Green Tea Polyphenols Induced Apoptosis And Expression Change Of BCL-2 And P53 Protein In Lung Cancer Cell

Background Tea which flavor is fragrant is consumed only second to water . A lot of laboratory experiments and epedemiologic studies have suggested that the consumption of green tea may reduced the risk of a variety of human cancers , including cancers of the lung ,skin,stomach and mammary glands etc. Green tea polyphanols (GTP), the main chemical componenes of green tea , has wide biological property . TPs can induce tumor cell apoptosis and inhibit proliferation . But the underlying mechanisms are not completely understood . It inhibits the processes of carcinogenesis by diverse mechanisms . Further research may provide us with more information about the anticancer activities of these promising compounds and facilitate the usage in cancer prevention and treatment.Objective To investigate whether green tea polyphenols (TPs) could induce apoptosis and affect apoptosis-associated gene bcl-2 and mutant type gene p53 expression in lung cancer SPC-Alcell.Methods SPC-Alcells were divided into seven groups after 24-hour culture at the concentration of 105/ml, that is control groups and six treatment groups . the latter were administered green tea polyphenols at concentration of 50ng/ml , 100ug/ml , 150ng/ml , 200ug/ml , 250ug/ml , 300ug/ml respectively . Inhibition of SPC-A1 cell growth is observed by MTT method . Apoptosis is detected by transmissional election microscope and change in expression of bcl-2 and p53 gene were determined by using immunohis to chemical SABCmethod .Results The proliferation of SPC-A1 were significantly inhibited by greentea polyphenol and the inhibitionrate was time-dependent (12-36h) and concentration-dependent (50ug/ml-150ug/ml). Its inhibitory effect decreased when the concentration exceeds 150ug/ml . Typical nuclear condensation was observed by tranmissional election microscope . Moreover , TPs downregulated bcl-2 and p53 expression in lung cancer SPC-A1 carcinoma cells .Conclusion TPs has the inhibitory effects on the growth of lung carcinoma SPC-A1 cells and one of the mechanisms could be the induction of appotesis in the tumor cell line . The apoptosis is associated with TPs-induced decrease of the bcl-2 and p53protein level in SPC-A1 cell line .