P-0020 Evodiamine Augments TNF-α- and Trail-Induced Apoptosis in Human Gastric Cancer Cells Via Inhibiting The NF-κB and PI3K/Akt Signaling Pathways

Abstract

ABSTRACT Introduction Traditional medicines not only provide important notion for finding novel drugs, also may supportive to reallocate drug discovery paradigm from ‘finding new-entity drugs’ to ‘combining existing agents and might even the combinations between such agents. Previously, we found that Evodiamine which is isolated from, Chinese traditional medicine, Evodia rutaecarpa significantly induces apoptosis in gastric cancer cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis and kills cancer cells with little or no adverse effects on normal cells. However, gastric cancer cells are less sensitive than other cancer cells to TRAIL-induced apoptosis and effect of Evodiamine on TNF-a- and TRAIL-induced apoptosis in human gastric cancer cells remain unexplored. This study was designed to investigate whether Evodiamine augments TNF-a- and TRAIL-induced apoptosis in gastric cancer cells. Methods The growth inhibitory effect of the Evodiamine, TNF-a, TRAIL, and their combinations on the viability of cells was determined by the MTT assay. Apoptosis and mitochondrial membrane potential was evaluated by flow cytometry and expression of pro-apoptotic and pro-survival proteins were analyzed by Western blotting. Results In the present study, we found that Evodiamine enhanced TNF-a- and TRAIL-induced apoptosis in human gastric cancer cells. As indicated by assays that measure mitochondrial membrane integrity, pro-survival proteins, and activation of caspase-8, caspase-9, and caspase-3, Evodiamine potentiated the TRAIL-induced apoptosis in human gastric cancer cells and converted TRAIL-resistant cells to TRAIL-sensitive cells. Here, we demonstrate the first evidence that Evodiamine effectively enhances TNF-a- and TRAIL-mediated cytotoxicity by suppressing pro-survival proteins including cFLIP, Bcl-2, and survivin and up-regulates Bax expression. Upon treatment with Evodiamine, the levels of survival proteins were strongly suppressed in gastric cancer cells. The down-regulation of these survival proteins could be regulated by repressing activation of NF-kB and Akt. Evodiamine also inhibited TNF-a- and TRAIL-induced transcriptional activity of NF-kB. In addition, this substance significantly enhanced both extrinsic and intrinsic apoptosis, which were induced by TRAIL. Conclusion Taken together, the results of the present study suggest that Evodiamine exhibits an ability to overcome TRAIL resistance and combination treatment of TRAIL and TNF-a together with Evodiamine may be an effective regimen for the treatment of advanced gastric cancer.