Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Sep 14, 2012; 18(34): 4781-4786
Published online Sep 14, 2012. doi: 10.3748/wjg.v18.i34.4781
Hyperthermia inhibits hypoxia-induced epithelial-mesenchymal transition in HepG2 hepatocellular carcinoma cells
Guang-Jin Yuan, Qian-Wen Li, Shun-Lin Shan, Wu-Ming Wang, Sen Jiang, Xi-Ming Xu
Guang-Jin Yuan, Qian-Wen Li, Shun-Lin Shan, Wu-Ming Wang, Sen Jiang, Cancer Center, the 82nd Hospital of the Chinese People’s Liberation Army, Huai’an 223001, Jiangsu Province, China
Xi-Ming Xu, Cancer Center, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
Author contributions: Yuan GJ and Li QW designed the study; Wang WM and Jiang S performed the majority of experiments; Shan SL analyzed the data; and Yuan GJ and Xu XM wrote the paper.
Supported by Medical Science and Technology Innovation Foundation of Nanjing Military Command of Chinese People’s Liberation Army, No. 11MA036; and Natural Science Foundation of China, No. 81000998
Correspondence to: Xi-Ming Xu, Professor, PhD, Cancer Center, Renmin Hospital of Wuhan University, No. 9 Ziyang road, Wuhan 430060, Hubei Province, China. whuxxm@yahoo.com
Telephone: +86-27-88041911 Fax: +86-27-88042292
Received: February 12, 2012
Revised: April 17, 2012
Accepted: April 22, 2012
Published online: September 14, 2012
Abstract

AIM: To investigate the effect of hyperthermia on hypoxia-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma (HCC) cells, and its mechanism.

METHODS: Cells were treated with hyperthermia at 43 °C for 0.5 h, followed by incubation under hypoxic or normoxic conditions for 72 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or Western blot. The protein and mRNA expressions of Snail were also determined by Western blot and reverse transcription-polymerase chain reaction. Cell migratory capacity was evaluated.

RESULTS: Hypoxia induced EMT in HepG2 cells, which was evidenced by morphological, molecular and functional changes, including the formation of a spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin was increased; also, the migratory capability was increased by 2.2 ± 0.20-fold as compared with normoxia. However, those effects were inhibited by hyperthermia pretreatment. Furthermore, protein synthesis and mRNA expression of Snail in the cells were enhanced by hypoxia as compared with normoxia, and also significantly inhibited by hyperthermia pretreatment.

CONCLUSION: Hyperthermia may inhibit hypoxia-induced EMT in HepG2 HCC cells, and the mechanism may involve inhibition of induced expression of Snail.

Keywords: Hyperthermia, Hypoxia, Epithelial-mesenchymal transition, Hepatocellular carcinoma, Snail