AZD5363 for 24hours in order to identify gene changes associated with perturbation of AKT signalling
2015-06-29 | E-GEOD-69893 | biostudies-arrayexpress
Project description:To investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). Another group received ED plus the antiestrogen fulvestrant (MCF7 wt only). Tumors with acquired or de novo resistance to these endocrine therapies were profiled for mRNA expression using Affymetrix Genechip arrays. Keywords: multiple group comparison
2008-12-01 | GSE8140 | GEO
Project description:To investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). Another group received ED plus the antiestrogen fulvestrant (MCF7 wt only). Tumors with acquired or de novo resistance to these endocrine therapies were profiled for mRNA expression using Affymetrix Genechip arrays. Keywords: multiple group comparison
2008-12-01 | GSE8139 | GEO
Project description:Acquired resistance to endocrine therapy occurs with high frequency in patients with luminal breast cancer (LBC). We report here the establishment of four patient-derived xenograft models of LBC with acquired resistance in vivo to tamoxifen and estrogen deprivation. CEL files represent expresison data generated from 5 replicates (independent mice) of the following tumor models: HBCx22 (parental), HBCx22 TamR (tamoxifen-resistant), HBCx22 OvaR (ovariectomy-resistant), HBCx34 (parental), HBCx34 TamR (tamoxifen-resistant), HBCx34 OvaR (ovariectomy-resistant)
2014-07-09 | E-GEOD-55561 | biostudies-arrayexpress
Project description:To investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). Another group received ED plus the antiestrogen fulvestrant (MCF7 wt only). Tumors with acquired or de novo resistance to these endocrine therapies were profiled for mRNA expression using Affymetrix Genechip arrays. This SuperSeries is composed of the SubSeries listed below.
2008-12-01 | GSE8141 | GEO
Project description:Acquired resistance to endocrine therapy occurs with high frequency in patients with luminal breast cancer (LBC). We report here the establishment of four patient-derived xenograft models of LBC with acquired resistance in vivo to tamoxifen and estrogen deprivation.
2014-07-09 | GSE55561 | GEO