Abstract 7192: Teriflunomide overcomes gemcitabine resistance by inhibiting the GSK3β/mTOR pathway in pancreatic cancer

Abstract

Abstract Background: Pancreatic cancer (PC) is a lethal malignancy that is partly attributable to the acquisition of chemoresistance to conventional chemotherapies. Hence, developing strategies to overcome such chemoresistance is essential. Teriflunomide, an active metabolite of leflunomide, has been widely utilized in managing autoimmune disorders, and emerging evidence suggests that it can augment the efficacy of chemotherapy in cancer. We investigated the therapeutic effect of teriflunomide in overcoming resistance to Gemcitabine-based therapy in PC. Methods: We performed docking and genomewide transcriptomic profiling analyses to identify therapeutic targets of Teriflunomide associated with Gemcitabine resistance (Gem-R) in PC. Subsequently, we analyzed the TCGA dataset to determine the prognostic significance of candidate genes in PC patients. A series of experiments were performed in PC cells, and the key findings were validated in patient-derived 3D organoids and a Gem-R Mia-PaCa2 xenograft model. Results: Docking and transcriptomic profiling studies identified GSK3β, MAPK8, and MAPK9 as potential targets of Teriflunomide, which were significantly upregulated in Gem-R cell lines (P < 0.05). GSK3β was independently associated with poor overall and disease-free survival in PC patients. Combined Teriflunomide and Gemcitabine treatment exhibited superior synergistic anti-tumor potential, as evidenced by reducing PC cell proliferation, clonogenicity, invasion, and migration. The combined treatment with Teriflunomide and Gemcitabine primarily inhibited GSK3β phosphorylation, resulting in the silencing of the downstream AKT/mTOR pathway. Lentiviral-based silencing of GSK3β inhibited the AKT/mTOR pathway and reduced the IC50s of Gemcitabine in PC cells. Furthermore, co-administrating both drugs to Gem-R Mia-PaCa-2 xenograft mice significantly reduced tumor growth rates and volumes. These findings were recapitulated in patient-derived 3D-organoids, where the combined treatment resulted in fewer and smaller organoids vs. each drug individually (P < 0.05). Conclusions: We provide novel evidence that Teriflunomide helps overcome resistance to Gemcitabine by inhibiting the GSK3β/AKT/mTOR pathway, which could improve treatment outcomes in PC. Citation Format: Caiming Xu, Yuan Li, Silei Sui, Meiling Chen, Laleh Melstorm, Haiyong Han, Steven T. Rosen, Ajay Goel. Teriflunomide overcomes gemcitabine resistance by inhibiting the GSK3β/mTOR pathway in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7192.