Drug-Induced p53 Activation Limits Pancreatic Cancer Initiation

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease, initiated predominantly by mutations inKras, which induce acinar-to-ductal metaplasia (ADM) and subsequent formation of precursor lesions, such as pancreatic intraepithelial neoplasia (PanIN). Progression to PDAC is frequently associated with mutations in the tumor suppressorTP53, presumably via disrupting p53-mediated cellular senescence of PanINs. WhetherTP53also has tumor-suppressive activity in earlier phases of PDAC initiation has been less clear. In this study, we investigate the impact of pharmacological stabilization of the wild-type p53 protein on the formation of ADM in aKras^G12D-driven mouse model of PDAC. Our findings demonstrate that p53 stabilization via Nutlin-3a significantly reduces both ADM and PanIN formation by promoting the differentiation of ADM into acinar cells. This differentiation coincides with p53-dependent upregulation of the transcription factor Mist1 (Bhlha15), a critical inducer of acinar cell identity. Our results reveal a role for p53 in tissue repair and maintenance of homeostasis in tumor suppression and suggest pharmacological engagement of p53 as an intervention strategy to prevent PDAC initiation.