Abstract 5653: The in vitro effects of aloe-emodin on head and neck squamous cell carcinoma

Abstract

Abstract Aloe emodin (AE) is an anthraquinone compound extracted from the leaves of aloe vera plants, which has been shown to have anti-neoplastic activities on various cancers. This study investigated the effects of AE on cell proliferation and apoptosis induction in head and neck squamous cell carcinoma (HNSCC) using a HEP-2 cell line model. HEP-2 cells were either left untreated, normal media, (Control) or treated with different concentrations of AE (6.25-100 µM) for 24 h. Cell proliferation was evaluated using MTS and crystal violet staining assays. Cell cycle was analysed using flow cytometry measuring DNA content (Propidum Iodide). Apoptosis was analysed by TUNEL and apoptotic gene expression was measured by human apoptosis RT2 Profilertm polymerase chain reaction array. Cell proliferation assays showed that AE inhibited cell proliferation in a dose dependent manner. MTS assay demonstrated a 26.96% and 43.12% decrease in cell proliferation at 6.25 and 12.5 µM, respectively. In confirmation of the MTS assay, crystal violet staining displayed 35.58% and 39.42% reduction in cell proliferation at 6.25 and 12.5 µM, respectively. Further, AE treatment demonstrated an increase in G1 cell cycle arrest compared to the control. Apoptosis analysis exhibited an increase in early and late stage apoptotic cells in the AE treated group. TUNEL assay demonstrated a 2 to 3 fold increase in apoptosis compared to the control. Finally, the apoptotic gene expression array revealed differential expression among the 12.5 µM AE treated cells and control cells of several genes involved in apoptosis including: TNF, BCL2, caspase and death domain gene families. In conclusion, we present original data for the first time showing AE is capable of producing anti-neoplastic effects, inhibiting cell proliferation and inducing apoptosis, in HNSCC. 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 5653.