Mutation profile of EGFR gene detected by denaturing high-performance liquid chromatography in Japanese lung cancer patients.
OBJECTIVE
EGFR mutations in lung cancer increase sensitivity to an EGFR tyrosine kinase inhibitor, gefitinib. Mutation analysis of EGFR is essential for prediction of gefitinib response and avoidance of the coincidental severe side effects for the unresponsive population. The purpose of the present study is to apply DHPLC as a screening system of detection of EGFR mutations for large scaled population.


METHODS
EGFR mutations were detected by both DHPLC procedure and direct sequencing using lung cancer tissue samples obtained from 97 patients (81 surgical specimens and 16 pleural effusions of non-resectable lung cancer patients).


RESULTS
DHPLC analysis detected EGFR mutations in 5 h as opposed to 18 h by direct sequencing for ten samples, and it costs eightfold more expensive by direct sequencing than DHPLC. In addition, DHPLC analysis was sixfold more sensitive than sequencing analysis for detection of the point mutation of exon 21, L858R. Using this system, EGFR mutations in exons 18, 19 and 21 were found in 34 of 97 patients (36%). Thirteen of the 15 patients with exon 21 mutations (87%) were female non-smokers, who were diagnosed with adenocarcinomas with the feature of BAC. Eight of the 18 patients with exon 19 mutations (44%) were 7 male and 1 female current or former smokers, and BAC feature was observed in 61% (8/18).


CONCLUSIONS
DHPLC analysis for screening followed by sequencing analysis appears to be more sensitive and accurate, as well as easier and faster. In addition, these results suggest different mutagenesis and carcinogenesis pathways for mutations.
Sueoka
Naoko
N
Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan. sueokan@cc.saga-u.ac.jp
Sato
Akemi
A
Eguchi
Hidetaka
H
Komiya
Kazutoshi
K
Sakuragi
Toru
T
Mitsuoka
Masahiro
M
Satoh
Toshimi
T
Hayashi
Shinichiro
S
Nakachi
Kei
K
Sueoka
Eisaburo
E
D001483:Base Sequence; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004252:DNA Mutational Analysis / Q000379:methods*; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons; D005260:Female; D006801:Humans; D007564:Japan; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009691:Nucleic Acid Denaturation
D066246:ErbB Receptors