茶多酚对小鼠肿瘤L_2细胞DNA引物酶-多聚酶α复合体活性的抑制作用

Inhibition effect of tea polyphenol on the activity of DNA primase-polymerase αcomplex from tumor L_2 cells in mice

目的 :探讨茶多酚的抗癌作用机理。方法 :应用DE 5 2和P 11层析柱分离小鼠肿瘤L2 细胞DNA引物酶 多聚酶α复合体 ,并通过闪烁计数仪测定茶多酚对DNA引物酶的影响。结果 :茶多酚对小鼠肿瘤L2 细胞DNA引物酶 多聚酶α复合体活性有抑制作用 ,半数抑制浓度 (IC50 )值为 2 0 2 8(15 17～ 2 7 13) μg/ml;对DNA引物合成有促进作用 ;对引物延长亦有明显抑制作用 ,其IC50 值为 36 43μg/ml。结论 :茶多酚对DNA引物酶 多聚酶α复合体和引物延长活性有抑制作用 ,DNA引物酶 多聚酶α复合体是茶多酚的靶点之一。

Objective: To investigate the mechanism of antitumor action of tea polyphenol (TP) Methods: DNA primase polymerase αcomplex was extracted from mice tumor cell line L 2 The crude enzyme was loaded on DE 52 column and P 11 column,sequentially, to obtain partial purified enzyme Effect of TP on DNA primase polymerase αcomplex activity was examined using Liquid Scintillation counter Results:It showed that IC 50 value of TP inhibiting DNA primase polymerase αcomplex activity was 20 28 (15 17～27 13) μg/ml TP could promote DNA primer synthesis but inhibit DNA primer extension IC 50 value of TP inhibiting DNA primer extension was 36 43 (12 55～105 25)μg/ml Conclusion: TP was shown to have inhibitory effect on activity of DNA primase polymerase αcomplex and primer extention DNA primase polymerase αcomplex may be one of the target of TP