title: Increased telomerase activity and absence of p53 mutation in oligoastrocytomas induced by N-ethyl-N-nitrosourea in rats.
abstract: 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.
authors.affiliation: Department of Oncological Pathology, Cancer Center, Nara Medical University, Kashihara, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sakitani
authors.forename: T
authors.initials: T
authors.lastname: Tsujiuchi
authors.forename: K
authors.initials: K
authors.lastname: Kobitsu
authors.forename: A
authors.initials: A
authors.lastname: Kido
authors.forename: K
authors.initials: K
authors.lastname: Iki
authors.forename: M
authors.initials: M
authors.lastname: Takahama
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Sakaki
authors.forename: D
authors.initials: D
authors.lastname: Nakae
authors.forename: Y
authors.initials: Y
authors.lastname: Konishi
authors.forename: M
authors.initials: M
authors.lastname: Tsutsumi
mesh_terms: 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*
chemical_list: D002273:Carcinogens; D009363:Neoplasm Proteins; D019098:Telomerase; D005038:Ethylnitrosourea