5-LOX siRNA对人肝癌HepG2细胞裸鼠瘤生长的作用和ERK的影响

目的研究5-脂氧合酶(5-LOX)siRNA转染人肝癌HepG2细胞后对裸鼠移植瘤生长的作用及对细胞外信号调节激酶(ERK)1/2信号通路的影响。方法将5-LOX siRNA转染人肝癌HepG2细胞,验证在细胞水平5-LOX表达受抑制。再用转染后的细胞建立裸鼠移植瘤模型。裸鼠分3组:转染组(接种5-LOX siRNA转染的HepG2)、转染空载体组(接种空白质粒转染的细胞)、未转染组(接种未转染的HepG2)。接种21 d后处死裸鼠,测量移植瘤体积。Westernblot和RT-PCR检测瘤体5-LOX、ERK1/2的蛋白和mRNA表达。结果转染组肿瘤平均体积与转染空载体组、未转染组比较明显减小(P<0.01),检测瘤体5-LOX、ERK1/2蛋白水平及mRNA表达量明显下降(P<0.05,P<0.01)。结论抑制5-LOX表达可显著抑制肝肿瘤生长,测得ERK1/2表达下降,提示其作用机制可能通过抑制ERK信号转导途径抑制肿瘤增殖。

Effects of 5-LOX siRNA on growth and ERK signal transduction pathway of HepG2 cell xenografts in nude mice

Objective To investigate the effect of 5-lipoxygenase(5-LOX)siRNA on proliferation of HepG2 cell xenografts in nude mice and extracellular signal-regulated kinase(ERK1/2) signal transduction pathway.Methods The HepG2 lines were transfected with 5-LOX siRNA,and 5-LOX′s expression were significantly decreased which detected by real-time florescence quantitative PCR method.The xenografts model derived from the transfected HepG2 cells which were established in nude mice.Nude mice were randomly divided into three groups: transfected group(inoculated with HepG2 cells transfected by 5-LOXsiRNA),free vector transfected group(negative control),untransfected group(normal HepG2 cell).The nude mice were killed 21 days later,tumor volumes were measured.Protein levels of 5-LOX,ERK1/2 were determined by Western blot,mRNA expression of 5-LOX,ERK1/2 were analyzed by RT-PCR.Results The average tumor volume in transfected group was significantly smaller than that in the negative control group and untransfected group(P<0.01).Protein levels and mRNA expression of 5-LOX,ERK1/2 were also significantly decreased in transfected group(P<0.05,P<0.01).Conclusion Inhibition of 5-LOX expression can significantly inhibit the growth of hepatocellular carcinoma and the expression of ERK1/2,which shows that 5-LOX siRNA may inhibit tumor proliferation via ERK signal transduction pathway.