Abstract 2237: Diclofenac as a dual inhibitor of cyclooxygenase and aldo-keto-reductase 1B10 inhibits pancreatitis-enhanced carcinogenesis in LSL-Kras G12D -Pdx-1-Cremice

Abstract

Abstract Diclofenac is one of non-steroid anti-inflammatory drugs and is recently identified as a competitive inhibitor of aldo-keto reductase family 1B10 (AKR1B10). AKR1B10 is an NADPH-dependent enzyme that exhibits lipid substrate specificity, especially for farnesyl and geranylgeranyl involved in protein prenylation (such as for Kras) and plays an oncogenic role in pancreatic carcinogenesis. In the present study, we determined the chemopreventive effects and mechanism of diclofenac on inhibiting pancreatitis-carcinogenesis in LSL-KrasG12D/Pdx1-Cre mice (called Pankras mice), particularly on Kras prenylation. Pancreatitis was induced by single i.p. injection of Cearulein (250ug/Kg body weight) for 5-week old mice, and one week after caerulein treatment, Pankras mice were fed an AIN-93M diet or a diet with 5 or 20ppm diclofenac (n=12 mice/group) for 7 months. The results showed that Diclofenac significantly reduced the severity of chronic pancreatitis, as measured by the extent of acini loss, inflammatory cell infiltration and stromal fibrosis. The progression of low-grade mPanIN I to high-grade mPanIN II/III and to invasive carcinoma was significantly suppressed and the tumor incidence significantly reduced to 50% and 17% in the mice treated with either 5ppm or 20 diclofenac compared to 86% in Pankras mice. Inhibition of membrane-bound mutant Kras (prenylated) and its transmitted phosphorylation of mitogen-activated protein kinase's kinase/extracellular signal-regulated kinases were demonstrated in pancreatic tissues by western blot assay. Analysis of the eicosanoid profile revealed a significant reduction of prostaglandin E2. These results indicate that diclofenac is a highly potential agent for preventing chronic pancreatitis and carcinogenesis, mainly via targeting mutant Kras and inflammation (Supported by NIH R01 CA164041). Citation Format: Jie Liao, Leyu Sun, Haonan Li, Rong Xia, Xiaoming You, Dandan Xu, Guang-Yu Yang. Diclofenac as a dual inhibitor of cyclooxygenase and aldo-keto-reductase 1B10 inhibits pancreatitis-enhanced carcinogenesis in LSL-KrasG12D-Pdx-1-Cremice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2237.