Abstract 4298: Investigating the potential of EO3001 as a therapeutic agent for clear cell ovarian cancers harboring ARID1A mutations

Abstract Introduction: Clear cell ovarian cancer (CCOC) is a histological subtype of ovarian cancer that is resistant to standard chemotherapies. Although it accounts for only around 6% of all ovarian cancer cases, it is the second leading cause of mortality among ovarian cancers. ARID1A loss-of-function mutations have been identified as a hallmark (∼65%) of CCOC. ARID1A, a key component of the SWI/SNF chromatin remodeling complex, plays a critical role in regulating gene expression. Loss of ARID1A disrupts the expression of SLC7A11, leading to decreased glutathione (GSH) levels and elevated reactive oxygen species (ROS) levels, while making cancer cells highly dependent on oxidative phosphorylation (OXPHOS). EO3001, a synthetic small molecule, can selectively transport extracellular Cu(II) to mitochondria, increasing mitochondrial ROS and inducing cuproptosis. Recent studies suggest that ARID1A-deficient CCOC cells are more vulnerable to EO3001. In this study, an ex vivo model, the pulmonary metastasis assay (PuMA), along with other in vitro models, was employed to assess the effectiveness of EO3001 in CCOC. PuMA enables the study of cancer cell growth in a more physiologically relevant microenvironment. In PuMA, fluorescently tagged cancer cells are inoculated into mouse lungs, which are then inflated with agarose gel, sectioned, and treated under different conditions. The growth of cells is quantified by fluorescence intensity from lung sections. Methods: Isogenic ARID1A wild-type and mutant CCOC cell lines (RMG-1, OVCA429, and JHOC-5) were generated using CRISPR-Cas9. The effects of EO3001 were evaluated using in vitro assays and PuMA. Cell viability, proliferation, ROS levels, glycolysis and OXPHOS activity, migration, and invasion were measured with and without EO3001 treatment under various stress conditions. Drug efficacy was validated in both short- and late-harvest PuMA models. Results: EO3001 demonstrated significant differential effects against ARID1A-deficient CCOC cells in both in vitro and ex vivo models. However, hypoxic conditions significantly diminished its efficacy, likely due to a metabolic shift between OXPHOS and glycolysis. Furthermore, Cu(II) concentration in the microenvironment remarkably impacts the efficiency of EO3001. Overall, EO3001 presents a promising therapeutic strategy for ARID1A-mutant CCOC as a single agent. Targeting the OXPHOS dependency in ARID1A-mutant CCOC cells and enriching Cu(II) concentration could further enhance the efficacy of EO3001. Citation Format: Yuchen Ding, Tsz Yin (Jacky) Lam, Yuting (Shary) Chen, Longyijie (Grace) Wei, Yuqin (Lucy) Li, Yuhan (Joyce) Zhang, Farhia Kabeer, Forouh Kalantari, Jeffrey Bacha, Dennis Brown, Sarath Kanekal, Neil Sankar, Michael Lizardo, Michelle Woo, Amal M. EL-Naggar, David Huntsman. Investigating the potential of EO3001 as a therapeutic agent for clear cell ovarian cancers harboring ARID1A mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4298.