多形胶质母细胞瘤细胞系端粒酶活性的测定

端粒缩短见于星形细胞瘤发展过程中，但其长度在胶质母细胞瘤／细胞系相对稳定，提示胶质瘤细胞内存在端粒修复机制的可能性．为证实此点，利用端粒重复片段扩增技术（ＴＲＡＰ），对８株人／大鼠多形胶质母细胞系的蛋白提取液中端粒酶活性加以测定．结果显示：８例胶质瘤样本的反应液均可见端粒ＰＣＲ扩增片段；用无ＤＮａｓｅ的ＲＮａｓｅ事先处理蛋白提取液，可明显降低或消除ＰＣＲ产物的出现，说明ＴＲＡＰ反应中的ＰＣＲ扩增是在端粒酶的介导下进行而非ＤＮＡ污染或其它端粒修复因子所致．从而不但建立起检测人癌细胞内端粒酶活性的可靠方法，也为针对端粒酶的胶质母细胞瘤生物／药物治疗提供了实验依据．

Telomerase Activity in Human and Rat Glioblastoma Cell Lines

A recent study demonstrated that telomere reduction could be observed during multi stage astrocarcinogenesis,but the length of telomeric restriction fragments (TRFs)was maintained relatively stable in primary and recurrent glioblastomas.To elucidate possible existence of telomere repair mechanism(s) in those tumor cells,telomerase activities in the protein extracts of seven human and one rat glioblastoma cell lines as well as in normal adult rat brain were analyzed with telomeric repeat amplification protocol (TRAP)with or without RNase (DNase free)treatment.It was revealed that after being electrophoresized in polyacrylamide gel,telomeric PCR fragments could be detected in all eight glioma samples but neither in their normal counterpart nor in the same eight samples pre treated with DNase free RNase,which confirmed the specificity of the TRAP results and suggested that the PCR amplification in TRAP reaction solutions were mediated,at least largely,by telomerase.In conclusion,the data show a generality of telomerase activities in glioblastomas and implicate a potential biological and/or pharmaceutical approach for the treatment of glioblastomas by downregulation of telomerase activities.