Expression of miR-133 in gastric cancer tissues and its effect on malignant behavior of human gastric cancer cells

XU Ronghua; HE Donglei; MENG Jin

Abstract：Objective To investigate the expression of microRNA?133 ( miR?133) in gastric cancer tissues and cell lines as well as its effect on apoptosis and invasion of gastric cancer cells. Methods The real?time quantitative PCR ( qPCR) was used to de?tect the miR?133 level in 64 cases of gastric cancer tissues and corresponding adjacent normal tissues. Then, we analyzed the relation?ship between miR?133 expression and clinical pathological parameters ( age, gender, tumor location, clinical stage, differentiation de?gree, invasion depth and lymph node metastasis) . The expression of miR?133 was detected in gastric cancer cell line AGS, SGC?7901, MKN?1, MKN?45, MGC?803, BGC?823 and GES?1, and the normal gastric mucosa cell line, GES?1, was used as the control. The gastric cancer cell with the lowest level of miR?133 was chosen for the transfection with the recombinant plasmid pCDNA3?1+miR?133. PI/Annexin V double staining and Transwell assay were used to detect the effect of miR?133 on apoptosis and invasion of cells. Results The relative expression of miR?133 in gastric carcinoma tissues was 0?347 ± 0?024, lower than that of the adjacent tissues ( P<0?05) . Its expression was related to clinical stage, differentiation, depth of invasion and lymph node metastasis ( P<0?05) . Compared with the GES?1 cells, the miR?133 levels of gastric cancer cells were lower ( P<0?05) , and the expression level of MKN?45 was low?est. Compared with other two groups at 48 and 96 h after transfection, the apoptosis level was higher but the number of the cells was de?creased in the overexpression group ( P<0?05) . Conclusion miR?133 was lowly expressed in gastric cancer tissues and cells, and up?regulation of miR?133 can inhibit the invasion and apoptosis of gastric cancer cells.