沉默Toll样受体4表达对肺腺癌A549细胞凋亡及细胞周期的影响

目的 探讨Toll样受体4（Toll-like receptor 4，TLR4）对肺腺癌A549细胞凋亡及细胞周期的影响。方法 体外化学合成针对TLR4的小干扰RNA（TLR4-siRNA），通过脂质体介导转染人肺腺癌A549细胞。采用Real-time PCR和流式细胞仪检测分析干扰后A549细胞中TLR4 mRNA及蛋白的表达情况。另外，采用流式细胞仪检测分析干扰72 h后细胞凋亡率和细胞周期的变化。结果 与对照组比较，转染TLR4-siRNA后，A549细胞中TLR4 mRNA及蛋白的表达显著下降（P<0.05），细胞的凋亡率明显增加（1.73 ± 0.32）% vs.（7.40 ± 0.75）%（P<0.01）]，细胞周期出现G0/G1期停滞（48.21 ± 1.15）%vs.（66.26 ± 2.45）%（P<0.05）]，同时S期细胞比例明显减少（34.25 ± 1.46）% vs.（22.63 ± 3.39）%（P<0.05）]。结论 TLR4-siRNA能有效沉默A549细胞中TLR4的表达，在促进细胞凋亡的同时能够影响细胞周期分布从而抑制肿瘤细胞的生长，特异性干预TLR4基因的表达有望成为治疗肺癌的一种新手段。

Effect of Silencing Toll-like Receptor 4 Expression on Cell Cycle and Apoptosis of Human Lung Adenocarcinoma Cells A549

Objective To explore the effect of Toll-like receptor 4 (TLR4) on cell cycle and apoptosis of human lung adenocarcinoma cells A549. Methods TLR4 specific small interfering RNA (TLR4-siRNA) was synthesized in vitro and transfected into A549 cells by Lipofectamine. The expression level of TLR4 mRNA and protein were examined by Real-time PCR and FCM. In addition, the apoptosis ratio and cell cycle were examined by FCM 72h after transfection. Results Compared with control group, TLR4-siRNA could significantly inhibit the expression of TLR4 mRNA and protein(P<0.05); the apoptosis ratio was significantly increased (1.73 ± 0.32)%  . (7.40 ± 0.75)% (P<0.01)], cell cycle was arrested in G0/G1 phase (48.21 ± 1.15)% vs. (66.26 ± 2.45)% (P<0.05)] and the percentage of S phase cells were decreased significantly (34.25 ±1.46)% vs. (22.63 ± 3.39)% (P<0.05)]. Conclusion TLR4-siRNA could effectively silence TLR4 expression in A549 cells, promote cell apoptosis and affect cell cycle to inhibit the growth of tumor cells. The specific intervention of TLR4 gene expression may be a new method for therapy of lung cancer.