Up-regulation of human cervical cancer proto-oncogene contributes to hepatitis B virus-induced malignant transformation of hepatocyte by down-regulating E-cadherin

Hepatocellular carcinoma (HCC) is one of the most fatal human malignancies, Human cervical cancer proto-oncogene (HCCR) aberrantly expressed in a number of malignant tumors, including HCC. HCC is associated with Hepatitis B virus (HBV) infection in a large percentage of cases. To explore the regulation and function of HCCR expression in the development of HCC, we detected HCCR expression in HBV expressing hepatocytes. Results showed that the expression of HCCR was higher in HBV-expressing hepatocytes than that in control cells. Examining different components of HBV revealed that the HBx promotes HCCR expression in hepatocytes via the T-cell factor (TCF)/β-catenin pathway. HCCR expression in HBx transgenic mice increased with as the mice aged and developed tumors. We also found that overexpression of HCCR in hepatocytes promoted cell proliferation, migration, and invasion and reduced cell adhesion. Suppressing HCCR expression abolished the effect of HBx-induced hepatocyte growth. In addition, HCCR represses the expression of E-cadherin by inhibition its promoter activity, which might correlate with the effects of HCCR in hepatocytes. Taken together, these results demonstrate that HBx-HCCR-E-cadherin regulation pathway might play an important role in HBV-induced hepatocarcinogenesis. They also imply that HCCR is a potential risk marker for HCC and/or a potential therapeutic target.