The effect of occult HBV infection on carcinogenesis of cryptogenic hepatocellular carcinoma

Objective To investigate the effect of occult HBV infection (OBI) on carcinogenesis of cryptogenic hepatocellular carcinoma. Methods Samples of hepatocellular carcinoma (HCC) and pericarcinomatous tissues obtained after hepatectomy from January 2011 to November 2013 at the Third Affiliated Hospital of Sun Yat-Sen University were collected. They were divided into two groups: the cryptogenic HCC group (the CH group, n=26) and the HBV related HCC group (the HH group, n=40). These samples were compared with the normal liver tissues obtained in 30 patients. HBV DNA was identified by the nested polymerase chain reaction and the immunohistochemical method was taken to examine the hepatitis B virus X protein (HBx) and Yes-associated protein (YAP) expressions. Results OBI was identified in 20 (77.8%) cryptogenic HCC patients and 8 (26.7%) in the control group. There was a significant difference between the two groups (χ2=14.072, P 0.05), but the YAP expression in the tumor tissues was significantly higher than that in the nontumorous tissues (P 0.05). However, their expressions in the cancerous tissue of the HH group and the CH group were significantly higher than in the normal liver tissues (P<0.05). Conclusion A high prevalence of HBV infection was observed in HBsAg-negative HCC and the high expressions of HBx and YAP might be involved in the process of cryptogenic hepatocellular carcinoma. Key words: Hepatocellular carcinoma, cryptogenic; Occult infection; Hepatitis B virus; Hepatitis B virus X protein; Yes-associated protein (YAP)