Increased telomerase activity and absence of p53 mutation in oligoastrocytomas induced by N-ethyl-N-nitrosourea in rats.
The question of whether the changes in telomerase activity and/or the alteration of the p53 gene are involved in the development of oligo-astrocytomas induced by N-ethyl-N-nitrosourea (ENU) in rats was addressed. Telomerase activity levels of oligo-astrocytomas, including early neoplastic lesions, were significantly increased as compared to the normal controls, correlating with the degree of malignancy. In contrast, no mutations of p53 exons 5-7 were found in early neoplastic lesions or oligo-astrocytomas. These results indicate that the activation of telomerase occurs during astrocytoma carcinogenesis and contributes to the development of brain tumors, but the alterations of p53, at least on exons 5-7, may not be involved in this process.
Sakitani
H
H
Department of Oncological Pathology, Cancer Center, Nara Medical University, Kashihara, Japan.
Tsujiuchi
T
T
Kobitsu
K
K
Kido
A
A
Iki
K
K
Takahama
M
M
Nakamura
M
M
Sakaki
T
T
Nakae
D
D
Konishi
Y
Y
Tsutsumi
M
M
D000818:Animals; D001254:Astrocytoma / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D001932:Brain Neoplasms / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D002273:Carcinogens; D005038:Ethylnitrosourea; D005260:Female; D016158:Genes, p53 / Q000235:genetics*; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D019098:Telomerase / Q000378:metabolism*
D002273:Carcinogens; D009363:Neoplasm Proteins; D019098:Telomerase; D005038:Ethylnitrosourea