Impact of BRCA mutation type in non-tumorous breast tissue transcriptome
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ABSTRACT:
PROVIDER: EGAS00001004890 | EGA |
REPOSITORIES: EGA
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Project description:We hypothesized that the transcriptome of primary cultures of morphologically normal ovarian surface epithelial cells could be altered by the presence of a heterozygous BRCA1 or BRCA2 mutation. We aimed to discover early events associated to ovarian carcinogenesis, which could represent putative targets for preventive strategies of this silent killer tumor. We identified the first molecular signature associated with French Canadian BRCA1 or BRCA2 founder mutations in morphologically normal ovarian epithelial cells. We discovered that wild-type and mutated BRCA2 allelic transcripts were expressed not only in morphologically normal but also in tumor cells from 8765delAG BRCA2 carriers. Further analysis of morphologically normal ovarian and tumor cells from C4446T BRCA1 carriers lead to the same observation. Our data support the idea that one single hit in BRCA1 or BRCA2 is sufficient to alter the transcriptome of phenotypically normal ovarian epithelial cell. The highest level of BRCA2 mutated allele transcript expression was measured in cells originating from the most aggressive ovarian tumor. The penetrance of the mutation and the aggressiveness of the related tumor could depend on a dosage effect of the mutated allele transcript. We studied the molecular profiles associated with 5 a priori classes of samples : 4 non-familial morphologically normal ovarian surface epithelium (NOSEs) : NM class, 2 BRCA1-mutated NOSEs : M1 class, 3 BRCA2-mutated NOSEs : M2 class, 3 BRCA1-mutated ovarian tumor cells (TOVs) : TM1 class and one BRCA2-mutated TOV :TM2 class. No technical replicates were included in this study. The following contrasts were computed : NM vs. M1, NM vs. M2, M1 vs. M2, M1 vs. TM1 and M (M1 union M2) vs. TM (TM1 union TM2).
2012-06-14 | E-GEOD-34928 | biostudies-arrayexpress
Project description:We hypothesized that the transcriptome of primary cultures of morphologically normal ovarian surface epithelial cells could be altered by the presence of a heterozygous BRCA1 or BRCA2 mutation. We aimed to discover early events associated to ovarian carcinogenesis, which could represent putative targets for preventive strategies of this silent killer tumor. We identified the first molecular signature associated with French Canadian BRCA1 or BRCA2 founder mutations in morphologically normal ovarian epithelial cells. We discovered that wild-type and mutated BRCA2 allelic transcripts were expressed not only in morphologically normal but also in tumor cells from 8765delAG BRCA2 carriers. Further analysis of morphologically normal ovarian and tumor cells from C4446T BRCA1 carriers lead to the same observation. Our data support the idea that one single hit in BRCA1 or BRCA2 is sufficient to alter the transcriptome of phenotypically normal ovarian epithelial cell. The highest level of BRCA2 mutated allele transcript expression was measured in cells originating from the most aggressive ovarian tumor. The penetrance of the mutation and the aggressiveness of the related tumor could depend on a dosage effect of the mutated allele transcript.
2012-06-15 | GSE34928 | GEO
Project description:We describe the gene expression profiles and enhancer landscape of normal myoepithelial cells and perturbations of these in BRCA1 and BRCA2 mutation carriers and in DCIS. We identified a myoepithelial transcription regulatory network orchestrated by p63 and TCF7 and defined the genomic targets of these transcription factors by ChIP-seq. While the majority of myoepithelial cells co-express p63 and TCF7 in normal breast of healthy women, the frequency of these cells is significantly lower in BRCA1 mutation carriers and in DCIS. Downregulation of p63 in MCF10DCIS cells leads to loss of myoepithelial cells and invasive tumors, whereas overexpression of TCF7 enhances tumor growth. Our findings suggest that loss of normal myoepithelial cell function facilitates in situ to invasive carcinoma transition and it may also enhance tumor initiation in BRCA mutation carriers.
2019-08-20 | GSE113909 | GEO
Project description:We describe the gene expression profiles and enhancer landscape of normal myoepithelial cells and perturbations of these in BRCA1 and BRCA2 mutation carriers and in DCIS. We identified a myoepithelial transcription regulatory network orchestrated by p63 and TCF7 and defined the genomic targets of these transcription factors by ChIP-seq. While the majority of myoepithelial cells co-express p63 and TCF7 in normal breast of healthy women, the frequency of these cells is significantly lower in BRCA1 mutation carriers and in DCIS. Downregulation of p63 in MCF10DCIS cells leads to loss of myoepithelial cells and invasive tumors, whereas overexpression of TCF7 enhances tumor growth. Our findings suggest that loss of normal myoepithelial cell function facilitates in situ to invasive carcinoma transition and it may also enhance tumor initiation in BRCA mutation carriers.
2021-04-27 | GSE113795 | GEO
Project description:Gene expression profiles of normal human mammary tissue from BRCA1 mutation carriers, non-BRCA1/2 mutation carriers and normal women. RNA was prepared from normal breast tissue (confirmed by pathology) from reduction mammoplasties (n=5) and prophylactic mastectomies of known BRCA1 (n=7) and non-BRCA1/2 mutation carriers (n=8). non-BRCA1/2 carriers were individuals with a strong family history of breast cancer (kConFab Category 1 (http://www.kconfab.org/Collection/Eligibility.shtml) where no mutation in BRCA1 or BRCA2 has been identified in the family by high sensitivity testing (http://www.kconfab.org/Progress/Sensitivity.shtml) of any individual affected by breast or ovarian cancer. Normal breast samples refer to reduction mammoplasty specimens, where family history is generally not known.
2009-08-01 | GSE17072 | GEO
Project description:Approximately 5% of all breast cancers can be attributed to an inherited mutation in one of two cancer susceptibility genes, BRCA1 and BRCA2. We searched for genes that have the potential to distinguish healthy BRCA1 and BRCA2 mutation carriers from non-carriers based on differences in expression profiling. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers. We identified 137 probe sets in BRCA1 carriers and 1345 in BRCA2 carriers with differential gene expression. Gene Ontology analysis revealed that most of these genes relate to regulation pathways of DNA repair processes, cell cycle regulation and apoptosis. Real-time PCR was performed on the 36 genes which were most prominently differentially expressed in the microarray assay; 21 genes were shown to be significantly differentially expressed in BRCA1 or BRCA2 mutation carriers as compared to controls (p<0.05). Based on a validation study with 40 mutation carriers and 17 non-carriers, a multiplex model that included six or more coincidental genes of 18 selected genes was constructed in order to predict the risk of carrying a mutation. The results using this model showed sensitivity 95% and specificity 88%. In summary, our study provides insight into the biological effect of heterozygous mutations in BRCA1 and BRCA2 genes in response to ionizing irradiation induced DNA damage. We also suggest a set of 18 genes that can be used as a prediction and screening tool for BRCA1 or BRCA2 mutational carriers by using easily obtained lymphocytes. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers Fresh blood samples were obtained from 9 BRCA1 and 8 BRCA2 mutation carriers and 9 mutation-negative women. Lymphocytes were collected from fresh blood samples, and RNA was extracted one hour after γ-irradiation
2013-01-10 | E-GEOD-39976 | biostudies-arrayexpress
Project description:Use of DNA damaging agents and RNA pooling to assess expression profiles associated with BRCA1 and BRCA2 mutation status in familial breast cancer patients Background: A large number of rare sequence variants of unknown clinical significance have been identified in the breast cancer susceptibility genes, BRCA1 and BRCA2. Determining the functional effect of these variants as well as their role in breast cancer susceptibility can be challenging using current classification methods. Methodology/Principal Findings: To identify predictors of pathogenic mutation status in familial breast cancer patients, we explored the use of gene expression arrays to assess the effect of two DNA damaging agents (irradiation and mitomycin C) on cellular response in relation to BRCA1 and BRCA2 mutation status. A range of regimes were used to treat 27 lymphoblastoid cell-lines (LCLs) derived from affected women in high-risk breast cancer families (nine BRCA1, nine BRCA2, and nine non-BRCA1/2 or BRCAX individuals) and nine LCLs from healthy individuals. Using an RNA pooling strategy, we found that treating LCLs with 1.2 μM mitomycin C and measuring the gene expression profiles 1 hour post-treatment had the greatest potential to discriminate BRCA1, BRCA2 and BRCAX mutation status. A classifier was built using the expression profile of nine QRT-PCR validated genes that were associated with BRCA1, BRCA2 and BRCAX status in RNA pools. These nine genes could distinguish BRCA1 from BRCA2 carriers with 83% accuracy in individual samples, but three-way analysis for BRCA1, BRCA2 and BRCAX had a maximum of 59% prediction accuracy. Conclusions/Significance: Our results suggest that, compared to BRCA1 and BRCA2 mutation carriers, non-BRCA1/2 (BRCAX) individuals are genetically heterogeneous. This study also demonstrates the effectiveness of RNA pools to compare the expression profiles of cell-lines from BRCA1, BRCA2 and BRCAX cases after treatment with irradiation and mitomycin C as a method to prioritize treatment regimes for detailed downstream expression analysis.
2010-01-20 | GSE17764 | GEO
Project description:Approximately 5% of all breast cancers can be attributed to an inherited mutation in one of two cancer susceptibility genes, BRCA1 and BRCA2. We searched for genes that have the potential to distinguish healthy BRCA1 and BRCA2 mutation carriers from non-carriers based on differences in expression profiling. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers. We identified 137 probe sets in BRCA1 carriers and 1345 in BRCA2 carriers with differential gene expression. Gene Ontology analysis revealed that most of these genes relate to regulation pathways of DNA repair processes, cell cycle regulation and apoptosis. Real-time PCR was performed on the 36 genes which were most prominently differentially expressed in the microarray assay; 21 genes were shown to be significantly differentially expressed in BRCA1 or BRCA2 mutation carriers as compared to controls (p<0.05). Based on a validation study with 40 mutation carriers and 17 non-carriers, a multiplex model that included six or more coincidental genes of 18 selected genes was constructed in order to predict the risk of carrying a mutation. The results using this model showed sensitivity 95% and specificity 88%. In summary, our study provides insight into the biological effect of heterozygous mutations in BRCA1 and BRCA2 genes in response to ionizing irradiation induced DNA damage. We also suggest a set of 18 genes that can be used as a prediction and screening tool for BRCA1 or BRCA2 mutational carriers by using easily obtained lymphocytes. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers
2013-01-10 | GSE39976 | GEO
Project description:Breast cancer is the most common cancer in females, affecting one in every eight women and accounting for the majority of cancer-related deaths in women worldwide. Germline mutations in the BRCA1 and BRCA2 genes are significant risk factors for specific subtypes of breast cancer. BRCA1 mutations are associated with basal-like breast cancers, whereas BRCA2 mutations are associated with luminal-like disease. Defects in mammary epithelial cell differentiation have been previously recognized in germline BRCA1/2 mutation carriers even before cancer incidence. However, the underlying mechanism is largely unknown. Here, we employ spatial transcriptomics to investigate defects in mammary epithelial cell differentiation accompanied by distinct microenvironmental alterations in preneoplastic breast tissues from BRCA1/2 mutation carriers and normal breast tissues from non-carrier controls. We uncovered spatially defined receptor-ligand interactions in these tissues for the investigation of autocrine and paracrine signaling. We discovered that β1-integrin-mediated autocrine signaling in BRCA2-deficient mammary epithelial cells may differ from BRCA1-deficient mammary epithelial cells. In addition, we found that the epithelial-to-stromal paracrine signaling in the breast tissues of BRCA1/2 mutation carriers is greater than in control tissues. More integrin-ligand pairs were differentially correlated in BRCA1/2-mutant breast tissues than non-carrier breast tissues with more integrin receptor-expressing stromal cells. Implications: These results suggest alterations in the communication between mammary epithelial cells and the microenvironment in BRCA1 and BRCA2 mutation carriers, laying the foundation for designing innovative breast cancer chemo-prevention strategies for high-risk patients.
2023-10-11 | GSE234017 | GEO
Project description:There are currently no screening methods for high grade ovarian cancer (HGOC) that guarantee effective early detection for high risk women such as germline BRCA mutation carriers. Therefore, the standard-of-care remains risk reducing salpingo-oophorectomy (RRSO) around age 40. Proximal liquid biopsy has been shown to be a promising source of biomarkers, but sensitivity has not yet qualified for clinical implementation. We report the discriminant performance of a novel proteomic classifier for detection of HGOC in high-risk population, and the safety and feasibility of simplified utero-tubal lavage (UtL) as a method for sampling proximal liquid biopsy.The training set included 93 women with high-risk for HGOC (BRCA1 and BRCA2 mutation carriers), including: 16 HGOC patients and 77 asymptomatic women, who donated UtL liquid biopsies, in 3 Israeli medical centers (Biomarkers for Early Detection of Ovarian Cancer Using Uterine Lavage (BEDOCA); ClinicalTrials.gov Identifier: NCT03150121). The proteome of the microvesicle fraction of the samples was profiled by mass spectrometry and a classifier was developed using logistic regression. An independent cohort of 104 BRCA mutation carriers was used as validation. Safety information was collected for all women who opted to UtL in a clinic setting.
2022-09-13 | PXD030390 | Pride