Telomerase Activity in Human Brain Tumors: Astrocytoma and Meningioma

Abstract

Somatic cells do not have telomerase activity but immortalized cell lines and more than 85 % of the cancer cells show telomerase activation to prevent the telomere from progressive shortening. The activation of this enzyme has been found in a variety of human tumors and tumor-derived cell lines, but only few studies on telomerase activity in human brain tumors have been reported. Here, we evaluated telomerase activity in different grades of human astrocytoma and meningioma brain tumors. In this study, assay for telomerase activity performed on 50 eligible cases consisted of 26 meningioma, 24 astrocytoma according to the standard protocols. In the brain tissues, telomerase activity was positive in 39 (65 %) of 50 patients. One sample t test showed that the telomerase activity in meningioma and astrocytoma tumors was significantly positive entirely (P < 0.001). Also, grade I of meningioma and low grades of astrocytoma (grades I and II) significantly showed telomerase activity. According to our results, we suggest that activation of telomerase is an event that starts mostly at low grades of brain including meningioma and astrocytoma tumors.

Comprehensive analysis of Iranian reports of pediatric central nervous system tumors

“…The study objectives were categorized as genetic (n = 9 articles [38, 44, 50, 56, 62, 65–66, 70–71], 449 patients), epidemiologic (n = 7 articles [47, 49, 60–61, 63, 69, 74], 13,193 patients), pathologic (n = 7 articles [46, 48, 52, 55, 67–68, 72], 4,365 patients), clinical (n = 6 articles [39, 41, 43, 45, 57, 76], 393 patients), radiologic (n = 4 articles [, 86 patients), radiotherapy (n = 3 articles [54, 58–59, 73], 54 patients), surgical (n = 2 articles [42, 51], 44 patients), or virologic [75] (n = 1, 58 patients).…”

Research Progress on the Antineoplastic Pharmacological Effects and Mechanisms of Litchi Seeds

“…Among of them, 85% of tumor cells are positively correlated with the activity of telomerase. As a result, considering the telomerase activity as tumor, therapeutic targets has attracted numerous attentions in contemporary medicine science [37] [38]. Xiao et al [39] imported the different doses of litchi water extract to investigate the anti-hepatoma effects and results showed that litchi water extract reduces significantly the ratio of liver tumor with a negative telomerase activity simultaneously.…”

The Evolving Role of Radiosurgery in the Management of Radiation-Induced Meningiomas: A Review of Current Advances and Future Directions

“…Pistolesi and colleagues, examining the case of an adult patient with RIM and multiple recurrences and metastases, demonstrated an increased expression of p53 and increased telomerase activity [52]. Although benign meningiomas have an overall lower telomerase activity, patients with Grade I meningiomas with an increased level of activity are at a greater risk of tumor recurrence even after GTR and, therefore, are more likely to require postoperative adjuvant radiation [53, 54]. Patients with high grade RIMs or those with multiple recurrences have been shown to have an increased vascularity and high levels of vascular endothelial growth factor (VEGF) mRNA expression as well; the expression of VEGF increases the risk of peritumoral edema, particularly following SRS [52, 55, 56].…”