Abstract 5804: A novel copper(II) complex of tolfenamic acid exhibits anticancer activity in pancreatic cancer cells via downregulation of transcription factors Sp1 and Sp3 and an anti-apoptotic protein, survivin

Despite advances in research, pancreatic cancer (PC) remains one of the most lethal malignancies. The five-year survival rate is 8% and standard treatment options often cause high toxicity. Thus, there is a pressing need for identifying less toxic yet more effective agents for the treatment of this malignancy. Tolfenamic acid (TA) is a NSAID used as migraine medicine but has recently been demonstrated in pre-clinical studies to have anti-cancer properties. It is known to downregulate the transcription factor Specificity protein 1 and 3 (Sp1, Sp3). Sp1 and Sp3 regulate several genes involved with apoptosis and cell growth, including survivin, an inhibitor of apoptosis. Recently, it has been suggested that a copper(II) complex of TA (Cu-TA) can produce a higher therapeutic response; however, its efficacy has yet to be tested in gastro-intestinal cancers. Previously we presented that both TA and Cu-TA caused a dose-dependent response in inhibition of cell growth in PC cells, however, Cu-TA had an enhanced effect. Here, we used human PC cell lines (MIA PaCa-2 and Panc1) to evaluate the therapeutic efficacy of Cu-TA. Physical characterization of Cu-TA was performed using Fourier-transform infrared spectroscopy (FTIR) to analyze purity. To demonstrate the compound's stability, dose curve with Cu-TA was carried out using a stock solution that is one-year old as well as a 6-month old stock solution. Cells were also treated with the components used in the formation of Cu-TA (CuCl2 and BPY) to ensure the anti-cancer activity is due to the Cu-TA compound as a whole and cell viability was measured at 24 and 48 h. Western blot and quantitative PCR (qPCR) was done to assess Cu-TA's effect on Sp1, Sp3 and survivin protein and mRNA levels at 24 and 48 h post-treatment. To evaluate potential cardiotoxicity, cardiomyocytes (H9C2) were treated with increasing dosages of Cu-TA or TA and cell viability was measured at 24 and 48 h. Cu-TA was highly effective in suppressing Sp1, Sp3 and survivin protein expression. qPCR results showed that survivin mRNA expression was significantly lower following both Cu-TA and TA treatment; however, the mRNA expression of Sp1 and Sp3 remained unaltered. This suggests that both Cu-TA and TA could be working through a similar mechanism by effecting Sp1 and Sp3 post-translationally, possibly by proteasome-dependent degradation. FTIR results confirmed Cu-TA's purity (>99%) while the dose curves demonstrated the compound's stability. Both Cu-TA and