The significant role of telomerase activity in human brain tumors

Abstract

BACKGROUND. In this study, telomerase activity in human brain tumors was analyzed. METHODS. Telomerase activity was examined in 41 brain tumor cases (20 of glioblastoma multiformes [GBMs] [14 primary tumors and 6 recurrent tumors], 3 anaplastic astrocytomas [AAs], 4 low grade astrocytomas [LGAs] [World Health Organization Grade 2], 2 oligodendrogliomas [OGs], 9 meningiomas [MNs], and 3 metastatic brain tumors [MBTs]) by means of telomeric repeat amplification protocol assay. The activity of telomerase was compared with histologic diagnosis, the MIB-1 proliferative cell index (PCI), and the patient's prognosis. RESULTS. Twelve of 20 GBMs, 2 of 2 OGs, and 3 of 3 MBTs demonstrated telomerase activity. AAs, LGAs, and MNs exhibited no activity. No clear correlations were confirmed in GBMs between telomerase activity and the MIB-1 PCI data. However, the telomerase activity tended to correlate with the patient's prognosis. CONCLUSIONS. These results suggest that telomerase activity may be an important marker of brain tumor malignancy. Furthermore, the change from negative activity to positive activity in the recurrent tumors appeared to be a useful prognosticator for malignant astrocytic tumor.