Abstract A27: Exploring the role of glycosylation in pancreatic disease

Pancreatic ductal adenocarcinoma (PDA) is almost uniformly lethal and surgical intervention is the only cure. Unfortunately, most patients are ineligible for resection because of the advanced stage of disease by the time of diagnosis. This is due in part to the lack of diagnostic tools, especially for families with elevated risk. The PDA biomarker, CA19-9, is measured in the blood to follow tumor burden longitudinally, but is neither sensitive nor specific enough to be used for diagnosis. The use of CA19-9 in PDA diagnosis is problematic given the elevation of CA19-9 in benign pancreatic disease, such as pancreatitis. While CA19-9 has been traditionally used as a diagnostic, retrospective studies reported that PDA patients who maintain a CA19-9 negative/low status have a significantly longer survival relative to those with higher CA19-9 levels in multivariate analyses. The functional significance of CA19-9 to PDA initiation, maintenance, and progression remains unclear due in part to the absence of this carbohydrate modification in mice. We found that expression of CA19-9 in the mouse pancreas is sufficient to induce pancreatitis, a benign proliferative condition that often confounds the diagnosis of PDA. Specifically, CA19-9 elevation resulted in rapid elevation of pancreatic enzymes in the blood, pancreatic infiltration of immune cells, acinar-to-ductal metaplasia and atrophy, as well as increased proliferation. Furthermore, we explored the utility of CA19-9 as a therapeutic target for both acute and chronic pancreatitis. This avenue of treatment strategy exhibits potential given that a pilot study demonstrated that turning off CA19-9 expression results in the normalization of pancreatic enzyme levels within four days following an acute episode of pancreatitis. Future work will focus on how elevation of this glycosylation modification mediates the development of pancreatitis by identifying the signaling pathways that are altered upon CA19-9 expression. In addition, we will explore the efficacy of therapeutically targeting CA19-9 in both pancreatitis and PDA with a larger goal of delineating the role of CA19-9 in pancreatic disease. Citation Format: Dannielle Engle, Herve Tiriac, Arnaud Pommier, Christina Schoepfer, Brandon Da Silva, Melissa Yao, Youngkyu Park, Michael A. Hollingsworth, David Tuveson. Exploring the role of glycosylation in pancreatic disease [abstract]. In: Proceedings of the AACR Special Conference: Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond; 2017 Sep 24-27; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(10 Suppl):Abstract nr A27.