To detect the expression of microRNA-451 (miR-451) in gastric cancer tissues, explore its relationship with clinicopathologic characteristics, and observe the effect on gastric cancer cell cycle by transfecting miR-451 mimics and inhibitors in gastric cancer cells.

Cancer tissues and para-carcinoma tissues were collected from 56 volunteers with gastric carcinoma. Real-time fluorescent quantitative PCR technology was used to test the relative expression level of miR-451 and analyze its level with selected clinicopathologic factors. Additionally, the highly differentiated MKN-28 and poorly differentiated BGC-823 gastric cancer cell lines transfected with targeted miRNA-451 mimics and targeted miRNA-451 inhibitors were used to detect the effects on cell cycle.

Compared with the para-carcinoma tissues, the miR-451 expression level in gastric cancer tissues was declined significantly (P < 0.05). The miR-451 expression level was correlated with differentiation degree and Lauren classification (P < 0.05). The in vitro study showed that the G0/G1 phase ratio of cells transfecting with miR-451 mimics was significantly higher than that in the control group (P < 0.05), while the ratio of cells transfecting with miR-451 inhibitors was significantly lower (P < 0.05).

Declining miR-451 expression may be related to the occurrence and development of gastric cancer. Low miR-451 expression could enhance cell division and accelerate gastric cell cycle process, but the high miR-451 expression would arrest cell cycle into G0/G1 phase. MiR-451 expression might be related to the differentiation degree and Lauren classification.