Evaluation of high-resolution melting analysis as a diagnostic tool to detect the BRAF V600E mutation in colorectal tumors

J Mol Diagn. 2009 Mar;11(2):140-7. doi: 10.2353/jmoldx.2009.080100. Epub 2009 Feb 12.

Abstract

BRAF V600E is the predominantly occurring mutation of the cytoplasmic kinase BRAF, and, in colorectal cancer, its determination provides a diagnostic exclusion criterion for hereditary nonpolyposis colorectal cancer. The aim of our study was to develop a sensitive BRAF V600E high resolution melting (HRM) assay. We first established and optimized the BRAF HRM assay using a cell line dilution model, enabling us to detect 1% mutant DNA in a background of wild-type DNA. In a comparison, DNA sequencing and real-time allele-specific PCR in the cell line dilution model HRM assay proved to be more sensitive than DNA sequencing and denaturing high performance liquid chromatography, retaining the same sensitivity as real-time allele-specific PCR. In a learning set of 13 patients with known BRAF V600 status, the mutation was detected with high concordance by all four methods. Finally, we validated the HRM assay on 60 formalin-fixed, paraffin-embedded colorectal cancer samples. Although all mutated samples were correctly identified by HRM, the detection limit of the HRM assay decreased when using low-quality DNA derived from formalin-fixed, paraffin-embedded samples. In conclusion, HRM analysis is a powerful diagnostic tool for detection of BRAF V600E mutation with a high sensitivity and high-throughput capability. Despite the expected decrease in sensitivity, HRM can reliably be applied in archival formalin-fixed, paraffin-embedded samples tissues.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cell Line, Tumor
  • Colorectal Neoplasms / diagnosis*
  • Colorectal Neoplasms / genetics
  • DNA Mutational Analysis / methods*
  • Formaldehyde / chemistry
  • Humans
  • Middle Aged
  • Molecular Diagnostic Techniques / methods*
  • Proto-Oncogene Proteins B-raf / genetics*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tissue Fixation
  • Transition Temperature

Substances

  • Formaldehyde
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf