三氧化二砷诱导鼻咽癌CNE-2Z细胞凋亡及其作用机制的初步研究

Preliminary Studies of Apoptosis in Human Nasopharyngeal Carcinoma CNE -2Z Cells Induced by Arsenic Trio xide and Its Mechanism

目的:研究三氧化二砷(As2O3)对人鼻咽癌CNE2Z细胞的生物学效应及其作用机制。方法:台盼蓝计数法计算As2O3的IC50;CNE-2Z细胞经As2O3处理后,通过流式细胞仪、荧光染色及DNA电泳检测细胞凋亡;流式细胞仪测定bcl2和bax阳性细胞百分率;罗丹明123染色后进行线粒体膜电位分析。结果:As2O3在一定浓度范围内以浓度依赖的方式抑制CNE2Z细胞生长,其IC50为(1.35±0.30)μmol/L;0.5～2.0μmol/LAs2O3处理CNE2Z细胞后,流式细胞仪检测出凋亡峰,荧光显微镜下可见明显的细胞凋亡形态特征,琼脂糖凝胶电泳出现DNA梯形条带;As2O3对bcl2的表达没有影响(P>0.05),但能显著增加bax的表达(P<0.01)及降低线粒体膜电位(P<0.01)。结论:As2O3在体外可诱导鼻咽癌CNE2Z细胞凋亡,其机制可能与上调bax表达和降低线粒体膜电位有关。

Objective：To investigate the pos sibility and t he mechanism of human nasopharyngeal carcinoma （NPC）CNE－２Z ce ll apoptosis induced by ars enic trioxide（As ２ O ３ ）．Methods ：The cytotoxic activity of As ２ O ３ was quantified by determining IC ５０ in CNE－２Z cells using trypan blue exc lusion．After treatment with As ２ O ３ ，apoptotic cells were detected with flow cytometry，fluorescence stain ing and DNA electrophoresis；the inf luence of As ２ O ３ on bcl－２and Bax expression was observed with flow cytometry；the ch ange o f mitochondrial membrane pote ntial（ΔΨm）was analyzed with flow cytometry aft er Rhodamine１２３staining．Results：As ２ O ３ inhibited the growth of CNE－２Z cells in a dose－dependent manner in a cert a in range of dose with a IC ５０ of １．３５±０．３０μmol ／L；Apoptotic peak，characteristic morphologic f eatures of apoptosis and DNA ladder were observed in CNE－２Z cells treated with ０．５－２．０μmol ／L As ２ O ３ ；After treatment with ２．０μmol ／L As ２ O ３ ，no change of Bcl－２protein level was observed（P＞０．０５），while Bax w as up－regulated signifi cantly（P＜０．０１）and a significant loss ofΔΨm wa s detected（P＜０．０１）．Conclusions ：As ２ O ３ may induce apoptosis of NPC CNE－２Z cells，and its mechanism is related to the up－regulation of Bax and loss ofΔΨm．