Master of Science (MS)
Medical Sciences Interdepartmental Area
Dr. Gregory G. Oakley
Dr. Peter J. Giannini
Dr. Sundaralingam Premaraj
High-grade serous ovarian cancer (HGSC) is the most common and deadly gynecologic malignancy. HGSC patients with BRCA1/2 mutations have homologous recombination deficiency (HRD), requiring parallel pathways to maintain genome integrity (e.g., PARP1, PARP2). Approximately 50% of ovarian carcinomas are estimated to exhibit HRD. For the remaining 50% and the large percentage of HRD patients with acquired or innate resistance to single-agent PARP inhibitors, there is a need to develop alternative therapeutic strategies.
Replication Protein A (RPA) is a heterotrimeric protein crucial for genome maintenance. Phosphorylation of RPA in DNA damage response (DDR) is a negative regulator of DNA end resection. RPA interacts with multiple proteins at the N-terminus of RPA1 (DBD-F) to function. A novel strategy is to specifically inhibit DBD-F with an inhibitor that blocks RPA protein-protein interactions, and combined with PARP inhibition, has the potential to increase replication stress and DNA damage while selectively inducing cell death in HGSC cells containing both wild-type and mutant BRCA1/2.
This thesis characterized PARP inhibitors with RPA inhibitors in HGSC cells. Examination includes the analysis ssDNA binding, dsDNA unwinding, cell viability, and detection of phosphorylation in biochemical markers via immunofluorescence (IF) studies. An enhanced effect was observed with RPA and PARP inhibition in cell viability assays, and markers of replication stress and DNA damage was observed in IF studies. Future studies will include in vivo characterization using xenografts in mouse models.
Tang, Yat, "Characterizing the Combination of RPA Inhibitors with PARP Inhibitors in High-Grade Serous Ovarian Cancer" (2019). Theses & Dissertations. 416.