下调miR-21 抑制PI3K / AKT 信号通路对白血病细胞增殖凋亡的影响

目的:探讨miR-21 对白血病K562 细胞增殖凋亡的影响及对PI3K/ AKT 信号通路的调控作用。方法:将K562 细胞分为对照组、miR-21 NC 组和miR-21 干扰组,对照组不做处理,后两组采用阳离子脂质体LipofectamineTM2000 转染miR-21 inhibitor 和miR-21 negative control。转染48 h 后,利用实时荧光定量(qRT-PCR)检测各组细胞中miR-21 mRNA 的表达情况,采用MTT 比色法检测miR-21 对细胞增殖率的影响,流式细胞仪检测miR-21 对细胞周期和凋亡率的影响,蛋白质免疫印迹法(Western blot)检测miR-21 对各组细胞中PI3K/ AKT 信号通路相关蛋白PI3K、AKT 和p-AKT 表达的影响。结果:miR-21 干扰组中细胞的miR-21 mRNA 表达水平和细胞的存活率较对照组和miR-21 NC 组均明显降低;与对照组和miR-21 NC 组比较,流式细胞仪检测miR-3 干扰组中G0/ G1 期所占细胞比例明显升高,S 期细胞所占比例明显下降,细胞的凋亡率明显升高。Western blot 检测p-AKT 的表达水平较对照组和miR-21 NC 组明显下降,但PI3K 和AKT 蛋白的表达水平变化不大。结论:下调miR-21 能够抑制白血病K562 细胞的增殖,促进其凋亡,其作用机制可以与抑制PI3K/ AKT 信号通路有关。

Effect of down-regulation of miR-21 on proliferation and apoptosis of leukemiccells by inhibiting PI3K / AKT signaling pathway

Objective:To investigate the effect of miR-21 on the proliferation and apoptosis of leukemia cell line K562 and the regulation of PI3K/ AKT signaling pathway.Methods:K562 cells were divided into control group,miR-21 NC group and miR-21 interference group,the first group without treatment,the two groups after using cationic liposome transfection of LipofectamineTM 2000 miR-21 inhibitor and miR-21 negative control.After transfection 48 h,the expression of miR-21 mRNA in cells was detected by Real-time fluorescence quantitative (qRT-PCR),MTT assay was used to test the effect of miR-21 on cell proliferation,flow cytometry was used to detected the effect of miR-21 on cell cycle apoptosis rate,the protein expression of PI3K,AKT and p-AKT in PI3K/ AKT signaling pathway after miR-21 transfection were detected by protein immunoblotting (Western blot).Results:The expression level of miR-21 mRNA and the survival rate of cells in the miR-21 interference group were significantly lower than those in the control group and the miR-21 NC group;compared with control group and miR-21 group NC,flow cytometry detected the cells accounted for proportion of G0/ G1 phase in miR-21 interference group increased significantly, the proportion of cells at S phase significantly decreased,and apoptosis rate increased significantly.Western blot test results show that the expression levels of p-AKT in miR-21 interference group were significantly lower than those in the control group and miR-21 NC group,but the expression levels of PI3K and AKT protein were not changed significantly.Conclusion:Down-regulation of miR-21 can inhibit the proliferation and promote apoptosis of leukemia K562 cells,and its mechanism may be related to the inhibition of PI3K/ AKT signaling pathway.