한국인 대장-직장암에서 Ras 암유전자의 점돌연변이

Abstract

The point mutations of ras oncogene in human tumor have been well documented. These mu¬tations have been exclusively localized to codon 12，13 and 61 of three ras genes(K-, H-，N-ras). We have evaluated the point mutation of c-K-ras and c-Ha-ras codon 12 in Korean colorectal cancers using recently developed PCR(Polymerase Chain Reaction) - RFLP(Restriction Fragment Length Polymorphism) method. The presence of mutations at codon 12 of c-Ha-ras and c-K-ras gene was examined by the en- dogeneous or primer mediated restriction fragment length polymorphism using polymerase chain reaction. Five of 30 colorectal cancers tested contained mutations at codon 12 of c-K-ras gene. On the other hand, no mutations were found at codon 12 of c-Ha-ras gene. The mutations were confirmed by PCR product cloning and nucleic acid sequencing. We think that PCR-RFLP method is accurate and time saving, and can be applied toward the rapid, non-radioactive screening of colorectal cancers. Key Words: Ras, mutation, Colorectal cancer