Abstract: Objective To investigate the expressions of miR-98-5p and AKT2 in human gastric cancer MGC803 cells, in order to explore the regulatory effect of miR-98-5p on AKT2 and on the proliferation of MGC803 cells. Methods MGC803 cells were cultured in vitro and cellular morphology changes were observed with phase contrast microscope. The expression of AKT2 in MGC803 cells was determined with immunocytochemistry. The regulatory relation of miR-98-5p and AKT2 was predicted by bioinformatics and identified using dual luciferase report system. Expressions of miR-98-5p and AKT2 were determined using real-time PCR and Western blotting after transfection of miR-98-5p mimics. The proliferation of MGC803 cells was detected by MTT assay and plate colony formation assay. Results Under phase contrast microscope, most of the MGC803 cells were fusiform or polygonal, few were quasi-circular. Immunocytochemistry indicated AKT2 expression in the cytoplasm, which looked sepia. MiRanda and TargetScan showed that miR-98-5p was well matched with AKT2 gene. Dual luciferase reporter system indicated that miR-98-5p could inhibit the expression of AKT2 by binding to its mRNA 3'UTR. Real-time PCR and Western blotting showed that over-expression of miR-98-5p down-regulated expression of AKT2 and suppressed the proliferation of MGC803 cells. Conclusion The miR-98-5p may negatively regulate the expression of AKT2 in human gastric cancer MGC803 cells and inhibit cell proliferation.

Key words: Serine-threonine kinase 2, miRNA, Human gastric cancer MGC803 cells