[Correlation between androgen receptor expression and hepatitis B virus X protein and its clinical significance in hepatocellular carcinoma].

OBJECTIVE

To investigate the expression of androgen receptor (AR) and hepatitis B virus X protein (HBx) in hepatocellular carcinoma (HCC), and analyze the relationship between AR and HBx expressions.

METHODS

Tumor tissues and peritumoral tissues of 83 HBV-associated HCC cases were investigated in this study. Fourteen cases of HBV-negative HCC and 13 cases of hemangioma peritumoral tissues were considered as control. AR and HBx mRNA levels were determined by quantitative fluorescence real-time RT-PCR and their protein levels were assayed by Western blot. The expression of AR and HBx proteins in tissues were examined with EnVision immunohistochemical staining. The methylation status of AR promoter was determined using methylation-specific PCR (MSP).

RESULTS

Both expression levels of AR mRNA and protein of the peritumoral tissues were significantly higher (0.17) than that of tumor tissues (0.09) in HBV-associated HCC (P < 0.01), but such a difference was not found in HBV-negative HCC (0.06 vs. 0.07, P > 0.05). The level of AR expression in peritumoral tissues was associated with tumor differentiation in HBV-associated HCC. AR mRNA and protein levels of peritumoral tissues in HBV-associated HCC were significantly higher than that in HBV-negative HCC and hemangioma (all P < 0.05). In the tumor tissues, HBV-associated HCC had significantly higher AR expression than HBV-negative HCC at mRNA level (P < 0.05), but not at protein level. Spearman rank correlation analysis showed that the AR mRNA or AR protein levels were positively correlated with HBx in both tumor and peritumoral tissues in HBV-associated HCC, but the expressions of AR and HBx were not associated with AR promoter methylation status. The relative expression levels of AR mRNA and protein in the HBV-associated peritumoral tissues were negatively correlated with tumor differentiation (r = -0.213, P < 0.05; r = -0.313, P < 0.05), the higher the AR expression, the poorer differentiation. But this correlation of AR mRNA and protein was not shown in the hepatocellular carcinoma tissues.

CONCLUSIONS

HBx may enhance AR expression in HBV-associated HCC, but AR promoter demethylation maybe not been involved in its main mechanism. An increased AR expression is probably an early event during the development and progression of HBV-associated HCC, and AR expression in the peritumoral tissue is correlated with HBV-associated HCC differentiation. AR may play different roles in HBV-associated HCC and HBV-negative HCC.