Brief Reports
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 28, 2005; 11(12): 1829-1832
Published online Mar 28, 2005. doi: 10.3748/wjg.v11.i12.1829
Apoptosis of human gastric cancer SGC-7901 cells induced by mitomycin combined with sulindac
Li Ma, Yong-Le Xie, Yi Yu, Qiu-Ning Zhang
Li Ma, Yong-Le Xie, Yi Yu, Qiu-Ning Zhang, Department of Gastroenterology, Second Affiliated Hospital, Lanzhou Medical University, Lanzhou 730030, Gansu Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Li Ma, Department of Gastroenterology, Second Affiliated Hospital, Lanzhou Medical University, Lanzhou 730000, Gansu Province, China. malilucky007@sina.com
Telephone: +86-931-8454165
Received: July 26, 2004
Revised: July 28, 2004
Accepted: September 4, 2004
Published online: March 28, 2005
Abstract

AIM: To investigate the effects of mitomycin (MMC) combined with sulindac on cell viability, apoptotic induction and expression of apoptosis-related gene Bcl-2 and cyclooxygenase-2 (COX-2) in gastric cancer SGC-7901 cells.

METHODS: Human gastric cancer SGC-7901 cells were divided into three treatment groups,namely sulindac treatment group, MMC treatment group and combined sulindac with MMC treatment group. After being treated with drugs, cell viability was examined by MTT assay. Flow cytometry was used to evaluate the cell cycle distribution and apoptotic rates. Morphology of the cells was observed under light microscope and interactive laser microscope. Expression of COX-2 and Bcl-2 was determined by immunocytochemical method.

RESULTS: After exposure for 12 h to three kinds of drugs, gastric cancer SGC-7901 cells presented some morphological features of apoptosis, including cell shrinkage, nuclear condensation, DNA fragmentation and formation of apoptotic bodies. Growth inhibition was more obvious in combined sulindac with MMC treatment group and sulindac treatment group than in MMC treatment group. The apoptotic rates in co-treated cells and MMC-treated cells 24 h after treatment were 12.0% and 7.2%, respectively. After exposure for 24 h to MMC, the expression of COX-2 and Bcl-2 protein was up-regulated, COX-2 levels were down-regulated but Bcl-2 gene expression was not changed significantly in combined treatment group.

CONCLUSION: MMC-induced apoptosis is reduced by up-regulating the expression of COX-2 and Bcl-2 genes. MMC combined with sulindac can suppress the growth of gastric cancer cells through induction of apoptosis mediated by down-regulation of apoptosis-related Bcl-2 and COX-2 gene.

Keywords: Apoptosis; Induced; Mitomycin with sulindac; Gastric cancer; SGC-7901