title: Activation of c-K-ras mutations in human gastrointestinal tumors.
abstract: OBJECTIVE
  Ras genes are the most frequently detected oncogenes in human malignancies. Data regarding the frequency of c-K-ras mutations in esophageal, gastric, and small bowel tumors are limited and controversial.
  
  
  METHODS
  DNA was extracted from 262 formalin-fixed, paraffin-embedded sections of gastrointestinal samples and tumors, including Barrett's esophagus, esophageal squamous cell carcinomas and adenocarcinomas, and small and large bowel adenomas and adenocarcinomas. The presence of c-K-ras codon 12 mutations was determined using a nonradioactive polymerase chain reaction-based restriction fragment length polymorphism assay.
  
  
  RESULTS
  c-K-ras mutations were detected in 1 of 39 (2%) patients with Barrett's esophagus, 1 of 21 (5%) adenocarcinomas, 0 of 27 squamous cell carcinomas of the esophagus, and 1 of 32 (3%) gastric adenocarcinomas. It was also present in 8 of 20 (40%) and 10 of 28 (36%) small bowel adenomas and adenocarcinomas, respectively. Similar numbers were observed in 10 of 25 (40%) large bowel adenomas and 11 of 30 adenocarcinomas (37%). Mutations were not associated with age, gender, histology, grade, stage, location, or mortality.
  
  
  CONCLUSIONS
  The frequency of codon 12 c-K-ras mutations in small and large bowel tumors is approximately 10-fold higher than that of tumors in the upper gastrointestinal tract.
authors.affiliation: GI Oncology Unit, Tel-Aviv University, Tel Aviv, Israel. narber@tasmc.health.co.il
authors.forename: N
authors.initials: N
authors.lastname: Arber
authors.forename: I
authors.initials: I
authors.lastname: Shapira
authors.forename: J
authors.initials: J
authors.lastname: Ratan
authors.forename: B
authors.initials: B
authors.lastname: Stern
authors.forename: H
authors.initials: H
authors.lastname: Hibshoosh
authors.forename: M
authors.initials: M
authors.lastname: Moshkowitz
authors.forename: M
authors.initials: M
authors.lastname: Gammon
authors.forename: I
authors.initials: I
authors.lastname: Fabian
authors.forename: Z
authors.initials: Z
authors.lastname: Halpern
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000236:Adenoma / Q000235:genetics*; D000483:Alleles; D001471:Barrett Esophagus / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D004252:DNA Mutational Analysis; D004938:Esophageal Neoplasms / Q000235:genetics; D005770:Gastrointestinal Neoplasms / Q000235:genetics*; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D007414:Intestinal Neoplasms / Q000235:genetics; D007557:Israel; D009519:New York City; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D013274:Stomach Neoplasms / Q000235:genetics