BRCA1 and BRCA2: breast/ovarian cancer susceptibility gene products and participants in DNA double-strand break repair
ABSTRACT BRCA1 and BRCA2 are tumor suppressor genes, familial mutations in which account for approximately 5% of breast cancer cases in the USA annually. Germ line mutations in BRCA1 that truncate or inactivate the protein lead to a cumulative risk of breast cancer, by age 70, of up to 80%, whereas the risk of ovarian cancer is 30-40%. For germ line BRCA2 mutations, the breast cancer cumulative risk approaches 50%, whereas for ovarian cancers, it is between 10 and 15%. Both BRCA1 and BRCA2 are involved in maintaining genome integrity at least in part by engaging in DNA repair, cell cycle checkpoint control and even the regulation of key mitotic or cell division steps. Unsurprisingly, the complete loss of function of either protein leads to a dramatic increase in genomic instability. How they function in maintaining genome integrity after the onset of DNA damage will be the focus of this review.
- SourceAvailable from: Michele Santangelo[Show abstract] [Hide abstract]
ABSTRACT: Increasing evidence demonstrates that target based-agents are active only in molecularly selected populations of patients. Therefore, the identification of predictive biomarkers has become mandatory to improve the clinical development of these novel drugs. Mutations of the epidermal growth factor receptor (EGFR) or rearrangements of the ALK gene in non-small-cell lung cancer, and BRAF mutations in melanoma are clear examples of driver mutations and predictive biomarkers of response to treatment with specific inhibitors. Predictive biomarkers might also identify subgroups of patients that are not likely to respond to specific drugs, as shown for KRAS mutations and anti-EGFR monoclonal antibodies in colorectal carcinoma. The discovery of novel driver molecular alterations and the availability of drugs capable to selectively block such oncogenic mechanisms is leading to a rapid increase in the number of putative biomarkers that need to be assessed in each single patient. In this respect, two different approaches are being developed to introduce a comprehensive molecular characterization in clinical practice: high throughput genotyping platforms, which allow the detection of recognized genetic aberrations in clinical samples, and next generation sequencing that can provide information on all the different types of cancer-causing alterations. The introduction of these techniques in clinical practice will increase the possibility to identify molecular targets in each individual patient, and will also allow to follow the molecular evolution of the disease during the treatment. By using these approaches the development of personalized medicine for cancer patients will finally become possible. J. Cell. Biochem. © 2012 Wiley Periodicals, Inc.Journal of Cellular Biochemistry 03/2013; 114(3). DOI:10.1002/jcb.24401 · 3.37 Impact Factor
Article: Familial Breast Cancer Risk[Show abstract] [Hide abstract]
ABSTRACT: The most well recognized breast cancer susceptibility genes are BRCA1 and BRCA2. Studies in individuals carrying mutations in these genes have led to clinical care guidelines for screening and prevention. Beyond BRCA1 and BRCA2, mutations in TP53, PTEN, STK11, and CDH1 also significantly increase the risk of breast cancer. Early identification of women at increased risk of breast cancer due to specific genetic susceptibility may lead to enhanced screening and prevention strategies and potentially improved overall survival for this group of patients as has been seen with carriers of BRCA1 and BRCA2 mutations. In addition to high penetrance genes, increasing numbers of genes that confer a moderate risk of breast cancer have been identified such as CHEK2, PALB2, and ATM; however, the clinical application of these genes is much more challenging. This review will discuss both high and moderate penetrance breast cancer susceptibility genes.Current Breast Cancer Reports 09/2013; 5(3). DOI:10.1007/s12609-013-0117-9