Expression of β-catenin Protein in Hepatocellular Carcinoma and Its Relationship with Alpha-fetoprotein

This study aimed to investigate the expression of beta-catenin in hepatocellular carcinoma (HCC) tissues and its relationship with alpha-fetoprotein (AFP) in HCC. Immunohistochemistry was used to determine the expression of beta-catenin in normal liver tissues (n=10), liver cirrhosis tissues (n=20), and primary HCC tissues (n=60). The relationship between beta-catenin expression and clinical parameters of HCC was investigated. Real-time PCR and Western blotting were used to detect the mRNA and protein expression levels of beta-catenin in the liver cancer cell line SMMC-7721 transfected with a plasmid encoding AFP, and also the mRNA and protein expression levels of beta-catenin were measured in the liver cancer cell line Huh7 before and after the transfection with AFP shRNA plasmids. The results showed that beta-catenin was only expressed on the cell membrane in normal liver tissues. Its localization to the cytoplasm and nucleus of cells was observed in a small proportion of cirrhotic tissues or adjacent HCC tissues, and such ectopic expression of beta-catenin was predominant in HCC tissues. The abnormal expression of beta-catenin was correlated with serum AFP levels, cancer cell differentiation and vascular invasion (P<0.05). Additionally, the increased expression of AFP resulted in the upregulation of beta-catenin mRNA and protein levels, while knockdown of AFP with AFP shRNA led to significantly decreased beta-catenin mRNA and protein levels (P<0.05). It was suggested that the abnormal expression of beta-catenin is implicated in hepatic carcinogenesis and development. AFP can lead to increased expression of beta-catenin, which may account for the poor prognosis of AFP-associated HCC patients.