Pancreatic cancer is a devastating disease with a five-year survival rate below 10%. One of the main factors underscoring this low survival rate is the lack of effective clinical treatments. Like most cancers, metabolic processes in pancreatic cancer cells are altered to facilitate macromolecular biosynthesis and protect against intra and extracellular stressors. Reactive oxygen species (ROS) are a byproduct of metabolism and represent a notable metabolic stress to pancreatic cancer cells. Previously, we described a new metabolic pathway in pancreatic cancer, mediated by cytosolic glutamate oxaloacetate transaminase 1 (GOT1), that is used to manage ROS by facilitating the coordination of cytosolic and mitochondrial metabolism and maintaining glutathione (GSH) pools. Ferroptosis is a recently described form of iron-dependent, non-apoptotic cell death caused by lipid peroxidation and mediated by loss of GSH pools. We found that GOT1 inhibition potentiated the activity of known ferroptotic agents. Further, we also discovered that GOT1 inhibition can engage ferroptosis when nodes in cysteine metabolism are inhibited. In this research proposal, we will determine how GOT1 inhibition promotes ferroptosis. Mechanistic insight from these studies will then be used to selectively target pancreatic cancers for ferroptotic cell death. This will be accomplished using metabolomics techniques in combination with genetic and pharmacological inhibitors of metabolism. In parallel, we will test combinations of ferroptotic agents with GOT1 inhibition in human patient-derived 3D culture models and in orthotopic mouse models to determine the translation value. Given the safety profile of GOT1 and some ferroptosis-inducers, the profound sensitivity of this combination in pancreatic cancer cells, and the desperate need for new strategies to treat pancreatic cancer, there is now a critical need to understand mechanistically what confers sensitivity to these combinations. Such insights may provide strategies to promote redox imbalance in pancreatic cancer, paving the way for tumor-selective, ferroptosis-based therapies.
Cancer cells rewire their metabolic programs to support tumor growth. We found that metabolic pathways to manage nutrient and redox stress are activated in pancreatic cancer, and that these may represent targetable vulnerabilities. This research proposal will study the mechanisms by which metabolic stress is regulated to define new drug targets and therapies for pancreatic cancer.
