Immunohistochemical analysis and mutational analyses of β-catenin, Axin family and APC genes in hepatocellular carcinomas

Several lines of evidence show that the development of hepatocellular carcinoma (HCC) requires an accumulation of genetic alterations. However, molecular mechanism in HCC carcinogenesis remains unsolved. A total of 89 HCC samples were analyzed in this study to determine how alterations in the Wnt signaling pathway associate with the carcinogenesis of HCC. beta-catenin immunohistochemistry showed positive nuclear staining in 24 (27.0%) of the 89 HCC samples, indicating the existence of alterations in the Wnt signaling pathway in those 24 HCC samples. Mutations in the beta-catenin, Axin1 and Axin2 genes were detected in 10 (41.7%), 13 (54.2%) and 9 (37.5%) of the 24 beta-catenin-positive samples, respectively, but no mutation was detected in the APC gene. In conclusion, in addition to mutations in the beta-catenin gene, mutations in the Axin1 and Axin2 genes may alter the Writ signaling pathway, resulting in accumulation of beta-catenin.