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.