title: K-ras point mutation detection in lung cancer: comparison of two approaches to somatic mutation detection using ARMS allele-specific amplification.
abstract: BACKGROUND
  The use of sensitive molecular techniques to detect rare cells in a population is of increasing interest to the molecular pathologist, but detection limits often are poorly defined in any given molecular assay. We combined the approaches of real-time quantitative PCR with ARMS(TM) allele-specific amplification in a novel assay for detecting mutant K-ras sequences in clinical samples.
  
  
  METHODS
  ARMS reactions were used to detect seven commonly occurring mutations in the K-ras oncogene. These mutations produce amino acid changes in codon 12 (Gly to Ala, Arg, Asp, Cys, Ser, or Val) and codon 13 (Gly to Asp). A control reaction was used to measure the total amount of amplifiable K-ras sequence in a sample so that the ratio of mutant to wild-type sequence could be measured. Quantitative data were confirmed for a selection of samples by an independent cloning and sequencing method. The assay was used to analyze 82 lung tumor DNA samples.
  
  
  RESULTS
  The assay detected K-ras mutations in 44% of adenocarcinomas, which is equivalent to frequencies reported in the literature using ultrasensitive techniques. Forty-six percent of squamous carcinomas were also positive. The ratio of mutant sequence in the tumor DNA samples was 0.04-100%.
  
  
  CONCLUSIONS
  The assay is homogeneous, with addition of tumor DNA sample being the only step before results are generated. The quantitative nature of the assay can potentially be used to define the analytical sensitivity necessary for any specified diagnostic application of K-ras (or other) point mutation detection.
authors: AstraZeneca, Alderley Park, Macclesfield, Cheshire SK10 4TG, United Kingdom. simon.clayton@astrazeneca.com
authors: S J
authors: SJ
authors: Clayton
authors: F M
authors: FM
authors: Scott
authors: J
authors: J
authors: Walker
authors: K
authors: K
authors: Callaghan
authors: K
authors: K
authors: Haque
authors: T
authors: T
authors: Liloglou
authors: G
authors: G
authors: Xinarianos
authors: S
authors: S
authors: Shawcross
authors: P
authors: P
authors: Ceuppens
authors: J K
authors: JK
authors: Field
authors: J C
authors: JC
authors: Fox
mesh_terms: D000483:Alleles; D014408:Biomarkers, Tumor / Q000235:genetics*; D003062:Codon; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques; D017354:Point Mutation; D018631:ras Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D003062:Codon; D018631:ras Proteins