siRNA特异性抑制K562细胞Livin基因表达及其诱导凋亡作用

本研究探讨小分子RNA干扰技术抑制livin基因表达对白血病细胞系K562细胞凋亡的影响。设计合成livin特异性小干扰RNA(siRNA),核转染K562细胞,培养转染后的K562细胞,用RT-PCR检测livin mRNA的表达,Western blot检测Livin蛋白的表达。以未转染细胞作对照,同时转染带有增强型绿色荧光蛋白的载体作为阳性对照,用流式细胞术检测其细胞绿色荧光以确定转染效率。用膜联蛋白Ⅴ及碘化丙锭双染法检测细胞凋亡率。结果表明,电穿孔的转染效率可达50%。siRNA既可以抑制livin mRNA表达,也可以抑制livin蛋白表达。特异性siRNA转染细胞后48 h细胞凋亡率为(27.41±2.30)%,与对照组(9.63±0.89%)比较明显提高(P<0.05)。结论:SiRNA可以抑制livin基因的表达,并能抑制livin基因的抗凋亡作用。

siRNA-induced down-regulation of Livin expression increases spontaneous apoptosis in K562 cell line

This study was aimed to observe the effects of siRNA on Livin expression and function in K562 cells. Livin siRNA were designed and synthesized, then were transfected into K562 cells by using AMAXA nucle transfactor. Expressions of Livin mRNA and protein in transfected K562 cells was detected by RT-PCR and Western blot respectively. Non-transfected cells were used as control. The enhanced green fluorescent protein plasmid was used as positive control and the transfection efficiency was detected by flow cytometry. Cell apoptosis was measured by flow cytometry with Annexin V-FITC/PI double staining. The results showed that the transfection efficiency of electroporation method was about 50. The synthesized siRNA inhibited livin expression at both mRNA and protein levels. The rate of K562 cell apoptosis increased from (9.63 ± 0.89) in control group to (12.07 ± 1.39) and (27.41 ± 2.30) at 24 h and 48 h after transfection, respectively (P < 0.05). It is concluded that the siRNA can inhibit anti-apoptosis of livin gene via down-regulating livin gene expression, which may provide the new method for anti-leukemia study.