Frequency and spectrum of c-Ki-ras mutations in human sporadic colon carcinoma, carcinomas arising in ulcerative colitis, and pancreatic adenocarcinoma

Environ Health Perspect. 1991 Jun;93:27-31. doi: 10.1289/ehp.919327.


Sporadic colon carcinomas, carcinomas arising in chronic ulcerative colitis, and pancreatic adenocarcinomas have been analyzed for the presence of c-Ki-ras mutations by a combination of histological enrichment, cell sorting, polymerase chain reaction, and direct sequencing. Although 60% (37/61) of sporadic colon carcinomas contained mutations in codon 12, only 1 of 17 specimens of dysplasia or carcinoma from ulcerative colitis patients contained c-Ki-ras mutations, despite a high frequency of aneuploid tumors. In contrast, a higher percentage (16/20 = 80%) of pancreatic adenocarcinomas contained mutations in c-Ki-ras 2, despite a lower frequency of DNA aneuploidy in these neoplasms. Moreover, the spectrum of mutations differed between sporadic colon carcinoma, where the predominant mutation was a G to A transition, and pancreatic carcinomas, which predominantly contained G to C or T transversions. These results suggest that the etiology of ras mutations is different in these three human neoplasms.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenocarcinoma / genetics*
  • Aneuploidy
  • Carcinoma / complications
  • Carcinoma / genetics*
  • Codon
  • Colitis, Ulcerative / complications*
  • Colitis, Ulcerative / genetics
  • Colon / pathology
  • Colonic Neoplasms / complications
  • Colonic Neoplasms / genetics*
  • DNA Damage
  • DNA Mutational Analysis
  • DNA, Neoplasm / genetics
  • Flow Cytometry
  • Genes, ras*
  • Humans
  • Mutation
  • Pancreatic Neoplasms / genetics*
  • Polymerase Chain Reaction
  • Proto-Oncogene Proteins p21(ras) / genetics*


  • Codon
  • DNA, Neoplasm
  • HRAS protein, human
  • Proto-Oncogene Proteins p21(ras)