Gastric Cancer
Copyright ©2007 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Aug 21, 2007; 13(31): 4185-4191
Published online Aug 21, 2007. doi: 10.3748/wjg.v13.i31.4185
Effects of AZT and RNA-protein complex (FA-2-b-β) extracted from Liang Jin mushroom on apoptosis of gastric cancer cells
Yan-Qing Sun, Tian-Kang Guo, Ya-Ming Xi, Che Chen, Jin Wang, Zi-Ren Wang
Yan-Qing Sun, Zi-Ren Wang, School of Life Science, Lanzhou University, Lanzhou 730000, Gansu Province, China
Tian-Kang Guo, Department of Surgery, The People’s Hospital of Gansu Province, Lanzhou 730000, Gansu Province, China
Ya-Ming Xi, Department of Hematology, First Affiliated Hospital of Lanzhou University, Lanzhou 730000, Gansu Province, China
Che Chen, Scientific Research Center, Gansu College of Traditional Chinese Medicine, Lanzhou 730000, Gansu Province, China
Jin Wang, Department of Hematology, Lanzhou University, Lanzhou 730000, Gansu Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Zi-Ren Wang, School of Life Science, Lanzhou University, Lanzhou 730000, Gansu Province, China. 40yanqingfang@163.com
Telephone: +86-13993193767 Fax: +86-931-8266957
Received: March 22, 2007
Revised: April 10, 2007
Accepted: April 18, 2007
Published online: August 21, 2007
Abstract

AIM: To investigate the synergistic effects of 3'-azido-3'-deoxythymidine (AZT) and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro.

METHODS: MTT analysis was made to examine the inhibition rate of MKN45 cells treated with AZT (2.5, 5, 10 and 20 mg/L) and FA-2-b-β (5, 10, 20 and 40 mg/L) singly and combinatively for 24, 48 and 72 h. Apoptotic effects were evaluated by morphological methods, DNA agarose gel electrophoresis and flow cytometry, respectively. Telomerase activity was estimated by TRAP-ELISA. The mRNA expression of caspase-3 and Bcl-2 were detected by RT-PCR.

RESULTS: AZT and FA-2-b-β could significantly inhibit MKN45 cell proliferation and induce its apoptosis. MKN45 cells were inhibited in dose- and time- dependent manner. The inhibition effect of AZT combined with FA-2-b-β was obviously better than that used singly (0.469 ±0.022 vs 1.075 ± 0.055, P < 0.05, 0.325 ± 0.029 vs 0.469± 0.022 P < 0.01). AZT used singly and combination of FA-2-b-β could decrease the activity of tumor cell telomerase, and AZT has synergistic function with FA-2-b-β. A certain concentration of AZT could up-regulate the expression of caspase-3 mRNA (r = 0.9969, P < 0.01), which was positively related to apoptosis rate, and could down-regulate the expression of Bcl-2 mRNA, which was negatively related to apoptosis rate (r = 0.926, P < 0.01). Furthermore, the effect of AZT combined with FA-2-b-β was significantly higher than that used singly.

CONCLUSION: Combination of AZT and FA-2-b-β has an obviously synergetic effect in the gastric cancer cells MKN45, which has provided a new approach to the treatment of gastric cancer clinically.

Keywords: AZT, FA-2-b-β, Apoptosis, Telomerase, Bcl-2, Caspase-3, MKN45 cell