Lipid storage and catabolism as drivers of metastatic invasion

Metastasis is the primary cause of cancer death, yet therapeutic strategies to inhibit metastatic invasion do not exist. The long-term goal of our research program is to define the molecular mechanisms driving metastatic invasion, with the goal of identifying novel therapeutic targets and strategies to improve cancer survival. While tumor cells are known to undergo metabolic reprogramming to support tumor growth, the metabolic drivers of metastasis are poorly understood. This proposed research will define how stored lipids are used as a fuel source to power metastatic invasion in pancreatic cancer. We have preliminary data that pancreatic tumor cells undergo a shift towards lipid storage, and that this is required for invasion. This occurs through a suppression of the hormone sensitive lipase (HSL) by the oncogene KRAS, leading to lipid accumulation and priming tumor cells for metastasis. These stored lipid droplets are then catabolized during the process of invasion via the action of lipases. This results in increased oxidative metabolism in the most migratory cells, thereby coordinating lipid droplet breakdown and fatty acid oxidation with cell migration. These data lead to the hypothesis for this proposed research that PDAC cells undergo a metabolic shift to favor the accumulation and storage of lipid droplets, which are catabolized during invasive migration to fuel oxidative phosphorylation to power metastasis. Using a combination of cell biology, biochemistry, and in vivo models, we will test this hypothesis by defining the mechanisms of lipase suppression leading to lipid droplet storage (Aim 1), and the coordinated and localized activation of lipolysis to drive tumor cell invasion (Aim 2). Successful completion of this research will provide fundamental advances in defining the metabolic pathways regulating invasive migration, with a focus on lipid droplets, and with the goal of identifying metabolic vulnerabilities in tumor cells that will provide targets for therapy to block metastasis and improve survival.