Molecular Mechanisms of Hepatocarcinogenesis Following Sustained Virological Response in Patients with Chronic Hepatitis C Virus Infection. Viruses. 2018;10. [PMID: 30274202 PMCID: PMC6212901 DOI: 10.3390/v10100531]

Immunosuppressive tumor microenvironment in the progression, metastasis, and therapy of hepatocellular carcinoma: from bench to bedside

Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy with high incidence, recurrence, and metastasis rates. The emergence of immunotherapy has improved the treatment of advanced HCC, but problems such as drug resistance and immune-related adverse events still exist in clinical practice. The immunosuppressive tumor microenvironment (TME) of HCC restricts the efficacy of immunotherapy and is essential for HCC progression and metastasis. Therefore, it is necessary to elucidate the mechanisms behind immunosuppressive TME to develop and apply immunotherapy. This review systematically summarizes the pathogenesis of HCC, the formation of the highly heterogeneous TME, and the mechanisms by which the immunosuppressive TME accelerates HCC progression and metastasis. We also review the status of HCC immunotherapy and further discuss the existing challenges and potential therapeutic strategies targeting immunosuppressive TME. We hope to inspire optimizing and innovating immunotherapeutic strategies by comprehensively understanding the structure and function of immunosuppressive TME in HCC.

Hepatitis C virus-induced differential transcriptional traits in host cells after persistent infection elimination by direct-acting antivirals in cell culture

Chronic hepatitis C virus infection (HCV) causes liver inflammation and fibrosis, leading to the development of severe liver disease, such as cirrhosis or hepatocellular carcinoma (HCC). Approval of direct-acting antiviral drug combinations has revolutionized chronic HCV therapy, with virus eradication in >98% of the treated patients. The efficacy of these treatments is such that it is formally possible for cured patients to carry formerly infected cells that display irreversible transcriptional alterations directly caused by chronic HCV Infection. Combining differential transcriptomes from two different persistent infection models, we observed a major reversion of infection-related transcripts after complete infection elimination. However, a small number of transcripts were abnormally expressed in formerly infected cells. Comparison of the results obtained in proliferating and growth-arrested cell culture models suggest that permanent transcriptional alterations may be established by several mechanisms. Interestingly, some of these alterations were also observed in the liver biopsies of virologically cured patients. Overall, our data suggest a direct and permanent impact of persistent HCV infection on the host cell transcriptome even after virus elimination, possibly contributing to the development of HCC.

Liver fibrosis estimated using extracellular volume fraction obtained from dual-energy CT as a risk factor for hepatocellular carcinoma after sustained virologic response: A preliminary case-control study

PURPOSE

To assess hepatocellular carcinoma (HCC) risk after sustained virologic response (SVR) through clinical data analyses, including evaluation of liver fibrosis using the extracellular volume fraction (ECV) obtained from dual-energy computed tomography (DECT).

METHODS

Ninety-two patients (52 men and 40 women; mean age, 69.9 years) with hepatitis C virus infection after SVR underwent DECT of the liver (3-minute equilibrium-phase images) between January 2020 and March 2022. The ECV was calculated by measuring iodine density; fibrous markers, including ECV, fibrosis-4 index, aspartate aminotransferase to platelet ratio index, and platelet count, were statistically analyzed (p < 0.05). The risk factors associated with HCC were analyzed using univariate and multivariate logistic regression analyses.

RESULTS

The ECV (26.1 ± 4.6 %) in patients with HCC (n,21) was significantly larger than the ECV (20.7 ± 3.3 %) in patients without HCC (n = 71) (p < 0.001). The cutoff value for the ECV was 24.3 %. The area under the operating characteristic curve of the ECV was 0.857, which was higher than that of the serum fibrosis markers. Older age, SVR achieved with interferon, alpha-fetoprotein level (>5 ng/mL), advanced fibrosis before treatment (>F3), and ECV were associated with HCC according to the univariate analysis. Multivariate analyses showed that ECV was the only factor independently associated with HCC (odds ratio 0.619, 95 % confidence interval 0.482-0.795, p < 0.001).

CONCLUSION

Liver fibrosis estimated using ECV can be a predictive marker in patients with HCC after SVR.

Role of p53 suppression in the pathogenesis of hepatocellular carcinoma

In the world, hepatocellular carcinoma (HCC) is among the top 10 most prevalent malignancies. HCC formation has indeed been linked to numerous etiological factors, including alcohol usage, hepatitis viruses and liver cirrhosis. Among the most prevalent defects in a wide range of tumours, notably HCC, is the silencing of the p53 tumour suppressor gene. The control of the cell cycle and the preservation of gene function are both critically important functions of p53. In order to pinpoint the core mechanisms of HCC and find more efficient treatments, molecular research employing HCC tissues has been the main focus. Stimulated p53 triggers necessary reactions that achieve cell cycle arrest, genetic stability, DNA repair and the elimination of DNA-damaged cells’ responses to biological stressors (like oncogenes or DNA damage). To the contrary hand, the oncogene protein of the murine double minute 2 (MDM2) is a significant biological inhibitor of p53. MDM2 causes p53 protein degradation, which in turn adversely controls p53 function. Despite carrying wt-p53, the majority of HCCs show abnormalities in the p53-expressed apoptotic pathway. High p53 in-vivo expression might have two clinical impacts on HCC: (1) Increased levels of exogenous p53 protein cause tumour cells to undergo apoptosis by preventing cell growth through a number of biological pathways; and (2) Exogenous p53 makes HCC susceptible to various anticancer drugs. This review describes the functions and primary mechanisms of p53 in pathological mechanism, chemoresistance and therapeutic mechanisms of HCC.

Regulatory Role of Ribonucleotide Reductase Subunit M2 in Hepatocyte Growth and Pathogenesis of Hepatitis C Virus

Hepatitis C virus (HCV) frequently causes chronic infection in the human liver, which may progress to advanced hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. HCV primarily infects highly differentiated quiescent hepatocytes and can modulate cell cycle-regulatory genes and proliferation pathways, which ultimately contribute to persistent infection and pathogenesis. On the other hand, several studies have shown differential regulation of HCV RNA and viral protein expression levels, depending on the proliferation state of hepatocytes and the phase of the cell cycle. HCV typically requires factors provided by host cells for efficient and persistent viral replication. Previously, we found that HCV infection upregulates the expression of ribonucleotide reductase subunit M2 (RRM2) in quiescent hepatocytes. RRM2 is a rate-limiting protein that catalyzes de novo synthesis of deoxyribonucleotide triphosphates, and its expression is highly regulated during various phases of the cell cycle. RRM2 functions as a pro-viral factor essential for HCV RNA synthesis, but its functional role in HCV-induced liver diseases remains unknown. Here, we present a comprehensive review of the role of the hepatocyte cell cycle, in correlation with RRM2 expression, in the regulation of HCV replication. We also discuss the potential relevance of this protein in the pathogenesis of HCV, particularly in the development of hepatocellular carcinoma.

Before Direct-Acting Antivirals for Hepatitis C Virus: Evaluation of Core Protein R70Q and L/C91M Substitutions in Chronically Infected Brazilian Patients Unresponsive to IFN and/or RBV

Although chronic hepatitis C has been effectively treated with direct-acting antivirals (DAAs), the use of conventional therapy with peg-interferon (Peg-IFN) or (predominantly) ribavirin (RBV), remains widespread. R70Q/H and L/C91M amino acid substitutions in the hepatitis C virus (HCV) core protein may modulate responses to IFN and/or RBV, and are associated with cirrhosis, hepatocellular carcinoma (HCC), insulin resistance, and liver steatosis. We evaluated the R70Q/H and L/C91M substitutions, clinical and epidemiological profiles, and risk factors of Brazilian patients chronically infected with HCV subgenotypes 1a and 1b (HCV-GT1a and HCV-GT1b) unresponsive to IFN and/or RBV therapy. Sequencing and pyrosequencing analyses and sociodemographic and clinical predictive variables were used to assess the relationship between R70Q/H and L/C91M substitutions. Leukocyte counts, ALT levels, and ALT/AST ratios were significantly reduced in treated individuals, but more of these patients had advanced fibrosis and cirrhosis. L91M was more prevalent (19.7%), occurring only in HCV-GT1b, followed by R70Q/P (11.5%) and R70P (1.4%). R70Q/P exhibited higher mean AST, ALT, and GGT values, whereas L91M showed higher mean GGT values. Pyrosequencing of the L91M position revealed mutant subpopulations in 43.75% of samples.

Role of hepatitis c virus in hepatocellular carcinoma and neurological disorders: an overview

The hepatitis C virus (HCV) causes serious issues, affecting 71 million people globally. The most common manifestations range from chronic hepatitis to liver cirrhosis, leading to hepatocellular carcinoma. Many mechanisms are known to play an important role in HCV-induced HCC. The interaction of viral proteins with host cells results in oxidative stress damage, liver inflammation, and irregularities in signaling pathways. These results in the activation of oncogenes and metabolic disturbances, liver fibrosis, and angiogenesis. Additionally, some non-coding RNAs (ncRNAs) and toll-like receptors have been identified and play a significant role in HCC development. This virus is also associated with impairment of the central nervous system, resulting in acute or sub-acute encephalopathy and inflammatory disorders. Neurological disorders are associated with the inflammatory responses of many cells, including microglia and astrocytes. Additionally, there are many other extrahepatic manifestations, including neurological disorders such as depression and fatigue, in 50% of infected patients. These manifestations include neuro-invasion, immune-mediated damage, neurotransmitter alterations, sensory-motor polyneuropathy, sensitivity loss, weakness of the leg, and cryoglobulinemia, which significantly results in a reduced quality of life. HCV infection may be improved using an appropriate diagnosis and direct antiviral therapy for sustained virological response. However, the success of therapy depends on the symptoms and organ damage, diagnosis, and therapeutic strategies applied. Some published reports have discussed that HCV is associated with both HCC and neurological disorders. Additionally, it has also been observed that individuals with HCC also develop neurological disorders compared with individuals with HCV alone. This review aims to provide an overview of the latest information about the relationship between HCV-induced HCC and their role in neurological disorders. Additionally, we have also discussed the progress made in the diagnosis, physio-pathological mechanisms, and strong antiviral therapies developed for HCV infection and HCC, as well as the latest advancements made in the study of the neurological disorders associated with HCV infection.

Safety and Antiviral Activity of EGFR Inhibition by Erlotinib in Chronic Hepatitis C Patients: A Phase Ib Randomized Controlled Trial

INTRODUCTION

Significant hepatocellular carcinoma (HCC) risk persists after chronic hepatitis C (CHC) cure. Preclinical studies have shown that erlotinib, an oral epidermal growth factor receptor (EGFR) inhibitor, has an antiviral activity and HCC chemopreventive effect. Erlotinib is metabolized in the liver, and its safety in patients with CHC is unknown. This study aimed to assess the safety and antiviral activity of erlotinib in patients with CHC.

METHODS

In this investigator-initiated dose-escalation phase Ib prospective randomized double-blind placebo-controlled study, noncirrhotic hepatitis C virus (HCV) patients received placebo or erlotinib (50 or 100 mg/d) for 14 days with a placebo-erlotinib ratio of 1:3. Primary end points were safety and viral load reduction at the end of treatment (EOT). The secondary end point was viral load reduction 14 days after EOT.

RESULTS

This study analyzed data of 3 patients receiving placebo, 3 patients receiving erlotinib 50 mg/d, and 3 patients receiving erlotinib 100 mg/d. One grade 3 adverse event was reported in the placebo group (liver enzymes elevation), leading to treatment discontinuation and patient replacement, and 1 in the erlotinib 100 mg/d group (pericarditis), which was not considered to be treatment-related. Grade 2 skin rash was observed in 1 erlotinib 100 mg/d patient. No significant HCV-RNA level reduction was noted during treatment, but 2 of the 3 patients in the erlotinib 100 mg/d group showed a decrease of >0.5 log HCV-RNA 14 days after EOT.

DISCUSSION

Erlotinib demonstrated to be safe in noncirrhotic CHC patients. An antiviral activity at 100 mg/d confirms a functional role of EGFR as an HCV host factor in patients. These results provide perspectives to further study erlotinib as an HCC chemopreventive agent in patients with CHC.

Biomarkers for the Detection and Management of Hepatocellular Carcinoma in Patients Treated with Direct-Acting Antivirals

Simple Summary

Chronic Hepatitis C virus (HCV) represents the main etiological factor for hepatocellular carcinoma (HCC) in developed countries. The introduction of direct-acting antivirals (DAAs) improved the eradication of the hepatitis C virus (HCV) but not the reduction in the incidence of HCV-associated HCC. Some patients still develop HCC, even after reaching a sustained virological response (SVR). This review is a summary of pre-clinical studies that investigated predictive biomarkers for HCC occurrence and recurrence in HCV-infected patients treated with DAAs. The presented biomarkers are found dysregulated in serum or tissue at specific time points (before, during, after DAA treatment or post SVR) and correlated with HCC-predisposing conditions. Thus, this review aims to improve the management of patients developing HCV-induced HCC.

Abstract

Hepatocellular carcinoma (HCC) is the sixth-most common type of cancer worldwide and chronic Hepatitis C virus (HCV) represents the main etiological factor in developed countries. HCV promotes hepatocarcinogenesis through persistent liver inflammation and dysregulation of cell signaling pathways. The introduction of direct-acting antivirals (DAAs) resulted in a significant improvement in the eradication of the virus, with an expected reduction of HCC incidence. However, the risk of HCC development can persist after DAA treatment. Recent studies have investigated the potential use of molecular biomarkers that predict HCC occurrence or recurrence helping the stratification of patients under surveillance. This review aimed to summarize all pre-clinical exploration of predictive biomarkers to identify DAA-treated patients at risk for HCC development. Dysregulated microRNAs, lncRNAs, histone modifications, cytokines, proteins, and sphingolipids represent various classes of HCC risk predictors identified in two different biological sources (tissue and serum). The non-invasive serum markers can provide a more accessible means to perform clinical monitoring and predict the risk of HCC. In addition, conditions like cirrhosis, predisposing to HCC, strongly correlate with most of the molecular predictors identified, supporting the value of these molecules as possible biomarkers of HCC in DAA-treated patients.

Association between direct-acting antiviral agents in hepatitis C virus treatment and hepatocellular carcinoma occurrence and recurrence: The endless debate

Since direct-acting antiviral agents (DAAs) have been introduced into hepatitis C virus treatment, the sustained viral response (SVR) rate has significantly increased to more than 95%. Scientific evidence supports the idea that SVR after interferon therapy has beneficial effects related to cirrhosis progression, resulting in a reduction in the incidence of hepatocellular carcinoma (HCC). However, a significant debate exists related to DAA impact on HCC development. We reviewed the current literature highlighting the controversial data related to DAA association with de novo HCC occurrence or recurrence and possible pathophysiology of HCC related to DAAs. After a review of the published literature, we believe that the current evidence does not confirm or repudiate a higher rate of de novo HCC occurrence or recurrence related to DAA therapy. More trials are needed to determine if there is an association between HCC occurrence or recurrence and DAA or if it is related to preexisting liver cirrhosis.

Therapeutic potential of camel milk exosomes against HepaRG cells with potent apoptotic, anti-inflammatory, and anti-angiogenesis effects for colostrum exosomes

This study aimed to evaluate and compare the therapeutic effect of camel milk exosomes derived from colostrum, early, mid, and late lactation periods on liver cancer HepaRG cells. These exosomes showed cytotoxicity on HepaRG while being safer on normal human liver THLE-2 cells. Among the four different isolated exosome groups, exosomes isolated from colostrum exhibited the highest apoptotic potential on HepaRG as indicated by highest DNA damage and upregulated expression of Bax and caspase3 expression, but with lowest Bcl2 expression. HepaRG-treated with colostrum-derived exosomes also exhibited the lowest expression of inflammation-related genes (TNFα, NFkB, TGFβ1, and Cox2) and the angiogenesis-related gene VEGF. Colostrum-derived exosomes had significantly higher expression of lactoferrin and kappa casein than other milk-derived exosomes. These results indicate that colostrum-derived exosomes have a more potent anti-cancer effect on HepaRG cells than exosomes derived from the early, mid, and lat lactation periods. This effect could be mediated through induction of apoptosis and inhibition of inflammation and angiogenesis. Therefore, these exosomes could be used as safe adjuvants/carriers to deliver chemotherapeutics and to potentiate their anticancer effect on liver cancer cells.

Liver fibrosis regression correlates with downregulation in liver angiogenesis in chronic hepatitis C through viral eradication

OBJECTIVES

The impact of viral eradication on hepatic angiogenesis is unknown. This study aimed to analyze the correlations of liver angiogenesis with liver fibrosis progression or regression in chronic hepatitis C (CHC) after viral eradication.

METHODS

From 2003 to 2020, a cohort of 130 eligible participants underwent paired percutaneous liver biopsies (median = 48 months apart; range = 46-62) at the treatment baseline and after sustained virological response to CHC treatment at the tertiary referral center. The collagen proportionate area (CPA) of liver tissue sections was determined using picrosirius red staining through digital image analysis. CD34 and α-smooth muscle actin (α-SMA) phenotypically quantitated liver angiogenesis and myofibroblasts, respectively, through immunohistochemistry staining, to correlate the total, portal, and extraportal liver angiogenesis with fibrogenesis.

RESULTS

Paired histology manifested significant regressions in fibrosis stages, and necroinflammatory grades (both P  < 0.001). The median of changes in CPAs (follow-up minus baseline) was -6.12% (interquartile range = -12.35 to -2.05%). The median of CPA changes per year was -1.38%/year (interquartile range = -2.98 to -0.51%/year). The significance of declines in total CD34 [coefficient (95% confidence interval), 5.577 (3.286-7.868); P  < 0.001] outweighed α-SMA declines, when explaining (R2 = 0.522; adjusted R2 = 0.502) the CPA declines through multiple regression analysis adjusting for other histological variables.

CONCLUSION

Through viral eradication in CHC, the downregulated liver angiogenesis significantly explains the CPA regression.

Molecular pathways in viral hepatitis-associated liver carcinogenesis: An update

Hepatocellular carcinoma (HCC) is the most common type of cancer among primary malignant tumors of the liver and is a consequential cause of cancer-related deaths worldwide. In recent years, uncovering the molecular mechanisms involved in the development and behavior of this tumor has led to the identification of multiple potential treatment targets. Despite the vast amount of data on this topic, HCC remains a challenging tumor to treat due to its aggressive behavior and complex molecular profile. Therefore, the number of studies aiming to elucidate the mechanisms involved in both carcinogenesis and tumor progression in HCC continues to increase. In this context, the close association of HCC with viral hepatitis has led to numerous studies focusing on the direct or indirect involvement of viruses in the mechanisms contributing to tumor development and behavior. In line with these efforts, this review was undertaken to highlight the current understanding of the molecular mechanisms by which hepatitis B virus (HBV) and hepatitis C virus (HCV) participate in oncogenesis and tumor progression in HCC and summarize new findings. Cumulative evidence indicates that HBV DNA integration promotes genomic instability, resulting in the overexpression of genes related to cancer development, metastasis, and angiogenesis or inactivation of tumor suppressor genes. In addition, genetic variations in HBV itself, especially preS2 deletions, may play a role in malignant transformation. Epigenetic dysregulation caused by both viruses might also contribute to tumor formation and metastasis by modifying the methylation of DNA and histones or altering the expression of microRNAs. Similarly, viral proteins of both HBV and HCV can affect pathways that are important anticancer targets. The effects of these two viruses on the Hippo-Yap-Taz pathway in HCC development and behavior need to be investigated. Additional, comprehensive studies are also needed to determine these viruses' interaction with integrins, farnesoid X, and the apelin system in malignant transformation and tumor progression. Although the relationship of persistent inflammation caused by HBV and HCV hepatitis with carcinogenesis is well defined, further studies are warranted to decipher the relationship among inflammasomes and viruses in carcinogenesis and elucidate the role of virus-microbiota interactions in HCC development and progression.

Change in γ-glutamyl transpeptidase activity as a useful tool in identifying a group of patients with elevated risk of hepatocellular carcinoma development after DAA treatment of chronic hepatitis C

Aim of the study

Hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) incidence will be diminishing due to use of direct acting antiviral agents (DAA), but there is still constant risk for HCC development. Elevated serum g-glutamyl transpeptidase (GGT) activity is associated with increased risk of liver cancer. In our study we tried to determine whether change in GGT activity may be useful in identifying patients with elevated risk of HCC development after DAA treatment.

Material and methods

The study population consisted of 111 patients with chronic hepatitis C (CHC) treated with DAA. Laboratory tests [alanine aminotransferase (ALT), GGT, a-fetoprotein (AFP)] and liver stiffness measurement (using FibroScan) were performed at the beginning and at the end of therapy.

Results

Pre-treatment ALT activity, GGT activity and AFP concentration in patients with CHC were directly associated with the stage of liver fibrosis. Elimination of HCV after DAA treatment caused significant reduction in serum GGT activity and was not associated with pre-treatment liver fibrosis. AFP concentration was significantly lower after treatment. It was observed regardless of pre-treatment AFP concentration, but the largest reduction was demonstrated in the group of patients with advanced fibrosis. In multivariate analysis there was no significant difference in GGT activity after treatment only in patients with pre-treatment normal AFP concentration and advanced liver fibrosis.

Conclusions

Patients who after achieving a sustained virological response (SVR) did not lower both AFP concentration and GGT activity may have higher risk of HCC development. Special monitoring may be required in patients with advanced liver fibrosis and normal AFP concentration before treatment.

Hepatocellular carcinoma recurrence after directly acting antivirals for chronic hepatitis C: a 2-year follow-up study

AIM OF THE STUDY

Data regarding hepatocellular carcinoma (HCC) recurrence after directly acting antivirals for hepatitis C are contradictory. Our aim was to study the HCC recurrence in patients who received directly acting antivirals after tumor ablation.

MATERIAL AND METHODS

This retrospective study included all Child-Pugh A and B patients with hepatitis C related < 5 cm single or up to 3 HCC without any vascular or extrahepatic involvement whose lesions were managed using microwave or radiofrequency ablation at the Internal Medicine Department of Alexandria Faculty of Medicine, in the period from 1 January 2016 to 31 December 2016, and then received directly acting antivirals.

RESULTS

Data from 52 patients were analyzed. Throughout the 2 years from ablation, 42.3% of patients experienced tumor recurrence (22 out of 52 patients). In addition, two subjects died and 4 subjects were lost to follow-up before any tumor recurrence.

CONCLUSIONS

Although our study included both modified Child-Pugh A and B patients and included lesions up to 5 cm treated using thermal ablation, the 2-year HCC recurrence rate was similar to that previously reported after surgical resection or radiofrequency ablation of lesions up to 3 cm in Child-Pugh A patients before development of directly acting antivirals.

p53 and rb promoter methylation in hepatitis C virus-related chronic hepatitis and hepatocellular carcinoma

Aim: To identify methylation in p53 and rb during hepatitis C virus (HCV) infection in individuals in Pakistan. Materials & methods: Methylation-specific PCR was used on liver biopsies from hepatocellular carcinoma and chronic hepatitis C patients and on blood samples from healthy individuals. Real-time PCR was used to assess changes in the expression of p53 and rb in Huh-7 cells transfected with HCV-3a. Results: The p53 and rb promoters were methylated in hepatocellular carcinoma patients. The presence of HCV-3a- Core (p = 0.03), HCV-3a- NS-3 (p = 0.01) and HCV-3a- NS-5a (p = 0.02) downregulated p53 expression. Exposure to HCV-3a- Core (p = 0.04) downregulated rb expression. Conclusion: It can be hypothesized that HCV-induced epigenetic modifications may lead to the development of hepatic cancer that in turn inactivates p53 and rb.

Risk of Hepatocellular Carcinoma after HCV Clearance by Direct-Acting Antivirals Treatment Predictive Factors and Role of Epigenetics

Direct-acting antivirals (DAAs) induce a rapid virologic response (SVR) in up to 99% of chronic hepatitis C patients. The role of SVR by DAAs on the incidence or recurrence of hepatocellular carcinoma (HCC) is still a matter of debate, although it is known that SVR does not eliminate the risk of HCC. In this review, we made an updated analysis of the literature data on the impact of SVR by DAAs on the risk of HCC as well as an assessment of risk factors and the role of epigenetics. Data showed that SVR has no impact on the occurrence of HCC in the short–medium term but reduces the risk of HCC in the medium–long term. A direct role of DAAs in the development of HCC has not been demonstrated, while the hypothesis of a reduction in immune surveillance in response to the rapid clearance of HCV and changes in the cytokine pattern influencing early carcinogenesis remains to be further elucidated. HCV induces epigenetic alterations such as modifications of the histone tail and DNA methylation, which are risk factors for HCC, and such changes are maintained after HCV clearance. Future epigenetic studies could lead to identify useful biomarkers and therapeutic targets. Cirrhosis has been identified as a risk factor for HCC, particularly if associated with high liver stiffness and α-fetoprotein values, diabetes and the male sex. Currently, considering the high number and health cost to follow subjects’ post-HCV clearance by DAAs, it is mandatory to identify those at high risk of HCC to optimize management.

Hepatitis C Virus and Hepatocellular Carcinoma: When the Host Loses Its Grip

Chronic infection with hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma (HCC). Novel treatments with direct-acting antivirals achieve high rates of sustained virologic response; however, the HCC risk remains elevated in cured patients, especially those with advanced liver disease. Long-term HCV infection causes a persistent and accumulating damage of the liver due to a combination of direct and indirect pro-oncogenic mechanisms. This review describes the processes involved in virus-induced disease progression by viral proteins, derailed signaling, immunity, and persistent epigenetic deregulation, which may be instrumental to develop urgently needed prognostic biomarkers and as targets for novel chemopreventive therapies.

Hepatitis C Virus Translation Regulation

Translation of the hepatitis C virus (HCV) RNA genome is regulated by the internal ribosome entry site (IRES), located in the 5’-untranslated region (5′UTR) and part of the core protein coding sequence, and by the 3′UTR. The 5′UTR has some highly conserved structural regions, while others can assume different conformations. The IRES can bind to the ribosomal 40S subunit with high affinity without any other factors. Nevertheless, IRES activity is modulated by additional cis sequences in the viral genome, including the 3′UTR and the cis-acting replication element (CRE). Canonical translation initiation factors (eIFs) are involved in HCV translation initiation, including eIF3, eIF2, eIF1A, eIF5, and eIF5B. Alternatively, under stress conditions and limited eIF2-Met-tRNA_i^Met availability, alternative initiation factors such as eIF2D, eIF2A, and eIF5B can substitute for eIF2 to allow HCV translation even when cellular mRNA translation is downregulated. In addition, several IRES trans-acting factors (ITAFs) modulate IRES activity by building large networks of RNA-protein and protein–protein interactions, also connecting 5′- and 3′-ends of the viral RNA. Moreover, some ITAFs can act as RNA chaperones that help to position the viral AUG start codon in the ribosomal 40S subunit entry channel. Finally, the liver-specific microRNA-122 (miR-122) stimulates HCV IRES-dependent translation, most likely by stabilizing a certain structure of the IRES that is required for initiation.

Single-molecular real-time deep sequencing reveals the dynamics of multi-drug resistant haplotypes and structural variations in the hepatitis C virus genome

While direct-acting antivirals (DAAs) for hepatitis C virus (HCV) have dramatically progressed, patients still suffer from treatment failures. For the radical eradication of HCV, a deeper understanding of multiple resistance-associated substitutions (RASs) at the single-clone level is essential. To understand HCV quasispecies and their dynamics during DAA treatment, we applied single-molecule real-time (SMRT) deep sequencing on sera from 12 patients with genotype-1b HCV infections with DAA treatment failures, both pre- and post-treatment. We identified >3.2 kbp sequences between NS3 and NS5A genes of 187,539 clones in total, classifying into haplotype codes based on the linkage of seven RAS loci. The number of haplotype codes during the treatment, per sample, significantly decreased from 14.67 ± 9.12 to 6.58 ± 7.1, while the number of nonsynonymous codons on the seven RAS loci, per clone, significantly increased from 1.50 ± 0.92 to 3.64 ± 0.75. In five cases, the minority multi-drug resistant haplotypes at pre-treatment were identical to the major haplotypes at relapse. Moreover, various structural variations (SVs) were detected and their dynamics analysed. These results suggest that SMRT deep sequencing is useful for detecting minority haplotypes and SVs, and to evaluate the dynamics of viral genomes at the single-clone level.

Reprogramming of cellular metabolic pathways by human oncogenic viruses

Oncogenic viruses, like all viruses, relies on host metabolism to provide the metabolites and energy needed for virus replication. Many DNA tumor viruses and retroviruses will reprogram metabolism during infection. Additionally, some viral oncogenes may alter metabolism independent of virus replication. Virus infection and cancer development share many similarities regarding metabolic reprogramming as both processes demand increased metabolic activity to produce biomass: cell proliferation in the case of cancer and virion production in the case of infection. This review discusses the parallels in metabolic reprogramming between human oncogenic viruses and oncogenesis.

Hepatitis C Virus Downregulates Core Subunits of Oxidative Phosphorylation, Reminiscent of the Warburg Effect in Cancer Cells

Hepatitis C Virus (HCV) mainly infects liver hepatocytes and replicates its single-stranded plus strand RNA genome exclusively in the cytoplasm. Viral proteins and RNA interfere with the host cell immune response, allowing the virus to continue replication. Therefore, in about 70% of cases, the viral infection cannot be cleared by the immune system, but a chronic infection is established, often resulting in liver fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Induction of cancer in the host cells can be regarded to provide further advantages for ongoing virus replication. One adaptation in cancer cells is the enhancement of cellular carbohydrate flux in glycolysis with a reduction of the activity of the citric acid cycle and aerobic oxidative phosphorylation. To this end, HCV downregulates the expression of mitochondrial oxidative phosphorylation complex core subunits quite early after infection. This so-called aerobic glycolysis is known as the “Warburg Effect” and serves to provide more anabolic metabolites upstream of the citric acid cycle, such as amino acids, pentoses and NADPH for cancer cell growth. In addition, HCV deregulates signaling pathways like those of TNF-β and MAPK by direct and indirect mechanisms, which can lead to fibrosis and HCC.

Role of Liver Stiffness Measurement in Predicting HCC Occurrence in Direct-Acting Antivirals Setting: A Real-Life Experience

PURPOSE

The aim of this study was to evaluate the relationship between the liver stiffness measurement and the risk of developing hepatocellular carcinoma (HCC) in HCV cirrhotic patients undergoing new direct-acting antivirals.

METHODS

From April 2015 to April 2017, all consecutive HCV cirrhotic patients treated by direct-acting antivirals were enrolled. A liver stiffness measurement was computed at baseline, and an ultrasound evaluation was provided for all patients at baseline and every 6 months until 1 year after the stopping of the antiviral therapy. The diagnosis of HCC was performed according to international guidelines by imaging technique workup.

RESULTS

Two hundred and fifty-eight HCV patients with a diagnosis of cirrhosis were identified. The median liver stiffness was 25.5 kPa. Thirty-five patients developed HCC. Patients were divided into three groups, based on their liver stiffness: < 20 kPa (n = 72), between 20 and 30 kPa (n = 92) and > 30 kPa (n = 94). Compared to the < 20 kPa and 20-30 kPa groups, the > 30 kPa group showed a statistically significant increased risk of HCC (p = 0.019; HR 0.329; 95% CI 0.131-0.830). A ROC curve analysis to assess the overall predictive performance of liver stiffness measurement on the HCC risk was performed. The results allow us to identify a cutoff value of liver stiffness measurement equal to 27.8 kPa, which guarantees the highest sensitivity and specificity (respectively, 72% and 65%).

CONCLUSIONS

The data underline that the baseline liver stiffness measurement and ultrasound surveillance is a valuable tool for assessing the risk of HCC in cirrhotic patients undergoing the direct-acting antivirals treatment.

Intermediate stage hepatocellular carcinoma: a summary review

It is well known that intermediate stage hepatocellular carcinoma (HCC) encompasses the widest class of patients with this disease. The main characteristic of this special sub-group of patients is that it is extensively heterogenous. This substantial heterogeneity is due to the wide range of liver functions of such patients and variable tumor numbers and sizes. Real world clinical data show huge support for transarterial chemo-embolization (TACE) as a therapeutic modality for intermediate stage HCC, applied in 50%-60% of those class of patients. There are special considerations in various international guidelines regarding treatment allocation in intermediate stage HCC. There is an epidemiological difference in HCC in eastern and western cohorts, and various guidelines have been proposed. In patients with HCC, it has frequently been reported that there is poor correlation between the clinical benefit and real gain in patient condition and the conventional way of tumor response assessment after locoregional treatments. This is due to the evaluation criteria in addition to the scoring systems used for treatment allocation in those patients. It became clear that intermediate stage HCC patients receiving TACE need a proper prognostic score that offers valid clinical prediction and supports proper decision-making. Also, it is the proper time to study more treatment options beyond TACE, such as multimodal regimens for this class of patients. In this review, we tried to provide a summary of the challenges and future directions in managing patients with intermediate stage HCC.

Humanized Mouse Models for the Study of Hepatitis C and Host Interactions

Hepatitis C virus (HCV) infection is commonly attributed as a major cause of chronic hepatotropic diseases, such as, steatosis, cirrhosis and hepatocellular carcinoma. As HCV infects only humans and primates, its narrow host tropism hampers in vivo studies of HCV-mammalian host interactions and the development of effective therapeutics and vaccines. In this context, we will focus our discussion on humanized mice in HCV research. Here, these humanized mice are defined as animal models that encompass either only human hepatocytes or both human liver and immune cells. Aspects related to immunopathogenesis, anti-viral interventions, drug testing and perspectives of these models for future HCV research will be discussed.

Addressing the Challenges of Hepatitis C Cure and Persistent Risk of Hepatocellular Carcinoma

Chronic hepatitis C virus (HCV) infection is a major cause of liver disease and hepatocellular carcinoma (HCC)-the second leading, and rising, cause of death due to cancer world-wide [...].

Hepatitis C Virus-Induced FUT8 Causes 5-FU Drug Resistance in Human Hepatoma Huh7.5.1 Cells

Hepatitis C virus (HCV) is a major cause of human chronic liver disease and hepatocellular carcinoma. Our recent studies showed that α1,6-fucosyltransferase (FUT8), a key glycosyltransferase, was the most up-regulated glycosyltransferase after the HCV infection of human hepatocellular carcinoma Huh7.5.1 cells. Here, we further studied the effects and possible mechanism of FUT8 on the proliferation of HCV and chemotherapy-resistance of HCV-infected Huh7.5.1 cells. The effects of FUT8 on the proliferation and drug resistance of HCV-infected Huh7.5.1 cells were analyzed by flow cytometry analysis (FCM), quantitative real-time polymerase chain reaction (qRT-PCR), Western blot analysis and lactate dehydrogenase (LDH) release assay. Results: We found that FUT8 not only promoted Huh7.5.1 proliferation by activating PI3K-AKT-NF-κB signaling, but also stimulated the expression of the drug-resistant proteins P-glycoprotein (P-gp) and multidrug resistance related protein 1 (MRP1) and enhanced the 5-fluorouracil (5-FU) chemo-resistance of Huh7.5.1 cells. Silencing of FUT8 reduced the cell proliferation and increased the 5-FU sensitivity of HCV-infected Huh7.5.1 cells. Inhibition of P-gp and MRP1 increased the 5-FU drug sensitivity in HCV infected Huh7.5.1 cells. HCV-induced FUT8 promotes proliferation and 5-FU resistance of Huh7.5.1 cells. FUT8 may serve as a therapeutic target to reverse chemotherapy resistance in HCV-infected Huh7.5.1 cells.

Melatonin maximizes the therapeutic potential of non-preconditioned MSCs in a DEN-induced rat model of HCC

Pretreatment of mesenchymal stem cells (MSCs) with melatonin (Mel) improves their potential therapeutic effect on chronic diseases and cancers. However, this preconditioning strategy may direct the effect of Mel toward MSCs alone and deprive cancer cells of the oncostatic effect of Mel. Herein, we hypothesized that Mel given before transplantation of non-preconditioned MSCs may maximize the therapeutic outcome via the oncostatic effect of Mel by preparing a suitable tumor microenvironment for MSCs. Female rats (n = 60) were equally divided into 6 groups; normal control, diethylnitrosamine (DEN), DEN + Mel, DEN + MSCs, DEN + MSCs preconditioned with Mel, and DEN + MSCs + Mel. The obtained data revealed that administration of Mel before MSCs treatment without preconditioning yielded a better ameliorative effect against DEN-induced hepatocellular carcinoma (HCC) as evidenced by: 1) reduced serum levels of alpha fetoprotein and gamma-glutamyl transferase; 2) decreased number and area of glutathione S-transferase placental positive foci; 3) induced apoptosis (as indicated by increased cleaved caspase-3 activity, upregulated expression of proapoptotic genes Bax and caspase 3 and downregulated expression of anti-apoptotic genes Bcl2, survivin); 4) decreased malondialdehyde level and increased activities of superoxide dismutase, catalase, and glutathione peroxidase enzymes; and 5) reduced inflammation, angiogenesis and metastasis as indicated by downregulated expression of interleukin 1 beta, nuclear factor kappa B, vascular endothelial growth factor, and matrix metallopeptidase 9 genes and upregulated expression of metalloproteinase inhibitor 1 gene. Thus, administration of Mel before MSCs (without preconditioning) fostered the survival and therapeutic potential of MSCs in HCC, possibly through induction of apoptosis and inhibition of inflammation and oxidative stress. This new strategy showed better therapeutic outcomes and may improve MSC-based therapies for HCC.

Non-Coding RNAs and Hepatitis C Virus-Induced Hepatocellular Carcinoma

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.