title: Beta-catenin blocks Kras-dependent reprogramming of acini into pancreatic cancer precursor lesions in mice.
abstract: Cellular plasticity in adult organs is involved in both regeneration and carcinogenesis. WT mouse acinar cells rapidly regenerate following injury that mimics acute pancreatitis, a process characterized by transient reactivation of pathways involved in embryonic pancreatic development. In contrast, such injury promotes the development of pancreatic ductal adenocarcinoma (PDA) precursor lesions in mice expressing a constitutively active form of the GTPase, Kras, in the exocrine pancreas. The molecular environment that mediates acinar regeneration versus the development of PDA precursor lesions is poorly understood. Here, we used genetically engineered mice to demonstrate that mutant Kras promotes acinar-to-ductal metaplasia (ADM) and pancreatic cancer precursor lesion formation by blocking acinar regeneration following acute pancreatitis. Our results indicate that beta-catenin is required for efficient acinar regeneration. In addition, canonical beta-catenin signaling, a pathway known to regulate embryonic acinar development, is activated following acute pancreatitis. This regeneration-associated activation of beta-catenin signaling was not observed during the initiation of Kras-induced acinar-to-ductal reprogramming. Furthermore, stabilized beta-catenin signaling antagonized the ability of Kras to reprogram acini into PDA preneoplastic precursors. Therefore, these results suggest that beta-catenin signaling is a critical determinant of acinar plasticity and that it is inhibited during Kras-induced fate decisions that specify PDA precursors, highlighting the importance of temporal regulation of embryonic signaling pathways in the development of neoplastic cell fates.
authors.affiliation: Diabetes Center, Department of Medicine, UCSF, San Francisco, California 94143, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Morris
authors.forename: David A
authors.initials: DA
authors.lastname: Cano
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sekine
authors.forename: Sam C
authors.initials: SC
authors.lastname: Wang
authors.forename: Matthias
authors.initials: M
authors.lastname: Hebrok
mesh_terms: D000208:Acute Disease; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D051152:Clusterin / Q000187:drug effects / Q000235:genetics; D051379:Mice; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000503:physiopathology; D010195:Pancreatitis / Q000150:complications / Q000473:pathology; D011230:Precancerous Conditions / Q000473:pathology* / Q000503:physiopathology; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000502:physiology*; D012038:Regeneration / Q000187:drug effects; D051176:beta Catenin / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D051152:Clusterin; D051176:beta Catenin; C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras)