端粒酶活性及其结构基因在人脑胶质瘤中的表达

Telomerase activity and expression of subunits in human gliomas

目的 研究分析端粒酶活性及相关结构基因在不同级别脑胶质瘤中的表达 ,探讨端粒酶与脑胶质瘤的相关性及其临床意义。方法 采集 40例脑胶质瘤手术切除标本、4例正常脑组织 ,通过半定量端粒重复序列扩增 (TRAP) 银染方法检测端粒酶活性水平 ;通过半定量逆转录 聚合酶链反应 (RT PCR)检测端粒酶相关结构基因hTR、TP1、hTRT的mRNA表达水平。结果 在40例胶质瘤标本的 3 3例 (82 .5 % )中检测出端粒酶活性 ,而在正常脑组织中无端粒酶活性的表达 ,不同级别脑胶质瘤之间端粒酶活性水平差异有显著性 ,脑胶质瘤端粒酶活性水平与hTRT基因的表达呈显著正相关 ,而与TP1、hTR的表达无显著相关。结论 端粒酶活性可以作为脑胶质瘤的恶性标记之一 ,hTRT基因是一个端粒酶的正调控结构基因 ,hTRT的表达与细胞永生化和恶性肿瘤形成过程中的端粒酶的激活机制有关 ,hTR基因是端粒酶活性必须的组分 。

Objective To study the correlation between telomerase and glioma with detecting the telomerase activity and the expression of telomerase subunits in different grades of glioma. Methods Forty rapidly surgically resected glioma specimens and 4 normal brain tissue were studied. Telomerase activity was detected by semi quantitative telomeric repeat amplification protocol (TRAP) silver staining. The expression of telomerase related major subunitshTR, TP1, hTRTmRNA was detected by using semi quantitative RT PCR. Results Telomerase activity was detectable in 33 of 40 (82.5%) gliomas specimens and not detectable in normal brain tissue. The levels of telomerase expression were associated with the grade of tumor. There was a significant correlation of telomerase activity with hTRT mRNA expression but not with TP1 and hTR expression. Conclusion Telomerase activity can be used as a special marker of gliomas and an index of maligant potential. Up regulation of hTRT may play a critically important role in the development of cell immortality and telomerase reactive, while hTR is required for telomerase but not sufficient by itself, and it's expression level is not corrected with telomerase activity.