title: Mutation analysis of BRAF exon 15 and KRAS codons 12 and 13 in Moroccan patients with colorectal cancer.
abstract: BACKGROUND
  The RAS/RAF/MEK/MAP kinase cascade transduces signals from the cell surface to the nucleus in order to control cellular responses including proliferation, differentiation and survival. We investigated the occurrence of BRAF exon 15 and KRAS codon 12 and 13 mutations in Moroccan patients with colorectal cancer.
  
  
  METHODS
  Sixty-two samples from patients with sporadic colorectal adenocarcinomas were studied for BRAF exon 15 and KRAS codon 12 and 13 mutations. DNA from paraffin-embedded tissue specimens was analyzed by a combination of polymerase chain reaction-high resolution melting and direct sequencing.
  
  
  RESULTS
  Of the analyzed specimens, 29% exhibited KRAS codon 12 or 13 mutations and only 1.6% carried a BRAF codon 600 mutation. KRAS mutations were more often observed in women (35.5%) than in men (22.6%). Patients in the age range between 41 and 60 years were more likely to be carriers of this mutation. No KRAS mutations were detected in patients aged >60 years.
  
  
  CONCLUSIONS
  Despite the limited study sample, our data suggest that KRAS mutations arise more frequently than BRAF mutations in Moroccan patients with colorectal carcinomas. The KRAS mutation status must be assessed in a large cohort of Moroccan patients to confirm these findings and to determine whether this mutation in combination with extrinsic, environmental or microenvironmental factors might be involved in the high frequency of colorectal cancer in middle-aged Moroccans.
authors.affiliation: Laboratoire de Biologie des Cancers, Equipe Micro-organismes et Facteurs Oncogènes, Faculté de Médecine et de Pharmacie, Fez, Morocco.
authors.forename: Bahia
authors.initials: B
authors.lastname: Bennani
authors.forename: Sophie
authors.initials: S
authors.lastname: Gilles
authors.forename: Frederic
authors.initials: F
authors.lastname: Fina
authors.forename: Isabelle
authors.initials: I
authors.lastname: Nanni
authors.forename: Sidi Adil
authors.initials: SA
authors.lastname: Ibrahimi
authors.forename: Afaf Amarti
authors.initials: AA
authors.lastname: Riffi
authors.forename: Chakib
authors.initials: C
authors.lastname: Nejjari
authors.forename: Dafr-Allah
authors.initials: DA
authors.lastname: Benajeh
authors.forename: Mohammed
authors.initials: M
authors.lastname: El Abkari
authors.forename: Pierre-Marie
authors.initials: PM
authors.lastname: Martin
authors.forename: L'Houcine
authors.initials: L
authors.lastname: Ouafik
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D003062:Codon; D015179:Colorectal Neoplasms / Q000235:genetics*; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009018:Morocco; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D017422:Sequence Analysis, DNA; D018631:ras Proteins / Q000235:genetics*
chemical_list: D003062:Codon; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins