Pathogenic mechanisms in HBV- and HCV-associated hepatocellular carcinoma

Frequency and geographic distribution of TERT promoter mutations in primary hepatocellular carcinoma

Primary hepatocellular carcinoma (HCC) mainly develops in subjects chronically infected with hepatitis B (HBV) and C (HCV) viruses through a multistep process characterized by the accumulation of genetic alterations in the human genome. Nucleotide changes in coding regions (i.e. TP53, CTNNB1, ARID1A and ARID2) as well as in non-coding regions (i.e. TERT promoter) are considered cancer drivers for HCC development with variable frequencies in different geographic regions depending on the etiology and environmental factors. Recurrent hot spot mutations in TERT promoter (G > A at-124 bp; G > A at -146 bp), have shown to be common events in many tumor types including HCC and to up regulate the expression of telomerases. We performed a comprehensive review of the literature evaluating the differential distribution of TERT promoter mutations in 1939 primary HCC from four continents. Mutation rates were found higher in Europe (56.6%) and Africa (53.3%) than America (40%) and Asia (42.5%). In addition, HCV-related HCC were more frequently mutated (44.8% in US and 69.7% in Asia) than HBV-related HCC (21.4% in US and 45.5% in Africa). HCC cases associated to factors other than hepatitis viruses are also frequently mutated in TERT promoter (43.6%, 52.6% and 57.7% in USA, Asia and Europe, respectively). These results support a major role for telomere elongation in HCV-related and non-viral related hepatic carcinogenesis and suggest that TERT promoter mutations could represent a candidate biomarker for the early detection of liver cancer in subjects with HCV infection or with metabolic liver diseases.

Hepatitis C virus core protein increases Snail expression and induces epithelial-mesenchymal transition through the signal transducer and activator of transcription 3 pathway in hepatoma cells

AIM

Aberrant expression of Snail, a mediator of epithelial-mesenchymal transition (EMT), is crucial for cancer invasiveness and metastasis. Although hepatitis C virus (HCV) core protein has been implicated in hepatocarcinogenesis, the relationship between HCV core and Snail expression has not been clarified.

METHODS

HepG2 and Huh7 stable cell lines were established by transfection with pcDNA-HCVc. HepG2-HCVc and Huh7-HCVc cells were co-administered with AG490. Cell migration and invasiveness were tested. STAT3 and Snail expression was analyzed by Real-time PCR and Western blot.

RESULTS

We found that HCV core is capable of increasing Snail expression and inducing EMT in hepatoma cells. HCV core-induced Snail expression was accompanied by activation of signal transducer and activator of transcription 3 (STAT3), inhibition of STAT3 abrogated HCV core-induced Snail expression and EMT. Furthermore, chromatin immunoprecipitation showed that phosphorylated STAT3 directly binds to the Snail promoter.

CONCLUSION

Collectively, these results suggest that HCV core would play a role in hepatocellular carcinoma invasiveness and metastasis by activating the STAT3 pathway, increasing Snail expression and subsequently triggering EMT. These findings would advance the understanding of HCV-mediated invasiveness and metastasis, and might provide a new potential therapeutic target for HCV-related hepatocellular carcinoma.

Hepatitis B virus PreS1 facilitates hepatocellular carcinoma development by promoting appearance and self-renewal of liver cancer stem cells

Hepatitis B virus (HBV) is a major etiologic agent of hepatocellular carcinoma (HCC). However, the molecular mechanism by which HBV infection contributes to HCC development is not fully understood. Here, we initially showed that HBV stimulates the production of cancer stem cells (CSCs)-related markers (CD133, CD117 and CD90) and CSCs-related genes (Klf4, Sox2, Nanog, c-Myc and Oct4) and facilitates the self-renewal of CSCs in human hepatoma cells. Cellular and clinical studies revealed that HBV facilitates hepatoma cell growth and migration, enhances white blood cell (WBC) production in the sera of patients, stimulates CD133 and CD117 expression in HCC tissues, and promotes the CSCs generation of human hepatoma cells and clinical cancer tissues. Detailed studies revealed that PreS1 protein of HBV is required for HBV-mediated CSCs generation. PreS1 activates CD133, CD117 and CD90 expression in normal hepatocyte derived cell line (L02) and human hepatoma cell line (HepG2 and Huh-7); facilitates L02 cells migration, growth and sphere formation; and finally enhances the abilities of L02 cells and HepG2 cells to induce tumorigeneses in nude mice. Thus, PreS1 acts as a new oncoprotein to play a key role in the appearance and self-renewal of CSCs during HCC development.

Hepatitis delta and HIV infection

Viral liver diseases are frequent comorbidities and major contributors to death in HIV-positive individuals on antiretroviral therapy. Although cure of hepatitis C and control of hepatitis B with antivirals avert liver disease progression in most HIV-coinfected patients, the lack of satisfactory treatment for hepatitis delta virus (HDV) infection remains a major threat for developing cirrhosis and liver cancer in this population. In the European Union (EU) and North America, sexual contact has replaced injection drug use that has been the major transmission route for HDV in HIV-positive persons. PegIFNα is the only approved HDV therapy; however, sustained HDV-RNA clearance is achieved by less than 25%. The recent discovery of sodium taurocholate cotransporting polypeptide as the key hepatitis B virus (HBV) and HDV cell entry receptor has opened the door to a new therapeutic era. Indeed, promising results have been released using Myrcludex-B, a sodium taurocholate cotransporting polypeptide inhibitor. More encouraging are data with new classes of HDV blockers, such as prenylation inhibitors (i.e. lonafarnib) and nucleic acid polymers. At this time, sustained suppression of HDV replication is the primary goal of HDV therapy, as it is associated with normalization of liver enzymes and histological improvement. Of note, the use of specific antivirals for HDV must be given along with anti-HBV agents to prevent HBV rebounds following removal of viral interference. The lack of persistent forms of HDV-RNA could provide a unique opportunity for curing hepatitis delta, even without eliminating HBV circular covalently closed DNA. Ultimately, suppression of HDV replication along with hepatitis B surface antigen clearance once drugs are off would be the best reflect of hepatitis delta cure.

In Vitro Antiviral Activity and Resistance Profile of the Next-Generation Hepatitis C Virus NS5A Inhibitor Pibrentasvir

Pibrentasvir (ABT-530) is a novel and pan-genotypic hepatitis C virus (HCV) NS5A inhibitor with 50% effective concentration (EC₅₀) values ranging from 1.4 to 5.0 pM against HCV replicons containing NS5A from genotypes 1 to 6. Pibrentasvir demonstrated similar activity against a panel of chimeric replicons containing HCV NS5A of genotypes 1 to 6 from clinical samples. Resistance selection studies were conducted using HCV replicon cells with NS5A from genotype 1a, 1b, 2a, 2b, 3a, 4a, 5a, or 6a at a concentration of pibrentasvir that was 10- or 100-fold over its EC₅₀ for the respective replicon. With pibrentasvir at 10-fold over the respective EC₅₀, only a small number of colonies (0.00015 to 0.0065% of input cells) with resistance-associated amino acid substitutions were selected in replicons containing genotype 1a, 2a, or 3a NS5A, and no viable colonies were selected in replicons containing NS5A from other genotypes. With pibrentasvir at 100-fold over the respective EC₅₀, very few colonies (0.0002% of input cells) were selected by pibrentasvir in genotype 1a replicon cells while no colonies were selected in other replicons. Pibrentasvir is active against common resistance-conferring substitutions in HCV genotypes 1 to 6 that were identified for other NS5A inhibitors, including those at key amino acid positions 28, 30, 31, or 93. The combination of pibrentasvir with HCV inhibitors of other classes produced synergistic inhibition of HCV replication. In summary, pibrentasvir is a next-generation HCV NS5A inhibitor with potent and pan-genotypic activity, and it maintains activity against common amino acid substitutions of HCV genotypes 1 to 6 that are known to confer resistance to currently approved NS5A inhibitors.

Oncolytic Virus-Based Immunotherapies for Hepatocellular Carcinoma

Hepatocellular carcinoma is highly refractory cancer which is resistant to conventional chemotherapy and radiotherapy, carrying a dismal prognosis. Although many anticancer drugs have been developed for treating HCC, sorafenib is the only effective treatment, but it only prolongs survival duration for about 3 months. Recently, oncolytic virotherapy has shown promising results in treating HCCs and the effects can be more enhanced by adopting immune modulatory molecules. This review discusses the current status of treating HCC and the effective strategy of oncolytic virus-based immunotherapy for the treatment of HCCs.

The risk of HCV infection among health-care workers and its association with extrahepatic manifestations (Review)

Health care workers (HCWs) are frequently exposed to different biological agents during their activities and are frequently monitored. Among these infectious agents, human hepatitis C (HCV) can infect HCWs. In this review article, the risk of HCV infection among HCWs is discussed along with extrahepatic HCV-related malignancies, such as non‑Hodgkin lymphoma. Accidental contamination, represented by percutaneous and mucocutaneous infections is the main risk factor for such infection. The compliance of the protection procedures, included in the current regulation for HCWs, is the most important issue to reduce the risk of pathogen infections that in turn may produce reduction of infection‑associated malignancies.

CAMK2γ in intestinal epithelial cells modulates colitis-associated colorectal carcinogenesis via enhancing STAT3 activation

Inflammation is one of the major risk factors for cancer. Here, we show that calcium/calmodulin-dependent protein kinase II gamma (CAMK2γ) in intestinal epithelial cells (IECs) modulates inflammatory signals and promotes colitis-associated cancer (CAC) in mice. We have identified CAMK2γ as a downstream target of colitis-induced WNT5a signaling. Furthermore, we have shown that CAMK2γ protects against intestine tissue injury by increasing IEC survival and proliferation. CAMK2γ knockout mice displayed reduced CAC. Furthermore, we used bone marrow transplantation to reveal that CAMK2γ in IECs, but not immune cells, was crucial for its effect on CAC. Consistently, transgenic over-expression of CAMK2γ in IECs accelerated CAC development. Mechanistically, CAMK2γ in IECs enhanced epithelial STAT3 activation to promote survival and proliferation of colonic epithelial cells during CAC development. These results thus identify a new molecular mechanism mediated by CAMK2γ in IECs during CAC development, thereby providing a potential new therapeutic target for CAC.

The role of exosomes in hepatitis, liver cirrhosis and hepatocellular carcinoma

Exosomes are small vesicles that were initially thought to be a mechanism for discarding unneeded membrane proteins from reticulocytes. Their mediation of intercellular communication appears to be associated with several biological functions. Current studies have shown that most mammalian cells undergo the process of exosome formation and utilize exosome‐mediated cell communication. Exosomes contain various microRNAs, mRNAs and proteins. They have been reported to mediate multiple functions, such as antigen presentation, immune escape and tumour progression. This concise review highlights the findings regarding the roles of exosomes in liver diseases, particularly hepatitis B, hepatitis C, liver cirrhosis and hepatocellular carcinoma. However, further elucidation of the contributions of exosomes to intercellular information transmission is needed. The potential medical applications of exosomes in liver diseases seem practical and will depend on the ingenuity of future investigators and their insights into exosome‐mediated biological processes.

Distinct patterns and prognostic values of tumor-infiltrating macrophages in hepatocellular carcinoma and gastric cancer

Background

Macrophages (Mφs) constitute a major component of the leukocyte infiltrate and perform distinct roles in different tumor microenvironments. This study aimed to characterize the distribution, composition and prognostic value of Mφs in hepatocellular carcinoma (HCC) and gastric cancer (GC).

Methods

Immunohistochemistry and immunofluorescence were used to identify Mφ subsets in HCC and GC tissues. Kaplan–Meier analysis and Cox regression models were applied to estimate the overall survival (OS) for HCC and GC patients.

Results

The results showed that the density of Mφs decreased in the intra-tumor region (IT) of HCC, but remarkably increased in the IT of GC, as compared with their non-tumor regions (NT). In HCC, most CD68⁺ Mφs were CD204⁺ and CD169⁺ cells in the NT region; however, there was a significant decrease in the percentage of CD169⁺ Mφ in the IT region. In contrast, CD68⁺ Mφs comprised a smaller percentage of CD204⁺ than the CD169⁺ subpopulation in the NT region, while more CD204⁺ but fewer CD169⁺ cells were present in the IT region of GC. The density of CD204⁺ Mφs correlated with poor prognosis in HCC, and CD169⁺ Mφs were associated with good survival in both HCC and GC. Moreover, the combination of low numbers of CD204⁺ and high numbers of CD169⁺ Mφs was associated with improved OS in both GC and HCC.

Conclusions

Mφs display tissue-specific distributions and distinct composition patterns in HCC and GC tissues. Our results suggested that different types of tumors might use diverse strategies to reconstitute Mφ patterns to promote tumor progression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1139-2) contains supplementary material, which is available to authorized users.

MicroRNA profile analysis in the liver fibrotic tissues of chronic hepatitis B patients

OBJECTIVE

We aimed to identify the features of microRNA (miRNA) at different fibrotic stages in patients with hepatitis B virus (HBV)-related liver fibrosis.

METHODS

Liver tissues were collected from 40 chronic hepatitis B (CHB) patients at fibrotic stages S0-4. Microarrays of miRNAs and genomic informatics analysis were performed.

RESULTS

In total, 105 miRNAs were differentially expressed in fibrotic tissues (S1-4 groups) compared with no fibrotic tissues (S0 group; P < 0.05). Combined with three classifications, 17 differential miRNAs were found to be closely related to fibrotic stages (over twofold change and P < 0.05). Five miRNAs had a signature that correlated with serum biochemical parameters and liver inflammatory grades. The receiver operating characteristic (ROC) curve showed that six miRNAs performed excellently in the diagnosis of liver fibrosis, with the area under the ROC curve (AUROC) over 0.8; among them hsa-miR-214-3p had the highest AUROC (0.867). Gene ontology functions of differential miRNAs mainly involved in the cellular and developmental processes, localization, biological regulation, binding, transcriptional regulator and organelle. We also found that 23 novel signaling pathways were dysregulated in the liver fibrosis.

CONCLUSIONS

MiRNA profile signature, including 17 differential miRNAs and 23 dysregulated signaling pathways, was associated with liver fibrosis. Hepatic inflammatory grades were correlated with the differential miRNA. Some miRNAs can be used for the diagnosis of liver fibrosis.

Genome-wide association study: new genetic insights into HBV/HCV-related hepatocellular carcinoma genomes

Hepatocellular carcinoma (HCC) is the third common cause of cancer-related death with highest prevalence in developing countries, such as Southeast China and Saharan African. The major pathogenic factors can be categorized into environmental effects and genetic variations, and it is mostly caused by hepatitis B or C virus (HBV and HCV). The geographic prevalence of chronic hepatitis B and C (CHB and CHC) varies, with HBV heavily-infected in developing countries and HCV prevalent in developed countries. The infection of either hepatitis virus B or C causes damage to the liver cells through cellular immune attack by the mechanism of inflammation. However, how liver cell injury progresses to HCC development is still poorly understood. Along with the maturation of genome-wide association study (GWAS) technology, the specific genetic mutations responsible for the progression from CHB or CHC to HCC have been identified. Moreover, the findings of similar studies for these variants are different from each other due to diverse populations. More functional experiments are warranted to confirm the precise roles of these genetic mutations in the correlations between HBV/HCV and HCC for the future clinical application.

COMMD7 promotes hepatocellular carcinoma through regulating CXCL10

Hepatocellular carcinoma (HCC) is still a heavy threat to public health. However, novel therapeutic and diagnostic method for HCC is still urgently needed thus far. Based on sequence analysis and homology comparison, we previously reported a novel gene termed COMMD7, which is mapped to 20q11.22 and promotes cell proliferation in HCC cells. But the molecular mechanisms underlying the pro-tumor property of COMMD7 are not fully addressed yet. In this study, we demonstrate that the conditional medium derived from COMMD7-overexpressed HCC cell promotes proliferation of naïve HCC cells. The over-expression of COMMD7 significantly induced the migratory and invasive in HCC cells. Mechanistic study found that over-expression of COMMD7 induces C-X-C motif chemokine 10 (CXCL10) expression. Blocking CXCL10 signal transduction by neutralizing antibody abolished COMMD7-mediated cell proliferation and migration. In conclusion, COMMD7 promotes hepatocellular carcinoma through regulating CXCL10. The present data suggests a potential role of CXCL10 in the oncogenic function of COMMD7, and will lead to a better understanding of the development of HCC.

Aberrant expression of cell cycle and material metabolism related genes contributes to hepatocellular carcinoma occurrence

This study aims to deepen our understanding of the molecular mechanism underlying the occurrence of hepatocellular carcinoma (HCC). We first downloaded a gene expression profile dataset GSE29721 (10 HCC and 10 control samples) from Gene Expression Omnibus database (http://www.ncbi.nlm.nih.gov/geo/). Differentially expressed genes (DEGs) were identified by the paired t-test using limma package. Pathway and functional enrichment analyses were performed with DAVID tools. Transcription factors were annotated with TRANSFAC database and tumor associated genes (TAGs) were annotated with TAG and TSGene databases. Protein-protein interaction (PPI) network was conducted using STRING online tool and function module was further identified with BioNet package. Totally, 527 up-regulated DEGs and 587 down-regulated DEGs were identified. GO functional and KEGG pathway enrichment analyses showed that the up-regulated DEGs were mainly related to cell division and cell cycle, while the down-regulated DEGs were largely related to material metabolism, especially secondary metabolism. Proteins encoded by DEGs CDK1, BUB1, CDC20, NCAPG, NDC80, CDCA8, MAD2L1, CCNB1, CCNA2 and BIRC5 were hub genes with high degrees in the PPI network; further module analysis detected a subnetwork consisting of 55 proteins, such as CYP2B6, ACAA1, BHMT and ALDH2. Taken together, aberrant expression of cell cycle related genes (e.g., CDK1, CCNA2, CCNB1, BUB1, MAD2L1 and CDC20) and material metabolism related genes (e.g., CYP2B6, ACAA1, BHMT and ALDH2) may contribute to HCC occurrence.

Hepatitis C Virus Induces MDSCs-Like Monocytes through TLR2/PI3K/AKT/STAT3 Signaling

BACKGROUND AND AIMS

Recent studies reveal the accumulation of myeloid derived suppressor cells (MDSCs) in human peripheral blood mononuclear cells (PBMCs) following HCV infection, which may facilitate and maintain HCV persistent infection. The mechanisms by which HCV induces MDSCs are poorly understood. In the present study, we investigated the mechanisms by which HCV induces MDSCs that lead to suppression of T cell proliferation and expansion of CD4+Foxp3+ regulatory T cells.

METHODS

Purified monocytes from healthy donors were cultured with HCV core protein (HCVc) or cell culture-derived HCV virions (HCVcc), and characterized the phenotype and function of these monocytes by flow cytometry, quantitative PCR, ELISA and western blot assays. In addition, peripheral blood from healthy donors and chronic HCV infected patients was collected, and MDSCs and CD4+CD25+CD127- regulatory T cells were analyzed by flow cytometry.

RESULTS

Both HCVc and HCVcc induced expression of IDO1, PD-L1 and IL-10, and significantly down-regulated HLA-DR expression in human monocytes. HCVc-treated monocytes triggered CD4+Foxp3+ Tregs expansion, and inhibited autologous CD4+ T cell activation in an IDO1-dependent fashion. Our results showed that HCV virions or HCV core proteins induced MDSC-like suppressive monocytes via the TLR2/PI3K/AKT/STAT3 signaling pathway. Monocytes derived from patients with chronic HCV infection displayed MDSCs characteristics. Moreover, the percentages of CD14+ MDSCs and CD4+CD25+CD127- Tregs in chronic HCV infected patients were significantly higher than healthy individuals, and the frequency of MDSCs correlated with CD4+CD25+CD127- Tregs.

CONCLUSIONS

HCV induced MDSC-like suppressive monocytes through TLR2/PI3K/AKT/STAT3 signaling pathway to induce CD4+Foxp3+ regulatory T cells and inhibit autologous CD4+ T cell activation. It will be of interest to test whether antagonizing suppressive functions of MDSCs could enhance immune responses and virus control in chronic HCV infection.

Genetic Variations in XRCC4 (rs1805377) and ATF6 (rs2070150) are not Associated with Hepatocellular Carcinoma in Thai Patients with Hepatitis B Virus Infection

The liver is one of the most common sites of cancer in the world, hepatocellular carcinoma (HCC) predominating. Chronic hepatitis B virus infection (CHB) is considered as an important potential risk factors for HCC. Different people have diverse responses to HBV infection regarding the likelihood of HCC development, and host factors such as single nucleotide polymorphisms (SNPs) might account for this. The present study was conducted to evaluate any association between SNP frequencies in two genes, XRCC4 (rs1805377) and ATF6 (rs2070150), and the risk of CHB and HCC development in Thai patients. The study covered 369 subjects including 121 HCC patients, 141 with chronic hepatitis B virus infection (CHB) and 107 healthy controls. With TaqMan real-time PCR, the results showed that no significant association between XRCC4 (rs1805377) and ATF6 (rs2070150) and risk of HCC in the Thai population. From this first study of the 2 polymorphisms and HCC in Thailand it can concluded that rs1805377 and rs2070150 polymorphisms may not be applicable as genetic markers in the Thai population for HCC assessment.

Expression of a hepatitis B virus pre-S2 deletion mutant in the liver results in hepatomegaly and hepatocellular carcinoma in mice

Hepatocellular carcinoma (HCC) is the most common form of liver cancer and has a poor prognosis and a low survival rate; its incidence is on the rise. Hepatitis B virus (HBV) infection is one of the main causes of HCC. A high prevalence of pre-S deletions of HBV surface antigen, which encompass T-cell and/or B-cell epitopes, is found in HBV carriers; antiviral therapy and viral immune escape may cause and select for these HBV mutants. In particular, the presence of pre-S2 deletion mutants is an important risk factor associated with cirrhosis and HCC. We generated Alb-preΔS2 transgenic mice that express a naturally occurring pre-S2 mutant protein containing a 33-nucleotide deletion (preΔS2); the aim was to investigate its effect on hepatocarcinogenesis. After 30 months of follow-up, the liver pathology of the mice fell into four groups: G1, chronic inflammation solely; G2, chronic inflammation and fibrosis; G3, inflammation, fibrosis, and hepatomegaly accompanied by rectal prolapse (4-12%); and G4, hepatomegaly and spontaneous HCC (12-15%). Striking degeneration of the endoplasmic reticulum (ER) was present in the mouse livers at an early stage (4 months old). At 8 months, overt ER stress and the Atf6 pathway of the unfolded protein response (UPR) were induced; at the same time, metabolic pathways associated with mevalonate and cholesterol biogenesis, involving the peroxisomes and the ER, were disturbed. At 20 months and older, the protein kinase RNA-like endoplasmic reticulum kinase (PERK) pathway of the UPR was induced and the Hippo transducer Yap was activated. Together, these ultrastructural aberrations and metabolic disturbance all seem to contribute to the molecular pathogenesis and hepatocarcinogenesis present in the Alb-preΔS2 mice. These findings may contribute to the development of therapies for the liver disorders and HCC associated with pre-S2 deletion mutations among HBV carriers. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Extended chain conformation of β-glucan and its effect on antitumor activity

Extended chain conformation of β-glucan visualized by AFM, and its molecular weight- and chain conformation-dependent antitumor activity.

Implications of oxidative stress on viral pathogenesis

Reactive species are frequently formed after viral infections. Antioxidant defences, including enzymatic and non-enzymatic components, protect against reactive species, but sometimes these defences are not completely adequate. An imbalance in the production of reactive species and the body's inability to detoxify these reactive species is referred to as oxidative stress. The aim of this review is to analyse the role of oxidative stress in the pathogenesis of viral infections and highlight some major therapeutic approaches that have gained importance, with regards to controlling virus-induced oxidative injury. Attention will be focused on DNA viruses (papillomaviruses, hepadnaviruses), RNA viruses (flaviviruses, orthomyxoviruses, paramyxoviruses, togaviruses) and retroviruses (human immunodeficiency virus). In general, viruses cause an imbalance in the cellular redox environment, which depending on the virus and the cell can result in different responses, e.g. cell signaling, antioxidant defences, reactive species, and other processes. Therefore, the modulation of reactive species production and oxidative stress potentially represents a novel pharmacological approach for reducing the consequences of viral pathogenesis.

Tumor-derived CD4+CD25+regulatory T cells inhibit dendritic cells function by CTLA-4

PURPOSE

CD4+CD25+regulatoryT cells (Tregs) play an important role in anti-tumor immune responses. Poor prognosis and declining survival rates have intimate connection with high Treg expression in cancer patients. Cytotoxic T Lymphocyte-associated protein (CTLA-4) is one of the most prominent molecules on Treg. In our previous research, we have demonstrated that HCC-derived Tregs can interfere with Dendritic cells (DCs) function and down-modulate CD80/CD86 on DCs in vitro in a cell-contact dependent way. However the mechanism of how HCC-derived Treg affect DC phenotype are not very clear. Therefore, we investigated the function of CTLA-4 in anti-tumor immune responses.

MATERIALS AND METHODS

We established BABL/C mouse with hepatocellular carcinoma model, and tumor-derived Tregs were purified by magnetic cell sorting using mouse CD4+CD25+regulatoryT cell isolation kit. Splenic DCs were enriched using CD11c-conjugated microbeads. Then splenic DCs co-cultured with tumor-derived Tregs and antibody-blocking experiments was performed.

RESULTS

In our research, we found the down-modulation of CD80/CD86 on DCs was inhibited by blocking CTLA-4. HCC-derived Tregs down-modulated CD80/CD86 on DCs in a CTLA-4-dependent way. Blockade of CTLA-4 can lead to increase DC-mediated immunity.

CONCLUSION

CTLA-4 play a vital role in Treg-mediated immnue inhibition and this discovery can open up new ideas for the development of therapeutic strategies.

Radiomics and circulating tumor cells: personalized care in hepatocellular carcinoma?

Personalized care in oncology is expected to significantly improve morbidity and mortality, facilitated by our increasing understanding of the molecular mechanisms driving tumors and the ability to target those drivers. Hepatocellular carcinoma has a very high mortality to incidence ratio despite localized disease being curable, emphasizing the importance of early diagnosis. Radiomics, the use of imaging technology to extrapolate molecular tumor data, and the detection of circulating tumor cells (CTCs) are two new technologies that could be incorporated into the clinical setting with relative ease. Here we discuss the molecular mechanisms leading to the development of hepatocellular carcinoma focusing on the latest developments in liver magnetic resonance imaging, CTC, and radiomic technology and their potential to improve diagnosis, staging, and therapy.

Redox proteomics screening cellular factors associated with oxidative stress in hepatocarcinogenesis

Liver cancer is a major global health problem being the sixth most common cancer and the third cause of cancer-related death, with hepatocellular carcinoma (HCC) representing more than 90% of primary liver cancers. Mounting evidence suggests that, compared with their normal counterparts, many types of cancer cell have increased levels of ROS. Therefore, cancer cells need to combat high levels of ROS, especially at early stages of tumor development. Recent studies have revealed that ROS-mediated regulation of redox-sensitive proteins (redox sensors) is involved in the pathogenesis and/or progression of many human diseases, including cancer. Unraveling the altered functions of redox sensors and the underlying mechanisms in hepatocarcinogenesis is critical for the development of novel cancer therapeutics. For this reason, redox proteomics has been developed for the high-throughput screening of redox sensors, which will benefit the development of novel therapeutic strategies for the treatment of HCC. In this review, we will briefly introduce several novel redox proteomics techniques that are currently available to study various oxidative modifications in hepatocarcinogenesis and summarize the most important discoveries in the study of redox processes related to the development and progression of HCC.

New chemical treatment options in second-line hepatocellular carcinoma: what to do when sorafenib fails?

INTRODUCTION

There have been no therapies available for patients who experience disease progression after sorafenib treatment. Regorafenib inhibits multiple kinases involved in tumor proliferation and neoangiogenesis, which has produced a survival benefit in hepatocellular carcinoma (HCC) after sorafenib failure. Other active candidate agents are c-Met inhibitors and immune checkpoint inhibitors. Areas covered: This paper presents an updated summary of the preclinical and clinical experience with regorafenib, c-Met inhibitors (tivantinib, cabozantinib and tepotinib), and a checkpoint inhibitor (nivolumab, pembrolizumab) in HCC. The reported data were obtained from abstracts of international conferences and journal articles published up to August 2016 and found in a PubMed search. Expert opinion: Based on favorable data from preclinical and clinical trials, regorafenib, c-Met inhibitor, and checkpoint inhibitors are promising agents for HCC after sorafenib failure. However, further efforts to maximize the survival benefit and minimize adverse events of these drugs in the treatment of HCC are still necessary. Additionally, searching for predictors of good responders could allow these new drugs to be applied in personalized treatments of HCC.

Investigating genetic characteristics of hepatitis B virus-associated and -non-associated hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a primary liver malignancy that mainly occurs in patients with chronic liver disease and cirrhosis. Risk factors for HCC include hepatitis B virus (HBV) infection. However, the specific role of HBV infection in HCC development is not yet completely understood. In order to reveal the effects of HBV on HCC, we compare the genes of HCC patients infected with HBV with those who are not infected.

METHODS

We encoded the genes of these two types of HCC in databases using enrichment scores of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway terms. A random forest algorithm was employed in order to distinguish these two types in the classifier, and a series of feature selection approaches was used in order to select their optimal features. Novel HBV-associated and -non-associated HCC genes were predicted, respectively, based on their optimal features in the classifier. A shortest-path algorithm was also employed in order to find all of the shortest-paths genes connecting the known related genes.

RESULTS

A total of 54 different features between HBV-associated and -non-associated HCC genes were identified. In total, 1236 and 881 novel related genes were predicted for HBV-associated and -non-associated HCC, respectively. By integrating the predicted genes and shortest path genes in their gene interaction network, we identified 679 common genes involved in the two types of HCC.

CONCLUSION

We identified the significantly different genetic features between two types of HCC. We also predicted related genes for the two types based on their specific features. Finally, we determined the common genes and features that were involved in both of these two types of HCC.

Oxidative Stress and Liver Cancer: Etiology and Therapeutic Targets

Accumulating evidence has indicated that oxidative stress (OS) is associated with the development of hepatocellular carcinoma (HCC). However, the mechanisms remain largely unknown. Normally, OS occurs when the body receives any danger signal-from either an internal or external source-and further induces DNA oxidative damage and abnormal protein expression, placing the body into a state of vulnerability to the development of various diseases such as cancer. There are many factors involved in liver carcinogenesis, including hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, alcohol abuse, and nonalcoholic fatty liver disease (NAFLD). The relationship between OS and HCC has recently been attracting increasing attention. Therefore, elucidation of the impact of OS on the development of liver carcinogenesis is very important for the prevention and treatment of liver cancer. This review focuses mainly on the relationship between OS and the development of HCC from the perspective of cellular and molecular mechanisms and the etiology and therapeutic targets of HCC.

CAMK2γ antagonizes mTORC1 activation during hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is one of the most deadly cancers that still lacks effective treatments. Dysregulation of kinase signaling has frequently been reported to contribute to HCC. In this study, we used bioinformatic approaches to identify kinases that regulate gene expression changes in human HCCs and two murine HCC models. We identified a role for calcium/calmodulin-dependent protein kinases II gamma isoform (CAMK2γ) in hepatocarcinogenesis. CAMK2γ^-/- mice displayed severely enhanced chemical-induced hepatocarcinogenesis compared with wild-type controls. Mechanistically, CAMK2γ deletion potentiates hepatic activation of mechanistic target of rapamycin complex 1 (mTORC1), which results in hyperproliferation of hepatocytes. Inhibition of mTORC1 by rapamycin effectively attenuates the compensatory proliferation of hepatocytes in CAMK2γ^-/- livers. We further demonstrated that CAMK2γ suppressed growth factor- or insulin-induced mTORC1 activation by inhibiting IRS1/AKT signaling. Taken together, our results reveal a novel mechanism by which CAMK2γ antagonizes mTORC1 activation during hepatocarcinogenesis.

A prominent role of Hepatitis D Virus in liver cancers documented in Central Africa

Background

Hepatocellular Carcinoma (HCC) is one of the commonest cancers in Central Africa, a region with the unusual peculiarity to be hyperendemic for infections with Hepatitis B, C and D viruses. However, data estimating the respective proportions of HCC cases attributable to these viruses are still limited in this area. The current study was undertaken to determine the role of these viruses in HCC compared to non-HCC Cameroonian patients.

Methods

A case–control study was conducted in the Gastroenterology Unit of Central Hospital of Yaounde in collaboration with Centre Pasteur of Cameroon. Blood samples of all HCC cases (n = 88) and matched control individuals without known liver disease (n = 85) were tested for serological markers of Hepatitis B, C and D viral infections using commercially available enzyme immune-assay kits. Hepatitis B and C viral loads were quantified for positive patients by real-time PCR using commercial kits.

Results

The mean age was 46.0 ± 18 and 42.1 ± 16 years old for HCC-patients and controls, respectively for a 2.3 Male/Female sex ratio. The prevalence of hepatitis B surface antigen, antibody to HCV and antibody to HDV were significantly higher in HCC patients (65.90, 20.26 and 26 % respectively) than in control patients (9.23, 4.62 and 1 %) (P < 2.5 10⁻⁵). The risk factors analysis showed that both HBV and HCV infections were strongly associated with HCC development in Cameroon with crude odds ratios of 15.98 (95 % CI 6.19-41.25) and 7.33 (95 % CI 2.09-25.77), respectively. Furthermore, the risk of developing HCC increased even more significantly in case of HBV and HDV co-infections with the odd ratio of 29.3 (95 % CI, 4.1-1231). HBV-DNA level was significantly higher in HBsAg-positive HCC-patients than in HBsAg-positive controls with (6.3 Log IU/mL and 5.7 Log IU/mL) respectively (P < 0.05).

Conclusion

HBV and HCV infections are the mains factors of HCC development in Cameroon. Our results show that patients co-infected with HDV are at very high risk to develop HCC. An active surveillance program of patients and, foremost, an easier access to antivirals and primary prevention measures are crucial steps to reduce the incidence of HCC in this country. Due to the lack of truly efficient antiviral therapy, the fate of HDV-infected patients remains, however, particularly worrying.

Liver Monocytes and Kupffer Cells Remain Transcriptionally Distinct during Chronic Viral Infection

Due to the scarcity of immunocompetent animal models for chronic viral hepatitis, little is known about the role of the innate intrahepatic immune system during viral replication in the liver. These insights are however fundamental for the understanding of the inappropriate adaptive immune responses during the chronic phase of the infection. We apply the Lymphocytic Choriomenigitis Virus (LCMV) clone 13 mouse model to examine chronic virus-host interactions of Kupffer cells (KC) and infiltrating monocytes (IM) in an infected liver. LCMV infection induced overt clinical hepatitis, with rise in ALT and serum cytokines, and increased intrahepatic F4/80 expression. Despite ongoing viral replication, whole liver transcriptome showed baseline expression levels of inflammatory cytokines, interferons, and interferon induced genes during the chronic infection phase. Transcriptome analyses of sorted KC and IMs using NanoString technology revealed two unique phenotypes with only minimal overlap. At the chronic viral infection phase, KC showed no increased transcription of activation markers Cd80 and Cd86, but an increased expression of genes related to antigen presentation, whereas monocytes were more activated and expressed higher levels of Tnf transcripts. Although both KCs and intrahepatic IM share the surface markers F4/80 and CD11b, their transcriptomes point towards distinctive roles during virus-induced chronic hepatitis.

Novel histone deacetylase inhibitor MPT0G009 induces cell apoptosis and synergistic anticancer activity with tumor necrosis factor-related apoptosis-inducing ligand against human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a frequent cause of cancer-related death; therefore, more effective anticancer therapies for the treatment of HCC are needed. Histone deacetylase (HDAC) inhibitors serve as promising anticancer drugs because they can induce cell growth arrest and apoptosis. We previously reported that 3-[1-(4-methoxybenzenesulfonyl)-2,3-dihydro-1H-indol-5-yl]-N-hydroxyacrylamide (MPT0G009)—a novel 1-arylsulfonyl-5-(N-hydroxyacrylamide)indolines compound—demonstrated potent pan-HDAC inhibition and anti-inflammatory effects. In this study, we evaluated the anti-HCC activity of MPT0G009 in vitro and in vivo. Growth inhibition, apoptosis, and inhibited HDAC activity induced by MPT0G009 were more potent than a marketed HDAC inhibitor SAHA (Vorinostat). Furthermore, MPT0G009-induced apoptosis of Hep3B cells was characterized by an increase in apoptotic (sub-G1) population, loss of mitochondrial membrane potential, activation of caspase cascade, increased levels of pro-apoptotic protein (Bim), and decreased levels of anti-apoptotic proteins (Bcl-2, Bcl-x_L, and FLICE-inhibitory protein); the downregulation FLIP by MPT0G009 is mediated through proteasome-mediated degradation and transcriptional suppression. In addition, combinations of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) with lower concentrations (0.1 μM) of MPT0G009 were synergistic in cell growth inhibition and apoptosis in HCC cells. In the in vivo model, MPT0G009 markedly reduced Hep3B xenograft tumor volume, inhibited HDAC activities, and induced apoptosis in the Hep3B xenografts. Our results demonstrate that MPT0G009 is a potential new candidate drug for HCC therapy.

Hepatitis B virus inhibits insulin receptor signaling and impairs liver regeneration via intracellular retention of the insulin receptor

Hepatitis B virus (HBV) causes severe liver disease but the underlying mechanisms are incompletely understood. During chronic HBV infection, the liver is recurrently injured by immune cells in the quest for viral elimination. To compensate tissue injury, liver regeneration represents a vital process which requires proliferative insulin receptor signaling. This study aims to investigate the impact of HBV on liver regeneration and hepatic insulin receptor signaling. After carbon tetrachloride-induced liver injury, liver regeneration is delayed in HBV transgenic mice. These mice show diminished hepatocyte proliferation and increased expression of fibrosis markers. This is in accordance with a reduced activation of the insulin receptor although HBV induces expression of the insulin receptor via activation of NF-E2-related factor 2. This leads to increased intracellular amounts of insulin receptor in HBV expressing hepatocytes. However, intracellular retention of the receptor simultaneously reduces the amount of functional insulin receptors on the cell surface and thereby attenuates insulin binding in vitro and in vivo. Intracellular retention of the insulin receptor is caused by elevated amounts of α-taxilin, a free syntaxin binding protein, in HBV expressing hepatocytes preventing proper targeting of the insulin receptor to the cell surface. Consequently, functional analyses of insulin responsiveness revealed that HBV expressing hepatocytes are less sensitive to insulin stimulation leading to delayed liver regeneration. This study describes a novel pathomechanism that uncouples HBV expressing hepatocytes from proliferative signals and thereby impedes compensatory liver regeneration after liver injury.

Circulating visfatin level is associated with hepatocellular carcinoma in chronic hepatitis B or C virus infection

Adipocytokines play an important role in adipose tissue homeostasis, especially in obesity-associated disorders such as non-alcoholic fatty liver and their complications including hepatocellular carcinoma (HCC). Although visfatin is an adipocytokine highly expressed in visceral fat that has been demonstrated to play a critical role in the progression of human malignancies, little is known about the role of visfatin in HCC associated with chronic hepatitis C virus (HCV) and hepatitis B virus (HBV) infection. In this study, we investigated whether plasma visfatin levels were altered in patients with HCC and the association between plasma visfatin levels and pretreatment hematologic profiles. Plasma visfatin levels were measured by enzyme-linked immunosorbent assays in 193 patients with different stages of HBV or HCV infection, and 92 healthy control subjects. The patients with HCC and chronic HCV or HBV infection had higher levels of visfatin than patients with HBV, HCV, and cirrhosis. In multivariate logistic regression analysis, levels of alpha-fetoprotein (AFP) (OR: 1.13, p=0.003), and plasma visfatin (OR: 1.17, p=0.046) were independently associated with HCC. Multiple stepwise regression analysis showed that plasma visfatin level was positively associated with age, aspartate aminotransferase to platelet ratio index (APRI), and AFP. Trend analyses confirmed that plasma visfatin concentration was associated with AFP>8ng/mL, cirrhosis, HCC, tumor size>5cm, and Barcelona Clinic Liver Cancer-C stage. These results suggested that the plasma visfatin level is associated with the presence of HCC, and that a higher plasma visfatin level may be important in the pathogenesis of HCC. Visfatin may act as both a protective and pro-inflammatory factor. Plasma visfatin concentration may serve as an additional tool to identify patients with more advanced necroinflammation.

Hepatitis C virus drives the pathogenesis of hepatocellular carcinoma: from immune evasion to carcinogenesis

Persistent hepatitis C virus (HCV) infection is associated with high incidence of hepatocellular carcinoma (HCC), the most common primary malignancy of the liver with over half a million new cases diagnosed annually worldwide. The aryl hydrocarbon receptor (AhR) is a ubiquitously expressed transcription factor and its activation by environmental chemicals and by its endogenous ligand kynurenine (Kyn) has been implicated in a variety of tumour-promoting processes such as transformation, tumorigenesis and in immunosuppression that enables tumour survival and growth. Kyn is generated constitutively by human tumour cells via tryptophan (Trp)-2,3-dioxygenase (TDO), a Trp-degrading enzyme expressed in liver, brain and cancer cells. Notably, it has been shown that TDO-derived Kyn suppresses anti-tumour immune responses, thus promoting tumour-cell survival through activation of the AhR pathway. In the context of HCV infection-associated HCC, it was shown that AhR signalling is increased in HCV-infected hepatocytes, and that modifications in the expression of AhR pathway-specific genes are associated with the progression of HCV infection into HCC. Based on these observations, we present and discuss here the hypothesis that HCV infection promotes HCC by modulation of the TDO-Kyn-AhR pathway, resulting in tumorigenesis as well as in suppression of both anti-HCV and anti-tumour immune responses.

Efficacy of Prophylactic Entecavir for Hepatitis B Virus-Related Hepatocellular Carcinoma Receiving Transcatheter Arterial Chemoembolization

BACKGROUND AND AIMS

Hepatitis B virus (HBV) reactivation was reported to be induced by transcatheter arterial chemoembolization (TACE) in HBV-related hepatocellular carcinonma (HCC) patients with a high incidence. The effective strategy to reduce hepatitis flares due to HBV reactivation in this specific group of patients was limited to lamivudine. This retrospective study was aimed to investigate the efficacy of prophylactic entecavir in HCC patients receiving TACE.

METHODS

A consecutive series of 191 HBV-related HCC patients receiving TACE were analyzed including 44 patients received prophylactic entecavir. Virologic events, defined as an increase in serum HBV DNA level to more than 1 log10 copies/ml higher than nadir the level, and hepatitis flares due to HBV reactivation were the main endpoints.

RESULTS

Patients with or without prophylactic were similar in host factors and the majorities of characteristics regarding to tumor factors, HBV status, liver function and LMR. Notably, cycles of TACE were parallel between the groups. Ten (22.7%) patients receiving prophylactic entecavir reached virologic response. The patients receiving prophylactic entecavir presented significantly reduced virologic events (6.8% vs 54.4%, p=0.000) and hepatitis flares due to HBV reactivation (0.0% vs 11.6%, p=0.039) compared with patients without prophylaxis. Kaplan-Meier analysis illustrated that the patients in the entecavir group presented significantly improved virologic events free survival (p=0.000) and hepatitis flare free survival (p=0.017). Female and Eastern Cooperative Oncology Group (ECOG) performance status 2 was the only significant predictors for virological events in patients without prophylactic antiviral. Rescue antiviral therapy did not reduce the incidence of hepatitis flares due to HBV reactivation.

CONCLUSION

Prophylactic entecavir presented promising efficacy in HBV-related cancer patients receiving TACE. Lower performance status and female gender might be the predictors for HBV reactivation in these patients.

EHHM, a novel phenolic natural product from Livistona chinensis, induces autophagy-related apoptosis in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) ranks the second cause of cancer-associated mortality worldwide. In the present study, the effects and mechanisms of a new phenolic natural product E-[6′-(5′-hydroxypentyl)tricosyl]-4-hydroxy-3-methoxycinnamate (EHHM) isolated from Livistona chinensis on the growth of HCC cells were investigated. It was observed that EHHM treatment significantly suppressed cell proliferation and colony formation, and induced cell apoptosis via a mitochondria-dependent caspase pathway in HepG2 cells in a time- and dose-dependent manner. Meanwhile, EHHM treatment also led to upregulated expression of autophagy protein 5 (Atg5), Beclin 1 and light chain 3 (LC3)-II proteins, and accumulation of green fluorescent protein-LC3 punctate florescent foci in HCC cells, suggesting that EHHM-induced apoptosis is accompanied by autophagy induction. Western blotting revealed that EHHM-induced autophagy is related to the inhibition of the Akt/mechanistic target of rapamycin/p70 ribosomal protein S6 kinase signaling pathway. Furthermore, treatment with Atg5 small interfering RNA or autophagy inhibitors significantly enhanced EHHM-mediated growth inhibition and apoptotic cell death, indicating that autophagy serves as a self-protective mechanism in EHHM-treated HCC cells, and that combined treatment with EHHM and autophagy inhibitors may be an effective therapeutic strategy for HCC.

Epithelial-to-mesenchymal plasticity of cancer stem cells: therapeutic targets in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most common and lethal malignancies worldwide despite the development of various therapeutic strategies. A better understanding of the mechanisms responsible for HCC initiation and progression is essential for the development of more effective therapies. The cancer stem cell (CSC) model has provided new insights into the development and progression of HCC. CSCs are specialized tumor cells that are capable of self-renewal and have long-term repopulation potential. As they are important mediators of tumor proliferation, invasion, metastasis, therapy resistance, and cancer relapse, the selective targeting of this crucial population of cells has the potential to improve HCC patient outcomes and survival. In recent years, the role of epithelial-to-mesenchymal transition (EMT) in the advancement of HCC has gained increasing attention. This multi-step reprograming process resulting in a phenotype switch from an epithelial to a mesenchymal cellular state has been closely associated with the acquisition of stem cell-like attributes in tumors. Moreover, CSC mediates tumor metastasis by maintaining plasticity to transition between epithelial or mesenchymal states. Therefore, understanding the molecular mechanisms of the reprograming switches that determine the progression through EMT and generation of CSC is essential for developing clinically relevant drug targets. This review provides an overview of the proposed roles of CSC in HCC and discusses recent results supporting the emerging role of EMT in facilitating hepatic CSC plasticity. In particular, we discuss how these important new insights may facilitate rational development of combining CSC- and EMT-targeted therapies in the future.

Systematic tracking of disrupted modules identifies significant genes and pathways in hepatocellular carcinoma

The objective of the present study is to identify significant genes and pathways associated with hepatocellular carcinoma (HCC) by systematically tracking the dysregulated modules of re-weighted protein-protein interaction (PPI) networks. Firstly, normal and HCC PPI networks were inferred and re-weighted based on Pearson correlation coefficient. Next, modules in the PPI networks were explored by a clique-merging algorithm, and disrupted modules were identified utilizing a maximum weight bipartite matching in non-increasing order. Then, the gene compositions of the disrupted modules were studied and compared with differentially expressed (DE) genes, and pathway enrichment analysis for these genes was performed based on Expression Analysis Systematic Explorer. Finally, validations of significant genes in HCC were conducted using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. The present study evaluated 394 disrupted module pairs, which comprised 236 dysregulated genes. When the dysregulated genes were compared with 211 DE genes, a total of 26 common genes [including phospholipase C beta 1, cytochrome P450 (CYP) 2C8 and CYP2B6] were obtained. Furthermore, 6 of these 26 common genes were validated by RT-qPCR. Pathway enrichment analysis of dysregulated genes demonstrated that neuroactive ligand-receptor interaction, purine and drug metabolism, and metabolism of xenobiotics mediated by CYP were significantly disrupted pathways. In conclusion, the present study greatly improved the understanding of HCC in a systematic manner and provided potential biomarkers for early detection and novel therapeutic methods.

HBx-related long non-coding RNA DBH-AS1 promotes cell proliferation and survival by activating MAPK signaling in hepatocellular carcinoma

Accumulating evidence supports an important role for the hepatitis B virus x protein (HBx) in the pathogenesis of hepatitis B virus (HBV)-induced hepatocellular carcinoma (HCC), but the underlying mechanisms are not entirely clear. Here, we identified a novel long noncoding RNA (lncRNA) DBH-AS1 involved in the HBx-mediated hepatocarcinogenesis. The levels of DBH-AS1 were positively correlated with hepatitis B surface antigen (HBsAg) and tumor size in HCC tissues. Functionally, transgenic expression of DBH-AS1 significantly enhanced cell proliferation and tumorigenesis, whereas short hairpin RNA knockdown of DBH-AS1 caused an inhibition of cell proliferation. Mechanistically, overexpression of DBH-AS1 induced cell cycle progression by accelerating G1/S and G2/M transition concomitantly with upregulation of CDK6, CCND1, CCNE1 and downregulation of p16, p21 and p27. We also found that enhanced DBH-AS1 expression inhibited serum starvation-induced apoptosis of HCC cells. In contrast, suppressed DBH-AS1 expression had opposite effects. Furthermore, DBH-AS1 was shown to activate MAPK pathway. We also provide evidence that DBH-AS1 could be significantly induced by HBx protein and markedly down-regulated by p53. Thus, we concluded that DBH-AS1 can be induced by HBx and inactivated by p53, and consequently promote cell proliferation and cell survival through activation of MAPK signaling in HCC. Our study suggests that DBH-AS1 acts as an oncogene for HCC.

Impact of non-neoplastic vs intratumoural hepatitis B viral DNA and replication on hepatocellular carcinoma recurrence

Background:

This study aims to determine the impact of intracellular hepatitis B virus (HBV) DNA, covalently closed circular DNA (cccDNA) and viral replicative activity in both tumour and non-neoplastic liver on prognosis and to determine the relationship of viral replicative activity and Ishak fibrosis in predicting outcome following resection.

Methods:

A total of 99 prospectively enrolled patients treated with primary liver resection for HBV-HCC are included. Intracellular HBV DNA and cccDNA were quantitated by real-time PCR. The RNA-sequencing (RNA-seq) was performed in a subset of 21 patients who had either minimal liver fibrosis (Ishak stages 0–2) or end-stage fibrosis (Ishak stage 6).

Results:

Tumour tissue contained a lower cccDNA copy number compared with paired non-neoplastic liver, and larger tumours (>3 cm) had less cccDNA compared with small tumours (⩽3 cm). High viral replicative activity in non-neoplastic liver was associated with higher HCC recurrence rate independent of Ishak fibrosis stage. Genes correlated with viral replicative activity in non-neoplastic liver (620 genes) were distinct from those associated with end-stage fibrosis (1226 genes). Genes associated with viral replicative activity were preferentially distributed in regions on chr3, chr16 and chr19.

Conclusions:

Viral replicative activity in non-neoplastic liver is associated with HCC recurrence through mechanisms that are distinct from and independent of Ishak fibrosis stage.

Identification of hub genes and pathways associated with hepatocellular carcinoma based on network strategy

The objective of this study was to identify hub genes and pathways associated with hepatocellular carcinoma (HCC) by centrality analysis of a co-expression network. A co-expression network based on differentially expressed (DE) genes of HCC was constructed using the Differentially Co-expressed Genes and Links (DCGL) package. Centrality analyses, for centrality of degree, clustering coefficient, closeness, stress and betweenness for the co-expression network were performed to identify hub genes, and the hub genes were combined together to overcome inconsistent results. Enrichment analyses were conducted using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. Finally, validation of hub genes was conducted utilizing reverse transcription-polymerase chain reaction (RT-PCR) analysis. In total, 260 DE genes between normal controls and HCC patients were obtained and a co-expression network with 154 nodes and 326 edges was constructed. From this, 13 hub genes were identified according to degree, clustering coefficient, closeness, stress and betweenness centrality analysis. It was found that reelin (RELN), potassium voltage-gated channel subfamily J member 10 (KCNJ10) and neural cell adhesion molecule 1 (NCAM1) were common hub genes across the five centralities, and the results of RT-PCR analysis for RELN, KCNJ10 and NCAM1 were consistent with the centrality analyses. Pathway enrichment analysis of DE genes showed that cell cycle, metabolism of xenobiotics by cytochrome P450 and p53 signaling pathway were the most significant pathways. This study may contribute to understanding the molecular pathogenesis of HCC and provide potential biomarkers for its early detection and effective therapies.

High-throughput T cell receptor sequencing reveals distinct repertoires between tumor and adjacent non-tumor tissues in HBV-associated HCC

T lymphocytes, which recognize antigen peptides through specific T cell receptors (TCRs), play an important role in the human adaptive immune response. TCR diversity is closely associated with host immune response and cancer prognosis. Although tumor-infiltrating T lymphocytes have implications for tumor prognosis, few studies have performed a detailed characterization of TCR diversity in both tumor and non-tumor tissues in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). Here, we performed high-throughput sequencing of the TCRβ chain complementarity determining region 3 (CDR3) of liver-infiltrating T cells from 48 HBV-associated HCC patients. A significantly higher average number of CDR3 aa clonotypes (2259 vs. 1324, p < 0.001), and significantly higher TCR diversity (Gini coefficient, p < 0.001; Simpson index, p < 0.01; Shannon entropy, p < 0.001) were observed in tumor tissues compared with adjacent non-tumor tissues. The ratio of highly expanded clones (HECs) was significantly higher in non-tumor tissues than in tumor tissues when the HEC threshold was defined as 2% or greater (p < 0.05). Our analysis of the median Morisita-Horn index indicated weak TCR repertoire similarity between tumor and matched non-tumor tissues. The median number of shared clones in tumor tissue and matched non-tumor tissue from each patient was 360.5, representing 5.1-15.8% (10.6 ± 0.4%) of all clones in each patient. We observed extensive heterogeneity of T lymphocytes in tumors and higher HEC ratios in adjacent non-tumor tissues of HCC patients. The differential T cell repertoires in tumor and non-tumor tissues suggest a distinct T cell immune microenvironment in patients with HBV-associated HCC.

Molecular mechanisms of hepatitis C virus-induced hepatocellular carcinoma

Hepatitis C virus (HCV) is a major leading cause of hepatocellular carcinoma (HCC). HCV-induced hepatocarcinogenesis is a multistep process resulting from a combination of pathway alterations that are either caused directly by viral factors or immune mediated as a consequence of a chronic state of inflammation. Host genetic variation is now emerging as an additional element that contribute to increase the risk of developing HCC. The advent of direct-acting antiviral agents foresees a rapid decline of HCC rate in HCV patients. However, a full understanding of the HCV-mediated tumourigenic process is required to elucidate if pro-oncogenic signatures may persist after virus clearance, and to identify novel tools for HCC prevention and therapy. In this review, we summarize the current knowledge of the molecular mechanisms responsible for HCV-induced hepatocarcinogenesis.

New horizon for radical cure of chronic hepatitis B virus infection

About 250 to 350 million people worldwide are chronically infected with hepatitis B virus (HBV), and about 700000 patients per year die of HBV-related cirrhosis or hepatocellular carcinoma (HCC). Several anti-viral agents, such as interferon and nucleos(t)ide analogues (NAs), have been used to treat this disease. NAs especially have been shown to strongly suppress HBV replication, slowing the progression to cirrhosis and the development of HCC. However, reactivation of HBV replication often occurs after cessation of treatment, because NAs alone cannot completely remove covalently-closed circular DNA (cccDNA), the template of HBV replication, from the nuclei of hepatocytes. Anti-HBV immune responses, in conjunction with interferon-γ and tumor necrosis factor-α, were found to eliminate cccDNA, but complete eradication of cccDNA by immune response alone is difficult, as shown in patients who recover from acute HBV infection but often show long-term persistence of small amounts of HBV-DNA in the blood. Several new drugs interfering with the life cycle of HBV in hepatocytes have been developed, with drugs targeting cccDNA theoretically the most effective for radical cure of chronic HBV infection. However, the safety of these drugs should be extensively examined before application to patients, and combinations of several approaches may be necessary for radical cure of chronic HBV infection.

Time for paradigm change in management of hepatocellular carcinoma: is a personalized approach on the horizon?

Hepatocellular carcinoma (HCC) is the fifth most frequent cancer form but the second leading cause of all cancer-related deaths. There are several reasons for high mortality in the HCC cohort: lack of effective screening programs and consequently late diagnosis, multifactorial origin with cumulative risk factors, complex carcinogenesis, tumor heterogeneity, unpredictable impacts of individual microenvironment on tumor development and progression, and, as the consequence, frequently untargeted therapy and cancer resistance toward currently applied treatment approaches. The currently applied 'treat and wait' approach is inappropriate in the overall HCC management. Urgent need in paradigm change toward predictive, preventive and personalized medicine is discussed in this review article. Innovative strategies for an advanced predictive, preventive and personalized medicine approach in the overall HCC management benefiting the patient are presented.