title: p53-independent WAF1 induction by ACNU in human glioblastoma cells.
abstract: The induction of WAF1 gene expression after the treatment with the anticancer agent 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU; nimustine hydrochloride) was studied in two human glioblastoma cell lines: U-87MG, which bears the wild-type p53 gene, and T98G, which bears the mutant p53 gene. A marked accumulation of WAF1 was observed 3 h after ACNU treatment in both cell lines. The induction of WAF1 mRNA by ACNU was detected by northern blot analysis in these cells. Binding activity of p53 to a p53 consensus sequence increased after treatment in U-87MG cells but not in T98G cells. The existence of a p53-independent WAF1 induction pathway was supported by the apparent accumulation of WAF1 after ACNU treatment in the p53-null human osteosarcoma cell line Saos-2. These findings suggest that there are two possible pathways for WAF1 induction: the p53-dependent pathway through the p53-responsive element and the p53-independent pathway through other elements.
authors.affiliation: Department of Neurosurgery, Nara Medical University, Kashihara, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Aoki
authors.forename: K
authors.initials: K
authors.lastname: Ohnishi
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: A
authors.initials: A
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Ohnishi
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Sakaki
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D015152:Blotting, Northern; D015153:Blotting, Western; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016158:Genes, p53; D005909:Glioblastoma / Q000188:drug therapy* / Q000378:metabolism*; D006801:Humans; D015376:Nimustine / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000502:physiology*
chemical_list: D000970:Antineoplastic Agents; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D016159:Tumor Suppressor Protein p53; D015376:Nimustine