Abstract C052: Induction of senescence by paclitaxel in high-grade serous ovarian carcinoma (HGSOC) cells renders the cells resistant to paclitaxel but sensitizes them to BCL-xL targeting agents

Abstract

Abstract High-grade serous ovarian carcinoma (HGSOC) is a very aggressive form of ovarian cancer, contributing to most ovarian cancer deaths. Paclitaxel is one of the major components of the first line treatment for HGSOC, but the development of chemoresistance to paclitaxel leads to the frequent relapse of the disease and poor prognosis in HGSOC patients. However, the mechanism underlying the chemoresistance has not been well established nor have the strategies to overcome the resistance been developed, which was investigated in the present study using three representative HGSOC cell lines (i.e. Kuramochi, OVCAR4, and OVCAR3 cells) in vitro. The results from our study show that induction of senescence contributes to paclitaxel-induced chemoresistance in HGSOC cells. More importantly, we found that senescent HGSOC cells induced by paclitaxel became highly dependent on BCL-xL for survival and thus were very sensitive to BCL-xL targeting agents, particularly to DT2216 (a BCL-xL specific proteolysis targeting chimera or PROTAC) and 753b (a BCL-xL and BCL-2 dual PROTAC). Because these PROTACs are more potent against senescent HGSOC cells but less toxic to platelets than ABT263 (a BCL-xL and BCL-2 dual inhibitor), they have the potential to be developed as new senolytics to overcome HGSOC chemoresistance to paclitaxel without causing the on-target and dose-limiting thrombocytopenia associated with ABT263 treatment. Citation Format: Yang Yang. Induction of senescence by paclitaxel in high-grade serous ovarian carcinoma (HGSOC) cells renders the cells resistant to paclitaxel but sensitizes them to BCL-xL targeting agents [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C052.