DNA Repair System: The Important Role in Cancers

Abstract

DNA repair is a key stone system for living cells to maintain DNA stability. The inactivation of this system resulting from mutation or epigenetic changes can cause cancers. Some cancers involve in some hereditary abnormalities e.g. the mutation of mismatch repair (MMR) gene causing hereditary nonpolyposis colorectal cancers (HNPCCs), Breast Cancer (BRCA) gene deficiency relating to hereditary breast and ovarian cancer syndromes. The expression of DNA repair genes plays an important role as a biomarker for many cancers and this expression increases the accuracy of diagnosis, anticipates prognosis and predicts chemotherapeutic responses. The mistake occurring during DNA repair pathways can allow cancer cells containing damaged DNA affected by cancer treatments, particularly chemotherapeutic agents to survive. Recently, new therapeutic trials are continuously developed to improve treatment responses. Interestingly, the inhibition of specific DNA repair by drugs is currently a novel cancer treatment option, which is expected to enhance the efficacy of treatment recognized as synthetic lethality, when it is combined with chemotherapy. Nevertheless, further clinical studies are essentially needed to confirm the benefits of using drugs for inhibition of specific DNA repair pathways.

Key words: DNA repair, cancer, targeted therapy, biomarker