Project description:Female BRCA1 mutation carriers have a nearly 80% probability of developing breast cancer during their life-time. We hypothesized that the breast epithelium at risk in BRCA1 mutation carriers harbors mammary epithelial cells (MECs) with altered proliferation and differentiation properties. Microarray studies revealed that PMEC colonies from BRCA1 mutation carriers anticipate expression profiles found in BRCA1-related tumors, and that the EGFR pathway is upregulated in BRCA1 mutation carriers compared ton non BRCA1 mutation carriers. Keywords: Class comparison and pathway analysis 10 colonies were collected and RNA was isolated using the Absolutely RNA Nanoprep kit, Stratagene. The arrays included duplicates from four normal controls and from two BRCA1 mutation carriers and single arrays from another two BRCA1 mutation carriers.
Project description:Mutations in BRCA1 and BRCA2 genes confer an increased lifetime risk for breast and ovarian cancer. Ovarian cancer risk can be decreased by risk-reducing salpingo-oophorectomy (RRSO). Studies on RRSO material have altered the paradigm of serous ovarian cancer pathogenesis. The purpose of this study was to identify candidate genes possibly involved in pathogenesis of serous ovarian cancer by carrying out a microarray analysis of differentially expressed genes in BRCA1/2- mutation positive ovarian and fallopian tube epithelium derived from RRSO surgery. Freshly frozen ovarian and fallopian tube samples from nine BRCA1/2 mutation carriers scheduled for RRSO were prospectively collected in comparison with five mutation-negative control patients undergoing salpingo-oophorectomy for benign indications. Microarray analysis of genome-wide gene expression was performed on ovarian and fallopian tube samples from BRCA1/2 and control patients. The validation of microarray data was performed by quantitative real-time polymerase chain reaction (qRT-PCR) in selected cases of RRSO samples, and also high grade serous carcinoma samples collected from patients with BRCA phenotype. From 22,733 genes, 454 transcripts were identified that were differentially expressed in BRCA1/2 mutation carriers when statistically compared to controls pooling all ovarian and fallopian tube samples together. Of these, 299 genes were statistically significantly downregulated and 155 genes were upregulated. Differentially expressed genes in BRCA1/2 samples reported here might be involved in serous ovarian carcinogenesis and provide interesting targets for further studies. Both fallopian tube and ovarian samples were collected from each BRCA1/2 mutation carrier resulting in eighteen mutation positive adnexal samples. Both fallopian tube and ovarian control samples were collected from one control patient while either ovarian or fallopian tube sample was available from four control patients, respectively, resulting in 6 adnexal control samples. High quality RNA was available from nine BRCA1/2-mutation positive ovarian and eight BRCA1/2-mutation positive fallopian tube samples and from three control ovarian and three control fallopian tube samples.
Project description:Mutations in BRCA1 and BRCA2 genes confer an increased lifetime risk for breast and ovarian cancer. Ovarian cancer risk can be decreased by risk-reducing salpingo-oophorectomy (RRSO). Studies on RRSO material have altered the paradigm of serous ovarian cancer pathogenesis. The purpose of this study was to identify candidate genes possibly involved in pathogenesis of serous ovarian cancer by carrying out a microarray analysis of differentially expressed genes in BRCA1/2- mutation positive ovarian and fallopian tube epithelium derived from RRSO surgery. Freshly frozen ovarian and fallopian tube samples from nine BRCA1/2 mutation carriers scheduled for RRSO were prospectively collected in comparison with five mutation-negative control patients undergoing salpingo-oophorectomy for benign indications. Microarray analysis of genome-wide gene expression was performed on ovarian and fallopian tube samples from BRCA1/2 and control patients. The validation of microarray data was performed by quantitative real-time polymerase chain reaction (qRT-PCR) in selected cases of RRSO samples, and also high grade serous carcinoma samples collected from patients with BRCA phenotype. From 22,733 genes, 454 transcripts were identified that were differentially expressed in BRCA1/2 mutation carriers when statistically compared to controls pooling all ovarian and fallopian tube samples together. Of these, 299 genes were statistically significantly downregulated and 155 genes were upregulated. Differentially expressed genes in BRCA1/2 samples reported here might be involved in serous ovarian carcinogenesis and provide interesting targets for further studies.
Project description:Female BRCA1 mutation carriers have a nearly 80% probability of developing breast cancer during their life-time. We hypothesized that the breast epithelium at risk in BRCA1 mutation carriers harbors mammary epithelial cells (MECs) with altered proliferation and differentiation properties. Microarray studies revealed that PMEC colonies from BRCA1 mutation carriers anticipate expression profiles found in BRCA1-related tumors, and that the EGFR pathway is upregulated in BRCA1 mutation carriers compared ton non BRCA1 mutation carriers. Keywords: Class comparison and pathway analysis
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
Project description:Identifying germline BRCA1/2 mutation carriers is vital for reducing their risk of breast and ovarian cancer; however, many carriers are not referred for genetic testing. While population-wide testing is not feasible, a cheap functional screen for phenotypic ‘BRCAness’ could guide efforts for focused genetic counseling and improve cancer prevention and early detection. The aim of this study was to derive a serum-based miRNA panel to identify BRCA1/2 mutation carriers among healthy controls. We performed a diagnostic biomarker study based on serum samples collected between by six international cohorts. Serum samples from 653 healthy women with known mutation status of BRCA1 and BRCA2 were used in the analysis. All individuals had no history of prior cancer or any detected malignancies for at least 12 months after sample collection. Among the study population, 350 (53.6%) subjects had BRCA mutations and 303 (46.4%) were BRCA1/2 – wild-type. In all individuals, we isolated and quantified miRNAs expression using RNA-sequencing. Variable selection based on differential expression analysis on merged, batch adjusted cohorts was performed to identify a set of miRNAs associated with BRCA mutation carrier status.
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.
Project description:The functional consequences of missense variants in disease genes are difficult to predict. We assessed if gene expression profiles could distinguish between BRCA1 or BRCA2 pathogenic truncating and missense mutation carriers and familial breast cancer cases whose disease was not attributable to BRCA1 or BRCA2 mutations (BRCAX cases). 72 cell lines from affected women in high-risk breast-ovarian families were assayed after exposure to ionising irradiation, including 23 BRCA1 carriers, 22 BRCA2 carriers, and 27 BRCAX individuals. A subset of 10 BRCAX individuals carried rare BRCA1/2 sequence variants considered to be of low clinical significance (LCS). BRCA1 and BRCA2 mutation carriers had similar expression profiles, with some subclustering of missense mutation carriers. The majority of BRCAX individuals formed a distinct cluster, but BRCAX individuals with LCS variants had expression profiles similar to BRCA1/2 mutation carriers. Gaussian Process Classifier predicted BRCA1, BRCA2 and BRCAX status with a maximum of 62% accuracy, and prediction accuracy decreased with inclusion of BRCAX samples carrying an LCS variant, and inclusion of pathogenic missense carriers. Similarly, prediction of mutation status with gene lists derived using Support Vector Machines was good for BRCAX samples without an LCS variant (82-94%), poor for BRCAX with an LCS (40-50%), and improved for pathogenic BRCA1/2 mutation carriers when the gene list used for prediction was appropriate to mutation effect being tested (71-100%). This study indicates that mutation effect, and presence of rare variants possibly associated with a low risk of cancer, must be considered in the development of array-based assays of variant pathogenicity. Keywords: cell type comparison, stress response
Project description:The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,000 CpGs in white blood cells from women with and without BRCA1 mutation. Whole blood samples were drawn from 30 BRCA1 mutation carriers (15 women with breast cancer and 15 healthy women with mean age 57.2) and 30 females without BRCA1 mutation (15 breast cancers and 15 healthy with mean age 57.1). All samples were collected between 2001 and 2008. The samples were drawn from women attending the General Faculty Hospital in Prague and the complete coding sequence, intron-exon junctions and large rearrangements for BRCA1 and BRCA2 genes were tested.
Project description:The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,000 CpGs in white blood cells from women with and without BRCA1 mutation. Whole blood samples were drawn from 30 BRCA1 mutation carriers (15 women with breast cancer and 15 healthy women with mean age 57.2) and 30 females without BRCA1 mutation (15 breast cancers and 15 healthy with mean age 57.1). All samples were collected between 2001 and 2008. The samples were drawn from women attending the General Faculty Hospital in Prague and the complete coding sequence, intron-exon junctions and large rearrangements for BRCA1 and BRCA2 genes were tested. Bisulphite converted DNA from the 60 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip v1.2