Abstract: Chemotherapy plays an important role in cancer treatment. With deeply understanding the mechanism of tumorigenesis, different chemotherapeutic drugs have been emerged as initial choices for cancer treatment. However, most patients gradually develop to chemotherapeutic resistance, resulting in failure to initial standard therapy. The mechanisms of chemoresistance are extensively explored. Recent studies indicated intrinsic or acquired alteration of DNA damage repair ability is the key determinant of chemoresistance. In this review, we present deregulation of DNA damage repair pathway in cancers and its involvement contributing to chemoresistance. Furthermore, we discuss strategies to sensitize chemotherapy by targeting at a parallel DNA repair pathway, which become promising approaches to overcome chemotherapeutic resistance.

Key words: oncotherapy, DNA damage, chemoresistance