Background and purpose:It has beenreported that miR-1284 is associated with gastric cancer lymph node metastasis in the research of microRNA microarray in human gastric cancer tissues. But the specific role of miR-1284 in gastric cancer has not been reported. The aim of this study was to investigate the effect of miR-1284 over-expression on the gene expression profiling and invasion/metastasis of human gastric cancer SGC-7901 cells. Methods:Gastric cancer SGC-7901 cells of LV-miR-1284 group were transfected with lentiviral vectors of miR-1284, cells of LV-NC-GFP group were transfected with lentiviral vectors without miR-1284, and cells of control group were not transfected with lentiviral vectors. The expression of miR-1284 was detected by the real-time fluorescent quantitative PCR. Differential expression genes were detected by the microRNA chip. Target genes of miR-1284 were predicted by the bioinformatics. Invasive ability was detected by the Transwell invasion assay. Metastasis ability was detected by subcutane-ously transplanted tumor model of nude mice.Results:Compared with LV-NC-GFP and control groups, the expressions of miR-1284 and 20 genes were up-regulated, and the expression of 17 genes was down-regulated in LV-miR-1284 group. One hundred and thirty-eight target genes of miR-1284 were predicted by the bioinformatics website. Compared with invasive cell number of LV-NC-GFP group (168.67±4.55) and control group (170.33±3.08), the ability of invasion ofcells was weakened in LV-miR-1284 group (70.00±2.37). Compared with the liver metastasis rate of LV-NC-GFP group (85.71%) and control group (85.71%), the ability of metastasis of cells was weakened in LV-miR-1284 group (14.29%). Conclusion:The ability of invasion and metastasis of SGC-7901 cells is suppressed by over-expression of miR-1284. The mechanism may be related to regulating the expression ofSUMO1 andJUNgenes.

AIM:To evaluate the correlation between microRNA-1284 (miR-1284) and gastric cancer, and to investigate the underlying mechanism.METHODS: The expression of miR-1284 was examined by real-time PCR in 63 gastric cancer ( GC) tissue samples and 63 non-malignant adjacent tissue samples.The correlation between miR-1284 and the clinicopathological feature of GC was analyzed.Lentiviral vector containing miR-1284 was constructed and transfected into GC SGC-7901 cells.After transfection, the expression of miR-1284 was examined by real-time PCR.The cell activity was evaluated by CCK-8 assay.The cell cycle and apoptosis were determined by flow cytometry.The ability of cell migra-tion was measured by wound-healing assay.The potential target gene of miR-1284 was predicted by online bioinformatic softwares.The expression of JAG1 mRNA was examined by real-time PCR.The protein levels of JAG1, Notch1 and NF-κB were analyzed by Western blotting.RESULTS:Compared with non-malignant adjacent tissue samples, the results of real-time PCR showed significant downregulation of miR-1284 in 42 GC tissue samples ( P<0.05 ) .The expression level of miR-1284 was not significantly associated with age and gender of the patients, tumor size, TNM staging and lymph node metastases (P>0.05), but significantly associated with histologic grading (P<0.05).Compared with LV-NC-GFP group and control group, after transfection of miR-1284 in LV-miR-1284 group, the expression of miR-1284 was significantly in-creased (P<0.05), the percentages of apoptotic cells and the cells in G0/G1 phase were significantly increased (P<0.05), the cells activity and ability of migration were significantly decreased (P<0.05), and the expression of JAG1, Notch1 and NF-κB was significantly decreased (P<0.05).CONCLUSION:The inhibitory effect of miR-1284 on gastric cancer may be associated with the regulation of its targeting gene JAG1.