Objective      To investigate the effect of overexpressed Golgi α-mannosidaseⅡ(GMⅡ) on the proliferation in human gastric cancer cell line BGC-823.       Methods      Eukaryotic GMⅡ overexpression plasmid EX-E2372-M03 was constructed and transferred into human gastric cancer cell line BGC-823 with Lipofectamine 2000. The cell strains with stable expression were screened

and the transfection efficiency was determined by fluorescent microscopy. RT-PCR were used to determine the mRNA expressions of GMⅡ

c-myc and bcl-2 in tran

sfected cells. Flow cytometry and MTT assay were used to determine the effects of overexpressed GMⅡ on cell cycle distribution and cell proliferation. Western blot analysis were used to detect the protein expression levels of GMⅡ

c-myc and bcl-2 in transfected cells.       Results      The mRNA and protein expression levels of GMⅡ increased significantly in gastric cancer cell line BGC-823 transfected with EX-E2372-M03 (P0.05)

and the mRNA and protein expression levels of c-myc were upregulated by overexpressed GMⅡ

but those of bcl-2 were not significantly affected. The MTT results showed that the proliferation activity of the cells transfected with EX-E2372-M03 was significantly higher than that of the control cells (P0.05). The flow cytometry results showed that compared with the control group

overexpressed GMⅡ led to a decrease in the percentage of cells in G

1

phase (P0.05)

and an increase in that in S phase (P0.05).       Conclusion      Overexpressed GMⅡ can promote the proliferation in gastric cancer cell line BGC-823

which may involve c-myc expression upregulation.