Propionyl-CoA catabolism is a metabolic gatekeeper for fatty acid oxidation in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) cells rely on fatty acid oxidation (FAO) for proliferation; however, the regulatory mechanisms governing this dependency and their clinical implications remain unclear. Here, we report that PDAC patients exhibit decreased plasma levels of propionyl-CoA intermediates, alongside accelerated propionyl-CoA catabolic activity within both human PDAC tumors and Pdx1-Cre/KrasG12D/+/Trp53R172H/+ (KPC) mouse tumors. Specifically, PDAC cells upregulate propionyl-CoA carboxylase (PCC) to accelerate propionyl-CoA catabolism, thereby establishing a metabolic signature distinct from that of healthy tissues. Mechanistically, PCC is essential for PDAC growth, not by fueling the TCA cycle, but by preventing toxic propionyl-CoA accumulation. We further demonstrate that elevated propionyl-CoA leads to the propionylation-induced inactivation of the mitochondrial fatty acid oxidation (FAO) enzyme ACAA2 at Lysine 137, thereby blocking the FAO flux required for tumor proliferation. Moreover, high PCCA expression in patient PDAC tumors is significantly associated with decreased lipid accumulation, and PDAC cells with high PCC levels are more sensitive to etomoxir-induced cell proliferation arrest. These findings establish the PCC-ACAA2 axis as a critical metabolic vulnerability and a promising target for diagnostic and therapeutic interventions in PDAC.