No incidence of BRAF mutations in salivary gland carcinomas--implications for anti-EGFR therapies

J Biomed Biotechnol. 2009:2009:501736. doi: 10.1155/2009/501736. Epub 2009 Jun 17.

Abstract

BRAF is the main effector of KRAS in the RAS-RAF-MAPK axis, a signaling pathway downstream of EGFR. The activation of this cascade is an important pathway in cancer development and is considered a key pathway for therapeutic molecules. Recent studies in metastatic colorectal cancer found that an oncogenic activation of BRAF by a point mutation in exon 15 (V600E) could bypass the EGFR-initiated signaling cascade with the effect that patients bearing the mutant BRAF allele are not likely to benefit from EGFR-targeted therapies. We designed an allele-specific PCR and screened 65 salivary gland carcinoma (SGC) of the main histopathological types for the BRAF V600E mutation. All 65 SGC in this cohort (100%) presented the BRAF wildtype. In a previous study, we found a KRAS wildtype in 98.5% of SGC. These findings imply that SGC rarely acquires mutations that result in a constitutive activation of the signaling cascade downstream of EGFR and this pleads in favor of further therapeutic trials with EGFR-targeting monoclonal antibodies.

MeSH terms

  • Alleles
  • DNA Mutational Analysis
  • ErbB Receptors / antagonists & inhibitors
  • Female
  • Humans
  • Male
  • Middle Aged
  • Point Mutation
  • Polymerase Chain Reaction
  • Proto-Oncogene Proteins B-raf / genetics*
  • Proto-Oncogene Proteins B-raf / metabolism
  • Salivary Gland Neoplasms / drug therapy
  • Salivary Gland Neoplasms / enzymology
  • Salivary Gland Neoplasms / genetics*
  • Signal Transduction

Substances

  • EGFR protein, human
  • ErbB Receptors
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf