Abstract 5694: Zapotin mediates its action by inducing p53 in wild-type p53 positive human lung cancer cells

Abstract

Abstract Lung cancer is the most common cancer worldwide, accounting for 1.2 million new cases annually. Despite the availability of several novel medications, very few have been found to be widely applicable or effective. Hence, the aim of present study was to assess the efficacy of Zapotin, a phytochemical present in the Mexican fruit Sapote blanco (Casimiroa edulis), in lung epithelial cells. Zapotin was chemically synthesized and the effects were evaluated on several human non-small cell lung cancer cell lines (A549 (p53 wild type), Calu-1(p53 null), H1993 (p53 mutated)) and the Normal Human Bronchial epithelial cell line (BEAS-2b) using cell proliferation assay (MTT Assay & Cell count method), apoptosis assay (TUNEL Assay), western blot analysis and RT-PCR. Significant growth inhibition of 66.91% and apoptosis was found to be induced in the A549 cells when treated with 1 μM zapotin for 72 hrs. On the other hand, no significant growth inhibition was noted for Beas-2b under the same conditions. Furthermore, the western blot analyses indicated that zapotin increased p53 and p21 protein expression in A549 cells but not in Beas-2b cells. Studies for p53 mRNA expression were completed on A549 and Beas-2b subsequent to treatment with zapotin and it showed to have no significant changes. This suggested that the activation of p53 is at protein level instead of transcriptional level. This is the first report to indicate that zapotin acts through p53 mediated pathway in wild-type p53 positive A549 cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5694.