Nuclear GSK-3β and Oncogenic KRas Promote Expansion of Terminal Duct Cells and the Development of Intraductal Papillary Mucinous Neoplasm

Intraductal papillary mucinous neoplasm (IPMN) represents one precursor lesion of pancreatic ductal adenocarcinoma (PDA), but the cell-of-origin remains unclear. Here we describe a new mouse model in which pancreas-specific Cre activation of a nuclear glycogen synthase kinase-3β transgene is combined with oncogenic KRas (referred to as KNGC). KNGC mice show accumulation of neoplastic ductal cells at 4-weeks that progressively develop into IPMN with low-grade dysplasia in advanced age. RNA-sequencing identified expression of several genes found in the terminal duct cell lineage including Agr2 and Aqp5. Interestingly, Aqp5, a water channel, was found to be required for the development of IPMN lesions in KNGC mice. Staining of human IPMN samples indicates that these preneoplastic lesions also arise from expansion of the terminal duct population. Altogether, these data highlight the utility of the KNGC model for understanding the biology of IPMN and potential utility in defining predictive biomarkers of IPMN – PDA development. Pancreas mRNA profiles of 4-weeks age littlermates Pdx1-cre (WT), Pdx1-cre/LSL-KRasG12D (KC), Pdx1-cre/LSL-nuclear GSK-3β (NGC), Pdx1-cre/LSL-KRasG12D/LSL-nuclear GSK-3β (KNGC) were generated by deep sequencing, in triplicate, using Illumina TruSeq v2 kit.