Abstract C089: A novel role of p53 in pancreatic acinar cell identity

Abstract

Abstract Pancreatitis is an inflammatory disease that affects acinar cells in the exocrine pancreas, and can be triggered by several factors, such as alcohol abuse, smoking and familial genetic alterations. Pancreatic injury associated with pancreatitis is characterized by inflammation, acinar cell death, and acinar-to-ductal metaplasia (ADM), a regenerative process in which metaplastic cells proliferate and re-differentiate into acinar cells. Recurrent pancreatitis can cause persistent ADM, impairing exocrine function and causing precancerous lesions known as pancreatic intraepithelial neoplasia (PanIN) that can initiate pancreatic ductal adenocarcinoma (PDAC), a nearly always fatal disease. Importantly, the lack of treatment options for pancreatitis patients reinforces the need for strategies that could resolve pancreatic damage and stop disease progression. We have recently shown that pancreatic cells harboring a hyperactive variant of p53 display increased resistance to developing acute pancreatitis induced by cerulein (a secretagogue which mimics cholecystokinin). Here, we show that p53 activation using the drug Nutlin-3a can repair the damage caused by cerulein-induced pancreatitis, and reduce the formation of PanIN lesions. This repair is achieved exclusively at low doses of Nutlin-3a, which cause a mild p53 activation, and is entirely dependent on the presence of the p53 gene. We have also identified novel p53 target genes relevant to acinar identity from ChIP-seq and RNA-seq data, and validated their dependence on p53 in mouse embryonic fibroblasts and in pancreatic precancerous lesions. Lastly, we have observed expression of p53 in the developing pancreas at embryonic day 15.5, indicating a potential function of p53 in pancreatic development. Our findings suggest a novel role of p53 in rescuing acinar cells from damage, and that p53 activation may be used as a treatment for pancreatitis and pancreatic cancer prevention. Citation Format: Jennifer J. Twardowski, Stephano S. Mello, Thomas I. Heist. A novel role of p53 in pancreatic acinar cell identity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C089.