土贝母皂苷诱导人鼻咽癌细胞株CNE-2Z细胞凋亡的研究

目的　研究土贝母皂苷 (下称皂苷 )对人鼻咽癌细胞株CNE 2Z细胞凋亡的影响。方法　MTT法检测皂苷对CNE 2Z细胞生长的影响 ;形态学方法 (荧光显微镜和透射电镜 )、流式细胞仪和DNA琼脂糖凝胶电泳观察和分析在皂苷作用下CNE 2Z细胞形态、DNA含量的变化和DNA断裂的情况 ;蛋白免疫印迹法检测凋亡相关基因bcl 2、bax和cas pase 3表达的变化。 结果　皂苷抑制CNE 2Z细胞的生长 ,其效果与皂苷的浓度和作用时间相关 ;诱导CNE 2Z细胞发生典型程序性死亡 ;凋亡抑制基因bcl 2表达逐渐减少 ;而凋亡诱导基因bax和caspase 3在 1、3、5h表达增高。 结论　诱导细胞凋亡是皂苷发挥抗瘤效果的一种重要机制 ;皂苷诱导的CNE 2Z细胞凋亡与bcl 2、bax和caspase 3基因有关

Induction of apoptosis in human nasopharyngeal carcinoma cell line CNE-2Z by tubeimosides

AIM To investigate whether tubeimosides induce apoptosis in CNE-2Z. METHODS Growth inhibition by tubeimosides was measured using MTT assay. The effect of tubeimosides on apoptosis induction of CNE-2Z cell line was studied by the fluorescent microscopy, electronic microscopy, DNA agarose gel electrophoresis, flow cytometry analysis. Western blotting was performed for detecting the apoptosis-related gene. RESULTS The growth of CNE-2Z cells was inhibited obviously by tubeimosides. CNE-2Z cells showed typical apoptotic features observed by fluorescent microscopy, electronic microscopy. DNA fragmentation into multiples of low molecular weight DNA(180～200 bp) was detected by agarose gel electrophoresis of DNA; Sub-G 1 peak was found by flow cytometry analysis, and the apoptosis index was 58 0%. The expression of bcl-2, inhibitor of apoptosis, decreased apparently; while that of bax, inducer of apoptosis, increased notably at 1, 3, 5 h after the addition of tubeimosides. The cleavage of caspase-3 was noticed at 1, 3, 5 h after the treatment of tubeimosides. CONCLUSION Tubeimosides could induce the apoptosis of CNE-2Z cells. The induction of apoptotic by tubeimosides was closely associated with bcl-2, bax and caspase-3.