ErbB-2/Her2/neu Overexpression and Estrogen-Dependency in Breast Carcinogenesis

摘要

BRCAl and BRCA2 are breast cancer susceptibility genes where mutations lead to cancer phenotypes that account for the hereditary breast and ovarian cancer syndrome 1-3 Hereditary breast cancer accounts for 5-10% of all breast cancers diagnosed each year4 and of these, BRCAl mutations are seen in 45-50% of these cases5. In sporadic breast and ovarian cancer, BRCAl mutations are rare6-7; however, 30-40% of sporadic cancers show reduced or absent expression of BRCA1(8). BRCAl is a nuclear protein that contains multiple functional domains interacting with numerous molecules, which include products of tumor-suppressor genes, oncogenes, DNA damage-repair proteins, cell cycle regulators and transcriptional activators and repressors9-10.