AAS ›› 2013, Vol. 44 ›› Issue (4 ): 492-497.doi: 10.3969/j.issn.0529-1356.2013.04.009

Previous Articles     Next Articles

Role of ZAC gene in the pathway of octreotide inhibiting proliferation of gastric cancer cells in vitro

DAI Wen 1,2 DING Yi1 ZHANG Qin-xian 1*   

  1. 1. Department of Histology and Embryology, College of Basic Science of Medicine, Zhengzhou University, Henan Key Laborary of Molecular Medicine, Zhengzhou 450052, China; 2. Clinical Laboratory,the 153rd Central Hospital of PLA Ji'nan Military Region, Zhengzhou 450042, China
  • Received:2012-09-13 Revised:2012-12-18 Online:2013-08-06 Published:2013-09-04

Abstract:

Objective To explore the role of ZAC gene in the pathway of somatostatin analogue, octreotide (OCT), inhibiting proliferation of gastric cancer cells. Methods The gastric cancer cells BGC823 and SGC7901 were treated with OCT at various concentrations for various times, respectively. MTT assay was used to screen effective condition of OCT for its antiproliferative action. After treatment with OCT (effective concentration/various times, effective time/various concentrations), the inducing effect of OCT on ZAC gene expression in gastric cancer cells was detected by Western blotting. Three fragments for ZAC gene RNA interference were inserted into pSUPER-EGFP-I vector to construct ZAC-shRNA expression vectors (pSUPER-EGFP-ZAC/1, pSUPER-EGFP-ZAC/2 and pSUPER-EGFP-ZAC/3), respectively. After identification by Hind Ⅲ/EcoRⅠdigestion and sequencing, the three ZAC-shRNA expression vectors were transfected into gastric cancer cells BGC823 and SGC7901, respectively. After G418 screening and RT-PCR identification, the gastric cancer cell lines in which ZAC gene was knock-down were established. Gastric cancer cells (control group) and those in which ZAC gene was knock-down (experimental group) were incubated with OCT at effective condition, the antiproliferative action of OCT was detected by MTT assay. Results The effective condition of OCT inhibiting proliferation of gastric cancer cells was 10nmol/L and treatmented for 24 hours. OCT induced ZAC gene expression in gastric cancer cells in a time-and dose-dependant manner. The results of Hind Ⅲ/EcoRⅠ digestion and sequencing indicated that ZAC-shRNA expression vectors were constructed successfully. The ZAC mRNA level in the gastric cancer cells transfected with shRNA-ZAC/2 was decreased significantly (P<0.05), which were the gastric cancer cell lines in which ZAC gene was knock-down. The proliferation of the gastric cancer cell lines in which ZAC gene was knock-down was significantly higher than that of corresponding BGC823 and SGC7901 (P<0.05). After OCT incubation, the proliferation of BGC823 and SGC7901 were decreased obviously (P<0.05); however, that of the cells in which ZAC gene was knock-down did not exhibit significant changes (P>0.05). Conclusion OCT induces ZAC gene expression in gastric cancer cells in a time-and dose-dependant manner. ZAC gene may play an important role in the pathway of OCT inhibiting the proliferation of gastric cancer cells.

Key words: Octreotide, ZAC, Gastric cancer cell, Proliferation, RNA interference, Western blotting