Single-Dose L-Lysine-Induced Pancreatitis Followed by Pancreatic Neoplastic Progression in Adult Kras/Trp53-Driven Mice.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal malignancy, highlighting the need for reproducible experimental systems that model pancreatic injury and subsequent neoplastic progression. Adult-onset genetically engineered models in which oncogenic Kras and mutant Trp53 are induced in the pancreas provide a relevant platform for studying PDAC pathogenesis, but efficient neoplastic progression often requires concomitant pancreatic injury. Cerulein-induced pancreatitis is widely used to provide an injury-associated inflammatory stimulus that promotes PDAC progression; however, repeated-injection regimens are labor-intensive and increase cumulative handling stress in animals. Here, we describe a dose-optimized, single-dose L-Lysine protocol designed to induce acute pancreatitis and characterize subsequent pancreatic neoplastic progression in adult-onset Kras/Trp53-driven mice. Tamoxifen-treated Ptf1a^CreER/+; Kras^LSL-G12D/+; Trp53^LSL-R172H/+; Rosa26-RFP mice received a single intraperitoneal injection of L-Lysine, followed by biochemical, histological, and immunohistochemical assessment of pancreatic injury and tumor development. A single 2.0 g/kg L-Lysine injection induced sublethal acute pancreatitis characterized by increased serum pancreatic enzymes, interstitial edema, inflammatory cell infiltration, acinar cell necrosis, and rapid mitochondrial alterations. During 3-6 months of follow-up, mice developed multifocal acinar-to-ductal metaplasia, PanIN lesions, invasive PDAC, and peritoneal dissemination. This protocol provides a simple, synchronized, and less labor-intensive model for studying pancreatic injury and subsequent neoplastic progression in adult-onset Kras/Trp53-driven mice.