Correlation between HBV protein preS2 and tumor markers of hepatocellular carcinoma

Detection of serum large and middle hepatitis B virus surface proteins: A novel potential diagnostic and prognostic biomarker for chronic hepatitis B

BACKGROUND

The significance of large (LHB) and middle (MHB) HBV surface proteins in chronic hepatitis B (CHB) remains uncertain. This study investigates the role of LHB and MHB in different infection phases and liver diseases.

METHODS

Serum samples from 217 patients with HBV chronic infection, CHB, liver cirrhosis (LC), and hepatocellular carcinoma (HCC) were subjected to quantification of LHB and MHB using ELISA.

RESULTS

Positive correlations were observed among LHB, MHB, and LHB/HBsAg, with HBV serum markers including HBsAg, HBeAg, and HBV DNA. (P < 0.0001). In HBeAg-positive chronic infection, LHB and MHB were higher than in HBeAg-positive CHB (P < 0.01). In HBeAg-negative chronic infection, LHB and MHB were lower than in HBeAg-negative CHB (P < 0.01). ROC analysis identified LHB and MHB as potential discriminators of CHB and chronic infection. LC and HCC exhibited lower LHB, MHB, and MHB/HBsAg than CHB (P < 0.05). Multivariate analysis found that age and the MHB/HBsAg serve as independent factors for the progression of CHB to end stage of liver disease.

CONCLUSIONS

LHB and MHB emerge as novel biomarkers distinguishing chronic infection and CHB. MHB/HBsAg shows promise as a predictor for CHB progression.

Pathogenicity and virulence of Hepatitis B virus

Hepatitis B virus (HBV) is a hepatotropic virus and an important human pathogen. There are an estimated 296 million people in the world that are chronically infected by this virus, and many of them will develop severe liver diseases including hepatitis, cirrhosis and hepatocellular carcinoma (HCC). HBV is a small DNA virus that replicates via the reverse transcription pathway. In this review, we summarize the molecular pathways that govern the replication of HBV and its interactions with host cells. We also discuss viral and non-viral factors that are associated with HBV-induced carcinogenesis and pathogenesis, as well as the role of host immune responses in HBV persistence and liver pathogenesis.

An Increase in the Levels of Middle Surface Antigen Characterizes Patients Developing HBV-Driven Liver Cancer Despite Prolonged Virological Suppression

Hepatitis B virus (HBV) contains three surface glycoproteins-Large-HBs (L-HBs), Middle-HBs (M-HBs), and Small-HBs (S-HBs), known to contribute to HBV-driven pro-oncogenic properties. Here, we examined the kinetics of HBs-isoforms in virologically-suppressed patients who developed or did not develop hepatocellular carcinoma (HCC). This study enrolled 30 chronically HBV-infected cirrhotic patients under fully-suppressive anti-HBV treatment. Among them, 13 patients developed HCC. Serum samples were collected at enrolment (T0) and at HCC diagnosis or at the last control for non-HCC patients (median (range) follow-up: 38 (12-48) months). Ad-hoc ELISAs were designed to quantify L-HBs, M-HBs and S-HBs (Beacle). At T0, median (IQR) levels of S-HBs, M-HBs and L-HBs were 3140 (457-6995), 220 (31-433) and 0.2 (0-1.7) ng/mL. No significant differences in the fraction of the three HBs-isoforms were noticed between patients who developed or did not develop HCC at T0. On treatment, S-HBs showed a >25% decline or remained stable in a similar proportion of HCC and non-HCC patients (58.3% of HCC- vs. 47.1% of non-HCC patients, p = 0.6; 25% of HCC vs. 29.4% of non-HCC, p = 0.8, respectively). Conversely, M-HBs showed a >25% increase in a higher proportion of HCC compared to non-HCC patients (50% vs. 11.8%, p = 0.02), in line with M-HBs pro-oncogenic role reported in in vitro studies. No difference in L-HBs kinetics was observed in HCC and non-HCC patients. In conclusion, an increase in M-HBs levels characterizes a significant fraction of HCC-patients while under prolonged HBV suppression and stable/reduced total-HBs. The role of M-HBs kinetics in identifying patients at higher HCC risk deserves further investigation.

Hepatitis B Virus preS2 Domain Promotes Angiogenesis in Hepatocellular Carcinoma via Transcriptional Activation of VEGFA Promoter

: Angiogenesis is closely related to the development and progression of hepatocellular carcinoma (HCC). Angiogenic factors have been confirmed to be overexpressed in HCC. The hepatitis B virus preS2 domain is a transactivator that plays an important role in hepatitis B virus (HBV)-related HCC. Here, we aimed to investigate the potential of the preS2 domain in inducing angiogenesis in HCC. A total of 25 cases of pathologically confirmed HCC were screened. The levels of preS2, CD34, and vascular endothelial growth factor A (VEGFA) in HCC samples were evaluated by immunohistochemistry (IHC). The proliferation of vascular endothelial cells was detected by CCK-8. Besides, VEGFA was analyzed by Western blot in HCC cells. The effect of preS2 on the VEGFA promoter was measured by dual-luciferase reporter assays. We found that preS2 domain-positive HCCs had significantly higher microvessel density (MVD) and VEGFA expression than preS2 domain-negative HCCs. Overexpression of preS2 upregulated VEGFA expression in HepG2 and activated vascular endothelial cell proliferation. However, blocking preS2 expression reduced VEGFA expression in HepG2.2.15 and inhibited the proliferation of vascular endothelial cells. In addition, a dual-luciferase assay indicated that the preS2 domain could activate VEGFA promoter activity. In conclusion, we showed that the expression of the preS2 domain promotes angiogenesis by transactivating the VEGFA promoter in HCC.

Hepatitis B virus X protein upregulates alpha-fetoprotein to promote hepatocellular carcinoma by targeting miR-1236 and miR-329

Hepatitis B virus (HBV) infection is the most common cause of hepatocellular carcinoma (HCC) worldwide, wherein the expression of alpha-fetoprotein (AFP) is reactivated to promote tumorgenesis. Hepatitis B virus X protein (HBx) protein encoded by the HBV virus X gene has been considered to be oncogenic and implicated in hepatocarcinogenesis. However, the relationship between HBx and abnormal AFP expression in HCC is yet to be fully understood. To explore the potential regulation of HBx on AFP re-expression in HCC, 97 HCC samples of different etiologies were analyzed, and extremely higher serum AFP levels were found in patients with HBsAg⁺ . Analyses of HBV-related HCC specimens showed that the expression of AFP was negatively correlated with the levels of miR-1236 and miR-329. Further analyses indicated that HBx promotes the expression of AFP by orchestrating the levels of miR-1236 and miR-329 both in vitro and in vivo. Specifically, miR-1236 and miR-329 bind to the potential target sequences in AFP mRNA 3'-untranslated region to suppress its expression. HBx transfection resulted in the significant decrement of these microRNAs and increment of AFP expression. Moreover, AFP promotes the proliferation of hepatoma cells and attenuates the proapoptotic effect of chemotherapy agents. These findings revealed a novel regulatory mechanism of HBx on the abnormal AFP expression in HCC, which may provide a therapeutic approach for combating HBV-related HCC by targeting the regulation of AFP expression.