Expression of miR-140 in human gastric cancer and its effect on function of SGC-7901 cells / 中国病理生理杂志

ABSTRACT

AIM:To explore the expression level of microRNA-140 ( miR-140 ) in human gastric cancer and normal gastric tissues, and the regulatory effect of miR-140 expression on the function of SGC-7901 cells.METHODS:The expression levels of miR-140 in human gastric cancer and normal gastric tissues were detected by real-time PCR.miR-140 mimics ( miR-140 up-regulated expression) and miR-140 inhibitors ( miR-140 down-regulated expression) were trans-fected into human gastric cancer SGC-7901 cells by liposome method.At the same time, the untransfected control group ( control group) and miRNA nonsense sequence transfection group ( NC group) were set up .The expression of miR-140 in the cells after transfection was detected by real-time PCR.The cell viability and growth inhibition rate with DDP were meas-ured by MTT assay.The cell cycle and apoptotic rate of SGC-7901 cells were analyzed by flow cytometry.The invasion a-bility of SGC-7901 cells was measured by Transwell assay.The protein expression of histone deacetylase 4(HDAC4) in the cells was determined by Western blot.RESULTS:The expression level of miR-140 in human gastric cancer tissues was significantly lower than that in normal gastric tissues (P<0.05).Compared with control group and NC group, the viability and invasion ability of the SGC-7901 cells were decreased, the cell cycle was arrested, the cell growth inhibition rate and apoptotic rate with DDP treatment were increased, and the protein expression of HDAC4 was down-regulated ( P<0.05) in miR-140 mimics group.However, in miR-140 inhibitors group, the viability and invasion ability of the SGC-7901 cells were increased, the cell cycle was promoted, the cell growth inhibition rate and apoptotic rate with DDP treatment were de-creased, and the protein expression of HDAC4 was up-regulated ( P<0.05 ) .CONCLUSION:The expression level of miR-140 in the gastric cancer tissues is low.miR-140 serves as a tumor suppressor to regulate the viability, apoptosis and invasion ability of gastric cancer cells, and to play a role by down-regulating HDAC4 protein.miR-140 may serve as a new target for diagnosis and treatment of gastric cancer.