Epigenetic Inactivation of the Chromosomal Stability Control Genes <i>BRCA1, BRCA2</i>, and <i>XRCC5</i> in Non–Small Cell Lung Cancer

Abstract

Our retrospective study provides compelling evidence that low mRNA and protein expression in the BRCA1/BRCA2 and XRCC5 genes occur in lung adenocarcinoma and squamous cell carcinoma, respectively, and that promoter hypermethylation is the predominant mechanism in deregulation of these genes. Alteration of the double-strand break repair pathway, perhaps by interacting with p53 and RB deregulation, is important in the pathogenesis of a subset of NSCLC.