Abstract A024: High throughput screen for identifying inducers of Autophagic Cell Death in Ovarian Carcinoma

Abstract Ovarian carcinoma continues to have the highest associated mortality among gynecologic malignancies. Despite surgery and chemotherapy, relapse and drug-resistant disease remains common. Thus, new therapeutic targets and improved combination regimens are needed. Autophagy is a conserved process cells use to remove and recycle old or damaged contents and maintain homeostasis, especially in times of cellular stress. Prolonged autophagy can result in cell death independently of apoptosis in a process known as autophagy cell death (ACD). This offers an alternative therapeutic strategy to target cancer cells, which are often resistant to apoptosis. In this study, we performed a high-throughput screen using the Mechanism Interrogation PlatE (MIPE) oncology library in HeyA8 and SKOV3 spheroids to identify drugs with high potential to induce ACD. Screening was performed in two phases: 1) Enrichment for compounds that decreased cell viability; 2) Enrichment for compounds able to induce autophagic flux in SKOV3 spheroids. We used a pft-LC3-RFP-GFP construct which was stably expressed in SKOV3 cells before 3-D culture as an autophagy index, and the accumulation of LC3-RFP in SKOV3 spheroids was measured in response to the treatments from MIPE compounds versus compared to control. An analog of the top hit of the screen results was the SIRT1 inhibitor, EX-527. We next performed a pharmacodynamic study in OVCA432-ip1-luc tumor-bearing mice to identify potential biomarkers of drug activity. We found that expression of the autophagy-related protein, LC3B, increased in tumors in a dose-dependent manner, forming loci indicative of autophagy flux at 20 mg/kg. Work is ongoing to identify rational combinations for use of EX-527 in management of ovarian carcinoma, and to characterize its mechanism of action. Citation Format: Pahul Hanjra, Andrea Liu, Marc Ferrer, Anil K. Sood, Yunfei Wen. High throughput screen for identifying inducers of Autophagic Cell Death in Ovarian Carcinoma abstract. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84 (5 Suppl₂): Abstract nr A024.