Pathogenesis of pancreatic cancer: lessons from animal models.

The past several decades have seen great effort devoted to mimicking the key features of pancreatic ductal adenocarcinoma (PDAC) in animals and have produced 2 robust models of this deadly cancer. Carcinogen-treated Syrian hamsters develop PDAC with genetic lesions, which reproduce those of human, including activation of the Kras oncogene, and early studies in this species validated nongenetic risk factors for PDAC including pancreatitis, obesity, and diabetes. More recently, PDAC research has been invigorated by the development of genetically engineered mouse models based on tissue-specific Kras activation and deletion of tumor suppressor genes. Surprisingly, mouse PDAC appears to arise from exocrine acinar rather than ductal cells, via a process of phenotypic reprogramming that is accelerated by inflammation. Studies in both models have uncovered molecular mechanisms by which inflammation promotes and sustains PDAC and identified targets for chemoprevention to suppress PDAC in high-risk individuals. The mouse model, in particular, has also been instrumental in developing new approaches to early detection as well as treatment of advanced disease. Together, animal models enable diverse approaches to basic and preclinical research on pancreatic cancer, the results of which will accelerate progress against this currently intractable cancer.