Abstract 277: The small molecule tolfenamic acid inhibits neuroblastoma cell growth through inducing apoptosis and causing cell cycle arrest potentially targeting Sp1 and survivin
Authors: Eslin Don , Sankpal Umesh T. , Lee Chris M. , Sutphin Robert M. , Maliakal Pius , Currier Erika , Sholler Giselle Saulnier , Basha Riyaz 
Published: August 2012

Neuroblastoma is an embryonal tumor of the peripheral sympathetic nervous system found in infants and children. Despite intensive therapy, the mortality rate of this malignancy remains more than 50%. The side effects of standard therapy can cause acute and long term damage and toxicity in various biological functions and can lead to the development of secondary tumors. Therefore there is an urgent need in identifying novel strategies in neuroblastoma that improve out come with less toxicity. Specificity proteins (Sp) regulate several important genes associated with neuroblastoma including MYCN and TrkA. Our aim was to exploit the strategy of targeting Sp proteins using TA in the treatment of neuroblastoma. In this study, we examined the anti-proliferative activity of TA using 7 neuroblastoma cell lines and evaluated the ability of TA to induce apoptosis, and cell cycle arrest using selected cell lines. Apoptosis in mammalian cells primarily takes place through extrinsic and intrinsic pathways. Specificity protein (Sp) transcription factors regulate several genes involved in cell proliferation, survival and angiogenesis. Tolfenamic acid (TA), a non-steroidal anti-inflammatory drug, is known to induce the degradation of Sp proteins and may serve as a novel anti-cancer agent. The objective of this investigation was to examine the anti-cancer activity of TA using established human neuroblastoma cell lines. We tested the anti-proliferative effect of TA using 7 human neuroblastoma cell lines. Cells were treated with TA (0/25/50/100μM) and cell viability was measured at 24, 48, and 72 h post-treatment. Selected neuroblastoma cell lines, LA1 55n and SH-SY5Y were treated with 50 μM TA for 24 and 48 h and tested for cell apoptosis using Annexin-V staining. Caspase activity was measured with caspase 3/7 Glo kit. Cell lysates were prepared and the expression of Sp1, survivin and c-PARP were evaluated through Western blot analysis. TA significantly inhibited the growth of neuroblastoma cells in a dose/time-dependent manner and significantly decreased Sp1 and survivin expression. Apart from cell cycle (G0/G1) arrest, TA caused significant increase in the apoptotic cell population, caspase 3/7 activity and c-PARP expression. These results show that TA effectively inhibits neuroblastoma cell growth potentially through suppressing mitosis, Sp1 and survivin expression, and inducing apoptosis. These results represent a novel strategy for using small molecules for the treatment of neuroblastoma.(Financial assistance: This study is supported by MD Anderson Cancer Center Orlando (RB); Run Way to Hope and Hyundai Hope on Wheels Scholar grant awarded to DE).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 277. doi:1538-7445.AM2012-277