改良的内切酶突变体富集法检测肺癌标本中EGFR基因突变

BACKGROUND AND OBJECTIVE: Epidermal growth factor receptor (EGFR) gene mutation in lung cancer is a reliable predictor of the efficacy of tyrosine kinase inhibitors, so detection of gene mutation has very important clinical significance. The aim of this study is to optimize conditions for restriction enzyme-based mutant enriched detection of EGFR mutation in lung cancer specimens. METHODS: EGFR somatic mutations identified in DNA specimens from 251 lung adenocarcinomas with modified mutant enriched method and direct sequencing were compared. The sensitivity of the modified method was determined by serial dilution of mutant-carrying lung cancer cells in wild-type cells. RESULTS: 46 deletion mutations in exon 19 and 26 point mutations in exon 21 were found by sequencing, while modified method identified another 78 deletions in exon 19 and 57 substitutions in exon 21 with a mutation rate of 53.8%. Sensitivity of this modified method was 0.5% (mutant/wild type) in serial diluted cells. CONCLUSION: The modified restriction enzyme-based method is convenient for clinical EGFR mutation screening in non-small cell lung cancer for its simpleness, cost-saving and high sensitivity.