摘要：To investigate if K-ras point mutations could occur at an early stage of urethane-induced lung tumorigenesis in mice, we applied a sensitive mutation specific PCR assay technique (MSPA) to DNA from lung at the early stage of this condition. At 7 or 14 d after urethane injection (750 mg/kg, i. p.), pulmonary DNA was isolated and the existence of activated K-ras gene with 61st codon A→T mutation was checked according to the MSPA. This technique can detect mutant alleles in the presence of a very large excess of normal ras alleles ; however, the K-ras point mutation could not be detected by the present MSPA. These results suggest that the K-ras point mutations did not occur at the stage of lung tumorigenesis in mice or that the number of mutant alleles was below the detectable range of the technique.
关键词：K-ras point mutation;lung tumorigenesis;mutant specific PCR assay
