EGCG通过降低Notch1和Jagged1表达抑制鼻咽癌干细胞SP18的增殖

目的探讨表没食子儿茶素没食子酸酯（EGCG）抑制鼻咽癌干细胞SP18增殖的机制。方法采用M1Tr法检测EGCG抑制SP18细胞增殖的IC50；选用细胞生长曲线、平皿克隆形成实验和软琼脂集落形成实验观察EGCG对鼻咽癌干细胞SP18增殖的影响；采用Westernblot检测NotcM和Jagged1蛋白表达。结果EGCG抑制SP18细胞增殖的IC50值为149．02mg／L；EGCG呈浓度和时间依赖性抑制SPl8细胞的增殖（n=3，P〈0．05）；EGCG呈浓度依赖性抑制Notch1和Jagged1蛋白的表达。结论EGCG能有效抑制鼻咽癌干细胞SP18的增殖，其可能通过降低Notch1和Jagged1蛋白的表达而发挥作用。

EGCG Decreased the Expression of Notch1 and Jagged1 Proteins andInhibited the Proliferation of Nasopharyngeal Cancer Stem Cell SP18

Objective To analyze the mechanism of Epigallocatechin-3-gallate （EGCG） inhibiting the proliferation of nasopbaryngeal cancer stem cell SP18. Methods 50% inhibiting concentration （ ICs0 ） of which EGCG inhibited the proliferation of nasopharyngeal cancer stem cell SP18 was detected by MTT method. The proliferation of SP18 cells affected by EGCG was analyzed by the cellular growth curve, colony formation and soft agar formation. Then the expression of Notehl and Jaggedl protein were respectively detected by Western blot in SP18 cells treated by EGCG. Results IC50, of which EGCG inbibted the proliferation of SP18 cells ,was 149.02 mg/L. The proliferation of SP18 cells was inhibited with EGCG concentration increasing and treatment time extending （ n = 3 ,P 〈 0.05 ）. The expression of Notchl and Jaggedl proteins in SP18 cells was obviously deceased with EGCG concentration increased. Conclusion EGCG can inhibit the proliferation of nasopharyngeal cancer stem cell SP18, which probably decreased the expression of Notchl and Jaggedl proteins to a- chieve the role.