茶多酚体外诱导人肺癌细胞凋亡的机理研究

目的探讨茶多酚诱导人肺癌细胞的凋亡作用及其相关机理。方法采用MTT法、激光共聚焦显微镜和流式细胞仪技术，体外观察茶多酚对肺癌细胞凋亡及相关蛋白表达的影响。结果不同浓度的茶多酚(50、100、200、400μg／ml)对肺癌细胞均有抑制作用，呈剂量依赖关系，抑制率(％)分别为28.69±1.27、46．19±1．79、64.61±1．29、75．90±1．96。在细胞增殖受到明显抑制时，细胞被阻滞于G0/G1期，不能进入S期及G2／M期，同时诱导肺癌细胞凋亡，凋亡率(％)分别为4.76±0．11、5．78±0．38、10.06±0．67、24．44±0．44。激光共聚焦显微镜双荧光标记可见细胞凋亡的形态学改变，与对照组比较，随着茶多酚浓度的增高，细胞内Ca^2+浓度、Annexin V表达和蛋白酪氨酸磷酸酶基因(PTEN)蛋白表达逐渐增高，细胞周期调控蛋白D1蛋白表达水平则呈逐渐下降。结论茶多酚可诱导人肺癌细胞的凋亡，其作用机制与改变细胞内Ca^2+浓度、FTEN蛋白和Cyclin D1蛋白表达有关。

Study on Mechanism of Tea Polyphenols in Inducing Human Lung Cancer Cell Apoptosis in vitro

OBJECTIVE: To investigate the apoptosis inducing effect of tea polyphenols (TPP) on human lung cancer cell (LCC) and its associative mechanism. METHODS: The apoptosis inducing effect of TPP on LCC in vitro, and its influence on expression of the related gene were determined by MTT assay, laser scanning confocal microscopy and flow cytometry. RESULTS: TPP in different concentration (50,100,200 and 400 microg/ml) had dose-dependent inhibitory effect on LCC, the inhibitory rate was 28.69+/-1.27% ,46. 19+/-1.79% ,64.61+/-1.29%, 75.90+/-1.96%, respectively. The inhibited LCC were blocked in (G0/G1 phase, and could not transferred to S and G2/ M phase of cell cycle. Meanwhile, TPP could induce apoptosis of LCC, the apoptotic rate being 4.76+/-0.11 %, 5.78+/-0.38 %, 10.06+/-0.67 %, 24.44+/-0.44 %, respectively. Morphologic changes of cells were seen in laser scanning confocal microscopy observation. Compared to the control group, intracellular Ca2+ concentration, Annexin V expression, phospatase and tensin homologe deleted on chromosome ten (PTEN) protein and expression gradually increased, while Cyclin D1 protein expression gradually decreased in the TPP treated groups along with the increasing of TPS concentration. CONCLUSION: TTP can induce LCC apoptosis, the mechanism is related to the change of intracellular Ca2+ concentration, PTEN protein and Cyclin D1 protein expression.