Ushijima T, Tsutsumi M, Sakai R, Ishizaka Y, Takaku F, Konishi Y, Takahashi M, Sugimura T, Nagao M
Carcinogenesis Division, National Cancer Center Research Institute, Tokyo.
Jpn J Cancer Res. 1991 Sep;82(9):965-8. doi: 10.1111/j.1349-7006.1991.tb01928.x.
Five pancreatic carcinomas induced by N-nitrosobis(2-hydroxypropyl)amine in Syrian golden hamsters were analyzed for activation of Ki-ras at codons 12 and 13, using the polymerase chain reaction and direct sequencing. The Ki-ras gene was shown to be activated in four of the five carcinomas, and the results were further confirmed by subcloning and sequencing. All the mutations involved a G-to-A transition at the second position of codon 12, which resulted in a change at the amino acid level from glycine to aspartic acid. This mutation is identical with that reported for pancreatic tumors of Syrian hamsters induced by N-nitrosobis(2-oxopropyl)amine.