Detection of ras gene mutations of primary hepatic malignant tumors by polymerase chain reaction and direct sequencing method

Abstract

Ras genes are converted to active oncogenes by point mutations occuring in either codon 12, 13 or 61. We used ploymerase chain reaction and direct sequence method for the analysis of these mutations. We examined 13 hepatocellular carcinomas, 8 cholangiocarcinomas, 2 hepatoblastomas and 1 biliary cystadenocarcinoma. Of these tumors, ras gene mutations were detected soley in cholangiocarcinomas. Cholangiocarcinoma showed a high incidence of K-ras gene mutation. Among 8 patients with cholangiocarcinoma, the mutation was detected at colon 12 in 4 and at colon 61 in 1. The incidence of K-ras gene mutation was especially high in the hilar type of cholangiocarcinoma as compared with the peripheral type.