Targeting lipid metabolism in pancreatic cancer [CRISPR]
Pancreatic ductal adenocarcinoma (PDAC) thrives in a nutrient-deprived 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 pre-clinical 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. Through comprehensive metabolic analyses we find that PIKfyve inhibition obligates PDAC to upregulate de novo lipid synthesis, a relationship previously undescribed. PIKfyve inhibition triggers a distinct lipogenic gene expression and metabolic program, creating a dependency on de novo lipid metabolism pathways, including genes such as FASN and ACACA. These results suggest that targeting PIKfyve disrupts lysosome-dependent lipid metabolism in PDAC and may be a favorable metabolic target for therapeutic development. Further, this data suggests that one could take advantage of this synthetic dependency by co-targeting PIKfyve and FASN or ACACA as a therapeutic strategy. Overall design: Human PDAC cells (MIA PaCa-2) were transduced with a pooled gRNA library (Addgene #110066).  After selection, untreated cells (initial population), or cells treated with DMSO (control) or apilimod for 14 days were harvested for a CRISPR screen.