Tamoxifen transcriptional regulation in human mammary epithelial and endometrial stromal cells
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PROVIDER: PRJNA418328 | ENA |
REPOSITORIES: ENA
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Project description:Tamoxifen transcriptional regulation in human endometrial stromal cells (HESC)
| PRJNA418377 | ENA
Project description:Tamoxifen (TAM), used for adjuvant therapy of breast cancer, also increases the risk of endometrial cancer. To compare TAM-induced transcriptional changes we examined human and monkey uterus, as well as cultured normal human mammary epithelial cells (NHMECs) and human endometrial stromal cells (HESCs). Uterine DNA from TAM-exposed women (n=15) and monkeys (Erythrocebus patas n=5, and Macaca fascicularis n=12) showed no difference in 5-methyl-cytosine (5-meC) levels compared to unexposed controls. Studies comparing NHMECs and HESCs exposed to 10 µM TAM for 48 hr showed cell-specific differences by microarray, with confirmation by RT-PCR. In TAM-exposed NHMECs there was significant up-regulation of interferon signaling and immune response pathways, while the TAM-exposed HESCs showed significant up-regulation of steroid and fatty acid biosynthesis pathways. Promoter region CpG islands of several genes highly up-regulated by TAM in each cell type (NHMECs: MX1 and STAT1; HESCs: PPARG, SREBF2, HMCGS and Prune2), were examined for 5-meC, but the levels (≤ 7%), were too low to measure accurately. We also examined several histone H3 lysine dimethylases by Western blot, and showed a significant depletion of total H3 histone, H3K4, H3K27 and H3K36 in TAM-exposed HESCs, with similar but non-significant changes in TAM-exposed NHMECs. Whereas TAM exposure had no discernible effect on 5-meC levels in primate uterus, TAM exposure induced up-regulation of different transcriptional pathways in NHMECs and HESCs, and concomitantly depleted H3 histone lysine dimethylase levels. Therefore, transcriptional dysregulation by TAM, including reduction of histone H3 dimethylase levels, may be related to TAM-induced endometrial carcinogenesis.
2018-11-01 | GSE106890 | GEO
Project description:Tamoxifen (TAM), used for adjuvant therapy of breast cancer, also increases the risk of endometrial cancer. To compare TAM-induced transcriptional changes we examined human and monkey uterus, as well as cultured normal human mammary epithelial cells (NHMECs) and human endometrial stromal cells (HESCs). Uterine DNA from TAM-exposed women (n=15) and monkeys (Erythrocebus patas n=5, and Macaca fascicularis n=12) showed no difference in 5-methyl-cytosine (5-meC) levels compared to unexposed controls. Studies comparing NHMECs and HESCs exposed to 10 µM TAM for 48 hr showed cell-specific differences by microarray, with confirmation by RT-PCR. In TAM-exposed NHMECs there was significant up-regulation of interferon signaling and immune response pathways, while the TAM-exposed HESCs showed significant up-regulation of steroid and fatty acid biosynthesis pathways. Promoter region CpG islands of several genes highly up-regulated by TAM in each cell type (NHMECs: MX1 and STAT1; HESCs: PPARG, SREBF2, HMCGS and Prune2), were examined for 5-meC, but the levels (≤ 7%), were too low to measure accurately. We also examined several histone H3 lysine dimethylases by Western blot, and showed a significant depletion of total H3 histone, H3K4, H3K27 and H3K36 in TAM-exposed HESCs, with similar but non-significant changes in TAM-exposed NHMECs. Whereas TAM exposure had no discernible effect on 5-meC levels in primate uterus, TAM exposure induced up-regulation of different transcriptional pathways in NHMECs and HESCs, and concomitantly depleted H3 histone lysine dimethylase levels. Therefore, transcriptional dysregulation by TAM, including reduction of histone H3 dimethylase levels, may be related to TAM-induced endometrial carcinogenesis.
2018-11-01 | GSE106891 | GEO
Project description:Tamoxifen, a small molecule inhibitor that binds the Estrogen Receptor alpha (ERα), blocks breast cancer progression while increasing the risk for endometrial cancer. In this study, we assessed genome-wide ERα-chromatin interactions in surgical specimens of endometrial tumors from patients who were previously treated for breast cancer with tamoxifen, and endometrial tumors from patients who were treated without tamoxifen. We compared ERα and signal at differential ERα sites in endometrial tumors of nine patients who received tamoxifen with endometrial tumors with six patients who never used tamoxifen. In addition, we performed H3K27ac (a marker for activity) ChIPs on the above mentioned endometrial tumors, and assed this signal at differential ERα sites. Compared to endometrial tumors of non-users, tamoxifen-associated endometrial tumors exposed higher H3K27ac intensities at ERα sites that are enriched in tamoxifen-associated endometrial tumors. Four tamoxifen-associated endometrial tumors that we used in our analysis have been previously published as Tumor A, B, D, and E in GSE81213.
2017-03-07 | GSE94523 | GEO
Project description:Tamoxifen, a small molecule inhibitor that binds the Estrogen Receptor alpha (ERα), blocks breast cancer progression while increasing the risk for endometrial cancer. In this study, we assessed genome-wide ERα-chromatin interactions in surgical specimens of endometrial tumors from patients who were previously treated for breast cancer with tamoxifen, and endometrial tumors from patients who were treated without tamoxifen. We compared ERα and signal at differential ERα sites in endometrial tumors of nine patients who received tamoxifen with endometrial tumors with six patients who never used tamoxifen. In addition, we performed H3K27ac (a marker for activity) ChIPs on the above mentioned endometrial tumors, and assed this signal at differential ERα sites. Compared to endometrial tumors of non-users, tamoxifen-associated endometrial tumors exposed higher H3K27ac intensities at ERα sites that are enriched in tamoxifen-associated endometrial tumors. Four tamoxifen-associated endometrial tumors that we used in our analysis have been previously published as Tumor A, B, D, and E in GSE81213.
2017-03-06 | GSE94031 | GEO
Project description:The molecular explanation for tamoxifen serving as a breast cancer treatment but displaying partial estrogenic in the uterus is not known. Previously, we reported that differential promoter context and cofactor recruitment contribute to the tissue specificity of tamoxifen. Here, we investigated the genomic basis for the partial oestrogenic activity of tamoxifen in the endometrium. We showed that tamoxifen not only affects the rate of transcription of oestrogen target genes but also targets a unique set of genes. Since oestrogen and tamoxifen are both able to bind to oestrogen receptors (ERs) and because both promote endometrial carcinogenesis, we hypothesized that the molecular effectors for ERs in endometrial carcinogenesis most likely reside in genes that are commonly targeted by oestrogen and tamoxifen. Among those target genes, we identified a paired-box gene PAX2 that is critically involved in cell proliferation and carcinogenesis in the endometrium. Our experiments also demonstrated that PAX2 is activated by oestrogen and tamoxifen in endometrial carcinomas but not in normal endometrium, and this activation is associated with cancer-linked hypomethylation of the PAX2 promoter. Experiment Overall Design: each experiment repeat 2 times.
2007-09-08 | E-GEOD-3013 | biostudies-arrayexpress
Project description:The tumor suppressor gene p53 is frequently mutated in human breast cancer and is a marker for poor prognosis and resistance to chemotherapy. Transplantation of p53-null mouse mammary epithelium into syngeneic wild-type mice leads to normal mammary gland development followed by spontaneous mammary tumors that recapitulate many of the phenotypic, molecular, and genetic features of human breast cancer. Using this genetically engineered mouse model, we have examined the molecular mechanisms underlying tamoxifen-dependent tumor prevention. To determine whether the changes observed in the ERα cistrome after tamoxifen exposure are reflected in changes in estrogen responsive gene signatures in p53-null mammary epithelial cells (MECs), we performed global gene expression analysis by microarray profiling of MECs isolated from control and tamoxifen-exposed mice 4 weeks after tamoxifen withdrawal and treated with E2 for 8h. We identified 245 differentially regulated genes (P<0.01 and FC>1.4). Of these, 177 genes (72%) were persistently upregulated and 68 genes (28%) were persistently downregulated after transient exposure to tamoxifen. These results indicate that transient exposure to tamoxifen leads to lasting intrinsic changes in gene expression profiles of p53-null mammary epithelial cells that persist after tamoxifen withdrawal.
2018-04-17 | GSE77948 | GEO
Project description:Tamoxifen transcriptional regulation in normal human mammary epithelial cells (NHMEC)
| PRJNA418338 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below.
2018-11-01 | GSE106892 | GEO
Project description:We sequenced mRNA of endometrial stromal fibroblasts from six mammalian species. Examination of mRNA levels in endometrial stromal fibroblasts from six mammalian species grown in culture with two biological replicates for each species
2016-08-01 | E-GEOD-67659 | biostudies-arrayexpress