Abstract 1710: Pharmacologic targeting or silencing of TRIP13 reduces progression of pancreatic ductal adenocarcinoma
Authors: Afaq Farrukh , Agarwal Sumit , Bajpai Prachi , Kim Hyung-Gyoon , Diffalha Sameer Al , Sugandha Shajan P. , Khushman Moh'd , Varambally Sooryanarayana , Manne Upender 
Published: June 2023

Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with a 5-year overall survival rate of &lt; 9%. Thus, there is a need to identify key driver signaling molecules that regulate PDAC progression and to target them for therapeutic intervention. Thyroid receptor-interacting protein 13 (TRIP13), an enzyme of the AAA-ATPase family, participates in spindle assembly checkpoints, double-strand DNA repair, and development of drug resistance. Recently, a small-molecule inhibitor of TRIP13, DCZ0415, was evaluated in experimental models of multiple myeloma and colorectal cancer. However, the expression, oncogenic role, and targeting of TRIP13 in PDAC are unknown. Thus, we examined the expression and role of TRIP13 in PDAC and investigated if targeting it with DCZ0415 had an inhibitory effect on phenotypic features, tumor growth, metastasis, and immune modulation.

Methods: Publicly available cancer OMICS datasets (TCGA and CPTAC) for TRIP13 expression were analyzed by using the UALCAN portal, and results were validated with human PDAC samples. To demonstrate the oncogenic role of TRIP13 in PDAC progression, we used silencing with shRNA or pharmacologic targeting by DCZ0415 and performed MTT, colony formation, wound healing, Transwell, and western blot assays in PDAC cell lines, and assessed tumor growth and metastasis in immunocompromised NSG mice. Immunostaining and western blotting were performed to ascertain the immuno-modulatory mechanism of DCZ0415 in an immunocompetent KPC murine model of PDAC.

Results: In human PDACs, TRIP13 is overexpressed at the mRNA and protein levels, relative to adjacent normal pancreatic tissues. Silencing of TRIP13 with shRNA or DCZ0415 treatment of PDAC cells reduced their proliferation, migration, and invasion; induced G2/M cell cycle arrest; and, by modulating Bcl-2 family proteins, increased apoptosis. Furthermore, DCZ0415 treatment or silencing of TRIP13 increased E-cadherin and decreased N-cadherin and vimentin, suggesting its involvement in the epithelial-mesenchymal transition process. Genetic manipulation or pharmacologic targeting of TRIP13 also resulted in reduced expression of FGFR4 and pSTAT3, leading to lower levels of β-catenin, cyclin D1, LEF1, and TCF1, indicating inactivation of the Wnt/β-catenin pathway. In a syngeneic PDCA model, DCZ0415 induced an immune response by increasing granzyme B and perforin and by decreasing PD1. DCZ0415 treatment also facilitated immune cell infiltration, as evident from elevated staining of CD3 and CD4 cells.

Conclusions: In sum, silencing of TRIP13 or treatment with DCZ0415 reduces PDAC progression by downregulating the FGFR4/STAT3/β-catenin pathway. DCZ0415 treatment also enhances anti-tumor immunity. These findings suggest that DCZ0415 can be developed as a therapeutic/immunostimulatory agent to improve treatment of PDAC patients expressing elevated levels of TRIP13.

Citation Format: Farrukh Afaq, Sumit Agarwal, Prachi Bajpai, Hyung-Gyoon Kim, Sameer Al Diffalha, Shajan P. Sugandha, Moh'd Khushman, Sooryanarayana Varambally, Upender Manne. Pharmacologic targeting or silencing of TRIP13 reduces progression of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1710.