Abstract 373: Comparison of the anti-cancer mechanism of tolfenamic acid and its copper (II) complex

Abstract Tolfenamic acid (TA), a non-steroidal anti-inflammatory drug, has demonstrated anti-cancer properties across multiple cancer models including prostate, pancreatic, ovarian, colon, leukemia, lung, and medulloblastoma. Studies have identified potential targets of TA including transcription factors Sp1, Sp3 and Sp4, anti-apoptotic proteins survivin and Bcl2, anti-angiogenic protein VEGF, and NFkB gene products. These interactions result in inhibition of cell proliferation, induction of apoptosis, and suppression of tumor growth in mouse models. To enhance the efficacy of TA, a novel copper (II) complex of TA ([Cu(TA)2(bpy)], bpy = 2,2’-bipyridine, Cu(II)-TA) was synthesized. Cell viability assays revealed that Cu(II)-TA exhibited greater anti-proliferative activity than TA, as indicated by lower IC50 values. However, the mechanism underlying this increased activity remains unclear. In this study, we compared the mechanism of action of TA and Cu(II)-TA in medulloblastoma cells. The anti-proliferative activity of the two compounds was assessed using a cell viability assay and the apoptotic activity was evaluated by caspase 3/7 activity assay. Cell cycle effects were analyzed by flow cytometry and DNA damage was assessed by measuring levels of phospho-H2AX using western blot and immunofluorescence microscopy. Consistent with previous findings, we observed increased anti-proliferative effects with Cu(II)-TA compared to TA in medulloblastoma cells. This enhanced activity was accompanied by increased apoptosis as indicated by higher caspase 3/7 activity. Cell cycle analysis by flow cytometry revealed distinct profiles for the inhibitors. TA treatment resulted in increased G2/M population, while Cu(II)-TA did not show a prominent or dose-dependent increase with treatment. Interestingly, TA induced greater DNA damage than Cu(II)-TA as indicated by increased phospho-H2AX levels detected by western blotting and immunofluorescence staining. These findings suggest that while Cu(II) enhances the anti-proliferative activity of TA, the underlying mechanisms differ, likely involving distinct proteins and pathways. Citation Format: Hayden Flume, Riva Sarkar, Tanaya Washington, Ethan Schroeder, Sakariyau A. Waheed, Kaylin L. Thomas, Stephen Beebe, Riyaz Basha, Alvin Holder, Umesh T. Sankpal. Comparison of the anti-cancer mechanism of tolfenamic acid and its copper (II) complex [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 373.