Background: miRNAs are involved in the process of tumorigenesis and metastasis as tumor suppressor genes or oncogenes. This work aims to explore the effect of miR-140 in the proliferation and invasion as well as metastasis of gastric cancer cells, as well as to provide new target for the diagnosis and therapy for gastric cancer. Methods: miR-140 mimics and miR-140 inhibitors were transfected to the SGC-7901 gastric cancer cells, the expression of miR- 140 and histone deacetylase4 (HDAC4) in human gastric cancer and normal gastric tissues was evaluated by quantitative reverse transcription-PCR (qRT-PCR), the HDAC4 protein level was evaluated by western blot method. The effects of miR-140 upregulation and downregulation on the invasion and metastasis ability of SGC-7901 cells were investigated by Transwell cell model. The samples were classified into control group by adding lipofectamine 2000, negative control group by adding miRNA unrelated sequence and lipofectamine 2000, miRNA up-regulated transfection group by adding miR-140 mimics and lipofectamine 2000 were added, as well as miRNA down-regulated transfection group by adding miR-140 inhibitors and lipofectamine 2000. Results: The effects of up and down regulation of miR-140 on the invasion and metastasis ability of SGC-7901 cells were determined by Transwell chamber model. The expression of miR-140 in gastric cancer cells was significantly lower than that of normal gastric tissue (p < 0.05). The invasion and metastasis ability of SGC-7901 cells in miR-140 mimics and miR-140 inhibitor groups were significantly lower and higher when compared with negative control (NC) and control groups, respectively. HDAC protein was significant up-expressed in miR-140 inhibitor group when compared with NC and control groups. All these differences were of statistical significance (p < 0.05). Conclusion: The expression level of miR-140 are associated with the invasive and metastatic properties of gastric cancer cells, which may serve as new target for the clinical treatment of gastric cancer.

gastric cancer; miR-140; HDAC4; SGC-7901; invasion; metastasis

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