Endocrine-Exocrine Signaling Drives Obesity-Associated Pancreatic Ductal Adenocarcinoma

Obesity is a major modifiable risk factor for pancreatic ductal adenocarcinoma (PDAC), yet how and when obesity contributes to PDAC progression is not well understood. Leveraging an autochthonous mouse model, we demonstrate a causal and reversible role for obesity in early PDAC progression, showing that obesity markedly enhances tumorigenesis, while genetic or dietary induction of weight loss intercepts cancer development. Molecular analyses of human and murine samples define microenvironmental consequences of obesity that foster tumorigenesis rather than new driver gene mutations, including significant pancreatic islet cell adaptation in obesity-associated tumors. Specifically, we identify aberrant beta cell expression of the peptide hormone cholecystokinin (Cck) in response to obesity and show that islet Cck promotes oncogenic Kras-driven pancreatic ductal tumorigenesis. Our studies argue that PDAC progression is driven by local obesity-associated changes in the tumor microenvironment and implicate endocrine-exocrine signaling beyond insulin in PDAC development. [Display omitted] •Obesity accelerates oncogenic Kras-driven pancreatic ductal tumorigenesis in mice•Genetic or dietary weight loss intercepts pancreatic cancer progression•Obesity is associated with aberrant pancreatic islet cholecystokinin expression•Islet cholecystokinin overexpression drives pancreatic ductal cancer development Obesity is an intrinsic driver of PDAC in mice, leading to a remodeling of beta cells to increase CCK secretion and playing a role early in pancreatic cancer development that can be intercepted by weight loss.