Brief Reports
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 21, 2005; 11(19): 2990-2993
Published online May 21, 2005. doi: 10.3748/wjg.v11.i19.2990
Docetaxel shows radiosensitization in human hepatocellular carcinoma cells
Chang-Xin Geng, Zhao-Chong Zeng, Ji-Yao Wang, Shi-Ying Xuan, Chong-Mao Lin
Chang-Xin Geng, Shi-Ying Xuan, Chong-Mao Lin, Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao University, Qingdao 266071, Shandong Province, China
Zhao-Chong Zeng, Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
Ji-Yao Wang, Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Chang-Xin Geng, Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao 266071, Shandong Province, China. changxin_geng@hotmail.com
Telephone: +86-532-5937758
Received: June 8, 2004
Revised: June 9, 2004
Accepted: August 5, 2004
Published online: May 21, 2005
Abstract

AIM: To determine the radiosensitizing potential of docetaxel in human hepatocellular carcinoma SMMC-7721 cells and its mechanisms.

METHODS: SMMC-7721 cells were incubated with docetaxel at 0.125, 0.25, and 0.5 nmoL/L for 24 h and at 0.125 and 0.25 nmol/L for 48 h before irradiation. Radiation doses were given from 0 to 10 Gy. Cell survival was measured by a standard clonogenic assay after a 9-d incubation. The reactive oxygen species (ROS) and glutathione (GSH) are detected after being given the same dose of docetaxel for the same time.

RESULTS: The sensitization enhancement ratios (SER) for SMMC-7721 cells determined at the 50% survival level were 1.15, 1.21 and 1.49 at 0.125, 0.25, and 0.5 nmol/L for pre-incubation of 24 h, respectively; the SER were 1.42, 1.67 at 0.125 and 0.25 nmol/L, for pre-incubation of 48 h, respectively. The ROS of SMMC-7721 cells increased and GSH decreased after pretreatment with the same doses of docetaxel for 24 or 48 h.

CONCLUSION: A radiosensitizing effect of docetaxel could be demonstrated unambiguously in this cell line used. In addition, our data showed that the mechanism of radiopotentiation by docetaxel probably does not involve a G2/M block in SMMC-7721 cells, and ROS generation and GSH deletion may play a key role in the radiosensitizing effect of docetaxel.

Keywords: Docetaxel; Hepatocellular carcinoma; SMMC-7721cell line; Radiosensitization; Reactive oxygen species