Objective：To identify the effects of miRNA-214 on cell cycle and apoptosis of gastric cancer cells, and its influence on PTEN protein level.
Methods：miRNA-214 in poorly differentiated human gastric cancer cell line BGC823, MKN45 and normal gastric mucosal cell line GES-1 was detected by real-time PCR. Antisense-miRNA-214 oligonucleotides(miRNA-214 inhibitor) were  transfected transiently into gastric cancer cell lines to down-regulate the expression of miRNA-214. The cell cycle and apoptosis rate were studied by flow cytometry. PTEN, the target gene of miRNA-214, was detected by immunofluorescence.
Results：The miRNA-214 was upregulated in gastric cancer cell BGC823 and MKN45 （P＜0.05） compared with normal gastric mucosal cell line GES-1. The transfection of miRNA-214 inhibitor downregulated miRNA-214 expression in BGC823 （P＜0.05）. G1-phase cells were increased in BGC823 and MKN45, ［(60.20±3.38)% vs. (49.33±7.99)% (P＜0.05)；(69.90±0.28) vs. (54.85±0.64)% (P＜0.05) respectively］ compared with the control groups. But the alteration of apoptotic rate was not significant(P＞0.1). The immunofluorescence result showed that PTEN was upregulated after transfection in both cell lines.
Conclusions：(1)miRNA-214 is upregulated in human gastric cancer cell BGC823 and MKN45. (2)miRNA-214 could reduce the G1-phase cells and increase S-phase cells in BGC823 and MKN45, and the downregulation of PTEN may be one of the mechanisms. (3)miRNA-214 has no effect on apoptosis of BGC823 and MKN45.