Open Access Highly Accessed Research article

β-Elemene-induced autophagy protects human gastric cancer cells from undergoing apoptosis

Jing Liu, Ye Zhang, Jinglei Qu, Ling Xu, Kezuo Hou, Jingdong Zhang, Xiujuan Qu* and Yunpeng Liu*

Author Affiliations

Department of Medical Oncology, the First Hospital of China Medical University, Shenyang 110001, P.R.China

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BMC Cancer 2011, 11:183  doi:10.1186/1471-2407-11-183

Published: 20 May 2011

Abstract

Background

β-Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anti-cancer effects against a broad spectrum of tumors. The mechanism by which β-elemene kills cells remains unclear. The aim of the present study is to investigate the anti-tumor effect of β-elemene on human gastric cancer cells and the molecular mechanism involved.

Results

β-Elemene inhibited the viability of human gastric cancer MGC803 and SGC7901 cells in a dose-dependent manner. The suppression of cell viability was due to the induction of apoptosis. A robust autophagy was observed in the cells treated with β-elemene; it was characterized by the increase of punctate LC3 dots, the cellular morphology, and the increased levels of LC3-II protein. Further study showed that β-elemene treatment up-regulated Atg5-Atg12 conjugated protein but had little effect on other autophagy-related proteins. PI3K/Akt/mTOR/p70S6K1 activity was inhibited by β-elemene. Knockdown of Beclin 1 with small interfering RNA, or co-treatment with the autophagy inhibitor, 3-methyladenine or chlorochine enhanced significantly the antitumor effects of β-elemene.

Conclusions

Our data provides the first evidence that β-elemene induces protective autophagy and prevents human gastric cancer cells from undergoing apoptosis. A combination of β-elemene with autophagy inhibitor might thus be a useful therapeutic option for advanced gastric cancer.