RNA-sequencing in mouse mastocytoma cell line P815
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE181773 | GEO | 2021/09/14
REPOSITORIES: GEO
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Project description:This study was performed to check that ESR1 and BMI1 are biologically active after lentiviral transduction of primary human mammary epithelial cells (HMECs) with lentiviral vectors expressing ESR1 and BMI1 from the human PGK promoter. ESR1 targets like PGR, PRLR and GREB1, but not TFF1 and XBP1, were induced by estradiol in the ESR1-expressing cells. BMI1 targets like BMI1, NEFL and CCND2 were repressed in the BMI1-expressing cells. BMI1 suppressed genes associated with squamous and neural differentiation in the ESR1 plus BMI1-expressing cells. Experiment Overall Design: Infect with lentiviruses 24 hours after reduction mammmoplasty. Grow cells in human mammosphere medium: Hepes-buffered DMEM/F12 supplemented with 20 ng/ml EGF, 1x B-27 (GIBCO) plus 1 nM 17-β-estradiol or 1 uM fulvestrant (ICI 182,780). Experiment Overall Design: Lentiviral vectors: pSD-82, ESR1; pSD-84, BMI1; pSD-86, gusA.
2008-06-14 | E-GEOD-6548 | biostudies-arrayexpress
Project description:The rediscovery of estrogen receptor (ESR1) mutations in metastatic breast cancer is current clinical scenario. We have modeled the three most frequent ESR1 mutations using stable lentiviral vectors in human breast cancer cell lines, and determined that they confer relative resistance to tamoxifen (Tam) in a cell-type specific manner due to distinct epigenetic changes. Resistance was only observed with concomitant engagement and activation of the insulin growth factor signaling pathway (IGF1R). The ESR1 mutants also exhibited enhanced binding with insulin growth factor receptor beta (IGF1Rβ). The selective estrogen degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while the combination treatment with the mTOR inhibitor everolimus, restored Tam sensitivity. Since we detected relatively high frequencies of these three mutations in primary breast tumors, our results suggest that clinical targeted sequencing of both primary and metastatic tumors may be justified and comination therapies considered.
2017-09-04 | GSE95529 | GEO
Project description:Gene expression profiling of invasive breast cancer events from the tamoxifen prevention trial validates low estrogen receptor mRNA level as the main determinant of tamoxifen resistance in estrogen receptor positive breast cancer. In NSABP Breast Cancer Prevention Trial (BCPT), tamoxifen reduced the incidence of estrogen receptor (ER) positive tumors but not estrogen receptor negative breast cancer. More importantly, only 69% of estrogen receptor positive tumors were prevented by tamoxifen. The ER positive tumors arising in tamoxifen arm provides an ideal clinical model for acquired tamoxifen resistance. Based on data from NSABP trial B14 which showed linear prediction of the degree of benefit from adjuvant tamoxifen by the levels of ESR1 mRNA coding for ER-alpha, we hypothesized a priori that level of ESR1 mRNA would be lower in ER positive tumors arising in tamoxifen arm compared to those in placebo arm of BCPT. Keywords: Gene expression profiling analysis
2011-12-08 | GSE12665 | GEO
Project description:To investigate response or resistance to endocrine therapy, mice with targeted over-expression of Esr1 or CYP19A1 to mammary epithelial cells were employed, representing two direct pathophysiological interventions in estrogen pathway signaling. Both Esr1 and CYP19A1 over-expressing mice responded to letrozole with reduced HAN prevalence and decreased mammary epithelial cell proliferation. CYP19A1 over-expressing mice were tamoxifen-sensitive but Esr1 over-expressing mice were tamoxifen-resistant. Increased ER expression occurred with tamoxifen resistance but no consistent changes in progesterone receptor, pSTAT3, pSTAT5, cyclin D1 or cyclin E levels in association with response or resistance was found. RNA-seq was employed to seek a transcriptome predictive of tamoxifen resistance using these models and a second tamoxifen-resistant model, BRCA1 deficient/Trp53 haploinsufficient mice. Sixty-eight genes associated with immune system processing were upregulated in tamoxifen-resistant Esr1 and Brca1 deficient mice whereas genes related to aromatic compound metabolic process were upregulated in tamoxifen-sensitive CYP19A1 mice. Interferon Regulatory Factor 7 was identified as a key transcription factor regulating these 68 immune processing genes. Two loci encoding novel transcripts with high homology to human IGLL1 were uniquely upregulated in the tamoxifen-resistant models. Letrozole proved to be a successful alternative to tamoxifen. Further study of transcriptional changes associated with tamoxifen resistance including immune-related genes could expand our mechanistic understanding and lead to biomarkers predictive of escape or response to endocrine therapies. Single- and paired-end mRNA-seq with WT, Esr1 over-expressing (CERM, tetracycline-operator(tet-op)-Esr1MMTV-rtTA), CYP19A1 over-expressing (AROM, tet-op-CYP19A1MMTV-rtTA) and Brca1 KO (BRCA, Brca1fl11/fl11/MMTV-Cre/p53+/- ) mice
2014-12-04 | E-GEOD-63857 | biostudies-arrayexpress
Project description:Reproductive senescence is an age-associated process in which reproductive capacity is reduced. In female mice this is associated with loss of oocytes and a corresponding reduction in ovarian estrogen production. Normal mammary gland development and function is linked to estrogen stimulation. In this study we utilize two genetically engineered mouse models of breast cancer risk, one with mammary-targeted conditional expression of Esr1, the RNA that encodes Estrogen Receptor alpha, and one with mammary-targeted conditional expression of CYP19A1, the RNA that encodes Aromatase, the enzyme that is responsible for estrogen synthesis from androgens to determine how reproductive senescence impacts the transcriptional response to commonly used anti-hormonals employed for breast cancer prevention, tamoxifen and letrozole. The goals of the study are, first, to test the extent to which each of these anti-hormonals alter the mammary gland transcriptome in mice undergoing reproductive senescence and, second, determine if the response is the same or different in the presence of Esr1 as compared to CYP19A1 transgene expression targeted to mammary epithelial cells. The objectives are to identify specific genes that are significantly differentially expressed genes within each model between treatment conditions control, tamoxifen and letrozole as well as between models under each of these conditions. Transcriptome comparisons between 18- and 20-month-old mice are used to identify differences between the two models as ovarian function diminishes during reproductive senescence. Transcriptome comparisons between cohorts of 20-month-old mice that received no anti-hormonal or a two-month-exposure to tamoxifen or letrozole beginning at age 18 months are used to identify similarities and differences between the two anti-hormonal treatments as well as similarities and differences between models.
2022-08-07 | GSE201326 | GEO
Project description:Estrogen Receptor (ESR1) drives growth in the majority of human breast cancers by binding to regulatory elements and inducing transcription events that promote tumor growth. Differences in enhancer occupancy by ESR1, contribute to the diverse expression profiles and clinical outcome observed in breast cancer patients. GATA3 is an ESR1 co-operating transcription factor mutated in breast tumors, however its genomic properties are not fully defined. In order to investigate the composition of enhancers involved in estrogen-induced transcription and the potential role of GATA3, we performed extensive ChIP-sequencing in unstimulated breast cancer cells and following estrogen treatment. We find that GATA3 is pivotal in mediating enhancer accessibility at regulatory regions involved in ESR1-mediated transcription. GATA3 silencing resulted in a global redistribution of co-factors and active histone marks prior to estrogen stimulation. These global genomic changes altered the ESR1 binding profile that subsequently occurred following estrogen, with events exhibiting both loss and gain in binding affinity, implying a GATA3 mediated re-distribution of ESR1 binding. The GATA3-mediated re-distributed ESR1 profile correlated with changes in gene expression, suggestive of its functionality. Chromatin loops at the TFF locus involving ESR1 bound enhancers occurred independently of ESR1 when GATA3 was silenced, indicating that GATA3, when present on the chromatin, may serve as a licensing factor for estrogen- ESR1 mediated interactions between cis-regulatory elements. Together these experiments suggest that GATA3 directly impacts ESR1 enhancer accessibility and may potentially explain the contribution of mutant-GATA3 in the heterogeneity of ESR1+ breast cancer. GATA and ER binding studied by chromatin immunoprecipitation in breast cancer cell lines, with and without estrogen stimulation and by knocking down GATA
2012-11-26 | E-GEOD-40129 | biostudies-arrayexpress
Project description:To investigate response or resistance to endocrine therapy, mice with targeted over-expression of Esr1 or CYP19A1 to mammary epithelial cells were employed, representing two direct pathophysiological interventions in estrogen pathway signaling. Both Esr1 and CYP19A1 over-expressing mice responded to letrozole with reduced HAN prevalence and decreased mammary epithelial cell proliferation. CYP19A1 over-expressing mice were tamoxifen-sensitive but Esr1 over-expressing mice were tamoxifen-resistant. Increased ER expression occurred with tamoxifen resistance but no consistent changes in progesterone receptor, pSTAT3, pSTAT5, cyclin D1 or cyclin E levels in association with response or resistance was found. RNA-seq was employed to seek a transcriptome predictive of tamoxifen resistance using these models and a second tamoxifen-resistant model, BRCA1 deficient/Trp53 haploinsufficient mice. Sixty-eight genes associated with immune system processing were upregulated in tamoxifen-resistant Esr1 and Brca1 deficient mice whereas genes related to aromatic compound metabolic process were upregulated in tamoxifen-sensitive CYP19A1 mice. Interferon Regulatory Factor 7 was identified as a key transcription factor regulating these 68 immune processing genes. Two loci encoding novel transcripts with high homology to human IGLL1 were uniquely upregulated in the tamoxifen-resistant models. Letrozole proved to be a successful alternative to tamoxifen. Further study of transcriptional changes associated with tamoxifen resistance including immune-related genes could expand our mechanistic understanding and lead to biomarkers predictive of escape or response to endocrine therapies.
2014-12-04 | GSE63857 | GEO
Project description:Gene expression profiling of invasive breast cancer events from the tamoxifen prevention trial validates low estrogen receptor mRNA level as the main determinant of tamoxifen resistance in estrogen receptor positive breast cancer. In NSABP Breast Cancer Prevention Trial (BCPT), tamoxifen reduced the incidence of estrogen receptor (ER) positive tumors but not estrogen receptor negative breast cancer. More importantly, only 69% of estrogen receptor positive tumors were prevented by tamoxifen. The ER positive tumors arising in tamoxifen arm provides an ideal clinical model for acquired tamoxifen resistance. Based on data from NSABP trial B14 which showed linear prediction of the degree of benefit from adjuvant tamoxifen by the levels of ESR1 mRNA coding for ER-alpha, we hypothesized a priori that level of ESR1 mRNA would be lower in ER positive tumors arising in tamoxifen arm compared to those in placebo arm of BCPT. Keywords: Gene expression profiling analysis Formalin fixed paraffin embedded tumor blocks with enough tumor tissue for RNA extraction were available from 108 cases (69 from placebo arm and 39 from tamoxifen arm) of the 264 that experienced invasive breast cancer (175 in placebo arm and 89 in tamoxifen arm) in BCPT before unblindings . Central ER immunohistochemistry identified 84 of them as ER positive (57 from placebo arm and 27 from tamoxifen arm). A novel protocol was developed and used to obtain microarray gene expression profiling from the degraded or fragmented RNA extracted from formalin fixed paraffin blocks.Hybridization intensity data were compiled using Partek Genomic Suite. After quantile normalization, genes with mean intensity below 500 were filtred out, which left 7743 probes with informative data. Data were log2 transformed for statistical analysis.
2011-12-08 | E-GEOD-12665 | biostudies-arrayexpress
Project description:Estrogen signaling in breast cancer cells relies on long-range chromatin interactions connecting distal regulatory elements bound by the estrogen receptor 1 (ESR1) to target gene promoters. This ensures stimulus and subtype-specific transcriptional responses. Expanding on the function of CTCF and the cohesin complex in breast cancer, we demonstrate that the chromatin-looping factor ZNF143 binds the promoter of most early-response estrogen target genes connected to distal regulatory elements in ESR1-positive breast cancer cells. Its chromatin occupancy is unaffected by estrogen stimulation, supporting a stable three-dimensional genomic architecture within the early response to estrogen. Its loss abrogates the estrogen-induced transcriptional response and growth of breast cancer cells. When taking into account CTCF, ZNF143 and cohesin complex subunits, we show that chromatin-looping factors are genetically altered in over 20% of ESR1-positive primary breast tumors. Furthermore, the overexpression of ZNF143, CTCF and RAD21, a cohesin complex subunit, in ESR1-positive breast tumors associates with a worse clinical outcome. Overall, our results suggest that ZNF143 is a new critical effector of the estrogen response and highlights the contribution of the chromatin looping machinery to ESR1-positive breast cancer development. mRNA profiles of MCF-7 cells (siCtl or siZNF143) under vehicle (EtOH) or E2 (10 uM 17-beta oestradiol) stimulation
2016-08-09 | E-GEOD-76453 | biostudies-arrayexpress
Project description:Expression of estrogen receptor (ESR1) determines whether a breast cancer patient receives endocrine therapy as part of their adjuvant care, but does not guarantee patient response. However, the molecular factors that define endocrine response in ESR1-positive breast cancer patients remain poorly understood. Here, we characterize the DNA methylome of endocrine sensitivity and demonstrate the potential impact of differential DNA methylation on endocrine response in breast cancer. We show that DNA hypermethylation occurs predominantly at estrogen-responsive enhancers and is associated with reduced ESR1 binding and decreased gene expression of key regulators of ESR1-activity; thus providing a novel mechanism by which endocrine response is abated in ESR1-positive breast cancers. Conversely, we delineate that ESR1-responsive enhancer hypomethylation is critical in transition from normal mammary epithelial cells to endocrine responsive ESR1-positive cancer. Cumulatively these novel insights highlight the potential of ESR1-responsive enhancer methylation to both predict ESR1-positive disease and stratify ESR1-positive breast cancer patients as responders to endocrine therapy. Methylation profiling with Illumina's HumanMethylation450K array was performed on ESR1-positive hormone sensitive MCF7 cells, and three different well characterised endocrine resistant MCF7-derived cell lines; tamoxifen-resistant (TAMR), fulvestrant-resistant (FASR) and estrogen deprivation resistant (MCF7X) cells. For each cell line two biological replicates were profiled bringing the number of samples to eight.
2015-07-01 | E-GEOD-69118 | biostudies-arrayexpress