摘要
目的:探讨熊果酸(UA)对胃癌细胞BGC-823增殖抑制和诱导凋亡的作用机制。方法:采用MTT法检测UA对BGC-823细胞的增殖抑制效应;用琼脂糖凝胶电泳观察DNA凋亡片段;流式细胞仪检测UA作用后BGC-823细胞的周期分布和凋亡率;用Fas单克隆抗体检测BGC-823细胞表面Fas的表达;Western blot检测BGC-823细胞Bcl-2的表达及caspase-3和caspase-8的活性。结果:UA对BGC-823细胞具有增殖抑制效应,并呈浓度和时间依赖性。UA作用24 h时半数抑制浓度(IC50)为43.10μmol/L。当UA浓度为50和60μmol/L时,琼脂糖凝胶电泳可呈现DNA凋亡梯带。随着UA浓度从20μmol/L递增到60μmol/L,周期检测发现BGC-823细胞出现亚G1峰逐步增高,S期阻滞增加,G1期下降。细胞内Bcl-2表达下降,caspase-3和caspase-8活性增加。BGC-823细胞表面未发现Fas的表达。结论:UA对BGC-823细胞有较强的增殖抑制和诱导凋亡作用,下调Bcl-2的表达及激活caspase-3、caspase-8可能是其诱导凋亡的机制。
Objective： To investigate ursolic acid （UA） proliferation inhibiting and apoptosis inducing effect on human gastric carcinoma cell line BGC-823. Methods： Cell proliferation inhibition was detected by MTT assay. DNA fragmentation was determined by DNA electrophoresis. Cell cycle and apoptosis rate were analyzed by flow cytometry （FCM）. Fas antigen expression on BGC-823 cell surface was detected with Fas monoclonal antibody and then analyzed by FCM. The expression of Bcl-2 and activity of caspase-8 and -3 were detected by Western blot. Results： UA can inhibit proliferation of BGC-823 cells effectively in a dose- and time-dependent manner. After BGC- 823 was treated by UA for 24 h, the IC50 value was 43.10 μmol/L. When UA concentration was 50 or 60 μmol/L, DNA ladder of apoptosis was observed by gel electrophoresis. While UA concentration was increased from 20 μmol/L to 60 μmol/L, cells in sub-G1 phase and S-phase were increased in cell cycle, but decreased in Gl-phase. UA decreased Bcl-2 protein levels and increased the activation of caspase-3 and caspase-8. The Fas expression on BGC-823 cells was not found. Conclusion： UA has inhibitory and apoptosis inducing effects on BGC-823 cells. Down- regulation of the expression of Bcl-2 and induction of activation of caspase-8 and -3 may contribute to its apoptosis effects.
出处
《武汉大学学报（医学版）》
CAS
2006年第3期299-302,共4页
Medical Journal of Wuhan University
作者简介
陈会敏，女，1978-，医学硕士生，从事肿瘤免疫学研究
通讯作者：张秋萍，女，1963-，医学博士，副教授，硕士生导师，主要从事肿瘤免疫学研究
