Breast Cancer Susceptibility Gene
According to a study published in American Journal of Human Genetics, a new gene involved in genetic susceptibility to breast cancer was discovered. According to researchers, XRCC2 gene mutations lead to breast cancer.Breast cancer is the most common malignancy in women. Studies show that 15% of healthy women with at least one first degree relative with breast cancer are at risk. So far, except for BRCA1 and BRCA2 gene mutations and some rare syndromes (such as mutations of TP53, STK11, PTEN, CDH1, NF1 or NBN), familial aggregation could not be proven.
The present study demonstrates the presence of mutations in other genes known so far (BRCA and BRCA2), namely XRCC2. Sean Tavtigian, Ph.D., Huntsman Cancer Institute (HCI) investigator and associate professor in the Department of Oncological Sciences at the University of Utah (U of U), one of Three Co-principal Investigators on the study, highlights the importance of this findings and the potential benefit that this discovery has in treating breast cancer. In addition, this research has an important role diagnose because healthy women who are carriers of this mutation can prevent cancer even before it to occur.
The discovery was made by tracking families who had a history of breast cancer but not yet discovered any known genes involved in this type of cancer. So far, familial aggregation of breast cancer was explained by mutations in BRCA1 and BRCA2, which are tumor suppressor genes. In normal cells, these genes have a role in the stability of genetic material (DNA) and prevent uncontrolled cell growth. Women who have a family history of cancer and have mutations in these genes have an increased risk of breast cancer or ovarian cancer. A person can find out if he is carrier of the mutation by taking blood and conducting genetic tests.
The research was based on the analysis of genes involved in DNA repair and was conducted using a technology called massively parallel sequencing exome capture (exome sequencing). Thus, researchers could investigate the whole human genome by following the exact order of nucleotides that encode proteins genes. Results showed that there are 2 different mutations in the XRCC2 gene involved in breast cancer. Dr. Tavtigian explains that one of the mutations cause an incomplete version of the protein, version that makes it inoperable. The other mutation is characterized by an amino acid change in protein structure.
In terms of therapeutic potential, Dr. Tavtigian said the new discovery could become the target in breast cancer chemotherapy. People who carry mutations in the gene XRCC2 may be treated with PARP inhibitors, drugs that kill cells bearing mutations in this gene.