Anti-HBV drugs suppress the growth of HBV-related hepatoma cells via down-regulation of hepatitis B virus X protein

Association of hepatitis B virus DNA levels with overall survival for advanced hepatitis B virus-related hepatocellular carcinoma under immune checkpoint inhibitor therapy

BACKGROUND

High hepatitis B virus (HBV) DNA level is an independent risk factor for postoperative HBV-associated liver cancer recurrence. We sought to examine whether HBV DNA level and antiviral therapy are associated with survival outcomes in patients with advanced hepatocellular carcinoma (HCC) treated with anti-programmed cell death protein 1 (PD-1)based immunotherapy.

METHODS

This single-institution retrospective analysis included 217 patients with advanced HBV-related HCC treated from 1 June 2018, through 30 December 2020. Baseline information was compared between patients with low and high HBV DNA levels. Overall survival (OS) and progression-free survival (PFS) were compared, and univariate and multivariate analyses were applied to identify potential risk factors for oncologic outcomes.

RESULTS

The 217 patients included in the analysis had a median survival time of 20.6 months. Of these HBV-associated HCC patients, 165 had known baseline HBV DNA levels. Baseline HBV DNA level was not significantly associated with OS (P = 0.59) or PFS (P = 0.098). Compared to patients who did not receive antiviral therapy, patients who received antiviral therapy had significantly better OS (20.6 vs 11.1 months, P = 0.020), regardless of HBV DNA levels. Moreover, antiviral status (adjusted HR = 0.24, 95% CI 0.094-0.63, P = 0.004) was an independent protective factor for OS in a multivariate analysis of patients with HBV-related HCC.

CONCLUSIONS

HBV viral load does not compromise the clinical outcome of patients with HBV-related HCC treated with anti-PD-1-based immunotherapy. The use of antiviral therapy significantly improves survival time of HBV-related HCC patients.

Tyrosine kinase inhibitors as potential sensitizers of adoptive T cell therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a high-incidence malignant tumor worldwide and lacks effective treatment options. Targeted drugs are the preferred recommendations for the systemic treatment of hepatocellular carcinoma. Immunotherapy is a breakthrough in the systemic treatment of malignant tumors, including HCC. However, either targeted therapy or immunotherapy alone is inefficient and has limited survival benefits on part of HCC patients. Investigations have proved that tyrosine kinase inhibitors (TKIs) have regulatory effects on the tumor microenvironment and immune response, which are potential sensitizers for immunotherapy. Herein, a combination therapy using TKIs and immunotherapy has been explored and demonstrated to improve the effectiveness of treatment. As an effective immunotherapy, adoptive T cell therapy in solid tumors is required to improve tumor infiltration and killing activity which can be possibly achieved by combination with TKIs.

Development of a nomogram to predict the risk of hepatocellular carcinoma in patients with hepatitis B-related cirrhosis on antivirals

Objective

Patients with compensated hepatitis B-related cirrhosis receiving antivirals are at the risk of hepatocellular carcinoma (HCC). This study aimed to develop and validate a nomogram for predicting the incidence of HCC in patients with hepatitis-B related cirrhosis.

Design

A total of 632 patients with compensated hepatitis-B related cirrhosis treated with entecavir or tenofovir between August 2010 and July 2018 were enrolled. Cox regression analysis was used to identify independent risk factors for HCC and a nomogram was developed using these factors. The area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analyses were used to evaluate the nomogram performance. The results were validated in an external cohort (n = 324).

Results

In the multivariate analysis, age per 10 years, neutrophil-lymphocyte ratio > 1.6, and platelet count < 86×10⁹/L were independent predictors of HCC occurrence. A nomogram was developed to predict HCC risk using these three factors (ranging from 0 to 20). The nomogram showed better performance (AUC: 0.83) than that of the established models (all P < 0.05). The 3-year cumulative HCC incidences in the low- (scores < 4), medium- (4-10), and high-risk (> 10) subgroups were 0.7%, 4.3%, and 17.7%, respectively, in the derivation cohort, and 1.2%, 3.9%, and 17.8%, respectively, in the validation cohort.

Conclusion

The nomogram showed good discrimination and calibration in estimating HCC risk in patients with hepatitis-B related cirrhosis on antivirals. High-risk patients with a score > 10 points require close surveillance.

Direct and indirect effects of IFN-α2b in malignancy treatment: not only an archer but also an arrow

Interferon-α2b (IFN-α2b) is a highly active cytokine that belongs to the interferon-α (IFN-α) family. IFN-α2b has beneficial antiviral, antitumour, antiparasitic and immunomodulatory activities. Direct and indirect antiproliferative effects of IFN-α2b have been found to occur via multiple pathways, mainly the JAK-STAT pathway, in certain cancers. This article reviews mechanistic studies and clinical trials on IFN-α2b. Potential regulators of the function of IFN-α2b were also reviewed, which could be utilized to relieve the poor response to IFN-α2b. IFN-α2b can function not only by enhancing the systematic immune response but also by directly killing tumour cells. Different parts of JAK-STAT pathway activated by IFN-α2b, such as interferon alpha and beta receptors (IFNARs), Janus kinases (JAKs) and IFN‐stimulated gene factor 3 (ISGF3), might serve as potential target for enhancing the pharmacological action of IFN-α2b. Despite some issues that remain to be solved, based on current evidence, IFN-α2b can inhibit disease progression and improve the survival of patients with certain types of malignant tumours. More efforts should be made to address potential adverse effects and complications.

Influence of weight management on the prognosis of steatohepatitis in chronic hepatitis B patients during antiviral treatment

BACKGROUND

Although concomitant nonalcoholic steatohepatitis (NASH) is common in chronic hepatitis B (CHB), the impact of viral factors on NASH and the outcome of CHB patients concomitant with NASH remain unclear. We aimed to investigate the outcomes of NASH in CHB patients receiving antiviral treatment.

METHODS

In the post-hoc analysis of a multicenter trial, naïve CHB patients receiving 72-week entecavir treatment were enrolled. We evaluated the biochemical, viral and histopathological responses of these patients. The histopathological features of NASH were also evaluated, using paired liver biopsies at baseline and week 72.

RESULTS

A total of 1000 CHB patients were finally enrolled for analysis, with 18.2% of whom fulfilling the criteria of NASH. A total of 727 patients completed entecavir antiviral treatment and received the second biopsy. Serum HBeAg loss, HBeAg seroconversion and HBV-DNA undetectable rates were similar between patients with or without NASH (P > 0.05). Among patients with NASH, the hepatic steatosis, ballooning, lobular inflammation scores and fibrosis stages all improved during follow-up (all P < 0.001), 46% (63/136) achieved NASH resolution. Patients with baseline body mass index (BMI) ≥ 23 kg/m² (Asian criteria) [odds ratio (OR): 0.414; 95% confidence interval (95% CI): 0.190-0.899; P = 0.012] and weight gain (OR: 0.187; 95% CI: 0.050-0.693; P = 0.026) were less likely to have NASH resolution. Among patients without NASH at baseline, 22 (3.7%) developed NASH. Baseline BMI ≥ 23 kg/m² (OR: 12.506; 95% CI: 2.813-55.606; P = 0.001) and weight gain (OR: 5.126; 95% CI: 1.674-15.694; P = 0.005) were predictors of incident NASH.

CONCLUSIONS

Lower BMI and weight reduction but not virologic factors determine NASH resolution in CHB. The value of weight management in CHB patients during antiviral treatment deserves further evaluation.

Prevention of Vertical Transmission of Hepatitis B Within a North Carolina Hospital System

PURPOSE

Hepatitis B virus (HBV) is a major contributor to liver-related disease globally. Vertical transmission of hepatitis B can lead to devastating outcomes in neonates, making prevention of transmission essential. Fortunately, prevention is possible with evidence-based interventions via guidelines from the American Association for the Study of Liver Diseases (AASLD). The purpose of this study was to assess compliance with AASLD guidelines at a tertiary referral hospital in North Carolina, and to suggest future quality improvement initiatives to improve care for this population.

METHODS

We performed a retrospective chart review, including data from all HBV-positive birthing persons at the tertiary referral hospital from April 1, 2014 through December 31, 2019. Data was then compared to AASLD guidelines.

FINDINGS

We identified 99 birthing persons who were hepatitis B positive at time of birth. Of the 99 birthing person/neonate dyads, nearly all infants received appropriate and timely HBV birth dose vaccination and HBIG administration. Risk status of HBV-infected birthing persons was completed in only 58% of this population. Of the individuals who were found to be high risk for vertical transmission of HBV, 75% received antiviral prophylaxis.

IMPLICATIONS

This study provides a current assessment of prevention practices in vertical transmission of HBV compared to published guidelines. The tertiary hospital studied generally implemented AASLD recommendations for prevention of vertical transmission. However, our data revealed that appropriate risk status testing could be improved. With improvement in risk status testing, antiviral prophylaxis can be provided, decreasing the likelihood of breakthrough HBV vertical transmission. Follow-up for HBV-infected birthing persons and HBV-exposed neonates is also a priority. Achieving full compliance with AASLD guidelines to prevent vertical transmission of HBV is possible, and we provide structure for quality improvement initiatives that aim to accomplish this.

Chronic hepatitis B infection with concomitant hepatic steatosis: Current evidence and opinion

With the increasing incidence of obesity and metabolic syndrome worldwide, concomitant nonalcoholic fatty liver disease (NAFLD) in patients with chronic hepatitis B (CHB) has become highly prevalent. The risk of dual etiologies, outcome, and mechanism of CHB with concomitant NAFLD have not been fully characterized. In this review, we assessed the overlapping prevalence of metabolic disorders and CHB, assessed the risk of advanced fibrosis/hepatocellular carcinoma in CHB patients concomitant with NAFLD, and discussed the remaining clinical issues to be addressed in the outcome of such patients. We also explored the possible roles of hepatitis B virus in the development of steatosis and discussed difficultiesof histological evaluation. For CHB patients, it is important to address concomitant NAFLD through lifestyle management and disease screening to achieve better prognoses. The assessment of progressive changes and novel therapies for CHB patients concomitant with NAFLD deserve further research.

NEDD4 Induces K48-Linked Degradative Ubiquitination of Hepatitis B Virus X Protein and Inhibits HBV-Associated HCC Progression

Neural precursor cell expressed developmentally downregulated gene 4 (NEDD4) plays two opposite roles in carcinogenesis. It has been reported that NEDD4 inhibits hepatocellular carcinoma (HCC) progression; however, little is known about its potential function and molecular mechanism in HCC in the context of hepatitis B virus (HBV) infection. In this study, we analyzed NEDD4 expression in 199 HCC specimens with or without HBV infection and observed that NEDD4 expression was unrelated to HBV exposure in HCC tumor tissue but that high NEDD4 expression conferred better overall survival (OS) and progression-free survival (PFS) than low NEDD4 expression in patients with HBV-associated HCC. Upregulation of NEDD4 inhibited proliferation, migration and invasion in HBV-related HCC cell lines. We demonstrated that NEDD4 interacts with HBV X protein (HBx) and that HBx upregulation could reverse the suppression of proliferation and mobility induced by NEDD4 overexpression. Furthermore, we confirmed that NEDD4 induced the degradation of HBx in a ubiquitin/proteasome-dependent manner via K48-linked ubiquitination. Our findings suggest that NEDD4 exerts a tumor-suppressive effect in HBV-associated HCC by acting as an E3 ubiquitin ligase for HBx degradation and provide new insights into the function of NEDD4.

Quantification and epigenetic evaluation of the residual pool of hepatitis B covalently closed circular DNA in long-term nucleoside analogue-treated patients

Hepatitis B virus (HBV) covalently closed circular (ccc)DNA is the key genomic form responsible for viral persistence and virological relapse after treatment withdrawal. The assessment of residual intrahepatic cccDNA levels and activity after long-term nucleos(t)ide analogues therapy still represents a technical challenge. Quantitative (q)PCR, rolling circle amplification (RCA) and droplet digital (dd)PCR assays were used to quantify residual intrahepatic cccDNA in liver biopsies from 56 chronically HBV infected patients after 3 to 5 years of telbivudine treatment. Activity of residual cccDNA was evaluated by quantifying 3.5 kB HBV RNA (preC/pgRNA) and by assessing cccDNA-associated histone tails post-transcriptional modifications (PTMs) by micro-chromatin immunoprecipitation. Long-term telbivudine treatment resulted in serum HBV DNA suppression, with most of the patients reaching undetectable levels. Despite 38 out of 56 patients had undetectable cccDNA when assessed by qPCR, RCA and ddPCR assays detected cccDNA in all-but-one negative samples. Low preC/pgRNA level in telbivudine-treated samples was associated with enrichment for cccDNA histone PTMs related to repressed transcription. No difference in cccDNA levels was found according to serum viral markers evolution. This panel of cccDNA evaluation techniques should provide an added value for the new proof-of-concept clinical trials aiming at a functional cure of chronic hepatitis B.

IFN-α2b inhibits the ethanol enriched-HBV cccDNA through blocking a positive feedback loop of HBx/MSL2/cccDNA/HBV/HBx in liver

Hepatitis B virus (HBV) is a major risk factor for liver diseases, in which HBV covalently closed circular DNA (cccDNA), as the genomic form that templates viral transcription, plays crucial roles in sustaining viral persistence. Clinically, the excessive ethanol intake accelerates the progression of liver diseases with HBV infection. Here, we supposed that ethanol might trigger HBV cccDNA in the liver. Interestingly, we observed that the ethanol remarkably elevated the levels of HBeAg, HBsAg, HBV DNA and cccDNA in HBV-expressing hepatoma cells. Mechanically, the ethanol increased the levels of HBx and MSL2 in vivo and in HBV-expressing HepG2 cells, but not in HBV-free HepG2 cells. Moreover, the down-regulation of MSL2 by small interference RNA could block the ethanol-promoted HBV cccDNA in HepG2.2.15 cells. As a commonly administered treatment for HBV, the effect of IFNα on ethanol-triggered HBV cccDNA remains poorly understood. Strikingly, we showed that the treatment with IFN-α2b inhibited the ethanol-promoted cccDNA through depressing MSL2 in the cells. Thus, we conclude that IFN-α2b inhibits the ethanol-enriched HBV cccDNA through blocking a positive feedback loop of HBx/MSL2/cccDNA/HBV/HBx. Our finding provides new insights into the mechanism by which IFN-α2b inhibits ethanol-enhanced HBV cccDNA. Therapeutically, IFNα may contribute to the cccDNA induced by ethanol in liver.

APEX1 is a novel diagnostic and prognostic biomarker for hepatocellular carcinoma

In this study, we analyzed the expression and clinical significance of apyrimidinic endodeoxyribonuclease 1 (APEX1) in hepatocellular carcinoma (HCC). The APEX1 mRNA and protein levels were significantly higher in HCC than adjacent normal liver tissues in multiple datasets from the Oncomine, GEO and TCGA databases. APEX1 levels were significantly higher in early-stage HCC patients with low alpha-fetoprotein expression. The positive predictive value (PPV) for APEX1 was significantly higher than the PPV for alpha-fetoprotein (67.91% vs. 55.22%) in HCC patients. High APEX1 expression correlated with resistance to sorafenib and anti-programmed death 1 (PD-1) therapies in HCC patients, and it associated with poorer overall survival, disease-specific survival, progression-free survival, and relapse-free survival in early- and advanced-stage HCC patients. High APEX1 expression also associated with poor prognosis in non-alcoholic, vascular invasion-negative, and hepatitis virus-negative HCC patients. These data suggest that APEX1 is a better diagnostic and prognostic biomarker than alpha-fetoprotein in HCC. Gene set enrichment analysis (GSEA) showed that APEX1 expression correlated with the DNA damage repair pathway in HCC tissues. These findings demonstrate that APEX1 is a potential diagnostic and prognostic biomarker in HCC.

Synthesis, pharmacological evaluation, and mechanistic study of adefovir mixed phosphonate derivatives bearing cholic acid and l-amino acid moieties for the treatment of HBV

The deficiency of nucleos(t)ide analogues (NAs) as anti-hepatitis B virus (HBV) drugs in clinical use is attributable to their insufficient enrichment in liver and non-target organ toxicity. We aimed to develop potent anti-HBV adefovir derivatives with hepatotrophic properties and reduced nephrotoxicity. A series of adefovir mono l-amino acids, mono cholic acid-drug conjugates were designed and synthesized, and their antiviral activity and uptake in rat primary hepatocytes and Na⁺-dependent taurocholate co-transporting polypeptide (NTCP)-HEK293 cells were evaluated. We isolated compound 6c as the optimal molecular candidate, with the highest antiviral activity (EC₅₀ 0.42 μmol/L, SI 1063.07) and highest cellular uptake in primary hepatocytes and NTCP-HEK293 cells. In-depth mechanistic studies demonstrated that 6c exhibited a lower toxicity in HK-2 cells when compared to adefovir dipivoxil (ADV). This is because 6c cannot be transported by the human renal organic anion transporter 1 (hOAT1). Furthermore, pharmacokinetic characterization and tissue distribution of 6c indicates it has favorable druggability and pharmacokinetic properties. Further docking studies suggested compounds with ursodeoxycholic acid and l-amino acid groups are better at binding to NTCP due to their hydrophilic properties, indicating that 6c is a potential candidate as an anti-HBV therapy and therefore merits further investigation.

LncRNA PCNAP1 modulates hepatitis B virus replication and enhances tumor growth of liver cancer

Rationale: Hepatitis B virus (HBV) is a major risk factor for liver cancer, in which HBV covalently closed circular DNA (cccDNA) plays crucial roles. However, the effect of pseudogene-derived long noncoding RNAs (lncRNAs) acting as functional regulators of their ancestral gene expression on HBV replication and hepatocellular carcinoma (HCC) remains unclear. In this study, we speculated that the pseudogene-derived lncRNA PCNAP1 and its ancestor PCNA might modulate HBV replication and promote hepatocarcinogenesis.

Methods: We investigated the roles of lncRNA PCNAP1 in contribution of HBV replication through modulating miR-154/PCNA/HBV cccDNA signaling in hepatocarcinogenesis by using CRISPR/Cas9, Southern blot analysis, confocal assays, et al. in primary human hepatocytes (PHH), HepaRG cells, HepG2-NTCP cells, hepatoma carcinoma cells, human liver-chimeric mice model, transgenetic mice model, in vitro tumorigenicity and clinical patients.

Results: Interestingly, the expression levels of PCNAP1 and PCNA were significantly elevated in the liver of HBV-infectious human liver-chimeric mice. Clinically, the mRNA levels of PCNAP1 and PCNA were increased in the liver of HBV-positive/HBV cccDNA-positive HCC patients. Mechanistically, PCNA interacted with HBV cccDNA in a HBc-dependent manner. PCNAP1 enhanced PCNA through sponging miR-154 targeting PCNA mRNA 3′UTR. Functionally, PCNAP1 or PCNA remarkably enhanced HBV replication and accelerated the growth of HCC in vitro and in vivo.

Conclusion: We conclude that lncRNA PCNAP1 enhances the HBV replication through modulating miR-154/PCNA/HBV cccDNA signaling and the PCNAP1/PCNA signaling drives the hepatocarcinogenesis. Our finding provides new insights into the mechanism by which lncRNA PCNAP1 enhances HBV replication and hepatocarcinogenesis.

Long non-coding RNA HULC activates HBV by modulating HBx/STAT3/miR-539/APOBEC3B signaling in HBV-related hepatocellular carcinoma

Long noncoding RNA HULC is identified and highly expressed in hepatocellular carcinoma (HCC). Hepatitis B virus (HBV) is a key driver of liver cancer. In the present study, we found that HULC remarkably elevated the levels of HBeAg, HBsAg, HBcAg, pgRNA, HBx, HBV DNA and covalently closed circular DNA (cccDNA), which activated the HBV replication in HBV-expressing hepatoma cells or de novo HBV-infected cell lines (PHH, HepG2-NTCP and dHepaRG). Mechanistically, HULC enhanced HBV cccDNA stability by down-regulating the APOBEC3B in hepatoma cells. HULC significantly up-regulated microRNA-539, which targeted the 3'UTR of APOBEC3B mRNA. Luciferase reporter gene assays revealed a putative STAT3-binding site located in the upstream of miR-539 promoter. Moreover, we identified that HULC was able to elevate HBx, which co-activated the STAT3 to stimulate the miR-539 promoter. Then, miR-539 down-regulated APOBEC3B and promoted HBV replication. Functionally, HULC enhanced the growth of hepatoma cells by activating HBV in vitro and in vivo, which could be blocked by overexpressing APOBEC3B. In conclusion, HULC activates HBV by modulating HBx/STAT3/miR-539/APOBEC3B signaling in HBV-related HCC.

When Hepatitis B Virus Meets Interferons

Chronic hepatitis B virus (HBV) infection imposes a severe burden on global public health. Currently, there are no curative therapies for millions of chronic HBV-infected patients (Lok et al., 2017). Interferon (IFN; including pegylated IFN) is an approved anti-HBV drug that not only exerts direct antiviral activity, but also augments immunity against HBV infection. Through a systematic review of the literature, here we summarize and present recent progress in research regarding the interactions between IFN and HBV as well as dissect the antiviral mechanisms of IFN. We focus on inhibition of HBV replication by IFN-stimulated genes (ISGs) as well as inhibition of IFN signaling by HBV and viral proteins. Finally, we briefly discuss current IFN-based HBV treatment strategies. This review may help to better understand the mechanisms involved in the therapeutic action of IFN as well as the crosstalk between IFN and HBV, and facilitate the development of both direct-acting and immunology-based new HBV drugs.

Tripartite Motif Containing 52 (TRIM52) Promotes Cell Proliferation in Hepatitis B Virus-Associated Hepatocellular Carcinoma

Background

Chronic hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC). HBV X protein (HBx) plays a crucial role in the development of HCC. Moreover, many tripartite motif (TRIM) family proteins exert diverse biological functions in hepatocarcinogenesis. However, as a novel member of this family, the specific effect of TRIM52 is still largely obscure. In the present study, we investigated the expression and function of TRIM52 in HBV-associated HCC.

Material/Methods

Fluorescence quantitative polymerase chain reaction (FQ-PCR) was performed to detect the HBV DNA levels in the peripheral blood of HCC patients. Quantitative real-time PCR (qRT-PCR) and Western blot analysis were performed to detect the expression of TRIM52, HBx, and NF-κB p65. HBx-pcDNA3.1 and TRIM52-shRNA were used to induce HBx ectopic expression and TRIM52 silencing, respectively. Pyrrolidine dithiocarbamate (PDTC) was used to block the activation of NF-κB. Cell proliferation was detected using the Cell Counting Kit-8 (CCK-8) assay.

Results

TRIM52 expression was up-regulated together with HBx in HBV-associated HCC tissues. Ectopic expression of HBx elevated TRIM52 expression in HepG2 cells. TRIM52 silencing repressed the proliferation of HepG2.2.15 cells. Moreover, NF-κB p65 expression was increased in HCC cell lines. Blocking NF-κB activation with PDTC suppressed TRIM52 expression and attenuated the viability of HepG2.2.15 cells.

Conclusions

These findings indicate that TRIM52 can promote cell proliferation and HBx may regulate TRIM52 expression via the NF-κB signaling pathway in HBV-associated HCC.