小分子干扰RNA下调硬脂酰辅酶A去饱和酶-1对肝癌HepG2细胞增殖及凋亡的影响

Effect of down-regulation of stearoyl-CoA desaturase-1 expression by siRNA inhibits cell on the proliferation and apoptosis of human hepatocellular carcinoma HepG2 cells

目的探讨小分子干扰RNA(siRNA)下调硬脂酰辅酶A去饱和酶-1(SCD-1)表达对肝癌细胞增殖和凋亡的影响。方法用设计合成的SCD-1 siRNA转染人肝癌细胞HepG2细胞株,转染后细胞分为3组:空白对照组(未做任何处理)、阴性对照组(对照siRNA转染)和SCD-1 siRNA组(SCD-1 siRNA转染)。采用反转录聚合酶链反应检测HepG2细胞SCD-1 mRNA的表达,噻唑蓝法检测HepG2细胞的增殖,用流式细胞术检测SCD-1 siRNA对HepG2细胞凋亡和细胞周期的影响。结果 SCD-1 siRNA组的SCD-1 mRNA表达明显低于空白对照组和阴性对照组(P<0.01);转染后24、48、72 h,SCD-1 siRNA组HepG2细胞增殖较空白对照组和阴性对照组明显减慢(P<0.01);SCD-1siRNA组HepG2细胞凋亡率明显高于空白对照组和阴性对照组(P<0.01);SCD-1 siRNA组HepG2细胞在合成前期(G0/G1期)的细胞比例明显高于空白对照组和阴性对照组,在合成期(S期)和合成后期(G2/M期)的细胞比例均明显低于空白对照组和阴性对照组(P<0.01)。空白对照组和阴性对照组HepG2细胞在SCD-1 mRNA表达、细胞增殖、细胞凋亡率及细胞周期方面差异均无统计学意义(P>0.05)。结论 siRNA可通过下调HepG2细胞SCD-1基因的表达,抑制HepG2细胞的增殖,并促进其凋亡。

Objective To investigate the effect of siRNA-induced stearoyl-CoA desaturase-1（SCD-1） down-regulation on the proliferation and apoptosis of human hepatocellular carcinoma cells and its mechanism.Methods Control siRNA and SCD-1 siRNA were transfected to human hepatocellular carcinoma HepG2 cells,respectively.After transfection,cells were divided into three groups：blank control group,negative control group and SCD-1 siRNA group.The expression of SCD-1 mRNA in HepG2 cell was detected by real-time fluorescent quantitative reverse transcription-polymerase chain reaction（RT-PCR）.The cell proliferation was detected by methyl thiazolyl tetrzaolium method.The effect of SCD-1 siRNA on the apoptosis and cell cycle of HepG2 cell were analyzed by flow cytometry.Results The expression of SCD-1 mRNA was declined more evidently in the SCD-1 siRNA group than that in blank control group and negative control group（P 〈0.01）.The cell proliferation was decreased more significantly after treating with SCD-1 siRNA for 24,48 and 72 h than that in blank control group and negative control group.Compared with blank control group and negative control group,the percentage of apoptotic cells was significantly increased in the SCD-1 siRNA group（P 〈0.01）.The cell ratio of HepG2 in G0/G1 phase in SCD-1 siRNA group increased significantly while the cell ratio of HepG2 in S phase and G2/M phase in SCD-1 siRNA group compared with blank control group and negative control group（P 〈0.01）.There was no significant difference of SCD-1 mRNA expression,apoptosis rate and cell cycle of HepG2 cell between blank control group and negative control group（P 〈0.05）.Conclusion siRNA can inhibit the cell proliferation and promote apoptosis of HepG2 cell by down-regulating the SCD-1 RNA in HepG2 cell.