Correlation between HBV protein preS2 and tumor markers of hepatocellular carcinoma.

BACKGROUND: Alpha-fetoprotein (AFP) and Glypican 3 (GPC3) are both oncogenes and reactivated in hepatocellular carcinoma (HCC). PreS2 has been proved to be an important transactivator in HCC. In this study, we aim to provide evidence that HBV protein preS2 is responsible for AFP and GPC3's reactivation in HCC. METHODS: Totally Sixty-three cases of HCC, aged 34-79, who were surgically treated and pathologically confirmed were enrolled. The levels of AFP in peripheral serum were detected with electrochemical luminescence method before surgery. Levels of GPC3 in HCC samples were evaluated by immunohistochemistry. Luciferase reporter assays were used to measure the effect of preS2 on AFP and GPC3 promoters. RESULTS: AFP level and GPC3 but not albumin were significantly higher in preS2-positive HCC samples than preS2-negative HCC samples. And the preS2 protein expression was positively related with serum AFP level and GPC3 expression. Furtherly, dual luciferase assay showed that preS2 activated AFP and GPC3 promoter activity. CONCLUSION: The expression of preS2 protein relates closely to HCC markers AFP and GPC3.