Similar Datasets
Project description:Current approaches to menopausal hormone therapy consist of compounds which provide tissue specific beneficial effects while working to minimize any increase in cancer risk associated with replacement therapy. In this study, an examination of the genomic distribution of histone modification and expression changes in two breast epithelial cell lines, the normal MCF10A cell line and the MCF-7 breast cancer cell line, upon treatment with several of the current therapies used for treating post-menopausal symptoms is presented. Analysis of the observed changes upon treatment with either 17-estradiol (E2), a combined treatment with the top 10 most abundant Premarin chemical equivalents (EC10), the non-steroidal SERM, Bazadoxifene (BZA) and the TSEC; BZA combined with EC10 (Duavee) or BZA combined with E2 provides evidence of expression changes in genes involved in DNA replication, nucleosome assembly, RNA-splicing and processing, biological regulation and cell signaling, and many of the known steroid response genes. There were distinct global changes in chromatin states observed that were specific to each of the breast epithelial cell type normal, basal MCF10A and ESR/PGR positive luminal breast cancer MCF7 cell lines and selective changes observed upon treatment with each of the treatment groups. Specifically, we observed a global loss of H3K4ac upon treatment with BZA. These changes were observed in both ESR1 bound and non-bound regions suggesting modifications in both promoters and enhancer regions. The levels of H3K4ac upon treatment of BZA showed a decrease below basal non-treated H3K4ac levels in MCF7. There was an increase observed with E2 and EC10 treatment in MCF7 that was mitigated by the addition of BZA to either steroid as a combined treatment. This study provides a better understanding of the role of epigenetic modifications in endocrine responsiveness and provides evidence of an improved therapeutic profile for combined TSEC compounds for treating and managing the overall physiological effects of declining estrogen.
2020-08-01 | GSE102469 | GEO
Project description:Current approaches to menopausal hormone therapy consist of compounds which provide tissue specific beneficial effects while working to minimize any increase in cancer risk associated with replacement therapy. In this study, an examination of the genomic distribution of histone modification and expression changes in two breast epithelial cell lines, the normal MCF10A cell line and the MCF-7 breast cancer cell line, upon treatment with several of the current therapies used for treating post-menopausal symptoms is presented. Analysis of the observed changes upon treatment with either 17-estradiol (E2), a combined treatment with the top 10 most abundant Premarin chemical equivalents (EC10), the non-steroidal SERM, Bazadoxifene (BZA) and the TSEC; BZA combined with EC10 (Duavee) or BZA combined with E2 provides evidence of expression changes in genes involved in DNA replication, nucleosome assembly, RNA-splicing and processing, biological regulation and cell signaling, and many of the known steroid response genes. There were distinct global changes in chromatin states observed that were specific to each of the breast epithelial cell type normal, basal MCF10A and ESR/PGR positive luminal breast cancer MCF7 cell lines and selective changes observed upon treatment with each of the treatment groups. Specifically, we observed a global loss of H3K4ac upon treatment with BZA. These changes were observed in both ESR1 bound and non-bound regions suggesting modifications in both promoters and enhancer regions. The levels of H3K4ac upon treatment of BZA showed a decrease below basal non-treated H3K4ac levels in MCF7. There was an increase observed with E2 and EC10 treatment in MCF7 that was mitigated by the addition of BZA to either steroid as a combined treatment. This study provides a better understanding of the role of epigenetic modifications in endocrine responsiveness and provides evidence of an improved therapeutic profile for combined TSEC compounds for treating and managing the overall physiological effects of declining estrogen.
2020-08-01 | GSE102436 | GEO
Project description:Epigenetic and Expression Profiling of Tissue Selective Estrogen Compounds in Breast Epithelial Cell Lines
| PRJNA397790 | ENA
Project description:Selective estrogen receptor modulators (SERMs), including the SERM/SERD bazedoxifene (BZA), are used to treat postmenopausal osteoporosis and may reduce breast cancer (BCa) risk. One of the most persistent unresolved questions regarding menopausal hormone therapy is compromised control of proliferation and phenotype because of short- or long-term administration of mixed-function estrogen receptor (ER) ligands. To gain insight into epigenetic effectors of the transcriptomes of hormone and BZA-treated BCa cells, we evaluated a panel of histone modifications. The impact of short-term hormone treatment and BZA on gene expression and genome-wide epigenetic profiles was examined in ERαneg mammary epithelial cells (MCF10A) and ERα+ luminal breast cancer cells (MCF7). We tested individual components and combinations of 17β-estradiol (E2), estrogen compounds (EC10) and BZA. RNA-seq for gene expression and ChIP-seq for active (H3K4me3, H3K4ac, H3K27ac) and repressive (H3K27me3) histone modifications were performed. Our results show that the combination of BZA with E2 or EC10 reduces estrogen-mediated patterns of histone modifications and gene expression in MCF-7ERα+ cells. In contrast, BZA has minimal effects on these parameters in MCF10A mammary epithelial cells. BZA-induced changes in histone modifications in MCF7 cells are characterized by altered H3K4ac patterns, with changes at distal enhancers of ERα-target genes and at promoters of non-ERα bound proliferation-related genes. Notably, the ERα target gene GREB1 is the most sensitive to BZA treatment. Our findings provide direct mechanistic-based evidence that BZA induces epigenetic changes in E2 and EC10 mediated control of ERα regulatory programs to target distinctive proliferation gene pathways that restrain the potential for breast cancer development.
| S-EPMC9302754 | biostudies-literature
Project description: Not available
| S-ECPF-TABM-657 | biostudies-other
Project description:The conjugated estrogen /: bazedoxifene tissue-selective estrogen complex (TSEC) is designed to minimize the undesirable effects of estrogen in the uterus and breast tissues and to allow the beneficial effects of estrogen in other estrogen-target tissues, such as the bone and brain. However, the molecular mechanism underlying endometrial and breast safety during TSEC use is not fully understood. Estrogen receptor ? (ER?)-estrogen response element (ERE)-DNA pull-down assays using HeLa nuclear extracts followed by mass spectrometry-immunoblotting analyses revealed that, upon TSEC treatment, ER? interacted with transcriptional repressors rather than coactivators. Therefore, the TSEC-mediated recruitment of transcriptional repressors suppresses ER?-mediated transcription in the breast and uterus. In addition, TSEC treatment also degraded ER? protein in uterine tissue and breast cancer cells, but not in bone cells. Interestingly, ER?-ERE-DNA pull-down assays also revealed that, upon TSEC treatment, ER? interacted with the F-box protein 45 (FBXO45) E3 ubiquitin ligase. The loss-of- and gain-of-FBXO45 function analyses indicated that FBXO45 is involved in TSEC-mediated degradation of the ER? protein in endometrial and breast cells. In preclinical studies, these synergistic effects of TSEC on ER? inhibition also suppressed the estrogen-dependent progression of endometriosis. Therefore, the endometrial and breast safety effects of TSEC are associated with synergy between the selective recruitment of transcriptional repressors to ER? and FBXO45-mediated degradation of the ER? protein.
| S-EPMC4702103 | biostudies-literature
Project description:Estrogen is a risk factor for breast cancer, yet its mechanism in the initiation of this disease is not clear. Here we use a model of estrogen-mediated malignant transformation of MCF-10F cells to identify the temporal acquisition of changes in genome structure and gene expression that correspond to the progressive transformed phenotype culminating in tumorigenesis. Genomic DNA and total RNA were isolated from MCF10F, trMCF (MCF10F transformed by 70 nM 17-beta estradiol), bsMCF (trMCF selected by Boyden chamber, tumorigenic), bcMCF(clones of bsMCF), and caMCF (cells from tumors of bsMCF grown in SCID mice). The Affymetrix 100k SNP and HG-U133_Plus_2 chips were used for genotyping and gene expression analyses. Changes in chromosomal copy number and loss of heterozygosity were progressive. Gross changes were rarely observed in the trMCF10F cells; the earliest was a gain in chromosome 1p, 1p36.12-1p36.21. In the bsMCF and their sub-clones bcMCF, additional gains were seen in chromosomes 1p, 1p36.12-1pter, 5q, 5q21.1-5q35.3, and 13q, 13q21.32-13q34; losses were detected in chromosomes 4 and 8p, 8p11.1-8p23.1. In the caMCF, additional losses were seen in chromosomes 3p, 3p12.1-3p14.1, 9p, 9p22.1-9p24.3, and 18q, 18q11.2-18q23. Using microarray analysis we were able, in some cases, to narrow the regions of interest and their associated candidate cancer genes. The observation of progressive genomic changes, along with the tumor phenotype of a poorly differentiated adenocarcinoma, indicate an underlying mechanism common to breast cancer development in humans, and adds to the evidence indicating that estrogens are mutagenic and contribute early to the process of breast cancer. Experiment Overall Design: Human MCF-10F cells were transformed by 70nM 17-beta-estradiol. The transformed cells were selected by Boyden chamber. The selected cells were injected into SCID mice and also cloned and expanded. The thus grown tumors were harvested for cell culture. Genomic DNA and total RNA were isolated from cell lines in each step for 100K SNP and gene expression microarray assay.
| S-ECPF-GEOD-5102 | biostudies-other
Project description:The Women's Health Initiative studies reported that the menopausal hormone therapy (MHT) regimen containing conjugated equine estrogen (CEE) and medroxyprogesterone acetate increased, whereas CEE alone reduced breast cancer incidence. These observations suggest the possibility that CEE might exert unique actions on breast and also suggest the need to eliminate the progestogen from MHT regimens. A MHT regimen called a tissue selective estrogen complex (TSEC), containing CEE plus bazedoxifene (BZA), to avoid the need for a progestogen, was developed and FDA approved. Our study addressed two questions regarding this TSEC: (i) whether CEE exert effects on breast cancer which differ from those of estradiol (E2 ) and (ii) whether BZA antagonize the effects of E2 and CEE on breast cancer? Two rodent models (NMU and ACI) were used to compare the effect of CEE with E2 on mammary tumor formation, proliferation and apoptosis. In both the NMU and ACI models, E2 significantly increased tumor incidence and multiplicity whereas in striking contrast CEE did not, even though the estrogenic effects of CEE and E2 on uterine weight were identical. Mechanistically E2 blocked whereas CEE stimulated apoptosis (cleaved caspase-3) in ACI animals and only E2 stimulated proliferation (Ki67). BZA exerted highly potent anti-estrogenic effects on tumors by completely blocking palpable tumor formation. These data suggest that the CEE/BZA TSEC may be a safer, breast-antagonistic, MHT agent for women and might have potential to prevent breast cancer while relieving menopausal symptoms.
| S-EPMC6377943 | biostudies-literature
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.
| S-ECPF-GEOD-19639 | biostudies-other
Project description:Breast cancer is the most diagnosed type of cancer amongst women in economically developing countries and globally. Most breast cancers express estrogen receptor alpha (ERα) and are categorized as positive (ER+) breast cancer. Endocrine therapies such as, selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), and selective estrogen receptor downregulators (SERDs) are used to treat ER+ breast cancer. However, despite their effectiveness, severe side-effects and resistance are associated with these endocrine therapies. Thus, it would be highly beneficial to develop breast cancer drugs that are as effective as current therapies, but less toxic with fewer side effects, and less likely to induce resistance. Extracts of Cyclopia species, an indigenous South African fynbos plant, have been shown to possess phenolic compounds that exhibit phytoestrogenic and chemopreventive activities against breast cancer development and progression. In the current study, three well characterized Cyclopia extracts, SM6Met, cup of tea (CoT) and P104, were examined for their abilities to modulate the levels of the estrogen receptor subtypes, estrogen receptor alpha and estrogen receptor beta (ERβ), which have been recognized as crucial to breast cancer prognosis and treatment. We showed that the Cyclopia subternata Vogel (C. subternata Vogel) extracts, SM6Met and cup of tea, but not the C. genistoides extract, P104, reduced estrogen receptor alpha protein levels while elevating estrogen receptor beta protein levels, thereby reducing the ERα:ERβ ratio in a similar manner as standard of care breast cancer endocrine therapies such as fulvestrant (selective estrogen receptor downregulator) and 4-hydroxytamoxifen (elective estrogen receptor modulator). Estrogen receptor alpha expression enhances the proliferation of breast cancer cells while estrogen receptor beta inhibits the proliferative activities of estrogen receptor alpha. We also showed that in terms of the molecular mechanisms involved all the Cyclopia extracts regulated estrogen receptor alpha and estrogen receptor beta protein levels through both transcriptional and translational, and proteasomal degradation mechanisms. Therefore, from our findings, we proffer that the C. subternata Vogel extracts, SM6Met and cup of tea, but not the C. genistoides extract, P104, selectively modulate estrogen receptor subtypes levels in a manner that generally supports inhibition of breast cancer proliferation, thereby demonstrating attributes that could be explored as potential therapeutic agents for breast cancer.
| S-EPMC10040842 | biostudies-literature