Role of APEX2 in DNA Repair Mechanisms

The proliferation of cancer strongly depends on flawless cell replication. DNA repair mechanisms are responsible for the cells to replicate without errors. We focused on studying apex2 and its function in the DNA repair pathway of mammalian cells. In BRCA-mutant tumors, apex2 has been identified as a potential synthetic lethal target. Studies in yeast showed that apn2 reduces the frequency of mutations and repairs damage caused by top1. We used CRISPR-Cas9 to knockout apex2 gene in HCT116 and U-2OS and tested genetic interaction between apex2, tdp1, ercc4 and apex1 using siRNA and drug sensitivity. Our results suggest that knockout of apex2 together with knockdown of tdp1 and ercc4 increased drug sensitivity