(PHILADELPHIA) – Researchers at the Abramson Family Cancer Research Institute of the University of Pennsylvania and the Dana-Farber Cancer Institute describe in this week’s issue of Science a new candidate breast-cancer susceptibility gene. The Rap80 gene is required for the normal DNA-repair function of the well-known breast cancer gene BRCA1. Cancer-causing mutations in the BRCA1 protein cause it to fail to bind to the Rap80 protein. Consequently, BRCA1 is unable to identify DNA damage sites in the genome. When BRCA1 fails to fix DNA damage, cancer-causing mutations accumulate, spawning the development of breast and ovarian malignancies.
