Genotyping of K-ras codons 12 and 13 mutations in colorectal cancer by capillary electrophoresis

J Chromatogr A. 2009 Jun 26;1216(26):5147-54. doi: 10.1016/j.chroma.2009.04.083. Epub 2009 May 3.

Abstract

Point mutations of the K-ras gene located in codons 12 and 13 cause poor responses to the anti-epidermal growth factor receptor (anti-EGFR) therapy of colorectal cancer (CRC) patients. Besides, mutations of K-ras gene have also been proven to play an important role in human tumor progression. We established a simple and effective capillary electrophoresis (CE) method for simultaneous point mutation detection in codons 12 and 13 of K-ras gene. We combined one universal fluorescence-based nonhuman-sequence primer and two fragment-oriented primers in one tube, and performed this two-in-one polymerase chain reaction (PCR). PCR fragments included wild type and seven point mutations at codons 12 and 13 of K-ras gene. The amplicons were analyzed by single-strand conformation polymorphism (SSCP)-CE method. The CE analysis was performed by using a 1x Tris-borate-EDTA (TBE) buffer containing 1.5% (w/v) hydroxyethylcellulose (HEC) (MW 250,000) under reverse polarity with 15 degrees C and 30 degrees C. Ninety colorectal cancer patients were blindly genotyped using this developed method. The results showed good agreement with those of DNA sequencing method. The SSCP-CE was feasible for mutation screening of K-ras gene in populations.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Codon*
  • Colorectal Neoplasms / genetics*
  • Electrophoresis, Capillary / methods*
  • Female
  • Genotype
  • Humans
  • Male
  • Middle Aged
  • Point Mutation*
  • ras Proteins / genetics*

Substances

  • Codon
  • ras Proteins