Genome-wide maps of ER and γH2AX binding and transcriptomes in BRCA1-deficient cells with E2 treatment
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PROVIDER: PRJNA823351 | ENA |
REPOSITORIES: ENA
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Project description:The goal of this study is to find out the relationship between ER-mediated transcription and DNA damage induced by estrogen(E2) and BRCA1 deficiency in MCF7. The DNA damage is marked by chromatin binding of γH2AX using ChIP-seq.
2022-04-07 | GSE200154 | GEO
Project description:We are studying the mechanisms by which the estrogen receptor, ERalpha, is recruited to and regulates genes with a non-direct DNA binding. We performed ChIP-chip for ERalpha in E2 treated HeLa-ER cells, and looked at 19000 RefSeq genes to determine binding patterns of the receptor at promoters. The experiment was performed in duplicate. ChIP-chip biological replicates for Eralpha in E2 treated HeLa-ER cells are included.
2011-02-22 | E-GEOD-22099 | biostudies-arrayexpress
Project description:We have analyzed, using DNA microarrays, putative differences in gene-expression level between hereditary BRCA1 mutation-linked and sporadic breast cancer. Our results show that a previously reported marked difference between BRCA1-mutation linked and sporadic breast cancer was probably due to uneven stratification of samples with different ER status and basal-like versus luminal-like subtype. We observed that apparent difference between BRCA1-linked and other types of breast cancer found in univariate analysis was diminished when data were corrected for ER status and molecular subtype in multivariate analyses. In fact, the difference in gene expression pattern of BRCA1-mutated and sporadic cancer is very discrete. These conclusions were supported by the results of Q-PCR validation. We also found that BRCA1 gene inactivation due to promoter hypermethylation had similar effect on general gene expression profile as mutation-induced protein truncation. This suggests that in the molecular studies of hereditary breast cancer, BRCA1 gene methylation should be recognized and considered together with gene mutation. We analyzed 35 breast cancer specimens. Surgical samples obtained during mastectomy were flash-frozen in liquid nitrogen and stored at -80°C. Only samples from patients without neoadjuvant chemotherapy were used in this study as chemotherapy may seriously affect gene expression profile. All tissue samples were collected at the Pomeranian Medical University in Szczecin. Seventeen tumor samples were collected from patients with hereditary breast cancer: 12 were derived from tumors affecting women with hereditary BRCA1 mutation, the only one from a woman with BRCA2 mutation, while another eight cases had familial history of breast/ovarian cancer, but were negative for the BRCA1/2 mutations (so called BRCAx cases). Proportion of BRCA1 and BRCA2 mutated tumors was typical for the Polish population. Ten samples were derived from patients with apparently sporadic disease (no familial history of cancer) while 4 patients had a history of familial cancer aggregation (FCA) but without prevalence of breast/ovarian cancers. Thus, these samples were merged with sporadic samples in most of the analyses. All BRCA1 mutation-linked tumors in our study were negative for estrogen receptor (by immunohistochemistry, standard procedures for ER, PGR and HER2 staining were applied), while the only BRCA2-mutated tumor was ER-positive. There were 26 ductal and 5 medullary carcinomas within the study group, which is consistent with the distribution of histopathological types in BRCA1 mutation carriers. Patients were diagnosed at stage T1-2, N0-1 and M0. Caution: this submission contains the data from 6 microarrays done on the normal/pathologically unchanged breast tissue from breast cancer patiets. The data from normal tissues was not analyzed in the paper BRCA1-related gene signature in breast cancer is strongly influenced by ER status and molecular type by Lisowska et al., 2011, Front Biosci (Elite Ed). 2011 Jan 1;3:125-36
2013-09-05 | E-GEOD-50567 | biostudies-arrayexpress
Project description:We have analyzed, using DNA microarrays, putative differences in gene-expression level between hereditary BRCA1 mutation-linked and sporadic breast cancer. Our results show that a previously reported marked difference between BRCA1-mutation linked and sporadic breast cancer was probably due to uneven stratification of samples with different ER status and basal-like versus luminal-like subtype. We observed that apparent difference between BRCA1-linked and other types of breast cancer found in univariate analysis was diminished when data were corrected for ER status and molecular subtype in multivariate analyses. In fact, the difference in gene expression pattern of BRCA1-mutated and sporadic cancer is very discrete. These conclusions were supported by the results of Q-PCR validation. We also found that BRCA1 gene inactivation due to promoter hypermethylation had similar effect on general gene expression profile as mutation-induced protein truncation. This suggests that in the molecular studies of hereditary breast cancer, BRCA1 gene methylation should be recognized and considered together with gene mutation.
2013-09-05 | GSE50567 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE21769: Genome wide expression analysis of ER alpha and beta with or without E2 treatment in U2OS cell line. GSE21770: Genome-wide maps of ER beta binding sites in U2OS cells Refer to individual Series
2010-05-11 | E-GEOD-21790 | biostudies-arrayexpress
Project description:Looking at the expression of ER alpha in BRCA1 and mutant tumours
2007-11-22 | E-TABM-366 | biostudies-arrayexpress
Project description:Purpose: As estrogen receptor (ER)-positive breast cancer in BRCA1 mutation carriers arises at an older age with less aggressive tumor characteristics than ER negative BRCA1 mutated breast cancer, it has been suggested that these tumors are ?sporadic? and not BRCA1-driven. With the introduction of targeted treatments specific for tumors with a non-functioning BRCA1 or BRCA2 gene, the question whether the BRCA genes are impaired in the tumor, is highly relevant. Therefore, we performed genomic profiling of BRCA1-mutated ER+ tumors. Experimental design: Genomic profiling, BRCA1 promoter methylation assessment, and loss of heterozygosity analysis were done on 16 BRCA1-mutated ER+ tumors. Results were compared with 57 BRCA1-mutated ER- tumors, 36 BRCA2-mutated ER+ associated tumors, and 182 sporadic ER+ tumors [GSE9021, GSE9114, GSE16511, GSE50407] Results: The genomic profile of BRCA1-mutated ER+ tumors was different from BRCA1-mutated ER- breast tumors, but highly similar to BRCA2-mutated ER+ tumors. In 83% of the BRCA1-mutated ER+ tumors, loss of the wildtype BRCA1 allele was observed. In addition, clinico-pathological variables in BRCA1-mutated ER+ cancer were also more similar to BRCA2-mutated ER+ and sporadic ER+ breast cancer than to BRCA1 mutated ER- cancers. Conclusions: As BRCA1-mutated ER+ tumors show a BRCAness copy number profile and LOH, it is likely that the loss of a functional BRCA1 protein plays a role in tumorigenesis in BRCA1-mutated ER+ tumors. Therefore, we hypothesize that these tumors are sensitive to drugs targeting the BRCA1 gene defect, providing new targeted treatment modalities for advanced BRCA-deficient, ER-positive breast cancer.
2016-10-01 | GSE77603 | GEO
Project description:Purpose: As estrogen receptor (ER)-positive breast cancer in BRCA1 mutation carriers arises at an older age with less aggressive tumor characteristics than ER negative BRCA1 mutated breast cancer, it has been suggested that these tumors are ?sporadic? and not BRCA1-driven. With the introduction of targeted treatments specific for tumors with a non-functioning BRCA1 or BRCA2 gene, the question whether the BRCA genes are impaired in the tumor, is highly relevant. Therefore, we performed genomic profiling of BRCA1-mutated ER+ tumors. Experimental design: Genomic profiling, BRCA1 promoter methylation assessment, and loss of heterozygosity analysis were done on 16 BRCA1-mutated ER+ tumors. Results were compared with 57 BRCA1-mutated ER- tumors, 36 BRCA2-mutated ER+ associated tumors, and 182 sporadic ER+ tumors [GSE9021, GSE9114, GSE16511, GSE50407]. Results: The genomic profile of BRCA1-mutated ER+ tumors was different from BRCA1-mutated ER- breast tumors, but highly similar to BRCA2-mutated ER+ tumors. In 83% of the BRCA1-mutated ER+ tumors, loss of the wildtype BRCA1 allele was observed. In addition, clinico-pathological variables in BRCA1-mutated ER+ cancer were also more similar to BRCA2-mutated ER+ and sporadic ER+ breast cancer than to BRCA1 mutated ER- cancers. Conclusions: As BRCA1-mutated ER+ tumors show a BRCAness copy number profile and LOH, it is likely that the loss of a functional BRCA1 protein plays a role in tumorigenesis in BRCA1-mutated ER+ tumors. Therefore, we hypothesize that these tumors are sensitive to drugs targeting the BRCA1 gene defect, providing new targeted treatment modalities for advanced BRCA-deficient, ER-positive breast cancer.
2016-10-01 | GSE77604 | GEO
Project description:Estrogen receptorï? beta (ER beta) has potent anti-proliferative and anti-inflammatory properties, suggesting that ER beta-selective agonists might be a new class of therapeutic and chemopreventative agents. To understand how ER beta regulates genes, we identified genes regulated by the unliganded and liganded forms of ER alpha and ER beta in U2OS cells. Microarray data demonstrated that virtually no gene regulation occurred with unliganded ER alpha, whereas many genes were regulated by estradiol (E2). These results demonstrate ER alpha requires a ligand to regulate a single class of genes. In contrast, ER beta regulated three classes of genes. Class I genes were regulated primarily by unliganded ER beta. Class II genes were regulated only with E2, whereas Class III genes were regulated by both unliganded ER beta and E2. There were 453 Class I genes, 258 Class II genes and 83 Class III genes. To explore the mechanism whereby ER beta regulates different classes of genes ChIP-seq was performed to identify ER beta binding sites and adjacent transcription factor motifs in regulated genes. AP1 binding sites were more enriched in Class I genes, whereas ERE, NFKB1 and SP1 sites were more enriched in class II genes. ER beta bound to all three classes of genes demonstrating that ER beta binding is not responsible for differential regulation of genes by unliganded and liganded ER beta. The coactivator, NCOA2 was differentially recruited to several target genes. Our findings indicate that the unliganded and liganded forms of ER beta regulate three classes of genes by interacting with different transcription factors and coactivators. U2OS cell lines are stably transfected with a doxycycline-inducible ER alpha or beta. 18 samples are analyzed with triplicate for each of the 6 conditions. The 6 conditions include ER alpha transfected without doxycycline added, ER alpha transfected with doxycycline added, ER alpha transfected with doxycycline added and E2 treatment, ER beta transfected without doxycycline added, ER beta transfected with doxycycline added, and ER beta transfected with doxycycline added and E2 treatment.
2010-05-28 | E-GEOD-21769 | biostudies-arrayexpress