【摘要】 研究表没食子儿茶素没食子酸酯(EGCG)通过PI3-K/Akt信号通路对人甲状腺乳头状癌细胞K1增殖和凋亡的影响。利用MTT法研究不同剂量EGCG对K1细胞的增殖作用;采用流式细胞术分析EGCG对K1细胞周期和凋亡影响;Westernblot方法检测分析EGCG对人甲状腺乳头状癌K1细胞PI3-K、Akt/p-Akt、mTOR、cyclin D1、CDK4、Bcl-2/Bad、cleaved-caspase-3蛋白表达影响。MTT结果显示EGCG作用后K1细胞增殖显著受到抑制,且表现出明显的剂量依赖性和时间依赖性(P<0.001);流式细胞术结果显示EGCG能够将K1细胞阻滞于G1期,并且产生剂量依赖性诱导K1细胞凋亡(P<0.001);Westernblot结果显示EGCG能够上调K1细胞促凋亡蛋白Bad及cleaved-caspase-3的表达,下调PI3-K、mTOR、cyclin D1、CDK4蛋白表达,降低AKT蛋白磷酸化及抑凋亡蛋白Bcl-2表达(P<0.05)。结果证明,EGCG能够通过PI3-K/Akt信号通路,诱导G1阻滞及细胞凋亡,抑制人甲状腺乳头状癌细胞K1增殖。更多还原

【Abstract】 The effects of EGCG(epigallocatecatechin gallate) on the proliferation and apoptosis of human papillary thyroid carcinoma cell(HPTCC) K1 via PI3-K/Akt signaling pathway were studied. MTT assay was used to study the proliferation of HPTCC K1 by EGCG. The effects of EGCG on cell cycle and apoptosis of HPTCC K1 were analyzed by flow cytometry. Western blot method was used to detect the effects of different doses of EGCG on the protein expression levels of PI3-K, Akt/p-Akt, mTOR, cyclin D1, CDK4, Bcl-2/Bad, and cleaved-caspase-3 in HPTCC K1. The results of MTT assay showed that the growth of K1 cell treated by EGCG was significantly inhibited and showed dose and time dependence(P<0.001). Flow cytometry results showed that EGCG could induce G1 phase arrest in HPTCC K1, and had dose-dependent apoptosis(P<0.001). Westernblot results showed that EGCG could up-regulate the proapoptotic protein Bad of papillary thyroid carcinoma cell K1, and it significantly increased the expression of cleaved-caspase-3, down-regulated the protein expression levels of PI3-K, mTOR, cyclin D1 and CDK4 and inhibited AKT protein phosphorylation and anti-apoptotic protein Bcl-2 expression(P<0.05). Therefore, EGCG can induce G1 phase arrest and apoptosis and inhibit the proliferation of HPTCC K1 through PI3-K/Akt signaling pathway.更多还原