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:Microarrays were used to determine relative global gene expression changes in WT and BRCA1-mutation carrier breast epithelium as well as tumors created from WT and BRCA1-mutation carrier breast epithelial cells. Total RNA was isolated from freshly dissociated mammary epithelilal cells obtained from disease-free prophylactic masectomy tissues of 4 different BRCA1-mutation carriers or 4 different reduction mammoplasty tissues from non-mutation carriers. Total RNA was also isolated from fresh tumor tissues derived from in vivo transformed human mammary epithelial cells created from cells obtained from WT or BRCA1-muation carrires. Dissociated mammary epithelial cells were transduced with lentiviruses encoding mutant p53, mutant ras, mutant PI3K and cyclin D1 and injected into in humanized glands. There were four tumor tissues isolated for each genetic background.
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:Microarrays were used to examine gene expression changes that may be present in the fallopian tube epithelium of morphologically normal BRCA1 mutation positive and negative subjects. Fallopian tube epithelia has been implicated as an early point of origin for serous carcninoma. By examining the early events present in the microenvironment of this tissue between BRCA1 mutation carriers and non-carriers, we hoped to elucidate mechanisms that may lead to the development of epithelial ovarian cancer. Laser microcapture of samples from 12 BRCA1 mutation carriers and 12 non-mutation subjects was performed. Samples were further grouped according to menstrual cycle.
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. Microarray expression profiles were obtained from whole pre-neoplastic breast tissue from three categories of patient, as described in the summary. Samples were checked for keratin gene expression levels as a marker for epithelium tissue, and a number of samples were removed because two or more keratin genes lacked detectable expression (BeadStudio detection p-value 0.01). One other sample was removed because its expression profile appeared abnormal. Out of 36 samples initially profiled, 20 passed the quality filters and were used for the final analysis.
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).
Project description:Microarrays were used to examine gene expression changes that may be present in the fallopian tube epithelium of morphologically normal BRCA1 mutation positive and negative subjects. Fallopian tube epithelia has been implicated as an early point of origin for serous carcninoma. By examining the early events present in the microenvironment of this tissue between BRCA1 mutation carriers and non-carriers, we hoped to elucidate mechanisms that may lead to the development of epithelial ovarian cancer.
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.