Abstract 2972: Effect of novel copper-tolfenamic acid complex on medulloblastoma cells
Authors: Hong Julie , Schullek Melissa , Smith John K. , Reitman Joseph , Dudhia Amil , Tallapaka Nihant , Basha Rassil , Brown Deondra T. , Chhabra Jaya , Holder Alvin , Sankpal Umesh T. 
Published: August 2019

Introduction. Medulloblastoma is the most common malignant brain tumor in children. New treatment strategies are urgently needed as the current options often result in significant long term neurocognitive and growth defects among survivors. We have previously demonstrated the anti-cancer activity of small-molecule non-steroidal anti-inflammatory drug tolfenamic acid (TA) in medulloblastoma cells and tumor model. The anti-cancer activity of TA can be correlated to its ability to downregulate the anti-apoptotic protein Survivin, cause cell cycle arrest, and induce apoptosis. A recent publication has shown that the activity of TA can be enhanced by forming a complex with copper (II). In this study we tested the function of the copper complex as an anti-cancer agent against pediatric medulloblastoma.

Methods. Pediatric medulloblastoma cell lines DAOY and D283 were used in this study. We have previously demonstrated the synthesis, stability, and anti-cancer activity of Copper-Tolfenamic acid (Cu-TA) complex using various cancer cell lines. The efficacy of Cu-TA against medulloblastoma cells was determined by studying the effect of increasing dose on cell viability, using the CellTiter-Glo Luminescent Cell Viability Assay. Further experiments, using optimized doses of Cu-TA, were carried out to determine its effect on cell cycle and its ability to induce apoptosis. Based on our previous results with TA, we also investigated the effect of Cu-TA on survivin protein levels.

Results. Inhibition of cell viability was observed with increasing doses of Cu-TA as well as with increasing time. The IC50 values were 2-fold lower compared to that of TA and were used in further experiments. Cell cycle analysis using propidium iodide staining and flow cytometry revealed that treatment with Cu-TA results in accumulation of cells in G0/G1 phase, as early as 12h after treatment. Cu-TA induced apoptosis was studied by flow cytometric analysis of AnnexinV stained cells and by western blot analysis of cleaved-PARP. At 48h post-treatment, significant increase in apoptosis was detected by flow cytometry, that also correlated with increased levels of c-PARP. Cu-TA treatment also resulted in a significant decrease in survivin levels compared to TA at 24 and 48h post-treatment.

Conclusion. Our earlier studies with TA have demonstrated its potential as an anti-cancer agent with relatively safe toxicity profile, both in vitro and in pre-clinical mouse model studies. TA also has the capability to enhance the response of standard treatments when used in combination. Here, we demonstrate the ability to increase the efficacy of TA when complexed with copper (II). Cu-TA, with its increased anti-cancer activity and potential to sensitize cells to chemotherapy and radiation, provides a novel therapeutic option for the treatment of medulloblastoma.

Citation Format: Julie Hong, Melissa Schullek, John K. Smith, Joseph Reitman, Amil Dudhia, Nihant Tallapaka, Rassil Basha, Deondra T. Brown, Jaya Chhabra, Alvin Holder, Umesh T. Sankpal. Effect of novel copper-tolfenamic acid complex on medulloblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2972.