Major HBV splice variant encoding a novel protein important for infection.

BACKGROUND & AIMS: HBV expresses more than 10 spliced RNAs from the viral pregenomic RNA, but their functions remain elusive and controversial. To address the function of HBV spliced RNAs, we generated splicing-deficient HBV mutants and conducted experiments to assess the impact of these mutants on HBV infection. METHODS: HepG2-NTCP cells, human hepatocyte chimeric FRG mice (hu-FRG mice), and serum from patients with chronic hepatitis B were used for experiments on HBV infection. Additionally, SHifter assays and cryo-electron microscopy were performed. RESULTS: We found the infectivity of splicing-deficient HBV was decreased 100-1,000-fold compared with that of wild-type HBV in hu-FRG mice. Another mutant, A487C, which loses the most abundant spliced RNA (SP1), also exhibits severely impaired infectivity. SP1 hypothetically encodes a novel protein HBcSP1 (HBc-Cys) that lacks the C-terminal cysteine from full-length HBc. In the SHifter assay, HBcSP1 was detected in wild-type viral particles at a ratio of about 20-100% vs. conventional HBc, as well as in the serum of patients with chronic hepatitis B, but not in A487C particles. When infection was conducted with a shorter incubation time of 4-8 h at lower PEG concentrations in HepG2-NTCP cells, the entry of the A487C mutant was significantly slower. SP1 cDNA complementation of the A487C mutant succeeded in rescuing its infectivity in hu-FRG mice and HepG2-NTCP cells. Moreover, cryo-electron microscopy revealed a disulfide bond between HBc cysteine 183 and 48 in the HBc intradimer of the A487C capsid, leading to a locked conformation that disfavored viral entry in contrast to the wild-type capsid. CONCLUSIONS: Prior studies unveiled the potential integration of the HBc-Cys protein into the HBV capsid. We confirmed the proposal and validated its identity and function during infection. IMPACT AND IMPLICATIONS: HBV SP1 RNA encodes a novel HBc protein (HBcSP1) that lacks the C-terminal cysteine from conventional HBc (HBc-Cys). HBcSP1 was detected in cell culture-derived HBV and confirmed in patients with chronic infection by both immunological and chemical modification assays at 10-50% of capsid. The splicing-deficient mutant HBV (A487C) impaired infectivity in human hepatocyte chimeric mice and viral entry in the HepG2-NTCP cell line. Furthermore, these deficiencies of the splicing-deficient mutant could be rescued by complementation with the SP1-encoded protein HBcSP1. We confirmed and validated the identity and function of HBcSP1 during infection, building on the current model of HBV particles.

HIV coinfection exacerbates HBV-induced liver fibrogenesis through a HIF-1α- and TGF-ß1-dependent pathway.

BACKGROUND & AIMS: Persons with chronic HBV infection coinfected with HIV experience accelerated progression of liver fibrosis compared to those with HBV monoinfection. We aimed to determine whether HIV and its proteins promote HBV-induced liver fibrosis in HIV/HBV-coinfected cell culture models through HIF-1α and TGF-ß1 signaling. METHODS: The HBV-positive supernatant, purified HBV viral particles, HIV-positive supernatant, or HIV viral particles were directly incubated with cell lines or primary hepatocytes, hepatic stellate cells, and macrophages in mono or 3D spheroid coculture models. Cells were incubated with recombinant cytokines and HIV proteins including gp120. HBV sub-genomic constructs were transfected into NTCP-HepG2 cells. We also evaluated the effects of inhibitor of HIF-1α and HIV gp120 in a HBV carrier mouse model that was generated via hydrodynamic injection of the pAAV/HBV1.2 plasmid into the tail vein of wild-type C57BL/6 mice. RESULTS: We found that HIV and HIV gp120, through engagement with CCR5 and CXCR4 coreceptors, activate AKT and ERK signaling and subsequently upregulate hypoxia-inducible factor-1α (HIF-1α) to increase HBV-induced transforming growth factor-ß1 (TGF-ß1) and profibrogenic gene expression in hepatocytes and hepatic stellate cells. HIV gp120 exacerbates HBV X protein-mediated HIF-1α expression and liver fibrogenesis, which can be alleviated by inhibiting HIF-1α. Conversely, TGF-ß1 upregulates HIF-1α expression and HBV-induced liver fibrogenesis through the SMAD signaling pathway. HIF-1α small-interfering RNA transfection or the HIF-1α inhibitor (acriflavine) blocked HIV-, HBV-, and TGF-ß1-induced fibrogenesis. CONCLUSIONS: Our findings suggest that HIV coinfection exacerbates HBV-induced liver fibrogenesis through enhancement of the positive feedback between HIF-1α and TGF-ß1 via CCR5/CXCR4. HIF-1α represents a novel target for antifibrotic therapeutic development in HBV/HIV coinfection. IMPACT AND IMPLICATIONS: HIV coinfection accelerates the progression of liver fibrosis compared to HBV monoinfection, even among patients with successful suppression of viral load, and there is no sufficient treatment for this disease process. In this study, we found that HIV viral particles and specifically HIV gp120 promote HBV-induced hepatic fibrogenesis via enhancement of the positive feedback between HIF-1α and TGF-ß1, which can be ameliorated by inhibition of HIF-1α. These findings suggest that targeting the HIF-1α pathway can reduce liver fibrogenesis in patients with HIV and HBV coinfection.

Serum MYCN as a predictive biomarker of prognosis and therapeutic response in the prevention of hepatocellular carcinoma recurrence.

The proto-oncogene MYCN expression marked a cancer stem-like cell population in hepatocellular carcinoma (HCC) and served as a therapeutic target of acyclic retinoid (ACR), an orally administered vitamin A derivative that has demonstrated promising efficacy and safety in reducing HCC recurrence. This study investigated the role of MYCN as a predictive biomarker for therapeutic response to ACR and prognosis of HCC. MYCN gene expression in HCC was analyzed in the Cancer Genome Atlas and a Taiwanese cohort (N = 118). Serum MYCN protein levels were assessed in healthy controls (N = 15), patients with HCC (N = 116), pre- and post-surgical patients with HCC (N = 20), and a subset of patients from a phase 3 clinical trial of ACR (N = 68, NCT01640808). The results showed increased MYCN gene expression in HCC tumors, which positively correlated with HCC recurrence in non-cirrhotic or single-tumor patients. Serum MYCN protein levels were higher in patients with HCC, decreased after surgical resection of HCC, and were associated with liver functional reserve and fibrosis markers, as well as long-term HCC prognosis (>4 years). Subgroup analysis of a phase 3 clinical trial of ACR identified serum MYCN as the risk factor most strongly associated with HCC recurrence. Patients with HCC with higher serum MYCN levels after a 4-week treatment of ACR exhibited a significantly higher risk of recurrence (hazard ratio 3.27; p = .022). In conclusion, serum MYCN holds promise for biomarker-based precision medicine for the prevention of HCC, long-term prognosis of early-stage HCC, and identification of high-response subgroups for ACR-based treatment.

HBV DNA Integration into Telomerase or MLL4 Genes and TERT Promoter Point Mutation as Three Independent Signatures in Subgrouping HBV-Related HCC with Distinct Features.

Introduction: A set of genetic mutations to classify hepatocellular carcinoma (HCC) useful to clinical studies is an unmet need. Hepatitis B virus-related HCC (HBV-HCC) harbors a unique genetic mutation, namely, the HBV integration, among other somatic endogenous gene mutations. We explored a combination of HBV DNA integrations and common somatic mutations to classify HBV-HCC by using a capture-sequencing platform. Methods: A total of 153 HBV-HCCs after surgical resection were subjected to capture sequencing to identify HBV integrations and three common somatic mutations in genomes. Three mutually exclusive mutations, HBV DNA integration into the TERT promoter, HBV DNA integration into MLL4, or TERT promoter point mutation, were identified in HBV-HCC. Results: They were used to classify HBV-HCCs into four groups: G1 with HBV-TERT integration (25.5%); G2 with HBV-MLL4 integration (10.5%); G3 with TERT promoter mutation (30.1%); and G4 without these three mutations (34.0%). Clinically, G3 has the highest male-to-female ratio, cirrhosis rate, and associated with higher early recurrence and mortality after resection, but G4 has the best outcome. Transcriptomic analysis revealed a grouping different from the published ones and G2 with an active immune profile related to immune checkpoint inhibitor response. Analysis of integrated HBV DNA provided clues for HBV genotype and variants in carcinogenesis of different HCC subgroup. This new classification was also validated in another independent cohort. Conclusion: A simple and robust genetic classification was developed to aid in understanding HBV-HCC and in harmonizing clinical studies.

Codelivery of TGFß and Cox2 siRNA inhibits HCC by promoting T-cell penetration into the tumor and improves response to Immune Checkpoint Inhibitors.

Upregulation of TGFß and Cox2 in the tumor microenvironment results in blockade of T-cell penetration into the tumor. Without access to tumor antigens, the T-cell response will not benefit from administration of the immune checkpoint antibodies. We created an intravenous polypeptide nanoparticle that can deliver two siRNAs (silencing TGFß and Cox2). Systemic administration in mice, bearing a syngeneic orthotopic hepatocellular carcinoma (HCC), delivers the siRNAs to various cells in the liver, and significantly reduces the tumor. At 2 mg/kg (BIW) the nanoparticle demonstrated a single agent action and induced tumor growth inhibition to undetectable levels after five doses. Reducing the siRNAs to 1mg/kg BIW demonstrated greater inhibition in the presence of PD-L1 mAbs. After only three doses BIW, we could still recover a smaller tumor and, in tumor sections, showed an increase in penetration of CD4+ and CD8+ T-cells deeper into the remaining tumor that was not evident in animals treated with non-silencing siRNA. The combination of TGFß and Cox2 siRNA co-administered in a polypeptide nanoparticle can act as a novel therapeutic alone against HCC and may augment the activity of the immune checkpoint antibodies. Silencing TGFß and Cox2 converts an immune excluded (cold) tumor into a T-cell inflamed (hot) tumor.

Serum RNase L levels in patients with chronic hepatitis B virus infection.

BACKGROUND/AIMS: Chronic hepatitis B virus (HBV) infection still poses a major threat to global health. Oligoadenylate synthetase-ribonuclease L (RNase L) antiviral pathway is one of interferon-induced antiviral effectors. The relationship between RNase L and HBV has never been investigated and we aim to examine the serum RNase L levels in patients with different stages of chronic HBV infection. METHODS: The patients were enrolled from 1985 to 2000, who had been HBsAg positive for longer than 6 months, at the National Taiwan University Hospital. In total, 426 patients with chronic HBV infection were included in this study, including 135 inactive carriers, 148 cirrhosis, and 143 hepatocellular carcinoma (HCC) cases. RESULTS: The RNase L levels increase as the disease severity increases. Higher RNase L levels were associated with higher HBV viral load, and the HBV-RNase L relationship was replaced by the disease severity status when adding disease status into the model. Compared with inactive carriers, the risk of liver cirrhosis was 60-fold (odds ratio = 60.8, 95% confidence interval = 3.49-1061) with the highest quintile of RNase L levels, after the adjustment of HBV DNA. The dose-response trend was statistically significant with quintiles and one increment of RNase L level in relation to liver cirrhosis. Similar results were found when HCC was compared with inactive carriers, while there was no association when compared between liver cirrhosis and HCC. CONCLUSIONS: A positive relationship between serum RNase L and HBV viral titers or advanced disease status is uncovered in this study. Further investigation in this area may provide more details of an innate immune response for HBV and opportunity for novel therapeutic strategy.

HBcrAg-based risk score performs better than the HBV DNA-based scores for HCC prediction in grey zone patients who are HBeAg-negative.

Background & Aims: Risk scores have been designed to predict the development of hepatocellular carcinoma (HCC) in treatment-naive patients with chronic hepatitis B (CHB). However, little is known about their predictive accuracy in HBeAg-negative patients in the grey zone (GZ). We aimed to develop a HBcrAg-based HCC risk score and explore whether it outperforms other risk scores in GZ patients. Methods: Two retrospective cohorts of HBeAg-negative patients with American Association for the Study of Liver Diseases-defined GZ were established for derivation and validation (Taiwanese, N = 911; Japanese, N = 806). All of them were non-cirrhotic at baseline and remained treatment-naive during the follow-up. The primary endpoint was HCC development. Results: In a median follow-up period of 15.5 years, 85 patients developed HCC in the derivation cohort. We found that age, sex, alanine aminotransferase, platelet count, and HBcrAg, but not HBV DNA levels, were independent predictors and a 20-point GZ-HCC score was developed accordingly. The 10-year and 15-year area under the ROC curve (AUROC) ranged from 0.83 to 0.86, which outperformed the HBV DNA-based HCC risk scores, including REACH-B and GAG-HCC scores (AUROC ranging from 0.66 to 0.74). The better performance was also validated in EASL- and Asian Pacific Association for the Study of the Liver-defined GZ patients. These findings remained consistent in the validation cohort. Finally, the low-risk and high-risk GZ patients (stratified by a score of 8) had an HCC risk close to inactive CHB and immune-active CHB patients, respectively, in both cohorts. Conclusions: The HBcrAg-based GZ-HCC score predicts HCC better than other HBV DNA-based risk scores in GZ patients who are HBeAg-negative patients, which may help optimise their clinical management. Impact and implications: We have developed a risk score based on HBcrAg, which has shown better predictive ability for HCC compared with other risk scores based on HBV DNA. Using a score of 8, GZ patients can be classified into low- and high-risk groups, which can guide follow up and early treatment, respectively. This validated risk score is a valuable tool for optimising the management of GZ patients who are HBeAg-negative.

Serial increase and high alpha-fetoprotein levels predict the development of hepatocellular carcinoma in 6 months.

AIM: Alpha-fetoprotein (AFP) checkup with abdominal ultrasonography for hepatocellular carcinoma (HCC) surveillance remains controversial. We evaluated a serial AFP-increase and high AFP levels in the prediction of HCC. METHODS: At-risk patients with chronic liver disease underwent HCC surveillance with trimonthly AFP measurement were included and categorized into HCC and non-HCC groups. Their AFP levels at 12, 9, and 6 months (-6M) before the outcome date were evaluated. Group-based trajectory analysis and multivariable regression analysis were performed to identify AFP trajectories as risk predictors for HCC. RESULTS: Overall, 2776 patients were included in the HCC (n = 326) and non-HCC (n = 2450) groups. Serial AFP levels were significantly higher in the HCC than the non-HCC groups. Trajectory analysis identified AFP-increase group (11%) increased 24-fold risks of HCC compared with the AFP-stable (89%) group. Compared with patients without the AFP-increase, a serial 3-month AFP-increase ≥10% elevated HCC risk by 12.1-fold (95% CI: 6.5-22.4) in 6 months, and the HCC risks increased 13-60 fold in patients with cirrhosis, hepatitis B, or C receiving antiviral therapy, or AFP levels <20 ng/ml. Combining serial AFP-increase ≥10% and AFP ≥20 ng/ml at -6M significantly increased 41.7-fold (95% CI: 13.8-126.2) HCC risks. In patients who underwent biannual AFP checkups, those with both 6-month AFP-increase ≥10% and AFP ≥20 ng/ml increased 22.1-fold (95% CI: 12.52-39.16) HCC risks in 6 months. Most HCCs were detected at an early stage. CONCLUSIONS: Serial 3-6-month AFP-increase of ≥10% previously and AFP level of ≥20 ng/ml significantly increased HCC risks in 6 months.

Distinct effects of hepatic steatosis and metabolic dysfunction on the risk of hepatocellular carcinoma in chronic hepatitis B.

OBJECTIVE: Chronic hepatitis B (CHB) and metabolic dysfunction-associated fatty liver disease (MAFLD) are the leading causes of hepatocellular carcinoma (HCC). We aim to explore the impact of concurrent MAFLD on the risk of HCC in CHB. METHODS: Patients with CHB were consecutively recruited from 2006 to 2021. MAFLD was defined by steatosis and either obesity, diabetes mellitus, or other metabolic abnormalities. The cumulative incidence of HCC and associated factors were compared between the MAFLD and non-MAFLD groups. RESULTS: 10,546 treatment-naïve CHB patients were included with a median follow-up of 5.1 years. CHB patients with MAFLD (n = 2212) had fewer hepatitis B e antigen (HBeAg)-positivity, lower HBV DNA levels, and Fibrosis-4 index compared with the non-MAFLD group (n = 8334). MAFLD was independently associated with a 58% reduced risk of HCC (adjusted hazard ratio [aHR] 0.42, 95% confidence interval [CI] 0.25-0.68, p < 0.001). Furthermore, steatosis and metabolic dysfunction had distinct effects on HCC. Steatosis was protective against HCC (aHR 0.45, 95% CI 0.30-0.67, p < 0.001), while a greater burden of metabolic dysfunction increased the risk (aHR 1.40 per dysfunction increase, 95% CI 1.19-1.66, p < 0.001). The protective effect of MAFLD was further confirmed in analysis with inverse probability of treatment weighting (IPTW), patients who had undergone antiviral therapy, those with probable MAFLD, and after multiple imputation for missing data. CONCLUSIONS: Concurrent hepatic steatosis is independently associated with a lower risk of HCC, whereas the increasing burden of metabolic dysfunction aggravates the risk of HCC in untreated CHB patients.

Pre-operative gamma-glutamyl transferase levels predict outcomes in hepatitis B-related hepatocellular carcinoma after curative resection.

BACKGROUND: Surgical resection is a curative therapy for early-stage hepatocellular carcinoma (HCC); however, HCC recurrence is not uncommon. Identifying outcome predictors helps to manage the disease. Gamma-glutamyl transferase (GGT) may predict the development of HCC, but its role to predict the outcomes after surgical resection of HCC was unclear. This study aimed to investigate pre-operative GGT levels for outcome prediction in patients with hepatitis B virus (HBV)-related HCC. METHODS: We conducted a retrospective cohort study to include patients with HBV-related HCC receiving surgical resection. Clinical information, HCC characteristics and usage of antiviral therapy were collected. A time-dependent Cox proportional hazard regression analysis were used to predict HCC recurrence and survival. RESULTS: A total of 699 consecutive patients with HBV-related HCC who received surgical resection with curative intent between 2004 and 2013 were included. After a median of 4.4 years, 266 (38%) patients had HCC recurrence. Pre-operative GGT positively correlated with cirrhosis, tumor burden and significantly increased in patients to develop HCC recurrence. Multivariable analysis demonstrated that pre-operative GGT ≥38 U/L increased 57% risk (hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.20-2.06) of recurrent HCC after adjustment for confounding factors. Specifically, pre-operative GGT ≥38 U/L predicted early (<2 years) HCC recurrence (HR: 1.94, 95% CI: 1.30-2.89). Moreover, pre-operative GGT ≥38 U/L predicted all-cause mortality (HR: 1.73, 95% CI: 1.06-2.84) after surgery. CONCLUSION: Pre-operative GGT levels ≥38 U/L independently predict high risks of HCC recurrence and all-cause mortality in HBV-related HCC patients receiving surgical resection.

Safety and dose escalation of the targeted oncolytic adenovirus OBP-301 for refractory advanced liver cancer: Phase I clinical trial.

OBP-301 is an oncolytic adenovirus modified to replicate within cancer cells and lyse them. This open-label, non-comparative, phase I dose-escalation trial aimed to assess its safety and optimal dosage in 20 patients with advanced hepatocellular carcinoma. Good tolerance was shown with a maximum tolerated dose of 6 × 1012 viral particles. The most common treatment-emergent adverse events were influenza-like illness, pyrexia, fatigue, decreased platelet count, abdominal distension, and anemia. Cohorts 4 and 5 had approximately 50% higher levels of CD8+ T cells in the peripheral blood after injection. The best target response occurred in 14 patients, 4 of whom had progressive disease. Multiple intratumoral injections of OBP-301 were well tolerated in patients with advanced hepatocellular carcinoma. The stable disease rate for the injected tumors was greater than the overall response rate, even with no obvious tumor response. OBP-301 might have a greater impact on local response as histological examination revealed that the presence of OBP-301 was consistent with the necrotic area at the injection site. Increased infiltration of CD8+ T cells and <1% PD-L1 expression were observed in tumors after injection. Improved antitumor efficacy might be achieved in future studies via viral injection with volume adjustment and in combination with other immuno-therapeutics.

Hepatitis D double reflex testing of all hepatitis B carriers in low-HBV- and high-HBV/HDV-prevalence countries.

Hepatitis D virus (HDV) infection occurs as a coinfection with hepatitis B and increases the risk of hepatocellular carcinoma, decompensated cirrhosis, and mortality compared to hepatitis B virus (HBV) monoinfection. Reliable estimates of the prevalence of HDV infection and disease burden are essential to formulate strategies to find coinfected individuals more effectively and efficiently. The global prevalence of HBV infections was estimated to be 262,240,000 in 2021. Only 1,994,000 of the HBV infections were newly diagnosed in 2021, with more than half of the new diagnoses made in China. Our initial estimates indicated a much lower prevalence of HDV antibody (anti-HDV) and HDV RNA positivity than previously reported in published studies. Accurate estimates of HDV prevalence are needed. The most effective method to generate estimates of the prevalence of anti-HDV and HDV RNA positivity and to find undiagnosed individuals at the national level is to implement double reflex testing. This requires anti-HDV testing of all hepatitis B surface antigen-positive individuals and HDV RNA testing of all anti-HDV-positive individuals. This strategy is manageable for healthcare systems since the number of newly diagnosed HBV cases is low. At the global level, a comprehensive HDV screening strategy would require only 1,994,000 HDV antibody tests and less than 89,000 HDV PCR tests. Double reflex testing is the preferred strategy in countries with a low prevalence of HBV and those with a high prevalence of both HBV and HDV. For example, in the European Union and North America only 35,000 and 22,000 cases, respectively, will require anti-HDV testing annually.

Serum cytokine profiles predict outcomes of chronic hepatitis B patients discontinuing entecavir or tenofovir therapy.

BACKGROUND/PURPOSE: Distinct hepatitis relapse has been observed after discontinuing entecavir (ETV) or tenofovir disoproxil fumarate (TDF) therapy in chronic hepatitis B (CHB) patients. End-of-therapy (EOT) serum cytokines were compared and used for outcome prediction. METHODS: A total of 80 non-cirrhotic CHB patients in a tertiary medical center in Taiwan who discontinued ETV (n = 51) or TDF (n = 29) therapy after fulfilling the APASL guidelines were prospectively enrolled. Serum cytokines were measured at EOT and 3rd month afterwards. Multivariable analysis was performed to predict virological relapse (VR, HBV DNA >2000 IU/mL), clinical relapse (CR, VR and alanine aminotransferase > 2-fold upper limit of normal) and hepatitis B surface antigen (HBsAg) seroclearance. RESULTS: Compared with TDF group, ETV stoppers had greater interleukin 5 (IL-5), IL-12 p70, IL-13, IL-17 A and tumor necrosis factor alpha (TNF-alpha) (all P < 0.05) at EOT. Older age, TDF use, higher EOT HBsAg and IL-18 (Hazard ratio [HR], 1.01; 95% CI, 1.00-1.02) levels at EOT predicted VR, while older age, higher EOT HBsAg and IL-7 (HR, 1.25; 95% CI, 1.00-1.56) levels predicted CR. In TDF stoppers, higher IL-7 (HR, 1.29; 95% CI, 1.05-1.60) and IL-18 (HR, 1.02; 95% CI, 1.00-1.04) levels predicted VR, while IL-7 (HR, 1.34; 95% CI, 1.08-1.65) and interferon-gamma (IFN-gamma) (HR, 1.08; 95% CI, 1.02-1.14) levels predicted CR. A lower EOT HBsAg level was associated with HBsAg seroclearance. CONCLUSION: Distinct cytokine profiles were observed after stopping ETV or TDF. Higher EOT IL-7, IL-18, and IFN-gamma could be probable predictors for VR and CR in patients discontinuing NA therapies.

Synergistic efficacy of telomerase-specific oncolytic adenoviral therapy and histone deacetylase inhibition in human hepatocellular carcinoma.

The telomerase-specific oncolytic adenovirus Telomelysin and the histone deacetylase inhibitor AR42 have demonstrated anticancer effects in preclinical models of human hepatocellular carcinoma (HCC). However, the clinical development of Telomelysin may be hindered by human antiviral immunity and tumor resistance. Combining oncolytic and epigenetic therapies is a viable approach for treating various cancers. This study investigated the potential synergism of Telomelysin and AR42 and the relevant underlying mechanisms. Telomelysin and AR42 exhibited synergistic antiproliferative effects in human HCC models in vitro and in vivo. Apoptosis induced by Telomelysin was significantly enhanced by AR42 in both PLC5 and Hep3B HCC cells. AR42 treatment unexpectedly attenuated the expression of the coxsackievirus and adenovirus receptor and the mRNA levels of human telomerase reverse transcriptase, which may be positively associated with the cytotoxicity of Telomelysin. Meanwhile, the cellular antiviral interferon response was not altered by AR42 treatment. Further, we found that Telomelysin enhanced Akt phosphorylation in HCC cells. AR42 reduced Telomelysin-induced phospho-Akt activation and enhanced Telomelysin-induced apoptosis. The correlation of Akt phosphorylation with drug-induced apoptosis was validated in HCC cells with upregulated or downregulated Akt signaling. Combination therapy with Telomelysin and AR42 demonstrated synergistic anti-HCC efficacy. Clinical trials investigating this new combination regimen are warranted.

Hepatitis B Virus DNA Integration Drives Carcinogenesis and Provides a New Biomarker for HBV-related HCC.

Hepatitis B virus (HBV) DNA integration is an incidental event in the virus replication cycle and occurs in less than 1% of infected hepatocytes during viral infection. However, HBV DNA is present in the genome of approximately 90% of HBV-related HCCs and is the most common somatic mutation. Whole genome sequencing of liver tissues from chronic hepatitis B patients showed integration occurring at random positions in human chromosomes; however, in the genomes of HBV-related HCC patients, there are integration hotspots. Both the enrichment of the HBV-integration proportion in HCC and the emergence of integration hotspots suggested a strong positive selection of HBV-integrated hepatocytes to progress to HCC. The activation of HBV integration hotspot genes, such as telomerase (TERT) or histone methyltransferase (MLL4/KMT2B), resembles insertional mutagenesis by oncogenic animal retroviruses. These candidate oncogenic genes might shed new light on HBV-related HCC biology and become targets for new cancer therapies. Finally, the HBV integrations in individual HCC contain unique sequences at the junctions, such as virus-host chimera DNA (vh-DNA) presumably being a signature molecule for individual HCC. HBV integration may thus provide a new cell-free tumor DNA biomarker to monitor residual HCC after curative therapies or to track the development of de novo HCC.

Metastatic tumor antigen 1 contributes to hepatocarcinogenesis posttranscriptionally through RNA-binding function.

BACKGROUND AND AIMS: Both nuclear and cytoplasmic overexpression of metastatic tumor antigen 1 (MTA1) contributes to tumorigenesis of HCC. Most studies have focused on nuclear MTA1 whose function is mainly a chromatin modifier regulating the expression of various cancer-promoting genes. By contrast, the molecular mechanisms of cytoplasmic MTA1 in carcinogenesis remain elusive. Here, we reveal a role of MTA1 in posttranscriptional gene regulation. APPROACH AND RESULTS: We conducted the in vitro and in vivo RNA-protein interaction assays indicating that MTA1 could bind directly to the 3'-untranslated region of MYC RNA. Mutation at the first glycine of the conserved GXXG loop within a K-homology II domain-like structure in MTA1 (G78D) resulted in the loss of RNA-binding activity. We used gain- and loss-of-function strategy showing that MTA1, but not the G78D mutant, extended the half-life of MYC and protected it from the lethal -7-mediated degradation. The G78D mutant exhibited lower activity in promoting tumorigenesis than wild-type in vitro and in vivo. Furthermore, RNA-immunoprecipitation sequencing analysis demonstrated that MTA1 binds various oncogenesis-related mRNAs besides MYC . The clinical relevance of cytoplasmic MTA1 and its interaction with MYC were investigated using HBV-HCC cohorts with or without early recurrence. The results showed that higher cytoplasmic MTA1 level and MTA1- MYC interaction were associated with early recurrence. CONCLUSIONS: MTA1 is a generic RNA-binding protein. Cytoplasmic MTA1 and its binding to MYC is associated with early recurrence in patients with HBV-HCC. This function enables it to regulate gene expression posttranscriptionally and contributes to hepatocarcinogenesis.

Sequential Therapy with Ropeginterferon Alfa-2b and Anti-Programmed Cell Death 1 Antibody for Inhibiting the Recurrence of Hepatitis B-Related Hepatocellular Carcinoma: From Animal Modeling to Phase I Clinical Results.

Hepatocellular carcinoma (HCC) usually recurs after curative surgical resection. Currently, no approved adjuvant therapy has been shown to reduce HCC recurrence rates. In this study, the in vivo effect of sequential combination treatment with recombinant mouse interferon-alpha (rmIFN-α) and an anti-mouse-PD1 antibody on hepatitis B virus (HBV) clearance in mice was evaluated. A Phase I clinical trial was then conducted to assess the safety, tolerability, and inhibitory activity of sequential therapy with ropeginterferon alfa-2b and nivolumab in patients with HCC recurrence who underwent curative surgery for HBV-related HCC. The animal modeling study showed that HBV suppression was significantly greater with the rmIFN-α and anti-PD1 sequential combination treatment in comparison with sole treatment with rmIFN-α or anti-PD1. In the Phase I study, eleven patients completed the sequential therapy with ropeginterferon alfa-2b every two weeks for six doses at 450 µg, followed by three doses of nivolumab every two weeks up to 0.75 mg/kg. A notable decrease in or clearance of HBV surface antigen was observed in two patients. The dose-limiting toxicity of grade 3 alanine transaminase and aspartate aminotransferase increases was observed in one patient. The maximum tolerated dose was then determined. To date, no HCC recurrence has been observed. The treatment modality was well tolerated. These data support the further clinical development of sequential combination therapy as a post-surgery prophylactic measure against the recurrence of HBV-related HCC.

Optimizing Survival Benefit by Surgical Resection by the Seven-Eleven Criteria in Barcelona Clinic Liver Cancer Stage A/B Hepatocellular Carcinoma beyond the Milan Criteria.

Introduction: Optimal treatment of hepatocellular carcinoma (HCC) beyond the Milan criteria is in debate. We aimed to identify candidates for surgical resection (SR) in Barcelona Clinic Liver Cancer (BCLC)-A/B HCC beyond the Milan criteria with survival benefit. Methods: Patients with BCLC-A/B HCC beyond the Milan criteria at the National Taiwan University Hospital during 2005 and 2019 were screened, and those who received transarterial chemoembolization (TACE) or SR were consecutively included. The tumor burden was classified by the seven-eleven criteria into low (≤7), intermediate (7-11), or high (>11). Multivariable Cox proportional hazard regression analysis was used for outcome prediction. Results: Overall, 474 patients who received SR (n = 247) and TACE (n = 227) were enrolled. Patients who underwent SR were significantly younger with better liver reserve. There were 76 (31%) and 129 (57%) deaths in the SR and TACE groups after a median follow-up of 3.9 and 2.1 years, respectively. The seven-eleven criteria could distinguish median overall survival (OS) among low (n = 149), intermediate (n = 203), and high (n = 122) tumor burden groups (7.7 vs. 6.9 vs. 2.8 years, respectively, p < 0.001). Patients receiving SR had a significantly higher median OS compared with TACE in those with intermediate (8.2 vs. 2.6 years, p < 0.001) and high (5.6 vs. 1.5 years, p = 0.001) tumor burden. After adjustment for age, sex, and liver reserve, SR was predictive for better OS in intermediate (adjusted hazard ratio [aHR]: 0.45, 95% confidence interval [CI]: 0.27-0.75) and high tumor burden groups (aHR: 0.54, 95% CI: 0.32-0.92). The survival benefit of SR especially confines to patients within 3 tumors. Conclusions: In patients with BCLC-A/B HCC beyond the Milan criteria with tumor burden beyond the up-to-7 criteria but within 3 tumors, SR has better OS than TACE and should be considered in resectable patients.

Exposure to Air Pollution and Survival in Follow-Up after Hepatocellular Carcinoma.

Introduction: Air pollutants are classified as carcinogens by the International Agency for Research on Cancer. Long-term exposure to ambient particulate matter with an aerodiameter of 2.5 µm or lower (PM2.5) has been reported to be linked with increased mortality due to hepatocellular carcinoma (HCC). However, the effects of air pollutants other than PM2.5 on HCC-related mortality have not been fully investigated. Accordingly, we conducted this study to assess the effect of long-term exposure to air pollutants (PM2.5 and nitrogen dioxide [NO2]) on HCC-related mortality. Method: In 2005, the Taiwan Liver Cancer Network (TLCN) was established by the National Research Program for Genomic Medicine to recruit liver cancer patients from 5 major medical centers in northern, central, and southern Taiwan. The TLCN had successfully recruited 9,344 patients by the end of 2018. In this study, we included 1,000 patients randomly sampled from the TLCN to assess the effect of exposure to air pollutants on HCC mortality after HCC diagnosis. Daily averages of PM2.5 and NO2 concentrations were retrieved from 77 air quality-monitoring stations and interpolated to the townships of patients' residences by using the Kriging method. The effect of air pollutants on HCC survival was assessed using a Cox proportional hazards model. Results: A total of 940 patients were included in the analysis. After adjusting for potential confounders and mutually adjusting for co-pollutants, we observed that the hazards ratio (95% confidence interval) for HCC-related mortality for every 1-µg/m3 increase in PM2.5 concentration was 1.11 (1.08-1.14) and that for every 1-ppb increase in NO2 concentration was 1.08 (1.03-1.13). Conclusion: Our study suggests that long-term exposure to PM2.5 and NO2 was associated with decreased survival time in patients with HCC in Taiwan.