Abstract 5384: Targeting PIKfyve-driven lipid homeostasis as a metabolic vulnerability in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) subsists in a nutrient-deregulated microenvironment, making it particularly susceptible to treatments that interfere with cancer metabolism. For example, PDAC utilizes and is dependent on high levels of autophagy and other lysosomal processes. Although targeting these pathways has shown potential in preclinical studies, progress has been hampered by the challenge of identifying and characterizing favorable targets for drug development. Here, we characterize PIKfyve, a lipid kinase integral to lysosomal functioning, as a novel and targetable vulnerability in PDAC. Employing a genetically engineered mouse model, we established the essential role of PIKfyve in PDAC progression. Further, through comprehensive metabolic analyses, we found that PIKfyve inhibition obligated PDAC to upregulate de novo lipid synthesis. PIKfyve inhibition triggered a distinct lipogenic gene expression and metabolic program, creating a dependency on de novo lipid metabolism pathways, by upregulating genes such as FASN and ACACA. In PDAC, the KRAS-MAPK signaling pathway is a primary driver of de novo lipid synthesis, specifically enhancing FASN and ACACA levels. Accordingly, the simultaneous targeting of PIKfyve and KRAS-MAPK resulted in the elimination of tumor burden in numerous preclinical human and mouse models, including endogenous genetically engineered models. Taken together, these studies suggest that disrupting lipid metabolism through PIKfyve inhibition induces synthetic lethality in conjunction with KRAS-MAPK-directed therapies for PDAC. Citation Format: Caleb Cheng, Jasmine Wisniewski, Sydney Peters, Rüya Pakkan, Jennifer P. Morton, Pietro Morlacchi, Yuanyuan Qiao, Costas A. Lyssiotis, Arul M. Chinnaiyan. Targeting PIKfyve-driven lipid homeostasis as a metabolic vulnerability in pancreatic cancer [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 5384.