Correlation of clinical features and telomerase activity in human gliomas

Telomerase is a ribonucleoprotein containing an RNA template that synthesiz es telomeric DNA. The expression of telomerase activity is concomitant with the attainment of immortality in tumor tissues and cells. In this report, we analyzed telomerase activity in 39 human gliomas with different histolog ical, and in 10 meningiomas, 3 neurinomas, and 2 normal brain tissues by us ing a polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay. Telomerase activity was detectable in almost all of the gliomas (36 of 39), but not in any of the meningiomas, neurinomas, or n ormal brain tissues. In addition, we also analyzed the level of telomerase activity in the 36 gliomas with positive telomerase activity. The relative telomerase activity of the glioma showed a clear association with the patho logical grade of glioma; i.e., most of the tumors with high telomerase acti vity were pathologically of high grade. And also the relative level of telo merase activity could be correlated with the survival time of the patients. These results suggest that the level of telomerase activity in brain tumor s is a diagnostic marker indicating the prognosis of the patient as well as the malignant potential of the tumor.