微小RNA-let-7a对黑素瘤细胞系A375细胞凋亡的影响

目的 研究微小RNA（microRNA）-let-7a对黑素瘤细胞系A375细胞凋亡的影响及其作用机制。方法 采用实时荧光定量PCR法（TaqMan探针法）检测microRNA-let-7a在A375细胞及黑素细胞的表达差异；然后用microRNA-let-7a的模拟物转染A375细胞，流式细胞仪检测其凋亡的改变；最后采用Western印迹检测转染后半胱天冬酶-3（caspase-3）蛋白的变化。结果 与黑素细胞相比，microRNA-let-7a在A375细胞中表达下降了0.462倍；采用microRNA-let-7a的模拟物转染后，与阴性对照（细胞凋亡率16.9%）相比，A375细胞凋亡（细胞凋亡率47.4%）增加；转染后caspase-3蛋白表达下调。结论 microRNA-let-7a可促进黑素瘤细胞系A375的凋亡，同时下调caspase-3蛋白的表达。

Effect of microRNA-let-7a on apoptosis in melanoma cell line A375

Objective To investigate the effect of microRNA-let-7a on apoptosis in melanoma cell line A375 and its mechanism. Methods The expression of microRNA-let-7a was detected in A375 cells and melanocytes by real-time PCR. Then, microRNA-let-7a mimics was transfected into A375 cells followed by the measurement of apoptosis and caspase-3 protein expression by flow cytometry and Western blotting, respectively. Results The expression level of microRNA-let-7a was reduced by 0.462 folds in A375 cells compared with melanocytes. The apoptosis rate was 47.4% in A375 cells transfected with microRNA-let-7a mimics, significantly higher than that in untransfected A375 cells (16.9%). A significant decline was observed in the expression of caspase-3 protein in A375 cells after transfection. Conclusion microRNA-let-7a can promote the apoptosis and downregulate caspase-3 protein expression, in A375 human malignant melanoma cells.