[Detection of K-ras oncogene mutations in human lung cancer by PCR-SSCP-DNA direct sequencing]

K-ras oncogene mutations were detected with PCR-SSCP-DNA direct sequencing technique in 40 cases of lung cancer. The result of PCR-SSCP silver staining indicated that the mutational rate was 30% (12/40), all mutations were observed in lung adenocarcinoma and its mutational rate was 44% (12/27). The result of DNA direct sequencing showed that 11 of the 12 positive samples screened by PCR-SSCP had mutation and 90% of K-ras mutations were in codon 12. The mutation was mainly G-->T transversion and G-->A transition. The study suggested that SSCP silver staining analysis is very useful in screening large amount of samples simultaneously and PCR-SSCP-DNA direct sequencing method is quite efficient for the detection of oncogene mutation.