摘要
目的Ｘ线诱导人鼻咽癌细胞系ＣＮＥ和ＣＮＥ－２凋亡及其相关基因的研究。方法应用ＤＮＡ荧光染料Ｈｏｅｃｈｓｔ３３３４２、免疫组化、ＲＴ－ＰＣＲ、ＤＮＡ杂交等方法进行观察和检验。结果一定剂量照射后，ＣＮＥ凋亡指数与时间、剂量有相关性，ＣＮＥ和ＣＮＥ－２两种细胞系存在明显不同的凋亡反应。免疫组化方法检测，ＣＮＥ的ｂｃｌ－２蛋白呈强阳性，而ＣＮＥ－２为阴性；进一步采用ＲＴ－ＰＣＲ方法检测，发现ＣＮＥ－２存在ｐ５３ｍＲＮＡ扩增产物，而ＣＮＥ却不存在。ＣＮＥ和ＣＮＥ－２的ｐ５３及ｂｃｌ－２基因的ＤＮＡ杂交结果均为阳性，但ＣＮＥ细胞ｐ５３基因的２．８ｋｂ片段较５．６ｋｂ片段明显减弱，说明在ＣＮＥ中存在ｐ５３基因的部分缺失。结论人鼻咽癌细胞系的凋亡指数有时间、剂量相关性；ＣＮＥ、ＣＮＥ－２两种细胞系的凋亡指数有明显差异，可能与ＣＮＥ中抗凋亡基因ｂｃｌ－２的过度表达及ｐ５３基因部分缺失密切相关。
Objective To study apoptosis induced by radiation in two nasopharyngeal carcinoma (NPC) cell lines, CNE and CNE 2. Methods Hoechst 33342 staining, immunocytochemical staining, RT PCR, DNA dot blotting and Southern blotting were used to identify apoptosis. Results A single dose of X irradiation resulted in apoptosis, the apoptotic index (AI) was time and dose dependent. Different apoptotic responses existed in the two cell lines. Immunocytochemical staining showed that bcl 2 protein was strongly positive in CNE but negetive in CNE 2. However, RT PCR revealed p53 mRNA in CNE 2 but not in CNE. p53 and bcl 2 genes were both present in the two cell lines as shown by DNA blotting, but the 2.8kb fragment of the p53 gene was much lower than the 5.6 Kb fragment in CNE which was clearly shown in Southern hybridization, suggestive of partial deletion of p53 gene in CNE. Conclusion Apoptotic response to radiation is different in 2 NPC cell lines. CNE is more radio resistant than CNE 2. Overexpression of bcl 2 protein and partial deletion of p53 gene may explain their difference in radio sensitivity.
出处
《中华肿瘤杂志》
CAS
CSCD
北大核心
1998年第2期119-121,共3页
Chinese Journal of Oncology
基金
国家自然科学基金
关键词
肿瘤细胞析
细胞凋亡
鼻咽肿瘤
相关基因
Tumor cell line Radiation Apoptosis Gene, p53 Nasopharyngeal neoplasms Gene, bcl 2
