DETECTION OF K-RAS MUTATIONS IN NONSMALL CELL LUNG-CARCINOMA

Forty-five non-small cell lung cancers (NSCLC) were examined for the p resence of K-ras mutations in codon 12 using RFLP (restriction fragmen t length polymorphism) and ARMS (amplification refractory mutation sys tem) assays. The RFLP analysis consisted of a PCR and subsequent diges tion of the product with BstNI. Three adenocarcinomas and one adenosqu amous carcinoma were shown to have mutations at codon 12. All of these samples were also examined using the ARMS assay for mutations at codo n 12 and second base G to A transitions at codon 13 of the K-ras gene. The same four samples were confirmed to have a single base change in codon 12. No G to A transitions were found at codon 13. The four mutat ions were: one G to C transversion, one G to A transition and two G to T transversions. All mutations occurred at the second position of cod on 12 as shown by the ARMS assay. Both of these techniques are rapid a nd reproducible for the identification of mutations in the K-ras gene and have potential for use in cancer diagnosis.