| Autor: |
Chong, Edith Y.Y., Pang, Jesse C.S., Ko, Chun-Wai, Poon, Wai-Sang, Ng, Ho-Keung |
| Zdroj: |
Pathology - Research and Practice; January 2000, Vol. 196 Issue: 10 p691-699, 9p |
| Abstrakt: |
Telomerase activation has been implicated as a major factor in the development of cancer. In our previous study we reported on the telomerase activity of a variety of gliomas. To further investigate the role of telomere and telomerase regulation in the pathogenesis of nonastrocytic gliomas, we examined the telomere length and the mRNA expression of telomerase reverse transcriptase gene (hTERT) and telomerase-associated protein (hTEP) in a series of 27 oligodendroglial and 18 ependymal tumors in this study. No statistical difference was found between the mean telomere length in telomerase-positive and telomerase-negative tumors (11.5 kb vs 13.1 kb; p = 0.424), although a slightly shorter length was observed in telomerase-positive oligodendroglial tumors. mRNA expression of hTERT was highly correlated with the telomerase activity status. hTERT was expressed in 818 (100%) and 212 (100%) telomerase-positive oligodendroglial and ependymal tumors, respectively, whereas 316 (50%) telomerase-negative oligodendroglial tumors and no telomerase-negative ependymal tumors showed expression. In contrast, hTEPI mRNA was widely expressed in both telomerase-positive and telomerase-negative oligodendroglial and ependymal tumors. Our data support the notion that hTERT plays a critical role in determining the enzymatic activity of human telomerase. It has recently been proposed that both p16INK4a/Rb pathway inactivation and telomerase activity were required for immortalization of epithelial cells. Although lack of p16INK4aexpression was detected in a substantial proportion of tumors, no correlation between the p16INK4aor pRb protein expression and telomerase activity was observed in our series of non-astrocytic tumors. |
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