title: KRAS codon 12 mutations occur very frequently in pancreatic adenocarcinomas.
abstract: DNAs from human pancreatic adenocarcinomas were analyzed for the presence of mutations in codons 12, 13 and 61 of the NRAS, KRAS and HRAS gene. Formalin-fixed and paraffin-embedded tissue was used directly in an in vitro amplification reaction to expand the relevant RAS sequences. The mutations were detected by selective hybridization using mutation-specific synthetic oligonucleotides. In 28 of the 30 patients we found a mutation in codon 12 of the KRAS gene. This result confirms the findings of Almoguera et al. [Cell 53 (1988) 549-554] that KRAS mutations occur frequently in adenocarcinomas of the exocrine pancreas. The mutations are predominantly G-T transversions, in contrast to the KRAS mutations in colon tumors which are mainly G-A transitions. Furthermore, in a portion of the tumors the mutation appears to be homozygous.
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D001483:Base Sequence; D003062:Codon / Q000302:isolation & purification*; D003110:Colonic Neoplasms / Q000235:genetics; D011905:Genes, ras / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics; D008969:Molecular Sequence Data; D009153:Mutagens; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000235:genetics*; D012333:RNA, Messenger / Q000302:isolation & purification*
chemical_list: D003062:Codon; D009153:Mutagens; D012333:RNA, Messenger