miR-140在人胃癌组织中的表达及对SGC-7901胃癌细胞功能的影响

Expression of miR-140 in human gastric cancer and its effect on function of SGC-7901 cells

目的:研究microRNA-140(miR-140)在人胃癌和正常胃组织中的表达水平,以及调控miR-140表达后对SGC-7901胃癌细胞功能的影响。方法:采用实时荧光定量PCR检测miR-140在人胃癌和正常胃组织中的表达水平;将miR-140 mimics(miR-140上调表达)和miR-140 inhibitors(miR-140下调表达)分别通过脂质体转染至人胃癌SGC-7901细胞中,同时设置未转染对照组(control组)和miRNA无义序列转染对照组(NC组)。实时荧光定量PCR检测转染后各组细胞中miR-140的表达变化;MTT方法检测各组细胞的生长活力和顺铂(DDP)作用下的生长抑制率;流式细胞术检测各组的细胞周期和凋亡率;Transwell实验检测各组细胞侵袭能力;Western blot检测各组细胞中组蛋白脱乙酰酶4(HDAC4)蛋白表达。结果:miR-140在人胃癌组织中表达水平显著低于正常胃组织(P<0.05)。与control和NC组相比,miR-140 mimics组中SGC-7901细胞活力和侵袭能力下降,细胞周期被阻滞,DDP作用下细胞生长抑制率和凋亡率上升,且HDAC4蛋白表达下调,差异均有统计学意义(P<0.05);而miR-140 inhibitors组中SGC-7901细胞活力和侵袭能力上升,细胞周期被促进,DDP作用下细胞生长抑制率和凋亡率下降,且HDAC4蛋白表达上调,差异均有统计学意义(P<0.05)。结论:miR-140在胃癌组织中低表达,可作为抑癌因子调控胃癌细胞活力、细胞周期变化、凋亡、侵袭并通过下调HDAC4发挥作用。miR-140可能作为胃癌诊断和治疗的新靶点。

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 transfected 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 measured by MTT assay. The cell cycle and apoptotic rate of SGC-7901 cells were analyzed by flow cytometry. The invasion ability 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 decreased,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.