[Study on mechanism of tea polyphenols in inducing human lung cancer cell apoptosis in vitro].

To investigate the apoptosis inducing effect of tea polyphenols (TPP) on human lung cancer cell (LCC) and its associative mechanism.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.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.TTP can induce LCC apoptosis, the mechanism is related to the change of intracellular Ca2+ concentration, PTEN protein and Cyclin D1 protein expression.