EGCG通过TGF-β1信号通路抑制PLA-802细胞的机制研究

目的 观察表没食子儿茶素-3-没食子酸酯(EGCG)对人横纹肌肉瘤细胞株PLA-802的抑制作用,以及对细胞内TGF-β1/Smad4的表达的影响,探索EGCG抑制横纹肌肉瘤细胞生长的机制.方法 体外培养人横纹肌肉瘤细胞株PLA-802,并用不同浓度的EGCG作用不同的时间.用MTT检测EGCG对PLA-802细胞生长情况的影响,用流式细胞术检测细胞周期的变化情况,RT-PCR和Westernblot分别检测细胞内TGF-β1和Smad4的mRNA和蛋白水平的表达.结果 MTT结果显示EGCG显著降低了PLA-802细胞的存活率((P＜0.05).流式细胞结果表明EGCG明显降低了S期而增加了G1期(P＜0.05).而TGF-β1和其下游因子Smad4的mRNA和蛋白水平的表达也明显受到EGCG的抑制,且这种抑制作用呈浓度-时间依赖性(P＜0.05).结论 EGCG发挥其抑制PLA-802细胞的作用可通过抑制TGF-β1信号通路,这或许将为临床治疗横纹肌肉瘤提供新的思路.

Inhibitory Effect of EGCG on PLA-802 Cell through Inhibiting TGF-β1 Signaling pathway

Objective To observe the inhibitory effect of epigallocatechin-3 gallste （EGCG） on human alveolar rhabdomyosarcoma cell line PLA-802 in vitro, and to detect the expression of TGF-betal and Smad4, and to explore its potential mechanisms. Method Human alveolar rhabdomyosarcoma cell line PLA-802 was cultured and treated with EGCG at different concentration and at different time points. The effects of EGCG on PLA-802 cells proliferation was studied by means of MTT;the cell cycle was detected with flow eytometry;RT-PCR and western blot were used to detect the expression of TGF-β1 and Smad4 at mRNA and protein levels. Results The viability of PLA-802 cells treated with EGCG was obviously decreased （ P 〈 0. 05 ）. Analysis of the cell cycle revealed that EGCG induced a significant decrease in cells in the S phase and an increase in cells in the G1 phase （ P 〈 0.05 ）. Furthermore, the expression of of TGF-131 and its downstream faetor-Smad4 at mRNA and protein levels were inhibited by EGCG in a concentration- and time-dependent manner （P 〈 0.05 ）. Conclusion EGCG probably played its inhibitory effects on PLA-802 cells through inhibiting the the activity of TGF-β1 signaling pathway, which will provide an important therapeutic potential for treating human aleovar rhabdomyosarcoma.