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Background & Aims: Hepatitis B surface antigen (HBsAg) loss or functional cure (FC) is considered the optimal therapeutic outcome for patients with chronic hepatitis B (CHB). However, the immune-pathological biomarkers and underlying mechanisms of FC remain unclear. In this study we comprehensively interrogate disease-associated cell states identified within intrahepatic tissue and matched PBMCs (peripheral blood mononuclear cells) from patients with CHB or after FC, at the resolution of single cells, to provide novel insights into putative mechanisms underlying FC., Methods: We combined single-cell transcriptomics (single-cell RNA sequencing) with multiparametric flow cytometry-based immune phenotyping, and multiplexed immunofluorescence to elucidate the immunopathological cell states associated with CHB vs. FC., Results: We found that the intrahepatic environment in CHB and FC displays specific cell identities and molecular signatures that are distinct from those found in matched PBMCs. FC is associated with the emergence of an altered adaptive immune response marked by CD4 cytotoxic T lymphocytes, and an activated innate response represented by liver-resident natural killer cells, specific Kupffer cell subtypes and marginated neutrophils. Surprisingly, we found MHC class II-expressing hepatocytes in patients achieving FC, as well as low but persistent levels of covalently closed circular DNA and pregenomic RNA, which may play an important role in FC., Conclusions: Our study provides conceptually novel insights into the immuno-pathological control of HBV cure, and opens exciting new avenues for clinical management, biomarker discovery and therapeutic development. We believe that the discoveries from this study, as it relates to the activation of an innate and altered immune response that may facilitate sustained, low-grade inflammation, may have broader implications in the resolution of chronic viral hepatitis., Impact and Implications: This study dissects the immuno-pathological cell states associated with functionally cured chronic hepatitis B (defined by the loss of HBV surface antigen or HBsAg). We identified the sustained presence of very low viral load, accessory antigen-presenting hepatocytes, adaptive-memory-like natural killer cells, and the emergence of helper CD4 T cells with cytotoxic or effector-like signatures associated with functional cure, suggesting previously unsuspected alterations in the adaptive immune response, as well as a key role for the innate immune response in achieving or maintaining functional cure. Overall, the insights generated from this study may provide new avenues for the development of alternative therapies as well as patient surveillance for better clinical management of chronic hepatitis B., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Although most hepatocellular carcinoma (HCC) cases are driven by hepatitis and cirrhosis, a subset of patients with chronic hepatitis B develop HCC in the absence of advanced liver disease, indicating the oncogenic potential of hepatitis B virus (HBV). We investigated the role of HBV transcripts and proteins on HCC development in the absence of inflammation in HBV-transgenic mice., Methods: HBV-transgenic mice replicating HBV and expressing all HBV proteins from a single integrated 1.3-fold HBV genome in the presence or absence of wild-type HBx (HBV1.3/HBVxfs) were analyzed. Flow cytometry, molecular, histological and in vitro analyses using human cell lines were performed. Hepatocyte-specific Stat3- and Socs3-knockout was analyzed in HBV1.3 mice., Results: Approximately 38% of HBV1.3 mice developed liver tumors. Protein expression patterns, histology, and mutational landscape analyses indicated that tumors resembled human HCC. HBV1.3 mice showed no signs of active hepatitis, except STAT3 activation, up to the time point of HCC development. HBV-RNAs covering HBx sequence, 3.5-kb HBV RNA and HBx-protein were detected in HCC tissue. Interestingly, HBVxfs mice expressing all HBV proteins except a C-terminally truncated HBx (without the ability to bind DNA damage binding protein 1) showed reduced signs of DNA damage response and had a significantly reduced HCC incidence. Importantly, intercrossing HBV1.3 mice with a hepatocyte-specific STAT3-knockout abrogated HCC development., Conclusions: Expression of HBV-proteins is sufficient to cause HCC in the absence of detectable inflammation. This indicates the oncogenic potential of HBV and in particular HBx. In our model, HBV-driven HCC was STAT3 dependent. Our study highlights the immediate oncogenic potential of HBV, challenging the idea of a benign highly replicative phase of HBV infection and indicating the necessity for an HBV 'cure'., Impact and Implications: Although most HCC cases in patients with chronic HBV infection occur after a sequence of liver damage and fibrosis, a subset of patients develops HCC without any signs of advanced liver damage. We demonstrate that the expression of all viral transcripts in HBV-transgenic mice suffices to induce HCC development independent of inflammation and fibrosis. These data indicate the direct oncogenic effects of HBV and emphasize the idea of early antiviral treatment in the 'immune-tolerant' phase (HBeAg-positive chronic HBV infection)., (© 2024 The Authors.)

Background & Aims: Circulating HBV RNAs have been proposed as a biomarker that reflects the transcriptional activity of covalently closed circular DNA (cccDNA) and may help to evaluate HBV treatment activity. Different research assays have been proposed and, although two PCR-based research use only investigational assays have been developed, the lack of standardized protocols represents an important limitation. Here we have designed and generated a stable clonal cell line producing an RNA-based standard for the calibration of PCR-based circulating HBV RNA assays., Methods: HBV RNA-producing Huh7-derived stable cell lines were generated by transfecting pTriEX plasmids containing 1.1 unit length HBV DNA genomes carrying mutations in the catalytic site (YMAA mutation) and the TP domain (Y63F) of the polymerase, and the ε-loop of the pregenomic (pg)RNA (mutation A1G)., Results: The clonal cell line (Huh7-3D29), carrying a double YMAA and Y63F mutation, displayed, and maintained over several passages in culture, a high RNA secretion phenotype with negligible residual secreted HBV DNA. Density gradient centrifugation showed that most of the secreted HBV RNA from Huh7-3D29 cells was detected in naked capsid and virion-like particles and only a minority in small extracellular vescicles. Nanopore sequencing of 5'RACE products shows that the majority of the Huh7-3D29-secreted HBV RNAs start at the 5' end of pgRNA and pgRNA-derived spliced RNAs. Finally, Huh7-3D29 cells showed a high and up-scalable secreted RNA yield allowing 1,300 standard curves in 9 days from one flask., Conclusion: We generated a clonal cell line that produces high quantities of HBV RNAs with very low quantities of contaminating HBV DNAs, representing a stable source of RNA standard for HBV RNA assay calibration., Impact and Implications: Several investigational assays and two research use only assays have been developed to detect and quantify circulating HBV RNAs, an emerging biomarker of covalently closed circular DNA transcriptional activity and target engagement by new HBV treatments. The lack of a unique molecular standard for circulating HBV RNA quantification represents an important limitation. Here we describe the generation of a stable clonal cell line producing and secreting an RNA-based standard containing all the HBV RNA species found in HBV patients' sera ( e.g. pgRNA, HBx transcripts). This new RNA standard can be used to calibrate all PCR-based assays for circulating HBV RNA quantification to evaluate, in a non-invasive manner, the size of the transcriptionally active cccDNA pool and the activity of novel strategies aimed at curing HBV infection., (© 2024 The Authors.)

Objective: Achieving HBV cure will require novel combination therapies of direct-acting antivirals and immunomodulatory agents. In this context, the toll-like receptor 8 (TLR8) agonist selgantolimod (SLGN) has been investigated in preclinical models and clinical trials for chronic hepatitis B (CHB). However, little is known regarding its action on immune effectors within the liver. Our aim was to characterise the transcriptomic changes and intercellular communication events induced by SLGN in the hepatic microenvironment., Design: We identified TLR8 -expressing cell types in the human liver using publicly available single-cell RNA-seq data and established a method to isolate Kupffer cells (KCs). We characterised transcriptomic and cytokine KC profiles in response to SLGN. SLGN's indirect effect was evaluated by RNA-seq in hepatocytes treated with SLGN-conditioned media (CM) and quantification of HBV parameters following infection. Pathways mediating SLGN's effect were validated using transcriptomic data from HBV-infected patients., Results: Hepatic TLR8 expression takes place in the myeloid compartment. SLGN treatment of KCs upregulated monocyte markers (eg, S100A12 ) and downregulated genes associated with the KC identity (eg, SPIC ). Treatment of hepatocytes with SLGN-CM downregulated NTCP and impaired HBV entry. Cotreatment with an interleukin 6-neutralising antibody reverted the HBV entry inhibition., Conclusion: Our transcriptomic characterisation of SLGN sheds light into the programmes regulating KC activation. Furthermore, in addition to its previously described effect on established HBV infection and adaptive immunity, we show that SLGN impairs HBV entry. Altogether, SLGN may contribute through KCs to remodelling the intrahepatic immune microenvironment and may thus represent an important component of future combinations to cure HBV infection., Competing Interests: Competing interests: FZ and BT received grants from Assembly, Beam Therapeutics, Blue Jay and JnJ; FZ had consulting activities with Assembly, Blue Jay and GSK. YCH receives grants from Gilead Sciences and Sysmex. FZ is an associate editor of the journal. SD, LL, NK, JJW, AHL, and SPF are or were employees of Gilead Sc., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Background: We evaluated long-term trajectories of circulating hepatitis B virus (HBV)-RNA and hepatitis B core-related antigen (HBcrAg) in persons with and without hepatitis B surface antigen (HBsAg) loss during tenofovir therapy in the Swiss HIV Cohort Study., Methods: We included 29 persons with HIV (PWH) with HBsAg loss and 29 matched PWH without loss. We compared HBV-RNA and HBcrAg decline and assessed the cumulative proportions with undetectable HBV-RNA and HBcrAg levels during tenofovir therapy using Kaplan-Meier estimates., Results: HBsAg loss occurred after a median of 4 years (IQR 1 - 8). All participants with HBsAg loss achieved suppressed HBV-DNA and undetectable HBV-RNA preceding undetectable qHBsAg levels, whereas 79% achieved negative HBcrAg. In comparison, 79% of the participants without HBsAg loss achieved undetectable HBV-RNA and 48% negative HBcrAg. After two years on tenofovir, an HBV RNA decline ≥1 log10 copies/ml had 100% sensitivity and 36.4% specificity for HBsAg loss, whereas an HBcrAg decline ≥1 log10 U/ml had 91.0% sensitivity and 64.5% specificity., Conclusions: HBV-RNA suppression preceded undetectable qHBsAg levels, and had high sensitivity but low specificity for HBsAg loss during tenofovir therapy in PWH. HBcrAg remained detectable in approximately 20% of persons with, and 50% of persons without HBsAg loss., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Objective: A convenient, reproducible biomarker of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) transcriptional activity is lacking. We measured circulating HBV RNA (cirB-RNA) in untreated and nucleos(t)ide analogues (NUC) treated chronic hepatitis B (CHB) patients to define its correlation with intrahepatic viral markers and HBV core-related antigen (HBcrAg)., Design: Paired liver biopsy and serum samples were collected from 122 untreated and 30 NUC-treated CHB patients. We measured cirB-RNA, HBV DNA, hepatitis B surface antigen (HBsAg), HBcrAg and alanine aminotransferase levels. cirB-RNA was quantified using an investigational HBV RNA assay for use on the cobas 6800 system. The test detects a region spanning the HBV canonical polyadenylation site. cccDNA and 3.5 kb RNA in liver tissue were assessed by quantitative PCR and droplet digital PCR., Results: cirB-RNA was detectable in 100% of HBeAg(+) chronic hepatitis (CH), 57% and 14% of HBeAg(-) CH and chronic infection untreated patients and 47% of NUC-treated patients. cirB-RNA undetectability was associated with lower intrahepatic cccDNA transcriptional activity, as well as serum HBcrAg, but no significant differences in HBsAg, in both untreated and treated patients. In untreated HBeAg(-) patients, cirB-RNA correlated with intrahepatic 3.5 kb RNA and cccDNA transcriptional activity, serum HBV DNA and HBcrAg, but not with HBsAg or total cccDNA levels. Combined undetectability of both cirB-RNA and HBcrAg detection in untreated HBeAg(-) patients identified a subgroup with the lowest levels of intrahepatic transcriptionally active cccDNA., Conclusion: Our results support the usefulness of quantification of circulating HBV RNA expressed from cccDNA as an indicator of intrahepatic active viral reservoir in both untreated and NUC-treated CHB patients., Trial Registration Number: NCT02602847., Competing Interests: Competing interests: BS, AH and MH are employees and stockholders of Roche Molecular Systems (Pleasanton, CA, USA). ED served as speaker for Gilead and Abbvie, participated in advisory board of Gilead, Abbvie and Roche, received grant from Gilead and travel grant from Gilead and Advanz Pharma. PL served as speaker and/or participated in advisory board for Roche Pharma/Diagnostics, Gilead Sciences, GSK, Abbvie, Janssen, Myr, Eiger, Antios, Aligos, Vir, Grifols, Altona, Roboscreen. FZ received consulting fees from: Aligos, Antios, Assembly, Gilead, GSK; FZ and BT received research funding to INSERM from: Assembly, Beam Therapeutics, Blue Jay and Janssen. FZ is an Associate Editor of the journal., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Bacterial infections are the most frequent precipitating event in patients with acute decompensation of cirrhosis (AD) and are associated with high mortality. Early diagnosis is challenging due to cirrhosis-related systemic inflammation. Here we investigated the potential of circulating microRNAs to diagnose bacterial infections and predict survival in cirrhotic patients with AD. High throughput profiling of circulating microRNAs was performed using the Nanostring technology in 57 AD patients and 24 patients with compensated cirrhosis (CC). Circulating miRs profiling showed that: (a) miRs differentially detected in AD vs. CC were mostly down-regulated; (b) a composite score including absolute neutrophil count, C reactive protein and miR-362-3p could diagnose bacterial infection with an excellent performance (AUC of 0.825 [95% CI = 0.671-0.980; p < 0.001]); (c) a composite score including miR-382-5p, miR-592 and MELD-Na improved 6-month survival prediction. Circulating miRs are strongly dysregulated in patients with AD and may help to improve bacterial infection diagnosis and survival prediction., Competing Interests: The authors declare no competing interests., (© 2023 The Authors.)

Background & Aims: Finite duration of treatment associated with HBsAg loss is the current goal for improved therapeutic approaches against chronic HBV infection, as it indicates elimination or durable inactivation of intrahepatic covalently closed circular DNA (cccDNA). To assist drug development, the definition of early predictive markers of HBsAg loss by assessing their value in reflecting intrahepatic cccDNA levels and transcriptional activity is essential. Fine needle aspirates (FNAs) have recently emerged as a less invasive alternative to core liver biopsy (CLB) and showed to be useful for investigating intrahepatic immune responses. The aim of this study was to optimise and validate the use of FNA vs. CLB to evaluate the intrahepatic viral reservoir., Methods: Paired FNA/CLB samples were obtained from patients with HBeAg+ chronic hepatitis (n = 4), HBeAg- chronic hepatitis (n = 4), and HBeAg- chronic infection (n = 1). One HBeAg+ patient was undergoing tenofovir treatment. HBV 3.5-kb RNA and cccDNA were quantified by droplet digital PCR., Results: cccDNA was quantifiable in all but one FNA/CLB pair, showing the highest levels in untreated HBeAg+ patients, except for the tenofovir-treated patient. Similarly, 3.5-kb RNA was detectable in all but one FNA sample and showed higher levels in HBeAg+ patients. When comparing cccDNA and 3.5-kb RNA quantification in FNA vs. CLB samples, no statistically significant differences were identified., Conclusions: These results demonstrate the possibility to quantify cccDNA and assess its transcriptional activity in patients with chronic hepatitis B by combining FNA and droplet digital PCR. This supports the use of FNA in clinical trials to evaluate the intrahepatic viral reservoir during the development of new antivirals and immunomodulatory agents., Impact and Implications: Chronic hepatitis B infection is characterised by a complex interplay between immune responses and viral replication in the liver, which determines the long-term outcome of the disease. In this study, we show that fine needle aspiration of the liver, a less-invasive alternative to core biopsies, allows the assessment of the hepatic viral reservoir., Competing Interests: FZ received grants from Assembly, Beam Therapeutics, and Evotec; FZ had consulting activities with Assembly, Blue Jay, Gilead, and GSK. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2023 The Authors.)

Background and Aims: Netrin-1 displays protumoral properties, though the pathological contexts and processes involved in its induction remain understudied. The liver is a major model of inflammation-associated cancer development, leading to HCC., Approach and Results: A panel of cell biology and biochemistry approaches (reverse transcription quantitative polymerase chain reaction, reporter assays, run-on, polysome fractionation, cross linking immunoprecipitation, filter binding assay, subcellular fractionation, western blotting, immunoprecipitation, stable isotope labeling by amino acids in cell culture) on in vitro-grown primary hepatocytes, human liver cell lines, mouse samples and clinical samples was used. We identify netrin-1 as a hepatic inflammation-inducible factor and decipher its mode of activation through an exhaustive eliminative approach. We show that netrin-1 up-regulation relies on a hitherto unknown mode of induction, namely its exclusive translational activation. This process includes the transfer of NTN1 (netrin-1) mRNA to the endoplasmic reticulum and the direct interaction between the Staufen-1 protein and this transcript as well as netrin-1 mobilization from its cell-bound form. Finally, we explore the impact of a phase 2 clinical trial-tested humanized anti-netrin-1 antibody (NP137) in two distinct, toll-like receptor (TLR) 2/TLR3/TLR6-dependent, hepatic inflammatory mouse settings. We observe a clear anti-inflammatory activity indicating the proinflammatory impact of netrin-1 on several chemokines and Ly6C+ macrophages., Conclusions: These results identify netrin-1 as an inflammation-inducible factor in the liver through an atypical mechanism as well as its contribution to hepatic inflammation., (© 2022 American Association for the Study of Liver Diseases.)

Background & Aims: Over time, chronic HCV infection can lead to hepatocellular carcinoma (HCC), a process that involves changes to the liver extracellular matrix (ECM). However, the exact mechanisms by which HCV induces HCC remain unclear. Therefore, we sought to investigate the impact of HCV on the liver ECM, with a focus on heparanase-1 (HPSE)., Methods: HPSE expression was assessed by quantitative reverse-transcription PCR, immunoblotting and immunofluorescence in liver biopsies infected or not with HCV, and in 10-day-infected hepatoma Huh7.5 cells. Cell lines deficient for or overexpressing HPSE were established to study its role during infection., Results: HCV propagation led to significant HPSE induction, in vivo and in vitro. HPSE enhanced infection when exogenously expressed or supplemented as a recombinant protein. Conversely, when HPSE expression was downregulated or its activity blocked, HCV infection dropped, suggesting a role of HPSE in the HCV life cycle. We further studied the underlying mechanisms of such observations and found that HPSE favored HCV release by enhancing CD63 synthesis and exosome secretion, but not by stimulating HCV entry or genome replication. We also showed that virus-induced oxidative stress was involved in HPSE induction, most likely through NF-κB activation., Conclusions: We report for the first time that HCV infection is favored by HPSE, and upregulates HPSE expression and secretion, which may result in pathogenic alterations of the ECM., Lay Summary: Chronic hepatitis C virus (HCV) infection can lead to hepatocellular carcinoma development in a process that involves derangement of the extracellular matrix (ECM). Herein, we show that heparanase-1, a protein involved in ECM degradation and remodeling, favors HCV infection and is upregulated by HCV infection; this upregulation may result in pathogenic alterations of the ECM., Competing Interests: Conflict of interest The authors declareno conflict of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2022 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background: The amount of HBV RNA in peripheral blood may reflect HBV covalently closed circular DNA (cccDNA) transcriptional activity within infected hepatocytes. Quantification of circulating HBV RNA (cirB-RNA) is thus a promising biomarker for monitoring antiviral treatment., Objectives: We evaluated the performance of an automated, prototype quantitative HBV RNA assay for use on the Roche cobas® 6800/8800 systems., Study Design: The sensitivity, specificity, linearity, and potential interference by HBV DNA of the cobas® HBV RNA assay were assessed using synthetic HBV armored RNA and clinical specimens., Results: cobas® HBV RNA results were linear between 10 and 10 7 copies/mL in clinical samples of several HBV genotypes, and up to 10 9 copies/mL with synthetic RNA. Precision and reproducibility were excellent, with standard deviation below 0.15 log 10 copies/mL and coefficients of variation below 5% throughout the linear range. The presence of HBV DNA had minimal (<0.3 log 10 copies/mL) impact on HBV RNA quantification at DNA:RNA ratios of up to approximately one million. In a panel of 36 untreated patient samples, cirB-RNA concentrations were approximately 200-fold lower than HBV DNA. cirB-RNA was detected in all 13 HBeAg-positive patients (mean 6.0 log 10 copies/mL), and in 20 of 23 HBeAg-negative patients (mean of quantifiable samples 2.2 log 10 copies/mL). Finally, cirB-RNA was detected in 12 of 20 nucleoside analog-treated patients (mean of quantifiable samples 3.4 log 10 copies/mL)., Conclusions: The cobas® 6800/8800 investigational HBV RNA assay is a high throughput, sensitive and inclusive assay to evaluate the clinical relevance of cirB-RNA quantification in patients with chronic hepatitis B., (Copyright © 2022. Published by Elsevier B.V.)

Background and Aims: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide, and finding a single reliable biomarker to follow liver degradation is a challenging task. To document the relationship between liver failure, hypoxia, and HCC, copper isotope variations (δ 65 Cu) were evaluated in the serum of HCC-negative and HCC-positive patients as a biomarker of hepatic failure., Methods: We analyzed Cu isotope variations in serum samples from 293 patients with potentially degraded liver functions presenting hepatitis B virus, hepatitis C virus, nonalcoholic steatohepatitis, and alcohol uptake (OH) etiologies and 105 controls. Ninety-five of the patients were diagnosed with HCC., Results: On average, the δ 65 Cu values of the serum of patients with F3-F4 fibrosis score or HCC-positive are low. The Cu isotope data are strikingly bimodal with well-defined δ 65 Cu modes which imperfectly reflect etiology. The population with normal values (ca -0.3‰) is progressively replaced by a population with atypical δ 65 Cu values (ca -0.8‰), which reflects the progressive degradation of hepatic functions., Conclusion: The clear bimodality does not correspond to a progressive shift of the δ 65 Cu values but to a replacement of one population by another. This bimodality sheds light on the persisting difficulties epitomized by α-fetoprotein in finding high-sensitivity and high-specificity HCC biomarkers. It is interpreted as a switch in the resistance of hepatic tissues to the oxidative stress that eventually leads to HCC oncogenesis., (© 2022 The Authors.)

Waterlogged archaeological wood is exposed to a high risk of biological degradation during the post-excavation phases of storage and restoration. For this reason, often biocides must be used to preserve wooden remains. In the present work three essential oils (cinnamon, wild thyme, and common thyme) were tested as possible alternative biocides to use in the preservation of waterlogged archaeological wood. The oils were first tested in vitro to establish the minimum inhibitory concentration (MIC) and to evaluate the biocidal activity on selected fungal strains. Then, the established MIC was applied on waterlogged archaeological wood samples and during an actual restoration treatment. The effectiveness of the oils was evaluated through cultural analyses, ATP quantification, and next-generation sequencing. The results showed that the oils caused a significant decrease in the vitality of fungal mycelia grown in vitro and of the microbiota present in treated wood and storage water. Furthermore, an influence on the composition of the bacterial communities of treated wood samples was observed. Although further tests are needed to evaluate interferences with the materials used during restoration procedures, essential oils could be considered as a possible alternative to the currently used biocide.

Objective: The HBV HBx regulatory protein is required for transcription from the covalently closed circular DNA (cccDNA) minichromosome and affects the epigenetic control of both viral and host cellular chromatin., Design: We explored, in relevant cellular models of HBV replication, the functional consequences of HBx interaction with DLEU2, a long non-coding RNA (lncRNA) expressed in the liver and increased in human hepatocellular carcinoma (HCC), in the regulation of host target genes and the HBV cccDNA., Results: We show that HBx binds the promoter region, enhances the transcription and induces the accumulation of DLEU2 in infected hepatocytes. We found that nuclear DLEU2 directly binds HBx and the histone methyltransferase enhancer of zeste homolog 2 (EZH2), the catalytic active subunit of the polycomb repressor complex 2 (PRC2) complex. Computational modelling and biochemical evidence suggest that HBx and EZH2 share two preferential binding sites in DLEU2 intron 1. HBx and DLEU2 co-recruitment on the cccDNA displaces EZH2 from the viral chromatin to boost transcription and viral replication. DLEU2-HBx association with target host promoters relieves EZH2 repression and leads to the transcriptional activation of a subset of EZH2/PRC2 target genes in HBV-infected cells and HBV-related HCCs., Conclusions: Our results highlight the ability of HBx to bind RNA to impact on the epigenetic control of both viral cccDNA and host genes and provide a new key to understand the role of DLEU2 and EZH2 overexpression in HBV-related HCCs and HBx contribution to hepatocytes transformation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Hepatitis C virus (HCV) virions contain a subset of host liver cells proteome often composed of interesting virus-interacting factors. A proteomic analysis performed on double gradient-purified clinical HCV highlighted the translation regulator LARP1 on these virions. This finding was validated using post-virion capture and immunoelectron microscopy, as well as immunoprecipitation applied to in vitro (Huh7.5 liver cells) grown (Gt2a, JFH1 strain) and patient-derived (Gt1a) HCV particles. Upon HCV infection of Huh7.5 cells, we observed a drastic transfer of LARP1 to lipid droplets, inducing colocalization with core proteins. RNAi-mediated depletion of LARP1 using the C911 control approach decreased extracellular infectivity of HCV Gt1a (H77), Gt2a (JFH1), and Gt3a (S52 chimeric strain), yet increased their intracellular infectivity. This latter effect was unrelated to changes in the hepatocyte secretory pathway, as evidenced using a functional RUSH assay. These results indicate that LARP1 binds to HCV, an event associated with retention of intracellular infectivity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Hepatitis C virus (HCV) infection is a worldwide health problem and is one of the main causes of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma (HCC). Despite recent improvements, effective treatments for HCC are still missing and new tools for early detection are needed. Non-coding RNAs (ncRNAs) have emerged as important regulators of gene expression and key players in human carcinogenesis, including HCC. Aberrant expression of ncRNAs is associated with HCC metastasis, invasion, dissemination, and recurrence. This review will focus on the recent advances in ncRNA expression profiles, their dysregulation in HCV-related HCC, and the clinical perspective of ncRNA signatures for the early detection of HCC.

In the liver, HBV and HCV infections, exposure to toxics, genetic and metabolic disorders may induce endoplasmic reticulum (ER) stress and the unfolding protein response (UPR). The UPR allows cells to reach ER homeostasis after lumen overload, but also fosters survival of damaged cells and therefore HCC onset. Dependence receptors such as UNC5A trigger apoptosis when unbound to their ligands. We have previously shown that the main dependence receptor ligand, netrin-1, could protect cells against UPR-induced apoptosis through sustained translation. In this study, we show that UNC5A is cumulatively downregulated by the UPR at the transcriptional level in vitro and at the translational level both in vitro and in vivo. We have found that the 5'-untranslated region of the UNC5A mRNA shares a certain homology degree with that of netrin-1, suggesting linked translational regulatory mechanisms, at least during the initial stages of the UPR. RNAi and forced expression studies identified UNC5A as a modulator of cell death in the context of the UPR. UNC5A decrease of association with polysomes and expression oriented cells towards UPR-associated hepatocytic survival. Such data indicate that cooperation between the UPR and UNC5A depletion as previously observed by ourselves in HCC patients samples may foster liver cancer development and growth., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Hepatitis C virus (HCV) infection is a leading cause of hepatocellular carcinoma (HCC), mainly through cirrhosis induction, spurring research for a deeper understanding of HCV versus host interactions in cirrhosis. The present study investigated crosstalks between HCV infection and UNC5A, a netrin-1 dependence receptor that is inactivated in cancer. UNC5A and HCV parameters were monitored in patients samples (n=550) as well as in in vitro. In patients, UNC5A mRNA expression is significantly decreased in clinical HCV(+) specimens irrespective of the viral genotype, but not in (HBV)(+) liver biopsies, as compared to uninfected samples. UNC5A mRNA is downregulated in F2 (3-fold; P=0.009), in F3 (10-fold, P=0.0004) and more dramatically so in F4/cirrhosis (44-fold; P<0.0001) histological stages of HCV(+) hepatic lesions compared to histologically matched HCV(-) tissues. UNC5A transcript was found strongly downregulated in HCC samples (33-fold; P<0.0001) as compared with non-HCC samples. In vivo, association of UNC5A transcripts with polyribosomes is decreased by 50% in HCV(+) livers. Consistent results were obtained in vitro showing HCV-dependent depletion of UNC5A in HCV-infected hepatocyte-like cells and in primary human hepatocytes. Using luciferase reporter constructs, HCV cumulatively decreased UNC5A transcription from the UNC5 promoter and translation in a UNC5A 5'UTR-dependent manner. Proximity ligation assays, kinase assays, as well as knockdown and forced expression experiments identified UNC5A as capable of impeding autophagy and promoting HCV restriction through specific impact on virion infectivity, in a cell death-independent and DAPK-related manner. In conclusion, while the UNC5A dependence receptor counteracts HCV persistence through regulation of autophagy in a DAPK-dependent manner, it is dramatically decreased in all instances in HCC samples, and specifically by HCV in cirrhosis. Such data argue for the evaluation of the implication of UNC5A in liver carcinogenesis.

Known activators of the Peroxisome Proliferator-Activated Receptor γ (PPARγ), thiazolidinediones (TZD) induce apoptosis in a variety of cancer cells through dependent and/or independent mechanisms of the receptor. We tested a panel of TZD (Rosiglitazone, Pioglitazone, Ciglitazone) to shed light on their potential therapeutic effects on three cervical cancer cell lines (HeLa, Ca Ski, C-33 A). In these cells, only ciglitazone triggered apoptosis through PPARγ-independent mechanisms and in particular via both extrinsic and intrinsic pathways in Ca Ski cells containing Human PapillomaVirus (HPV) type 16. It also inhibits cervical cancer xenograft development in nude mice. Ciglitazone kills cervical cancer cells by activating death receptor signalling pathway, caspase cascade and BH3 interacting-domain death agonist (Bid) cleavage through the up-regulation of Death Receptor 4 (DR4)/DR5 and soluble and membrane-bound TNF related apoptosis inducing ligand (TRAIL). Importantly, the drug let TRAIL-resistant Ca Ski cells to respond to TRAIL through the downregulation of cellular FLICE-Like Inhibitory Protein (c-FLIP) level. For the first time, we revealed that ciglitazone is able to decrease E6 viral oncoprotein expression known to block TRAIL pathway and this was associated with cell death. Our results highlight the capacity of ciglitazone to restore TRAIL sensitivity and to prevent E6 blocking action to induce apoptosis in cervical cancer cells., Competing Interests: CONFLICTS OF INTEREST The authors declare that they have no conflict of interest.

Hepatitis C virus (HCV) is an oncogenic virus associated with the onset of hepatocellular carcinoma (HCC). The present study investigated the possible link between HCV infection and Netrin-1, a ligand for dependence receptors that sustains tumorigenesis, in particular in inflammation-associated tumors. We show that Netrin-1 expression is significantly elevated in HCV+ liver biopsies compared to hepatitis B virus (HBV+) and uninfected samples. Furthermore, Netrin-1 was upregulated in all histological stages of HCV+ hepatic lesions, from minimal liver fibrosis to cirrhosis and HCC, compared to histologically matched HCV- tissues. Both cirrhosis and HCV contributed to the induction of Netrin-1 expression, whereas anti-HCV treatment resulted in a reduction of Netrin-1 expression. In vitro, HCV increased the level and translation of Netrin-1 in a NS5A-La-related protein 1 (LARP1)-dependent fashion. Knockdown and forced expression experiments identified the receptor uncoordinated receptor-5 (UNC5A) as an antagonist of the Netrin-1 signal, though it did not affect the death of HCV-infected cells. Netrin-1 enhanced infectivity of HCV particles and promoted viral entry by increasing the activation and decreasing the recycling of the epidermal growth factor receptor (EGFR), a protein that is dysregulated in HCC. Netrin-1 and HCV are, therefore, reciprocal inducers in vitro and in patients, as seen from the increase in viral morphogenesis and viral entry, both phenomena converging toward an increase in the level of infectivity of HCV virions. This functional association involving a cancer-related virus and Netrin-1 argues for evaluating the implication of UNC5 receptor ligands in other oncogenic microbial species.

Background & Aims: Netrin-1, a multifunctional secreted protein, is up-regulated in cancer and inflammation. Netrin-1 blocks apoptosis induced by the prototypical dependence receptors deleted in colorectal carcinoma and uncoordinated phenotype-5. Although the unfolded protein response (UPR) triggers apoptosis on exposure to stress, it first attempts to restore endoplasmic reticulum homeostasis to foster cell survival. Importantly, UPR is implicated in chronic liver conditions including hepatic oncogenesis. Netrin-1's implication in cell survival on UPR in this context is unknown., Methods: Isolation of translational complexes, determination of RNA secondary structures by selective 2'-hydroxyl acylation and primer extension/dimethyl sulfate, bicistronic constructs, as well as conventional cell biology and biochemistry approaches were used on in vitro-grown hepatocytic cells, wild-type, and netrin-1 transgenic mice., Results: HepaRG cells constitute a bona fide model for UPR studies in vitro through adequate activation of the 3 sensors of the UPR (protein kinase RNA-like endoplasmic reticulum kinase (PERK)), inositol requiring enzyme 1α (IRE1α), and activated transcription factor 6 (ATF6). The netrin-1 messenger RNA 5'-end was shown to fold into a complex double pseudoknot and bear E-loop motifs, both of which are representative hallmarks of related internal ribosome entry site regions. Cap-independent translation of netrin 5' untranslated region-driven luciferase was observed on UPR in vitro. Unlike several structurally related oncogenic transcripts (l-myc, c-myc, c-myb), netrin-1 messenger RNA was selected for translation during UPR both in human hepatocytes and in mice livers. Depletion of netrin-1 during UPR induces apoptosis, leading to cell death through an uncoordinated phenotype-5A/C-mediated involvement of protein phosphatase 2A and death-associated protein kinase 1 in vitro and in netrin transgenic mice., Conclusions: UPR-resistant, internal ribosome entry site-driven netrin-1 translation leads to the inhibition of uncoordinated phenotype-5/death-associated protein kinase 1-mediated apoptosis in the hepatic context during UPR, a hallmark of chronic liver disease.

There is growing evidence that virus particles also contain host cell proteins, which provide viruses with certain properties required for entry and release. A proteomic analysis performed on double-gradient-purified hepatitis C virus (HCV) from two highly viraemic patients identified the phosphatidylinositol 3,5-bisphosphate 5-phosphatase FIG4 (KIAA0274) as part of the viral particles. We validated the association using immunoelectron microscopy, immunoprecipitation and neutralization assays in vitro as well as patient-derived virus particles. RNA interference-mediated reduction of FIG4 expression decreased cholesteryl ester (CE) levels along with intra- and extracellular viral infectivity without affecting HCV RNA levels. Likewise, overexpressing FIG4 increased intracellular CE levels as well as intra- and extracellular viral infectivity without affecting viral RNA levels. Triglyceride levels and lipid droplet (LD) parameters remained unaffected. The 3,5-bisphosphate 5-phosphatase active site of FIG4 was found to strongly condition these results. Whilst FIG4 was found to localize to areas corresponding to viral assembly sites, at the immediate vicinity of LDs in calnexin-positive and HCV core-positive regions, no implication of FIG4 in the secretory pathway of the hepatocytes could be found using either FIG4-null mice, in vitro morphometry or functional assays of the ERGIC/Golgi compartments. This indicates that FIG4-dependent modulation of HCV infectivity is unrelated to alterations in the functionality of the secretory pathway. As a result of the documented implication of CE in the composition and infectivity of HCV particles, these results suggest that FIG4 binds to HCV and modulates particle formation in a CE-related manner.

Objective: Inflammation and oxidative stress drive disease progression in chronic hepatitis C (CHC) towards hepatocellular carcinoma. HCV is known to increase intracellular levels of reactive oxygen species (ROS), but how it eliminates ROS is less well known. The role of the ROS scavenger glutathione peroxidase 4 (GPx4), induced by HCV, in the viral life cycle was analysed., Design: The study was performed using a replicative in vitro HCV infection model and liver biopsies derived from two different CHC patient cohorts., Results: A screen for HCV-induced peroxide scavengers identified GPx4 as a host factor required for HCV infection. The physiological role of GPx4 is the elimination of lipid peroxides from membranes or lipoproteins. GPx4-silencing reduced the specific infectivity of HCV by up to 10-fold. Loss of infectivity correlated with 70% reduced fusogenic activity of virions in liposome fusion assays. NS5A was identified as the protein that mediates GPx4 induction in a phosphatidylinositol-3-kinase-dependent manner. Levels of GPx4 mRNA were found increased in vitro and in CHC compared with control liver biopsies. Upon successful viral eradication, GPx4 transcript levels returned to baseline in vitro and also in the liver of patients., Conclusions: HCV induces oxidative stress but controls it tightly by inducing ROS scavengers. Among these, GPx4 plays an essential role in the HCV life cycle. Modulating oxidative stress in CHC by specifically targeting GPx4 may lower specific infectivity of virions and prevent hepatocarcinogenesis, especially in patients who remain difficult to be treated in the new era of interferon-free regimens., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: The endothelium lines blood and lymph vessels and protects underlying tissues against external agents such as viruses, bacteria and parasites. Yet, microbes and particularly viruses have developed sophisticated ways to bypass the endothelium in order to gain access to inner organs. De novo infection of the liver parenchyma by many viruses and notably hepatitis viruses, is thought to occur through recruitment of virions on the sinusoidal endothelial surface and subsequent transfer to the epithelium. Furthermore, the liver endothelium undergoes profound changes with age and in inflammation or infection. However, primary human liver sinusoidal endothelial cells (LSECs) are difficult to obtain due to scarcity of liver resections. Relevant derived cell lines are needed in order to analyze in a standardized fashion the transfer of pathogens across the liver endothelium. By lentiviral transduction with hTERT only, we have immortalized human LSECs isolated from a hereditary hemorrhagic telangiectasia (HHT) patient and established the non-transformed cell line TRP3. TRP3 express mesenchymal, endothelial and liver sinusoidal markers. Functional assessment of TRP3 cells demonstrated a high capacity of endocytosis, tube formation and reactivity to immune stimulation. However, TRP3 displayed few fenestrae and expressed C-type lectins intracellularly. All these findings were confirmed in the original primary LSECs from which TRP3 were derived suggesting that these features were already present in the liver donor. We consider TRP3 as a model to investigate the functionality of the liver endothelium in hepatic inflammation in infection., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Interpatient heterogeneity of hepatocellular carcinoma has been in-depth addressed. Intrapatient heterogeneity is less known. Four clones were freshly isolated from an Edmondson grade I HCV-associated hepatocellular carcinoma. Biochemical approaches, functional assays and cytogenetics were used. Albumin inducibility was uncoupled from canonical cytokeratin profiles, suggesting pathological combinations of hepatospecific and biliary markers. Poor differentiation and TGFβ's proproliferative effect on all clones were observed. TGFβ, Interferon α and doxorubicin sensitivity levels were found highly heterogeneous. Progenitor and stem cells markers OV6 and EpCAM were mutually exclusively expressed. All clones were CD44+, while none expressed CD90, CD133, or CD117. Three clones displayed a liver progenitor OV6+ phenotype, and were susceptible to hepatocytic differentiation, among which one fibroblastoid clone displayed intrahepatic parenchymal engraftment capability. A fourth clone, the less motile, displayed a cancer stem cell EpCAM+ phenotype, was essentially β-catenin negative, and was as expected devoid of hepatocytic differentiation capability, yet the most sensitive to doxorubicin treatment. Cytogenetics evidenced in all clones a t(12;22)(p11;q11) translocation found in several myelodysplastic syndromes. All clones, that probably derive from EpCAM+ tumor cells, display aberrant E-cadherin cytosolic localization. Because of their diverse pathophysiolocal features, these freshly isolated, low population doubling-defined, HCC clones may provide novel opportunities to tackle HCC heterogeneity in a single patient background for therapy improvement purposes, especially regarding recently developed targeted strategies., (© 2013 Wiley Periodicals, Inc.)

Background: Ciglitazone belongs to the thiazolidinediones class of antidiabetic drug family and is a high-affinity ligand for the Peroxisome Proliferator-Activated Receptor γ (PPARγ). Apart from its antidiabetic activity, this molecule shows antineoplastic effectiveness in numerous cancer cell lines., Methodology/principal Findings: Using RT4 (derived from a well differentiated grade I papillary tumor) and T24 (derived from an undifferentiated grade III carcinoma) bladder cancer cells, we investigated the potential of ciglitazone to induce apoptotic cell death and characterized the molecular mechanisms involved. In RT4 cells, the drug induced G2/M cell cycle arrest characterized by an overexpression of p53, p21(waf1/CIP1) and p27(Kip1) in concomitance with a decrease of cyclin B1. On the contrary, in T24 cells, it triggered apoptosis via extrinsic and intrinsic pathways. Cell cycle arrest and induction of apoptosis occurred at high concentrations through PPARγ activation-independent pathways. We show that in vivo treatment of nude mice by ciglitazone inhibits high grade bladder cancer xenograft development. We identified a novel mechanism by which ciglitazone kills cancer cells. Ciglitazone up-regulated soluble and membrane-bound TRAIL and let TRAIL-resistant T24 cells to respond to TRAIL through caspase activation, death receptor signalling pathway and Bid cleavage. We provided evidence that TRAIL-induced apoptosis is partially driven by ciglitazone-mediated down-regulation of c-FLIP and survivin protein levels through a proteasome-dependent degradation mechanism., Conclusions/significance: Therefore, ciglitazone could be clinically relevant as chemopreventive or therapeutic agent for the treatment of TRAIL-refractory high grade urothelial cancers.

Thiazolidinediones, including rosiglitazone and troglitazone, are insulin-sensitizing drugs and high-affinity ligands for the peroxisome proliferator-activated receptor gamma (PPARgamma). Apart from their antidiabetic activity, these molecules possess antitumor properties. We investigated their potential apoptotic effects on RT4 (derived from a well-differentiated Grade I papillary tumor) and T24 (derived from an undifferentiated Grade III carcinoma) bladder cancer cells. Rosiglitazone induced G2/M or G0/G1 phase cell cycle arrest in RT4 and T24 cells, respectively. Only troglitazone triggered apoptosis via extrinsic and intrinsic pathways in both cell lines. Interestingly, rosiglitazone amplified TRAIL-induced apoptosis in TRAIL-sensitive RT4 cells or let TRAIL-resistant T24 cells to respond to TRAIL. Thiazolidinediones acted through PPARgamma activation-independent mechanisms. The underlying mechanisms involved for the first time in cancer cells the upregulation of soluble and/or membrane-bound TRAIL. This was associated with increased cell surface death receptor 5 expression and c-FLIP and survivin downregulation, mediated in part through proteasome-dependent degradation in troglitazone-promoted cell death. Therefore, the combination of rosiglitazone and TRAIL could be clinically relevant as chemopreventive or therapeutic agents for the treatment of TRAIL-resistant high-grade urothelial cancers.

Aim: The effect of combining sodium butyrate (NaB), a histone deacetylase inhibitor, and 7-hydroxy-staurosporine (UCN-01) on cytotoxicity in human cervical carcinoma cells was evaluated., Materials and Methods: HeLa and CaSki cells were treated using NaB alone or in combination with staurosporine (STS) or its analog UCN-01. Cytotoxicity was determined by flow cytometry and morphological assays. Apoptotic pathways were characterized by Western blotting and immunostaining. CaSki cells were also xenografted into nude mice to assess the in vivo effects of NaB/UCN-01 combination., Results: Treatment with NaB and STS or UCN-01 resulted in enhanced apoptosis of cancer cells. Apoptosis involved mitochondrial pathways and overexpression of p53 and p73. In concordance, co-treatment modulated some p53/p73 downstream targets such as p21, BAX, BCL-2 and BCL-X(L), leading to increased caspase-3 and poly(ADP-ribose) polymerase cleavage. In vivo, NaB/UCN-01 combination exerted a substantial tumour growth suppression effect compared with single treatment., Conclusion: UCN-01 was shown to be a potentiator of NaB therapy for cervical cancer cells.

Superficial pT1 bladder tumors are characterized by a high risk of recurrence and progression in grade and stage. Few studies provided evidence that loss of adipocyte-fatty acid binding protein (A-FABP) expression was associated with bladder cancer progression. A-FABP is a lipid binding protein playing a role in intracellular lipid transport and metabolism, as well as in signal transduction. We reported from bladder tumors that decrease of A-FABP transcript level significantly correlated to tumor stage and to histologic grade (p < 0.05). Namely, in poor prognosis high grade pT1 tumors there was a loss of A-FABP expression compared to good prognosis tumors suggesting that re-expression of A-FABP could be a therapeutic approach in early stage bladder cancer to prevent disease progression. We demonstrated for the first time that this marker is upregulated by Peroxisome Proliferator-Activated Receptor (PPAR) alpha, beta and gamma in T24 cells (derived from an undifferentiated grade III carcinoma) and only by PPARbeta in RT4 cells (derived from a well differentiated grade I papillary tumor). This effect occurred through a PPAR-dependent transcriptional mechanism without modifying mRNA stability and interestingly required de novo protein synthesis. Data as a whole suggest a prognostic significance of A-FABP in bladder cancer outcome and the potential utility of overexpression of this protein by PPAR agonists open up new perspectives in the treatment of bladder cancer. (c) 2008 Wiley-Liss, Inc.

Altered angiogenic response is associated with high-grade cervical dysplasia and with invasive squamous carcinoma of the cervix. Vascular Endothelial Growth Factor (VEGF) is one of the most potent inducers of angiogenesis and is up-regulated in carcinoma of the cervix. Infection by high-risk human papillomavirus and persistent expression of viral oncogene E6 are etiologically linked to the development of cervical cancer. E6 is able to immortalize cells and induce malignant transformation by inactivating p53. In cervical cancer, regulation of VEGF expression is poorly described. Thus, we investigated whether E6 oncoprotein could regulate VEGF expression in HPV18-positive cervical cancer-derived HeLa cells harboring a wild-type p53. The alternative splicing of vegf mRNA renders three major isoforms of 121, 165 and 189 amino-acids in humans. We have designed isoform specific real time QRT-PCR assays to quantitate vegf transcripts and VEGF121 was the predominant isoform. Silencing HPV18 E6 mRNA with specific siRNA reduced VEGF121 expression by at least 50% whereas silencing of p53 did not alter its expression. Treatment with cycloheximide did not inhibit E6-induced VEGF121 expression. Collectively, these results suggest that HPV18 E6 oncoprotein contributes to tumor angiogenesis by inducing VEGF transcription from the promoter in a p53-independent manner.

The viral gene for the killer protein 4 (KP4) has been explored for its antifungal effect in genetically modified wheat to defeat specifically the seed-transmitted smut and bunt diseases. In vitro both important seed-transmitted diseases of wheat, loose smut (Ustilago tritici) and stinking smut (Tilletia caries), are susceptible to KP4, whereas all other organisms tested so far proved to be not susceptible to KP4. For studies in planta we used stinking smut as a model fungus. In greenhouse experiments, two KP4-transgenic wheat lines showed up to 30% lower symptom development as compared to the nontransgenic control. As the last step in the proof of concept, field-testing has shown for the first time increased fungal resistance of a transgene in wheat. Due to its specificity against smuts and bunts, KP4 presents a very low risk to humans and the environment. Field-testing in Switzerland is regulated by a strong law, which for research is acceptable if legally and scientifically correctly applied.