茶多酚和茶色素对肝癌细胞株HepG2细胞周期的影响

Effects of tea polyphenols and tea pigments on cell cycle of HepG2 cells

为探讨茶对肝癌细胞周期的影响 ,体外培养人肝癌细胞株HepG2 ,加入终浓度为 50mg L和 1 0 0mg L茶多酚和茶色素作用 48h后 ,流式细胞仪分析DNA含量 ,Westernblot观察对细胞周期蛋白P2 1 WAF1 CIP1 和细胞周期素D1 (cyclinD1 ) ,RT PCR检测细胞周期素依赖激酶 4 (Cdk4)在mRNA水平上的表达情况。结果表明 ,茶多酚和茶色素引起了细胞周期G1 期阻滞 (G1 arrest) ,抑制了cyclinD1蛋白的表达 ,诱导了P2 1 WAF1 CIP1 蛋白的表达增加 ,并且显著抑制了Cdk4在mRNA水平上的表达。因此 。

The effects of tea polyphenols and tea pigments on cell cycle of hepatic cancer cells were studied. HepG2 cells were incubated with 50 and 100 mg/L tea polyphenols and tea pigments for 48h respectively. Flow cytometry, Western blot and RT PCR analysis were used. Flow cytometry analysis showed that tea polyphenols and tea pigments induced G 1 arrest. Western blot analysis showed tea polyphenols and tea pigments significantly inhibited the expression of cyclin D1 protein and induced higher expression of P21 WAF1/CIP1 protein. The result of RT PCR analysis demonstrated that Cdk4 was significantly inhibited by tea polyphenols and tea pigments. It is concluded that the induction of cell cycle arrest may be an important mechanism of tea on cancer prevention.