PROJECT SUMMARY Pancreatic ductal adenocarcinoma (PDA) remains largely incurable and recent studies have shown that the metabolic pathways of PDA cells are profoundly rewired. Nonetheless, this metabolic rewiring may also engender liabilities that can be exploited for PDA treatment. Using genetically-engineered mouse models and pancreatic ductal organoids, we previously showed that PDA cells are dependent upon KRAS-mediated increases in protein synthesis. As several key oncogenic signaling pathways converge on the eukaryotic translation initiation factor 4F (eIF4F), we recently examined whether an inhibitor (CR-31) of its associated RNA helicase (eIF4A) affects the viability of PDA cells. Strikingly, CR-31 impaired the translation of mRNAs encoding enzymes involved in various metabolic pathways selectively in cells of PDA, but not normal, ductal organoids. Moreover, while gemcitabine, the only existing monotherapy for PDA, does not extend the survival of PDA- bearing mice, we observed that CR-31 alone suppressed PDA tumor growth in vivo. Thus, we hypothesize that eIF4A is a key regulator of pancreatic cancer translation with unique potential as a therapeutic target against PDA. To realize the potential of eIF4A inhibition in the clinical setting, we propose to define the mechanism of eIF4A-dependent transcript-specific translation in pancreatic cancer cells (Aim 1), determine the translational targets of eIF4A that promote PDA (Aim 2), and identify adaptations induced by eIF4A inhibition that can be co- targeted to more effectively treat this lethal malignancy (Aim 3). This project builds on our expertise in PDA biology, organoid culture, RNA genomic analysis, as well as access to patient-derived specimens to evaluate clinical relevance. In addition to illuminating basic mechanisms, the proposed studies will test several novel treatment options for PDA.