Abstract:

Objective  To investigate the targeted regulation of mitogen-activated protein kinase 9 （MAP3K9） expression by microRNA-148a-3p （miR-148a-3p） and its effect on proliferation and apoptosis of gastric cancer cells. MethodsGastric cancer MGC-803 cells at the logarithmic growth phase were transfected with miR-148a-3p mimics （mimics group） and negative control （NC group）， and the untransfected MGC-803 cells were used as control group. Real-time quantitative PCR （QPCR） was used to detect the expression of miR-148a-3p after transfection in each group to evaluate the transfection efficiency. MTT proliferation assay was conducted to evaluate the proliferation. Flow cytometry was used to detect apoptosis in each group. The expression of Bcl-2， Bax， caspase-3 and MAP3K9 were detected by QPCR and Western blotting， respectively. The targeting relationship between miR-148a-3p and MAP3K9 was verified by double luciferase report assay. Results The Results  of QPCR showed that the expression of miR-148a-3p in control group， NC group and mimics group were 1.021±0.123， 1.087±0.196 and 2.854±0.368， respectively. Compared with control group and NC group， the expression of miR-148a-3p in mimics group was higher （P＜0.05）. The proliferation activity of MGC-803 cells in mimics group was weaker than that in the other two groups （P＜0.05）. The apoptotic rate in mimics group was （15.2±1.6）％， higher than （3.5±0.9）％ of control group and （4.5±1.1）％ of NC group （P＜0.05）. Compared with other two groups， the expressions of MAP3K9 and Bcl-2 were down-regulated in the mimics group， while the expressions of Bax and caspase-3 were up-regulated significantly （P＜0.05）. Double luciferase assay confirmed that MAP3K9 was the direct target of miR-148a-3p. Conclusion MiR-148a-3p can inhibit the proliferation and induce apoptosis of MGC-803 cells as anti-cancer factor possibly by targeting MAP3K9. MiR-148a-3p／MAP3K9 axis has a certain application prospect in the prevention and treatment of gastric cancer.

Key words: Gastric cancer, MicroRNA-148a-3p, Mitogen-activated protein kinase 9（MAP3K9）, Proliferation, Apoptosis