title: K-ras gene mutation in early ductal lesions induced in a rapid production model for pancreatic carcinomas in Syrian hamsters.
abstract: The presence of K-ras gene mutation was examined in experimentally induced preneoplastic pancreatic ductal lesions. Syrian hamsters received 70 mg/kg of N-nitrosobis(2-oxopropyl)amine (BOP) followed by repeated exposure to an augmentation pressure regimen consisting of choline-deficient diet combined with DL-ethionine and L-methionine and administration of 20 mg/kg BOP. After two augmentation pressure cycles, pancreatic ductal cell hyperplasias appeared and after three cycles, atypical hyperplasias of pancreatic ductal cells and intraductal carcinomas developed. K-ras mutations were detected by single-strand conformation polymorphism analysis of polymerase chain reaction products and nucleotide sequencing. The results showed that K-ras mutation had occurred in one of 9 simple hyperplasias of pancreatic ductal epithelium, in 5 of 9 atypical hyperplasias, and in 4 of 8 intraductal carcinomas. The findings thus suggested that K-ras is activated in association with very early stage malignant transformation of pancreatic ductal cells in hamsters.
authors.affiliation: Department of Oncological Pathology, Nara Medical University.
authors.forename: M
authors.initials: M
authors.lastname: Tsutsumi
authors.forename: S
authors.initials: S
authors.lastname: Kondoh
authors.forename: O
authors.initials: O
authors.lastname: Noguchi
authors.forename: K
authors.initials: K
authors.lastname: Horiguchi
authors.forename: E
authors.initials: E
authors.lastname: Kobayashi
authors.forename: S
authors.initials: S
authors.lastname: Okita
authors.forename: K
authors.initials: K
authors.lastname: Ohashi
authors.forename: K
authors.initials: K
authors.lastname: Honoki
authors.forename: T
authors.initials: T
authors.lastname: Tsujiuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Konishi
mesh_terms: D000818:Animals; D001483:Base Sequence; D002277:Carcinoma / Q000235:genetics*; D003062:Codon; D006224:Cricetinae; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D011905:Genes, ras; D006965:Hyperplasia; D008647:Mesocricetus; D008969:Molecular Sequence Data; D009153:Mutagens; D009154:Mutation; D009602:Nitrosamines; D010183:Pancreatic Ducts / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000235:genetics*
chemical_list: D003062:Codon; D017931:DNA Primers; D009153:Mutagens; D009602:Nitrosamines; C013622:nitrosobis(2-oxopropyl)amine