title: Highly conserved sequence of exon 15 BRAF gene and KRAS codon 12 mutation among Greek patients with colorectal cancer.
abstract: BACKGROUND
  The RAS/RAF/MEK/MAP kinase pathway is essential to intracellular signaling transduction regulating cell proliferation, differentiation and death. We investigated the occurrence of exon 15 BRAF and KRAS codon 12 mutations among Greek patients with colorectal cancer.
  
  
  METHODS
  Sixty-one samples from patients with sporadic colorectal adenocarcinomas were studied for exon 15 BRAF mutations. DNA from surgically resected specimens was analyzed by a combination of polymerase chain reaction and direct sequencing. KRAS codon 12 mutational analysis was technically possible in 58 samples (58/61) by a combination of polymerase chain reaction and restriction fragment length polymorphism.
  
  
  RESULTS
  No exon 15 BRAF mutations were detected in any of the colon cancer specimens. The frequency of KRAS codon 12 mutations was 29.3% (17/58). Patients aged < or = 70 years more frequently presented carcinomas harboring KRAS codon 12 mutations than patients aged >70 years (p=0.028). Patients between 61 and 70 years of age were more likely to be carriers of this mutation (p=0.040).
  
  
  CONCLUSIONS
  Despite the limited study sample, our data suggest that BRAF mutations might be present less frequently than KRAS mutations in Greek patients with colorectal carcinomas. Further research involving larger patient series will be necessary to confirm these findings and to assess possible ethnic, environmental and lifestyle influences on BRAF and KRAS mutagenesis.
authors: Laboratory of Virology, Medical School, University of Crete, Heraklion, Crete, Greece.
authors: E K
authors: EK
authors: Symvoulakis
authors: A
authors: A
authors: Zaravinos
authors: D
authors: D
authors: Panutsopulos
authors: O
authors: O
authors: Zoras
authors: E
authors: E
authors: Papalambros
authors: F
authors: F
authors: Sigala
authors: D A
authors: DA
authors: Spandidos
mesh_terms: D000368:Aged; D003062:Codon / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics*; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D005260:Female; D006115:Greece; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*
chemical_list: D003062:Codon; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras)