• mice treated with doxycycline (dox) at 4-6 weeks of age to induce Kras2 expression begin to show low-grade pancreatic intraepithelial neoplasia (PanIN) beginning at 3 weeks after dox treatment
• mice treated with dox at 4-6 weeks of age show PanIN, surrounded by areas of fibrosis and embedded in the acinar parenchyma after 18 weeks on dox and by 23 weeks, large areas of the pancreatic parenchyma are substituted with PanIN lesions of different grade, with frank adenocarcinoma seen in 1 of 2 mice
• mice kept on dox for 23 weeks show reversion of PanINs when dox is removed for 2 weeks
• adult mice treated with dox 72 hours prior to injection with the cholecystokinin analog cerulein, to induce acute pancreatitis, develop low- and high-grade PanIN lesions at 5 weeks after induction
• mice treated with dox 72 hours prior to induction of pancreatitis also show reversion of PanINs when dox is removed for 2 weeks