[Detection of point mutations of C-Ki-ras oncogene in colon cancer by PCR using specific oligonucleotide probes]

Activation of C-Ki-ras oncogene by point mutation within codon 12,13 was determined by Polymerase Chain Reaction (PCR) using specific oligonucleotide probes. In 9 of 42 colon cancer specimens point mutations in codon 12 of C-Ki-ras oncogene were found. The point mutations identified were GGT(Gly)----GAT(Asp) (4 cases), GGT (Gly)----TGT (Cys) (3 cases) and GGT(Gly)----GTT(Val) (2 cases), respectively. Two types of point mutations (GGT----GAT, GGT----TGT) were found simultaneously in one specimen. The results showed that there was no relationship between the point mutation of C-Ki-ras oncogene and patient's sex, age, state of metastasis or prognosis.