title: Low frequency of ras activation in 2-acetylaminofluorene- and 3'-methyl-4-(dimethylamino)azobenzene-induced rat hepatocellular carcinomas.
abstract: Activation of ras protooncogenes in 11 2-acetylaminofluorene (AAF)-induced hepatocellular carcinomas (HCCs) or liver cell lines and 9 3'-methyl-(dimethylamino)azobenzene (3'-Me-DAB)-induced HCCs in rats was examined using the NIH3T3 cell transfection assay and oligonucleotide hybridization analysis. Only one cell line established from a AAF-treated rat liver demonstrated transforming activity with a point mutation and ATTA transversion at the second position of H-ras codon 61. The rates of ras activation were thus very low for both AAF- and 3'-Me-DAB-induced rat HCCs, the results thus extending and confirming the findings indicating that ras activation in rat HCCs induced by various type of carcinogens is infrequent.
authors.affiliation: Department of Pathology, Cancer Institute, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: G H
authors.initials: GH
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: K
authors.initials: K
authors.lastname: Nomura
authors.forename: K
authors.initials: K
authors.lastname: Ohtake
authors.forename: T
authors.initials: T
authors.lastname: Kitagawa
mesh_terms: D015073:2-Acetylaminofluorene / Q000494:pharmacology*; D000818:Animals; D015139:Blotting, Southern; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D002471:Cell Transformation, Neoplastic; D004247:DNA / Q000032:analysis; D005786:Gene Expression Regulation / Q000187:drug effects; D011905:Genes, ras / Q000187:drug effects*; D008113:Liver Neoplasms / Q000235:genetics*; D008297:Male; D008749:Methyldimethylaminoazobenzene / Q000494:pharmacology*; D009154:Mutation; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D051381:Rats; D012091:Repetitive Sequences, Nucleic Acid; D014162:Transfection
chemical_list: D008749:Methyldimethylaminoazobenzene; D004247:DNA; D015073:2-Acetylaminofluorene