Abstract 5491: Targeting importin-YAP axis in pancreatic ductal adenocarcinoma

Abstract

Abstract Background: To date, pancreatic ductal adenocarcinoma (PDAC) remains to have a dismal prognosis, with a 5-year survival rate of only 10%, which brings out an imperative to develop new therapeutic strategies to improve patient outcome. Recently, aberrant nucleocytoplasmic transport machinery in cancer cells has emerged as a rational therapeutic target. We aim to validate the nuclear importin complex involved in the import of macromolecules across the nuclear membrane as a potential therapeutic target in PDAC. Methods: Tet-inducible shRNA and FDA-approved agent (Ivermectin) were used for the inhibition of importins. Cell death (apoptosis and pyroptosis) was detected by western blot. In vivo tumor growth of human and mouse PDAC cells was evaluated in immunocompetent and immunodeficient animal models. MTT assay was employed to evaluate the patient-derived organoid viability following drug treatment. Results: We found that PDAC cells/patients harbored unusually higher levels of importins. Inducible knockdown of importin-α2/α5 (KPNA2/KPNA1) or importin-β1 (KPNB1) strongly suppressed PDAC tumor growth and induced apoptosis and pyroptosis. Interestingly, the importin inhibitor Ivermectin (an FDA-approved antiparasitic agent) worked effectively in PDAC cells, patient-derived organoids and animal models. Mechanistically, we show that importins associate with YAP (the transcriptional coactivator of the Hippo pathway) and control its expression at mRNA levels. In line with these observations, the expression levels of importin-αs, importin-β1, and YAP are positively correlated in PDAC patients. Conclusion: Our study identifies the importin complex as a prognostic marker and therapeutic target for pancreatic cancer and is expected to provide preclinical evidence for the evaluation of Ivermectin in PDAC patients. Citation Format: Renya Zeng, Jixin Dong. Targeting importin-YAP axis in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5491.