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Background & Aims: Patients with chronic hepatitis B virus (HBV) infection have a high risk for developing hepatocellular carcinoma (HCC). Patients with lower levels of hepatitis B surface antigen (HBsAg) have higher chances of losing HBsAg than those with high levels. However, little is known about whether higher levels of HBsAg increase risk for HCC. Methods: We followed 2688 Taiwanese HBsAg-positive patients without evidence of cirrhosis for a mean time period of 14.7 years. In addition to the known risk factors of HCC, we investigated the association between levels of HBsAg and development of HCC. Results: Of the patients followed, 191 developed HCC, with an average annual incidence rate of 0.5%. Baseline levels of HBsAg and HBV were associated with development of HCC, and risk increased with level. Compared to HBsAg level, by receiver operating characteristic curve analysis, HBV DNA level better predicted the development of HCC during 10-year and 15-year periods (both, P < .001). However, when we evaluated hepatitis B e antigen−negative patients with levels of HBV DNA <2000 IU/mL, factors that determined HCC risk included sex, age, and levels of alanine aminotransferase and HBsAg (≥1000 IU/mL), but not level of HBV DNA. Multivariate analysis showed that the adjusted hazard ratio for HCC in patients with levels of HBsAg ≥1000 IU/mL versus <1000 IU/mL was 13.7 (95% confidence interval: 4.8−39.3). Conclusions: Among patients infected with HBV genotype B or C, determinants of HCC risk include their sex, age, hepatitis B e antigen status, HBV genotype, and levels of alanine aminotransferase and HBV DNA, but not level of HBsAg. Among hepatitis B e antigen−negative patients with low viral loads, HCC risk is determined by levels of HBsAg and alanine aminotransferase and age, but not HBV DNA. [ABSTRACT FROM AUTHOR]

Background & Aims: This study aimed at investigating mutations in the hepatitis B surface protein (HBsAg) in occult hepatitis B virus (HBV) infection (OBI) and their influence on viral antigenicity and phenotype. Methods: The characteristics of 61 carriers with OBI (OBI group), 153 HBsAg(+) carriers with serum HBsAg ⩽100IU/ml (HBsAg-L group) and 54 carriers with serum HBsAg >100IU/ml (HBsAg-H group) from 38,499 blood donors were investigated. Mutations in the major hydrophilic region (MHR) of the viral sequences were determined. Thirteen representative MHR mutations observed in OBI sequences were antigenically characterized with a panel of monoclonal antibodies (MAbs) and commercial HBsAg immunoassays and functionally characterized in HuH7 cells and hydrodynamically injected mice. Results: Of 61 OBI sequences, 34 (55.7%) harbored MHR mutations, which was significantly higher than the frequency in either the HBsAg-L (34.0%, p =0.003) or the HBsAg-H group (17.1%, p <0.001). Alterations in antigenicity induced by the 13 representative MHR mutations identified in the OBI group were assessed by reacting recombinant HBV mutants with 30 different MAbs targeting various epitopes. Four out of the 13 mutations (C124R, C124Y, K141E, and D144A) strongly decreased the analytical sensitivity of seven commercial HBsAg immunoassays, and 10 (G119R, C124Y, I126S, Q129R, S136P, C139R, T140I, K141E, D144A, and G145R) significantly impaired virion and/or S protein secretion in both HuH7 cells and mice. Conclusions: MHR mutations alter antigenicity and impair virion secretion, both of which may contribute to HBsAg detection failure in individuals with OBI. [Copyright &y& Elsevier]

Background & Aims: Previously we reported that Akt inactivation determines the sensitivity of hepatocellular carcinoma (HCC) cells to bortezomib. Here we report that combined treatment with sorafenib and bortezomib shows synergistic effects in HCC. Methods: HCC cell lines (PLC/PRF/5, Huh-7, and Hep3B) were treated with sorafenib and/or bortezomib and analyzed in terms of apoptosis signal transduction. In vivo efficacy was determined in nude mice with PLC/PRF/5 xenografts. Results: Pretreatment with sorafenib enhanced bortezomib-induced apoptotic cell death by restoring bortezomib’s ability to inactivate Akt in PLC/PRF/5 cells. Knocking down Akt1 by RNA-interference overcame apoptotic resistance to bortezomib in PLC/PRF/5 cells and ectopic expression of active Akt in HCC cells abolished the bortezomib sensitizing effect of sorafenib, indicating Akt inactivation plays a key role in mediating the combinational effects. Moreover, okadaic acid, a protein phosphatase 2A (PP2A) inhibitor, reversed down-regulation of phospho-Akt (P-Akt) expression induced by co-treatment with sorafenib and bortezomib, and 1, 9 di-deoxy-forskolin, a PP2A agonist, restored bortezomib’s effect on P-Akt and apoptosis. Importantly, silencing of PP2A by RNA-interference reduced the apoptotic effect induced by sorafenib–bortezomib co-treatment, indicating that PP2A is indispensable for mediating the effects of these drugs. Notably, sorafenib with bortezomib increased PP2A activity in PLC/PRF/5 cells without altering protein levels of PP2A complex or the interaction between PP2A and Akt proteins. Finally, sorafenib plus bortezomib significantly suppressed PLC/PRF/5 xenograft tumor growth, down-regulated P-Akt expression, and up-regulated PP2A activity. Conclusions: The combination of sorafenib and bortezomib shows synergy in HCC through PP2A-dependent Akt inactivation. [Copyright &y& Elsevier]