title: K-ras activation in gastric epithelial tumors in Japanese.
abstract: Point mutation in codons 12, 13 and 61 of the K-ras oncogene in gastric epithelial tumors were investigated by polymerase chain reaction from sections of formalin-fixed, paraffin-embedded tissue followed by dot-blot hybridization with mutation-specific oligonucleotide probes. Point mutations were found specifically in four of 20 tumors of intestinal histological subtype; GGT to GAT in three cases and to GTT in one case, all in codon 12 of K-ras. These mutations were also confirmed by direct sequencing. In contrast, none of 11 diffuse-type tumors showed K-ras point mutations. While K-ras point mutations may not be frequent events in gastric tumorigenesis, the similarity of the intestinal-type gastric tumors and colorectal tumors for K-ras point mutations as well as the association of mutations in K-ras with a particular gastric tumor histology implicates K-ras activation in the development of these tumors.
authors.affiliation: Department of Pathology, Kagawa Medical School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Miki
authors.forename: M
authors.initials: M
authors.lastname: Ohmori
authors.forename: A O
authors.initials: AO
authors.lastname: Perantoni
authors.forename: T
authors.initials: T
authors.lastname: Enomoto
mesh_terms: D000236:Adenoma / Q000208:ethnology / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D003062:Codon; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D011905:Genes, ras; D006801:Humans; D007564:Japan / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000208:ethnology / Q000235:genetics*
chemical_list: D003062:Codon; D004273:DNA, Neoplasm; D015345:Oligonucleotide Probes