Vintner Grant funded by the 2018 V Foundation Wine Celebration in memory of Mary Weber Novak
A hallmark of cancer is a defective repair of DNA damage, which supports genetic alterations to drive cancer growth and resistance to drugs. Therefore, effectively targeting DNA repair defects of cancers is perhaps the most attractive strategy to kill cancer cells. Indeed, inhibition of DNA repair by specific small-molecule enzyme inhibitors has proven to be effective in selectively killing breast cancers that already have defective DNA repair function. However, cancer cells frequently develop resistance to these drugs, and therefore there is a critical need to develop safe and effective alternatives to current cancer drugs. A reversible protein modification, called poly(ADP-ribosyl)ation, is essential for DNA repair. ARH3 digests poly(ADP-ribose) to protect cells from poly(ADP-ribose)-mediated cell death. Cells lacking the gene that encodes the ARH3 protein are healthy yet show an increased poly(ADP-ribose)-mediated cell death following DNA damage. This suggests inhibition of ARH3 as an effective strategy to kill cancers with high poly(ADP-ribose) levels. We have found unique structural features in ARH3 that are important for its function, and developed new tools to study the ARH3 function. In this proposal, we seek to develop small molecules that specifically inhibit ARH3 function by focusing on the mechanisms underlying the ARH3 function. Our proposed research will advance our understanding of the role of ARH3 during cellular responses to DNA damage and contribute to the development of new cancer drugs.