Similar Datasets
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: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:We performed microRNA microarrays from total RNA extracted from 47 breast cancer tumors with known BRCA1 protein status to identify potential regulators of BRCA1 expression. BRCA1 positive tumors ( H-score ≥50) were divided into two groups: “BRCA1 intermediate”, defined by an H-score between 50 and 90, both values included, and “BRCA1 positive”, including tumors with H-score above 90
2020-11-01 | GSE144405 | GEO
Project description:Genomic profile of 47 tumors from hereditary breast cancer cases by Array CGH, 7 of which were BRCA mutation carriers (4 in BRCA2 and 3 in BRCA1), previously analyzed for BRCA1 expression by immunohistochemistry. Our goal was to identify specific alterations for BRCA1 not expressing tumors
2015-07-07 | GSE70541 | GEO
Project description:Breast tumors from BRCA1 germ line mutation carriers typically exhibit features of the basal-like molecular subtype. However, the specific genes recurrently mutated as a consequence of BRCA1 dysfunction have not been fully elucidated. In this study, we utilized gene expression profiling to molecularly subtype 577 breast tumors, including 73 breast tumors from BRCA1/2 mutation carriers. Focusing on the RB1 locus, we analyzed 33 BRCA1-mutated, 36 BRCA2-mutated and 48 non-BRCA1/2-mutated breast tumors using a custom-designed high-density oligomicroarray covering the RB1 gene. We found a strong association between the basal-like subtype and BRCA1-mutated breast tumors and the luminal B subtype and BRCA2-mutated breast tumors. RB1 was identified as a major target for genomic disruption in tumors arising in BRCA1 mutation carriers and in sporadic tumors with BRCA1 promoter-methylation, but rarely in other breast cancers. Homozygous deletions, intragenic breaks, or microdeletions were found in 33% of BRCA1-mutant tumors, 36% of BRCA1 promoter-methylated basal-like tumors, 13% of non-BRCA1 deficient basal-like tumors, and 3% of BRCA2-mutated tumors. In addition, RB1 was frequently inactivated by gross gene disruption in BRCA1-related hereditary breast cancer and BRCA1-methylated sporadic basal-like breast cancer, but rarely in BRCA2-hereditary breast cancer and non-BRCA1-deficient sporadic breast cancers. Together, our findings demonstrate the existence of genetic heterogeneity within the basal-like breast cancer subtype that is based upon BRCA1-status.
2012-06-27 | GSE25307 | GEO
Project description:Breast tumors from BRCA1 germ line mutation carriers typically exhibit features of the basal-like molecular subtype. However, the specific genes recurrently mutated as a consequence of BRCA1 dysfunction have not been fully elucidated. In this study, we utilized gene expression profiling to molecularly subtype 577 breast tumors, including 73 breast tumors from BRCA1/2 mutation carriers. Focusing on the RB1 locus, we analyzed 33 BRCA1-mutated, 36 BRCA2-mutated and 48 non-BRCA1/2-mutated breast tumors using a custom-designed high-density oligomicroarray covering the RB1 gene. We found a strong association between the basal-like subtype and BRCA1-mutated breast tumors and the luminal B subtype and BRCA2-mutated breast tumors. RB1 was identified as a major target for genomic disruption in tumors arising in BRCA1 mutation carriers and in sporadic tumors with BRCA1 promoter-methylation, but rarely in other breast cancers. Homozygous deletions, intragenic breaks, or microdeletions were found in 33% of BRCA1-mutant tumors, 36% of BRCA1 promoter-methylated basal-like tumors, 13% of non-BRCA1 deficient basal-like tumors, and 3% of BRCA2-mutated tumors. In addition, RB1 was frequently inactivated by gross gene disruption in BRCA1-related hereditary breast cancer and BRCA1-methylated sporadic basal-like breast cancer, but rarely in BRCA2-hereditary breast cancer and non-BRCA1-deficient sporadic breast cancers. Together, our findings demonstrate the existence of genetic heterogeneity within the basal-like breast cancer subtype that is based upon BRCA1-status. Gene expression profiling of breast tumors. Dual color common reference gene expression study using 55K oligonucleotide microarrays.
2012-06-26 | E-GEOD-25307 | biostudies-arrayexpress
Project description:Purpose: Loss-of-function mutations of the breast cancer type 1 susceptibility protein (BRCA1) are associated with breast (BC) and ovarian cancer (OC). We assessed responses to histone deacetylase inhibitors (HDACi) and performed genome-wide RNA and chromatin immunoprecipitation (ChIP)-sequencing in isogenic OC cells UWB1.289 (carrying a BRCA1 mutation) and UWB1.289 transduced with wild type BRCA1. Experimental Design: Gene expression profiles of cells harboring mutated vs. functional BRCA1 and treated with the HDACi were integrated with chromatin mapping of histone H3 lysine 9 or 27 acetylation (H3K9ac, H3K27ac) at active promoters and enhancers. Key pathways found deregulated in BRCA1 mutated cells were validated. Results: Gene networks activated in BRCA1-mutated vs. BRCA1+ OC cells relate to Cellular Movement, Cellular Development, Cellular Growth and Proliferation and shared upstream regulators included TGFb1, TNF, and IFN-g. The IFN-g pathway was significantly altered in response to HDACi in BRCA1+ vs. BRCA1-mutated cells and in BRCA1-mutated/or low vs. BRCA1-normal ovarian tumors profiled in the TCGA database. Key IFN-γ-induced genes upregulated at baseline in BRCA1-mutated vs. BRCA1+ OC and BC cells included CXCL10, CXCL11, and IFI16. Increased localization of STAT1 to the promoters of these genes was observed in BRCA1-mutated cells, resulting in diminished cellular responses to IFN-γ or to STAT1 knockdown. The IFN-g signature was associated with improved survival among tumors profiled by the TCGA. Conclusions: Transcriptomic changes affecting IFN-γ response are associated with inactivating BRCA1 mutations in OC. These alterations could contribute to diminished anti-tumor immunity in BRCA1 mutated cells or tumors.
2019-12-31 | GSE131140 | GEO
Project description:BRCA1 is biallelically deleted or mutated in at least 1.9% of prostate tumors, but whether BRCA1 deficiency influences resistance to androgen deprivation therapy (ADT) and prostate cancer development remains elusive. Here we surprisingly find that in human, BRCA1 heterozygous deletion is observed in approximately 13% of human prostate cancers, is more prevalent in neuroendocrine prostate tumors and predicts worse survival than BRCA1 homozygous deletion. In mice, we show that Brca1 heterozygosity (HET) but not Brca1 full inactivation (KO) accelerates early tumor development, invasion and resistance to ADT in Pten-null prostate tumors. Furthermore, pre-malignant tumors and organoids derived from Brca1 HET mice undergo neuroendocrine differentiation and exhibit elevated levels of the unfolded protein response potentially as a pro-survival mechanism, but not those of Brca1 KO. Our findings thus provide important insights into clinical management of prostate cancer patients, suggesting that patients heterozygous for Brca1 are prone to developing resistance to ADT and should be treated differently from patients with complete Brca1 loss.
2024-02-01 | GSE176280 | GEO
Project description:Genomic profile of 47 tumors from hereditary breast cancer cases by Array CGH, 7 of which were BRCA mutation carriers (4 in BRCA2 and 3 in BRCA1), previously analyzed for BRCA1 expression by immunohistochemistry. Our goal was to identify specific alterations for BRCA1 not expressing tumors DNA from 47 Tumors versus DNA pool from normal tissue. BRCA1 expression, Hierarchical clustering and overall survival analyses.
2015-07-07 | E-GEOD-70541 | biostudies-arrayexpress
Project description:We analysed a cohort of 75 BRCA1, BRCA2 and non-BRCA1/2 breast tumors by gene expression profiling and found that 74% BRCA1 tumors were basal-like, 73% of BRCA2 tumors were luminal A or B, and 52% non-BRCA1/2 tumors were luminal A. Thirty-four tumors were also analysed by single nucleotide polymorphism-comparative genomic hybridization (SNP-CGH) arrays. Copy number data could predict whether a tumor was basal-like or luminal with high accuracy, but could not predict its mutation class. Basal-like BRCA1 and basal-like non-BRCA1 tumors were very similar, and contained the highest number of chromosome aberrations. We identified regions of frequent gain containing potential driver genes in the basal (8q and 12p) and luminal A tumors (1q and 17q). Regions of homozygous loss associated with decreased expression of potential tumor suppressor genes were also detected, including in basal tumors (5q and 9p), and basal and luminal tumors (10q). This study highlights the heterogeneity of familial tumors and the clinical consequences for treatment and prognosis.
2009-12-16 | GSE19177 | GEO