Amplification and enhanced expression of cellular oncogene c-Ki-ras-2 in a human epidermoid carcinoma of the lung.

The level of c-Ki-ras-2-specific mRNA was found to be markedly enhanced (10- to 20-fold) in a human epidermoid lung carcinoma transplanted into nude mice, compared with that in other lung carcinomas. Analysis of DNA revealed that c-Ki-ras-2 gene was amplified approximately 10-fold in this carcinoma, while c-Ha-ras, c-myc and c-sis were not amplified. Chromosome abnormalities were also observed in this carcinoma.