Expression of aspartyl beta-hydroxylase and its clinicopathological significance in hepatocellular carcinoma

The human aspartyl beta-hydroxylase is a highly conserved enzyme that hydroxylates epidermal growth factorlike domains in transformation-associated proteins. The aspartyl beta-hydroxylase gene is upregulated in many human malignancies. The purpose of this study was to investigate the expression of aspartyl beta-hydroxylase in hepatocellular carcinoma. Aspartyl beta-hydroxylase mRNA levels were measured in 161 hepatocellular carcinomas and paired nontumorous liver tissues by conventional and real-time RT-PCR. Immunohistochemical staining of aspartyl beta-hydroxylase was performed using EnVision Plus system. The results showed that aspartyl beta-hydroxylase was overexpressed in 150 of 161 hepatocellular carcinomas （93 %）, including 45 of 48 unifocal small hepatocellular carcinomas （94 % ）. Aspartyl beta-hydroxylase was highly expressed in hepatocellular carcinoma cells in contrast to its low level of expression in non-neoplastic liver cells. The protein expression level of aspartyl heta-hydroxylase in the hepatocellular carcinoma was parallel with the mRNA expression level （r=0. 659 4, P〈 0. 000 1）. A significantly higher tumor aspartyl beta-hydroxylase overexpression level was associated with the presence of intrahepatic metastasis and the progression of histological grades.

Expression of aspartyl beta-hydroxylase and its clinicopathological significance in hepatocellular carcinoma