LAUSR

Background and Purpose: Copper is a crucial structural component for many significant enzymes, as well as a key catalytic co-factor in redox processes. The flexible Cu(I/II) redox behavior facilitates the formation of copper complexes that are more potent and less toxic. The anticancer activity of several agents can be enhanced by forming copper complexes. The purpose of this study is to evaluate the anti-proliferative effects of two copper (II) complexes, copper-tolfenamic acid (Cu-TA) and copper thiosemicarbazone (Cu-acetylethTSC or CuTSC) against medulloblastoma (MB). MB is a cancer of the cerebellum which is associated with frequent relapse and drug resistance with the current treatments. It necessitates the development of alternative strategies. The anti-cancer activity of Cu-TA was evaluated in laboratory testing in some cancer models, but it has not been studied in MB. CuTSC against colorectal cancer, leukemia and breast cancer has been studied but it has not in MB. Methods: TA and TSC were complexed with Cu and Cu-TA and CuTSC complexes were characterized through colorimetric/mass spectrometric analyses. Cancer cells and cardiomyocytes were cultured using standard protocols and cell viability was measured using Cell Titer-Glo kit (Promega). Protein expression was determined by Western blot analysis. Experiments/Results: CuTA and CuTSC complexes showed proper characterization and stability during the testing period. Cardiomyocytes (H9C2) and human cancer cell lines representing breast, Ewing sarcoma and MB were screened for anti-proliferative activity of these two Cu complexes. While, cell viability was inhibited in all cancer cell lines, MB cell lines (DAOY and D283) showed higher efficacy while H9C2 cell viability was not affected. To understand the underlying mechanism of action, the effect of Cu-TA was assessed on the expression of c-PARP, Specificity protein 1 (Sp1) and an antiapoptotic protein, survivin. Western blot results revealed a clear decrease in the expression of both Sp1 and survivin and upregulation of c-PARP. Discussion/Conclusion: Both Cu-TA and CuTSC treatments result in a dose-time dependent anti-proliferative activity against cancer cells but not affecting non-malignant cardiomyocyte cells. Cu-TA can inhibit Sp1 and survivin and increase PARP cleavage suggesting the effect on Sp1-regulated oncogenes and an induction of apoptotic pathways. The studies to establish crossing of Blood Brain Barrier and further understand the underling mechanisms of these two Cu complexes in single and combination treatment alongside chemotherapeutic agents are currently under investigation. Citation Format: Hope Korshie Fiadjoe, Christoffer Lambring, Umesh T. Sankpal, Duaa Alajroush, Alvin A. Holder, Riyaz Basha. Anti-proliferative effect of two copper complexes against medulloblastoma cells [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 6255.