Molecular mechanistic insight of hepatitis B virus mediated hepatocellular carcinoma

The oncogenic role of hepatitis B virus X gene in hepatocarcinogenesis: recent updates

Hepatocellular carcinoma (HCC) is the most prevalent form of primary liver cancers with high mortality rate. Among its various etiological factors, one of the major risk factors for HCC is a chronic infection of hepatitis B virus (HBV). HBV X protein (HBx) has been identified to play an important role in the HBV-induced HCC pathogenesis since it may interfere with several key regulators of many cellular processes. HBx localization within the cells may be beneficial to HBx multiple functions at different phases of HBV infection and associated hepatocarcinogenesis. HBx as a regulatory protein modulates cellular transcription, molecular signal transduction, cell cycle, apoptosis, autophagy, protein degradation pathways, and host genetic stability via interaction with various factors, including its association with various non-coding RNAs. A better understanding on the regulatory mechanism of HBx on various characteristics of HCC would provide an overall picture of HBV-associated HCC. This article addresses recent data on HBx role in the HBV-associated hepatocarcinogenesis.

Circular RNA cFAM210A, degradable by HBx, inhibits HCC tumorigenesis by suppressing YBX1 transactivation

Hepatitis B protein x (HBx) has been reported to promote tumorigenesis in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), but the mechanism awaits further investigation. In this study, we found that cFAM210A (a circular RNA derived from the third exon of transcript NM_001098801 of the FAM210A gene; CircBase ID: hsa_circ_0003979) can be silenced by HBx. cFAM210A expression was downregulated and negatively correlated with tumorigenesis in patients with HBV-related HCC. Furthermore, cFAM210A reduced the proliferation, stemness, and tumorigenicity of HCC cells. Mechanistically, HBx increased the N6-methyladenosine (m6A) level of cFAM210A by promoting the expression of RBM15 (an m6A methyltransferase), thus inducing the degradation of cFAM210A via the YTHDF2-HRSP12-RNase P/MRP pathway. cFAM210A bound to YBX1 and inhibited its phosphorylation, suppressing its transactivation function toward MET. These findings suggest the important role of circular RNAs in HBx-induced hepatocarcinogenesis and identify cFAM210A a potential target in the prevention and treatment of HBV-related HCC.

Gut virome-colonising Orthohepadnavirus genus is associated with ulcerative colitis pathogenesis and induces intestinal inflammation in vivo

OBJECTIVES

Ulcerative colitis (UC) is a chronic inflammatory disorder of unknown aetiology. Gut virome dysbiosis is fundamental in UC progression, although its role in the early phases of the disease is far from fully understood. Therefore, we sought to investigate the role of a virome-associated protein encoded by the Orthohepadnavirus genus, the hepatitis B virus X protein (HBx), in UC aetiopathogenesis.

DESIGN

HBx positivity of UC patient-derived blood and gut mucosa was assessed by RT-PCR and Sanger sequencing and correlated with clinical characteristics by multivariate analysis. Transcriptomics was performed on HBx-overexpressing endoscopic biopsies from healthy donors.C57BL/6 mice underwent intramucosal injections of liposome-conjugated HBx-encoding plasmids or the control, with or without antibiotic treatment. Multidimensional flow cytometry analysis was performed on colonic samples from HBx-treated and control animals. Transepithelial electrical resistance measurement, proliferation assay, chromatin immunoprecipitation assay with sequencing and RNA-sequencing were performed on in vitro models of the gut barrier. HBx-silencing experiments were performed in vitro and in vivo.

RESULTS

HBx was detected in about 45% of patients with UC and found to induce colonic inflammation in mice, while its silencing reverted the colitis phenotype in vivo. HBx acted as a transcriptional regulator in epithelial cells, provoking barrier leakage and altering both innate and adaptive mucosal immunity ex vivo and in vivo.

CONCLUSION

This study described HBx as a contributor to the UC pathogenesis and provides a new perspective on the virome as a target for tailored treatments.

Mechanism of HBx carcinogenesis interaction with non-coding RNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an extremely malignant tumor that affects individuals throughout the world. One of the main causes of HCC is hepatitis B virus (HBV). Therefore, it is crucial to understand the mechanisms underlying HBV carcinogenesis. Increasing evidence suggests that the HBV X protein (HBx), which is encoded by HBV, plays a significant role in cell apoptosis, DNA damage repair, and cell cycle regulation. This ultimately leads to the development of HCC. Additionally, recent studies have shown that non-coding RNA (ncRNA) also contributes to the carcinogenesis and pathogenesis of different of tumors. ncRNA plays a significant role in the formation of HCC by regulating the inflammatory signaling pathway, activating immune cells, and modifying epigenetics. However, it remains unclear whether ncRNA is involved in the regulation of the carcinogenic mechanisms of HBx. This article reviews the carcinogenic mechanism of HBx and its interaction with ncRNA, providing a novel strategy for the clinical diagnosis and treatment of HCC.

The role of hepatitis B virus genome variations in HBV-related HCC: effects on host signaling pathways

Hepatocellular carcinoma (HCC) is a significant global health issue, with a high prevalence in many regions. There are variations in the etiology of HCC in different regions, but most cases are due to long-term infection with viral hepatitis. Hepatitis B virus (HBV) is responsible for more than 50% of virus-related HCC, which highlights the importance of HBV in pathogenesis of the disease. The development and progression of HBV-related HCC is a complex multistep process that can involve host, viral, and environmental factors. Several studies have suggested that some HBV genome mutations as well as HBV proteins can dysregulate cell signaling pathways involved in the development of HCC. Furthermore, it seems that the pathogenicity, progression of liver diseases, response to treatment and also viral replication are different among HBV mutants. Understanding the relationship between HBV genome variations and host signaling pathway alteration will improve our understanding of the molecular pathogenesis of HBV-related HCC. Furthermore, investigating commonly dysregulated pathways in HBV-related HCC is necessary to discover more specific therapeutic targets and develop more effective strategies for HCC treatment. The objective of this review is to address the role of HBV in the HCC progression and primarily focus on the impacts of HBV genome variations on HCC-related signaling pathways.

Peripheral immune characteristics of hepatitis B virus-related hepatocellular carcinoma

Background

Liver cancer is the sixth most common cancer worldwide and the third leading cause of cancer-related death. As a chronic liver disease, many studies have shown that the immune response plays a key role in the progression of liver cancer. Chronic hepatitis B virus (HBV) infection is one of the high-risk factors for HCC, accounting for 50%–80% of HCC cases worldwide, and little is known about the immune status of HBV associated hepatocellular carcinoma (HBV-HCC), therefore, we aimed to explore the changes in peripheral immunity in patients with HBV-HCC.

Methods

In this study, patients with HBV-HCC (n=26), patients with hepatitis B-related cirrhosis (HBV-LC) (n=31) and healthy volunteers (n=49) were included. The lymphocytes and their subpopulation phenotypes in peripheral blood were characterized. In addition, we explored the effect of viral replication on peripheral immunity in patients with HCC and analyzed the circulating immunophenotypic characteristics at different stages of HCC with flow cytometry.

Results

Firstly, our results showed that the percentages of total αβ T cells in the peripheral blood of HBV-HCC patients was significantly decreased compared to healthy subjects. Secondly, we found that naïve CD4+ T cells in HBV-HCC patients were significantly reduced, terminally differentiated CD8+ T cells, homing memory CD8+ T cells and Th2 cells were increased in peripheral circulation in HBV-HCC patients. Moreover, in the peripheral blood of HBV-HCC patients, expression of TIGIT on CD4+ T cells and PD-1 on the surface of Vδ 1 T cells was increased. In addition, we found that sustained viral replication resulted in up-regulation of TIM3 expression on CD4+ T cells, and TIM3+ γδ T cells increased in peripheral circulation in patients with advanced HBV-HCC.

Conclusion

Our study showed that circulating lymphocytes in HBV-HCC patients exhibited features of immune exhaustion, especially in HCC patients with persistent viral replication and in patients with intermediate and advanced HBV-HCC, including decreased frequency of T cells and elevated expression of inhibitory receptors including TIGIT and TIM3 on CD4+ T cells and γδ T cells. Meanwhile, our research suggests that the combination of CD3+ T cell and CD8+HLADR+CD38+ T cell may be a potential diagnostic indicator for HBV-HCC. These findings could help us to better understand the immune characteristics of HBV-HCC and explore the immune mechanisms and immunotherapy strategies for HBV-HCC.

Hepatitis B virus X protein promotes MAN1B1 expression by enhancing stability of GRP78 via TRIM25 to facilitate hepatocarcinogenesis

BACKGROUND

GRP78 has been implicated in hepatocarcinogenesis. However, the clinical relevance, biological functions and related regulatory mechanisms of GRP78 in hepatitis B virus (HBV)-associated hepatoma carcinoma (HCC) remain elusive.

METHODS

The association between GRP78 expression and HBV-related HCC was investigated. The effects of HBV X protein (HBX) on GRP78 and MAN1B1 expression, biological functions of GRP78 and MAN1B1 in HBX-mediated HCC cells and mechanisms related to TRIM25 on GRP78 upregulation to induce MAN1B1 expression in HBX-related HCC cells were examined.

RESULTS

GRP78 expression was correlated with poor prognosis in HBV-positive HCC. HBX increased MAN1B1 protein expression depending on GRP78, and HBX enhanced the levels of MAN1B1 to promote proliferation, migration and PI3-K/mTOR signalling pathway activation in HCC cells. GRP78 activates Smad4 via its interaction with Smad4 to increase MAN1B1 expression in HBX-expressing HCC cells. TRIM25 enhanced the stability of GRP78 by inhibiting its ubiquitination. HBX binds to GRP78 and TRIM25 and accelerates their interaction of GRP78 and TRIM25, leading to an increase in GRP78 expression.

CONCLUSIONS

HBX enhances the stability of GRP78 through TRIM25 to increase the expression of MAN1B1 to facilitate tumorigenesis, and we provide new insights into the molecular mechanisms underlying HBV-induced malignancy.

A Semi-mechanistic Model to Characterize the Long-Term Dynamics of Hepatitis B Virus Markers During Treatment With Lamivudine and Pegylated Interferon

Antiviral treatments against hepatitis B virus (HBV) suppress viral replication but do not eradicate the virus, and need therefore to be taken lifelong to avoid relapse. Mathematical models can be useful to support the development of curative anti-HBV agents; however, they mostly focus on short-term HBV DNA data and neglect the complex host-pathogen interaction. This work aimed to characterize the effect of treatment with lamivudine and/or pegylated interferon (Peg-IFN) in 1,300 patients (hepatitis B envelope antigen (HBeAg)-positive and HBeAg-negative) treated for 1 year. A mathematical model was developed incorporating two populations of infected cells, namely I 1 , with a high transcriptional activity, that progressively evolve into I 2 , at a rate δ tr , representing cells with integrated HBV DNA that have a lower transcriptional activity. Parameters of the model were estimated in patients treated with lamivudine or Peg-IFN alone (N = 894), and the model was then validated in patients treated with lamivudine plus Peg-IFN (N = 436) to predict the virological response after a year of combination treatment. Lamivudine had a larger effect in blocking viral production than Peg-IFN (99.4-99.9% vs. 91.8-95.1%); however, Peg-IFN had a significant immunomodulatory effect, leading to an enhancement of the loss rates of I 1 (×1.7 in HBeAg-positive patients), I 2 (> ×7 irrespective of HBeAg status), and δ tr (×4.6 and ×2.0 in HBeAg-positive and HBeAg-negative patients, respectively). Using this model, we were able to describe the synergy of the different effects occurring during treatment with combination and predicted an effect of 99.99% on blocking viral production. This framework can therefore support the optimization of combination therapy with new anti-HBV agents.

Hepatitis B virus X protein increases LASP1 SUMOylation to stabilize HER2 and facilitate hepatocarcinogenesis

The hepatitis B virus (HBV) X protein (HBX), a viral macromolecule, plays a vital role in the development of HBV-related hepatocellular carcinoma (HCC). Increased expression of HER2 is linked to HBV infection, and HBX is responsible for HER2 upregulation in HCC. Nevertheless, the underlying molecular mechanisms are not yet fully understood. In the study, we discovered that HBX promoted HER2 expression to facilitate the sensitization of the insulin signaling pathway and enhance the growth and migration of HCC cells. Mechanistically, the viral protein enhanced the stability of HER2 by preventing its ubiquitination-mediated proteasomal degradation through LASP1, which could bind to HER2. Furthermore, increased SUMOylation of LASP1 contributed to the upregulation of HER2 and the interaction of LASP1 with HER2. In addition, RANBP2 and RANGAP1 were found to interact with LASP1 and promote SUMOylation of LASP1 to upregulate HER2 expression in HBX-associated hepatoma cells. In summary, our work provides a novel insight into hepatocarcinogenesis mediated by HBX and estimates the detailed mechanisms related to the increase in HER2 regulated by the viral protein, which might help provide a theoretical basis for identifying novel targets for HBV-positive HCC treatment.

Transcriptomic Analysis of Hepatitis B Infected Liver for Prediction of Hepatocellular Carcinoma

Hepatocellular cancer (HCC) is a leading cause of cancer-related mortality worldwide, and chronic hepatitis B virus infection (CHB) has been a major risk factor for HCC development. The pathogenesis of HBV-related HCC has been a major focus revealing the interplay of a multitude of intracellular signaling pathways, yet the precise mechanisms and their implementations to clinical practice remain to be elucidated. This study utilizes publicly available transcriptomic data from the livers of CHB patients in order to identify a population with a higher risk of malignant transformation. We report the identification of a novel list of genes (PCM1) which can generate clear transcriptomic sub-groups among HBV-infected livers. PCM1 includes genes related to cell cycle activity and liver cancer development. In addition, markers of inflammation, M1 macrophages and gamma delta T cell infiltration are present within the signature. Genes within PCM1 are also able to differentiate HCC from normal liver, and some genes within the signature are associated with poor prognosis of HCC at the mRNA level. The analysis of the immunohistochemical stainings validated that proteins coded by a group of PCM1 genes were overexpressed in liver cancer, while minimal or no expression was detected in normal liver. Altogether, our findings suggest that PCM1 can be developed into a clinically applicable method to identify CHB patients with a higher risk of HCC development.

Detection and monitoring of HBV-related hepatocellular carcinoma from plasma cfDNA fragmentation profiles

Most hepatocellular carcinomas (HCCs) are associated with hepatitis B virus infection (HBV) in China. Early detection of HCC can significantly improve prognosis but is not yet fully clinically feasible. This study aims to develop methods for detecting HCC and studying the carcinogenesis of HBV using plasma cell-free DNA (cfDNA) whole-genome sequencing (WGS) data. Low coverage WGS was performed for 452 participants, including healthy individuals, hepatitis B patients, cirrhosis patients, and HCC patients. Then the sequencing data were processed using various machine learning models based on cfDNA fragmentation profiles for cancer detection. Our best model achieved a sensitivity of 87.10% and a specificity of 88.37%, and it showed an increased sensitivity with higher BCLC stages of HCC. Overall, this study proves the potential of a non-invasive assay based on cfDNA fragmentation profiles for the detection and prognosis of HCC and provides preliminary data on the carcinogenic mechanism of HBV.

The pathogenesis of liver cancer and the therapeutic potential of bioactive substances

Liver cancer is the third most common cause of cancer-related deaths in the world and has become an urgent problem for global public health. Bioactive substances are widely used for the treatment of liver cancer due to their widespread availability and reduced side effects. This review summarizes the main pathogenic factors involved in the development of liver cancer, including metabolic fatty liver disease, viral infection, and alcoholic cirrhosis, and focuses on the mechanism of action of bioactive components such as polysaccharides, alkaloids, phenols, peptides, and active bacteria/fungi. In addition, we also summarize transformation methods, combined therapy and modification of bioactive substances to improve the treatment efficiency against liver cancer, highlighting new ideas in this field.

The First Yarrowia lipolytica Yeast Models Expressing Hepatitis B Virus X Protein: Changes in Mitochondrial Morphology and Functions

Chronic hepatitis B virus infection is the dominant cause of hepatocellular carcinoma, the main cause of cancer death. HBx protein, a multifunctional protein, is essential for pathogenesis development; however, the underlying mechanisms are not fully understood. The complexity of the system itself, and the intricate interplay of many factors make it difficult to advance in understanding the mechanisms underlying these processes. The most obvious solution is to use simpler systems by reducing the number of interacting factors. Yeast cells are particularly suitable for studying the relationships between oxidative stress, mitochondrial dynamics (mitochondrial fusion and fragmentation), and mitochondrial dysfunction involved in HBx-mediated pathogenesis. For the first time, genetically modified yeast, Y. lipolytica, was created, expressing the hepatitis B virus core protein HBx, as well as a variant fused with eGFP at the C-end. It was found that cells expressing HBx experienced stronger oxidative stress than the control cells. Oxidative stress was alleviated by preincubation with the mitochondria-targeted antioxidant SkQThy. Consistent with these data, in contrast to the control cells (pZ-0) containing numerous mitochondrial forming a mitochondrial reticulum, in cells expressing HBx protein, mitochondria were fragmented, and preincubation with SkQThy partially restored the mitochondrial reticulum. Expression of HBx had a significant influence on the bioenergetic function of mitochondria, making them loosely coupled with decreased respiratory rate and reduced ATP formation. In sum, the first highly promising yeast model for studying the impact of HBx on bioenergy, redox-state, and dynamics of mitochondria in the cell and cross-talk between these parameters was offered. This fairly simple model can be used as a platform for rapid screening of potential therapeutic agents, mitigating the harmful effects of HBx.

Construction and experimental verification of user-friendly molecular subtypes mediated by immune-associated genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) accounts for third most cancer death globally, and its prognosis continues to be poor even with many novel therapeutic approaches emerging. The advent of immunotherapy seems to offer new hope, but low response rates are an unresolved problem. To gain further knoeledge of the effect of immune-related genes in HCC, we examined the connection between immune-related genes and the immune microenvironment in HCC through the HCC transcriptome dataset. The study also aimed to construct and experimentally validate user-friendly molecular subtypes mediated by immune-related genes in HCC. The immune cell infiltration patterns differs in HCC adjacent non-disease tissues and cancerous tissues. Patients with HCC could be classified into 2 subtypes: subtype A and subtype B. Specifically, subtype A shows characteristics of a hot tumor, in which the infiltration of cells exhibiting antigens and the expression of other crucial factors associated with immune function are higher than in a cold tumor. In addition, we identified Hub genes for the different subtypes and constructed a prognostic prediction model based on six genes (KLRB1, KLF2, S100A9, MSC, ANXA5, and IMPDH1). Further experimental analysis of HCC samples exhibited that the expression levels of KLF2 and ANXA5 were associated with immune cell infiltration and expression of PD-L1 in cancer tissues. Our work suggests that the expression of immune-related genes has crucial effect on the tumor microenvironment and prognosis of HCC patients and may be associated with immunotherapeutic response, which provides new clues for the widespread and effective application of immunotherapy in HCC.

Long noncoding RNAs in hepatitis B virus replication and oncogenesis

Several diverse long noncoding RNAs (lncRNAs) have been identified to be involved in hepatitis B virus (HBV) replication and oncogenesis, especially those dysregulated in HBV-related hepatocellular carcinoma (HCC). Most of these dysregulated lncRNAs are modulated by the HBV X protein. The regulatory mechanisms of some lncRNAs in HBV replication and oncogenesis have been characterized. Genetic polymorphisms of several lncRNAs affecting HBV replication or oncogenesis have also been studied. The prognosis of HCC remains poor. It is important to identify novel tumor markers for early diagnosis and find more therapeutic targets for effective treatments of HCC. Some dysregulated lncRNAs in HBV-related HCC may become biomarkers for early diagnosis and/or the therapeutic targets of HCC. This mini-review summarizes these findings briefly, focusing on recent developments.

Effect of mutations across reverse transcriptase region on HBV replication and progression of liver diseases in Chinese patients

It was known that mutations in the RT region were mainly related to nucleot(s)ide analogs resistance. Increasing studies indicated that RT mutations were related to advanced liver diseases (ALD) and had effects on HBV replication, but the distribution characteristics of mutations across RT region in the development of liver diseases and the effect of RT mutations on HBV replication were not fully clarified. HBV RT region was direct-sequenced in 1473 chronic HBV-infected patients. Mutation frequencies were analyzed to identify the specific mutations differing between groups classified by genotypes, loads of HBV DNA, or progression of liver diseases. In the range of rt145-rt290, rt145, rt221, rt222, rt267, and rt271 were the genotype-polymorphic sites, while rt238 was the genotype-specific sites. Mutations at rt163, rt173, rt180, rt181, rt184, rt191, rt199, and rt214 were more frequent among patients with C-genotype HBV, while those at rt220, rt225, rt226, rt269, and rt274 were more frequent among patients with B-genotype HBV. RtM204V/I could reduce the HBV DNA loads while rtQ/L267H/R could increase the HBV DNA loads. RtV214A/E/I (OR 3.94, 95% CI 1.09 to 14.26) was an independent risk factor for advanced liver diseases. In summary, the hotspots of mutations were different between B and C genotypes. Besides the effect on the S region, RT mutations had effects on HBV replication by other unknown ways. RtV214A/E/I was found to be an independent risk factor for ALD, suggesting that mutations at rt214 site could be used as a potential virological marker for the liver disease progression.

Hepatitis B Virus-Associated Hepatocellular Carcinoma

Hepatitis B virus (HBV) is DNA-based virus, member of the Hepadnaviridae family, which can cause liver disease and increased risk of hepatocellular carcinoma (HCC) in infected individuals, replicating within the hepatocytes and interacting with several cellular proteins. Chronic hepatitis B can progressively lead to liver cirrhosis, which is an independent risk factor for HCC. Complications as liver decompensation or HCC impact the survival of HBV patients and concurrent HDV infection worsens the disease. The available data provide evidence that HBV infection is associated with the risk of developing HCC with or without an underlying liver cirrhosis, due to various direct and indirect mechanisms promoting hepatocarcinogenesis. The molecular profile of HBV-HCC is extensively and continuously under study, and it is the result of altered molecular pathways, which modify the microenvironment and lead to DNA damage. HBV produces the protein HBx, which has a central role in the oncogenetic process. Furthermore, the molecular profile of HBV-HCC was recently discerned from that of HDV-HCC, despite the obligatory dependence of HDV on HBV. Proper management of the underlying HBV-related liver disease is fundamental, including HCC surveillance, viral suppression, and application of adequate predictive models. When HBV-HCC occurs, liver function and HCC characteristics guide the physician among treatment strategies but always considering the viral etiology in the treatment choice.

Regulation of Pattern-Recognition Receptor Signaling by HBX During Hepatitis B Virus Infection

As a small DNA virus, hepatitis B virus (HBV) plays a pivotal role in the development of various liver diseases, including hepatitis, cirrhosis, and liver cancer. Among the molecules encoded by this virus, the HBV X protein (HBX) is a viral transactivator that plays a vital role in HBV replication and virus-associated diseases. Accumulating evidence so far indicates that pattern recognition receptors (PRRs) are at the front-line of the host defense responses to restrict the virus by inducing the expression of interferons and various inflammatory factors. However, depending on HBX, the virus can control PRR signaling by modulating the expression and activity of essential molecules involved in the toll-like receptor (TLR), retinoic acid inducible gene I (RIG-I)-like receptor (RLR), and NOD-like receptor (NLR) signaling pathways, to not only facilitate HBV replication, but also promote the development of viral diseases. In this review, we provide an overview of the mechanisms that are linked to the regulation of PRR signaling mediated by HBX to inhibit innate immunity, regulation of viral propagation, virus-induced inflammation, and hepatocarcinogenesis. Given the importance of PRRs in the control of HBV replication, we propose that a comprehensive understanding of the modulation of cellular factors involved in PRR signaling induced by the viral protein may open new avenues for the treatment of HBV infection.

LncRNA TSPEAR-AS1 predicts poor prognosis in patients with hepatitis B virus-associated hepatocellular carcinoma and promotes metastasis via miR-1915-5p

BACKGROUND

Hepatitis B virus-related hepatocellular carcinoma (HBV-HCC) will contribute to more than half of the liver deaths worldwide. This study aimed to investigate the prognostic value of TSPEAR-AS1 in HBV-HCC and its role in the HBV-HCC progression.

METHODS

HBV-HCC tissue and adjacent non-cancerous tissues (ANT) were detected to figure out the expression level of TSPEAR-AS1 using real-time quantitative PCR. The relationship between TSPEAR-AS1 expression and each important clinical characteristic was evaluated. And the prognostic significance of TSPEAR-AS1 was assessed by Kaplan-Meier curve and Cox regression analysis. CCK-8 and Transwell assays were performed to observe the effects of TSPEAR-AS1 on HBV-HCC cell proliferation, migration, and invasion.

RESULTS

The TSPEAR-AS1 expression was downregulated in HBV-HCC tissues, as well as in HBV-HCC cell lines. The downregulation of TSPEAR-AS1 showed a significant association with TNM stage, clinical stage, and vascular invasion and predicted poor prognosis of HBV-HCC patients. Overexpression of TSPEAR-AS1 inhibited HBV-HCC cell ability of proliferation, migration, and invasiveness. TSPEAR-AS1 may bind to miR-1915-5p in HCC.

CONCLUSION

TSPEAR-AS1 expression was downregulated in HBV-HCC and may serve as a potential prognostic factor. TSPEAR-AS1 might exert a suppressor role in HBV-HCC through inhibiting tumor cell proliferation, migration, and invasion.

IL-6 Promoter Hypomethylation Acts As a Diagnostic Biomarker in Hepatitis B Virus-Associated Hepatocellular Carcinoma

Background

New biomarkers are needed to detect hepatocellular carcinoma at an earlier stage and to individualize treatment strategies. IL-6 has been proven to be associated with liver cancer in numerous studies.

Aim

To evaluate the value of the IL-6 promoter methylation level as a noninvasive biomarker for the diagnosis of liver cancer.

Methods

A retrospective analysis of 165 patients with HBV-associated hepatocellular carcinoma (HCC), 198 patients with chronic hepatitis B (CHB) and 31 healthy controls were involved. The methylight was detected the methylation level of the IL-6 promoter in peripheral blood mononuclear cells (PBMCs), clinical and laboratory parameters were obtained.

Results

IL-6 promoter methylation levels were significantly lower in patients with HCC (median 53.59%, interquartile range 52.01–54.75%) than in those with CHB (median 56.05%, interquartile range 54.65–57.67%; P<0.001). The level of IL-6 mRNA in patients with HCC (median 0.371, interquartile range 0.173-0.671) was significantly higher than that in patients with CHB (median 0.203, interquartile range 0.108-0.354; P<0.001) and HCs (median 0.189, interquartile range 0.140-0.262; P=0.001). Meanwhile, the PMR value of IL-6 was notably negatively correlated with the mRNA expression level (Spearman’s R=-0.201, P<0.001). The IL-6 PMR value of HCC patients in age (Spearman’s R=0.193, P=0.026) and TBIL (Spearman’s R=0.186, P=0.032) were very weak correlated. At the same time, the level of IL-6 promoter methylation was also an independent factor in the development of liver cancer. When the IL-6 promoter methylation level was used to diagnose HCC, its detective value was superior to AFP [area under the receiver operating characteristic curve (AUC) 0.773 vs. 0.686, P=0.027], And the combined use of AFP and IL-6 methylation level can improve the area under the receiver operating characteristic curve (p=0.011).

Conclusion

IL-6 promoter hypomethylation is present in hepatocellular carcinoma, and it may be used as a noninvasive biomarker to detect early liver cancer.

Downregulated lncRNA SNHG18 Suppresses the Progression of Hepatitis B Virus-Associated Hepatocellular Carcinoma and Meditates the Antitumor Effect of Oleanolic Acid

Purpose

Oleanolic acid (OA) has been widely reported to possess antitumor effects, but the specific molecular mechanism underlying its inhibition of hepatocellular carcinoma (HCC) progression remains unclear. This study aims to uncover the mechanism of OA antitumor effect on HBV-associated HCC and identify a potential biomarker for tumor progression.

Patients and Methods

The effect of OA on major cellular processes of HBV-associated HCC cells was evaluated by CCK8 and Transwell assay. The potential molecular mechanism was assessed by cell transfection. This study also enrolled 111 HCC patients infected with HBV to evaluate the prognostic potential of lncRNA SNHG18 (SNHG18) in HBV-associated HCC.

Results

The inhibitory effect of OA was observed in the critical cellular processes of HBV-associated HCC cells, which depend on OA concentration. Downregulated SNHG18 in HBV-associated HCC was demonstrated to be involved in disease development and predict patients’ prognosis. The downregulation of SNHG18 dramatically promoted cellular processes of HBV-associated HCC could reverse the inhibitory effect of OA.

Conclusion

SNHG18 served as a tumor suppressor and prognostic biomarker of HBV-associated HCC. Enhancing SNHG18 might be the mechanism underlying the antitumor effect of OA in HBV-associated HCC.

A Pyroptosis-Based Prognostic Model for Immune Microenvironment Estimation of Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC), an aggressive malignant tumor, has a high incidence and unfavorable prognosis. Recently, the synergistic effect of pyroptosis in antitumor therapy and regulation of tumor immune microenvironment has made it possible to become a novel therapeutic method, but its potential mechanism still needs further exploration.

Methods

Differentially expressed genes with prognostic value in Liver Hepatocellular Carcinoma Project of The Cancer Genome Atlas (TCGA-LIHC) cohort were screened and incorporated into the risk signature by Cox proportional hazards regression model and least absolute shrinkage and selection operator. Kaplan-Meier (KM) curves and receiver operating characteristic (ROC) curves were applied to conduct survival comparisons and estimate prediction ability. The dataset of Liver Cancer-RIKEN, Japan Project from International Cancer Genome Consortium (ICGC-LIRI-JP) cohort was used to verify the reliability of the signature. Correlation analysis between clinicopathological characteristics, immune infiltration, drug sensitivities, and risk scores was conducted. Functional annotation analyses were performed for the genes differentially expressed between high-risk and low-risk groups.

Results

A risk signature consisting of 6 pyroptosis-related genes in HCC was developed and validated. KM curves and ROC curves revealed its considerable predictive accuracy. Higher risk scores meant more advanced grade, higher alpha-fetoprotein level, and stronger invasive ability. Overexpressed genes in high-risk population were more enriched in the immune-associated pathways, and these patients might be more sensitive to immune checkpoint inhibitors instead of Sorafenib. Intriguingly, 6 identified genes were promising to be prognostic biomarkers and therapeutic targets of HCC.

Conclusions

The signature may have crucial clinical significance in predicting survival prognosis, immune infiltration, and drug efficacy based on pyroptosis-related genes.

LncRNA ILF3-AS1 promotes cell migration, invasion and EMT process in hepatocellular carcinoma via the miR-628-5p/MEIS2 axis to activate the Notch pathway

BACKGROUND

Long non-coding RNAs (lncRNAs) are essential indicators for hepatocellular carcinoma. LncRNAs can exert the same functions as their antisense mRNAs. ILF3 is an oncogene in hepatocellular carcinoma. ILF3 divergent transcript (ILF3-AS1) is the antisense RNA of ILF3, and has been reported as an oncogene in various cancers.

AIMS

To explore the role of lncRNA ILF3-AS1 in malignant phenotypes of hepatocellular carcinoma cells.

METHODS AND RESULTS

RT-qPCR analysis revealed that ILF3-AS1 was significantly upregulated in hepatocellular carcinoma cells. The hepatocellular carcinoma cell viability was suppressed by silenced ILF3-AS1. Transwell and wound healing assays showed that ILF3-AS1 downregulation inhibited cell invasion and migration. The levels of proteins associated with epithelial-mesenchymal transition (EMT) process and the Notch pathway were detected by western blot analysis. Luciferase reporter, RNA pull down and RIP assays were used to investigate the relationship between ILF3-AS1 and downstream target genes. ILF3-AS1 competed with meis homeobox 2 (MEIS2) for miR-628-5p in hepatocellular carcinoma cells. ILF3-AS1 elevated the levels of key proteins on the Notch pathway. Rescue assays demonstrated that MEIS2 reversed the antitumor effects of silenced ILF3-AS1 on hepatocellular carcinoma. In vivo assays demonstrated that ILF3-AS1 silencing inhibited the hepatocellular carcinoma tumor growth.

CONCLUSIONS

ILF3-AS1 promoted hepatocellular carcinoma progression via the Notch pathway and miR-628-5p/MEIS2 axis.

A Pleiotropic Role of the Hepatitis B Virus Core Protein in Hepatocarcinogenesis

Chronic hepatitis B virus (HBV) infection is one of the most common factors associated with hepatocellular carcinoma (HCC), which is the sixth most prevalent cancer among all cancers worldwide. However, the pathogenesis of HBV-mediated hepatocarcinogenesis is unclear. Evidence currently available suggests that the HBV core protein (HBc) plays a potential role in the development of HCC, such as the HBV X protein. The core protein, which is the structural component of the viral nucleocapsid, contributes to almost every stage of the HBV life cycle and occupies diverse roles in HBV replication and pathogenesis. Recent studies have shown that HBc was able to disrupt various pathways involved in liver carcinogenesis: the signaling pathways implicated in migration and proliferation of hepatoma cells, apoptosis pathways, and cell metabolic pathways inducing the development of HCC; and the immune system, through the expression and production of proinflammatory cytokines. In addition, HBc can modulate normal functions of hepatocytes through disrupting human host gene expression by binding to promoter regions. This HBV protein also promotes HCC metastasis through epigenetic alterations, such as micro-RNA. This review focuses on the molecular pathogenesis of the HBc protein in HBV-induced HCC.

Hepatitis B x antigen (HBx) is an important therapeutic target in the pathogenesis of hepatocellular carcinoma

Hepatitis B virus (HBV) is a human pathogen that has infected an estimated two billion people worldwide. Despite the availability of highly efficacious vaccines, universal screening of the blood supply for virus, and potent direct acting anti-viral drugs, there are more than 250 million carriers of HBV who are at risk for the sequential development of hepatitis, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). More than 800,000 deaths per year are attributed to chronic hepatitis B. Many different therapeutic approaches have been developed to block virus replication, and although effective, none are curative. These treatments have little or no impact upon the portions of integrated HBV DNA, which often encode the virus regulatory protein, HBx. Although given little attention, HBx is an important therapeutic target because it contributes importantly to (a) HBV replication, (b) in protecting infected cells from immune mediated destruction during chronic infection, and (c) in the development of HCC. Thus, the development of therapies targeting HBx, combined with other established therapies, will provide a functional cure that will target virus replication and further reduce or eliminate both the morbidity and mortality associated with chronic liver disease and HCC. Simultaneous targeting of all these characteristics underscores the importance of developing therapies against HBx.

HBV HBx-Downregulated lncRNA LINC01010 Attenuates Cell Proliferation by Interacting with Vimentin

Hepatitis B virus (HBV) infection is closely related to hepatocellular carcinoma (HCC) development. To investigate the mechanism of HBV causing HCC, we previously analyzed the transcription of the HBV-transgenic cell line HepG2-4D14 and parental HepG2 cells and identified a subset of long noncoding RNAs (lncRNAs) differentially expressed between them. In this study, we focus on lncRNA LINC01010, as it is significantly downregulated in HepG2-4D14 cells and in liver tissues of HCC patients, and positively correlated with survival. We found that HBV-encoded HBx can reduce the transcription of LINC01010. Functional analysis showed that the overexpression of LINC01010 inhibits proliferation, migration and invasion of HepG2 cells while the knockdown of LINC01010 promotes these processes. By taking the approach of RNA immunoprecipitation (RIP) and mass spectrometry, we identified that LINC01010 can interact with vimentin. Further studies demonstrated that LINC01010 negatively affects the vimentin network extension and causes more rapid subunit exchange and lower stability of vimentin filaments. In addition, LINC01010 can reduce the amount of insoluble vimentin within cells, which suggests that LINC01010 interfers with vimentin polymerization. These data indicate that LINC01010 can inhibit the assembly of vimentin filament. Thus, we revealed that HBV HBx-downregulated LINC01010, which suppresses cell proliferation and migration by negatively regulating the formation of vimentin filament. Taken together, LINC01010 is a potential tumor suppressor that may restrain HBV-related HCC development.

Systematic analysis of the mechanism of Xiaochaihu decoction in hepatitis B treatment via network pharmacology and molecular docking

Hepatitis B (HB) is a globally prevalent infectious disease caused by the HB virus. Xiaochaihu decoction (XCHD) is a classic herbal formula with a long history of clinical application in treating HB. Although the anti-HB activity of XCHD has been reported, systematic research on the exact mechanism of action is lacking. Here, a network pharmacology-based approach was used to predict the active components, important targets, and potential mechanism of XCHD in HB treatment. Investigation included drug-likeness evaluation; absorption, distribution, metabolism, and elimination (ADME) screening; protein-protein interaction (PPI) network construction and cluster analysis; Gene Ontology (GO) analysis; and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. Molecular docking was adopted to investigate the interaction between important target proteins and active components. Eighty-seven active components of XCHD and 155 anti-HB targets were selected for further analysis. The GO enrichment and similarity analysis results indicated that XCHD might perform similar or the same GO functions. Glycyrrhizae Radix (GR), one of the seven XCHD herbs, likely exerts some unique GO functions such as the regulation of interleukin-12 production, positive regulation of interleukin-1 beta secretion, and regulation of the I-kappaB/NF-kappaB complex. The PPI network and KEGG pathway analysis results showed that XCHD affects HB mainly through modulating pathways related to viral infection, immunity, cancer, signal transduction, and metabolism. Additionally, molecular docking verified that the active compounds (quercetin, chrysin, and capsaicin) could bind with the key targets. This work systematically explored the anti-HB mechanism of XCHD and provides a novel perspective for future pharmacological research.

Impact of interleukin IL-6 rs-1474347 and IL-10 rs-1800896 genetic polymorphisms on the susceptibility of HCV-infected Egyptian patients to hepatocellular carcinoma

Hepatitis C virus (HCV) is considered leading cause of cirrhosis and hepatocellular carcinoma (HCC). We aimed to examine the association of IL-6 and IL-10 single-nucleotide polymorphisms with the progression of chronic HCV (CHC) infection to cirrhosis and HCC. For comparative purposes, four groups were enrolled; chronic HCV group (CHC, n = 22), HCV-related liver cirrhosis group (HCV-LC, n = 22), HCV-related HCC group (HCV-HCC, n = 54), and an apparently healthy control group (controls, n = 48). HCC diagnosis and staging were in concordance to Barcelona Clinic Liver Cancer (BCLC) staging system. IL-6 rs-1474347 and IL-10 rs-1800896 genotyping was performed by allelic (VIC- and FAM-labeled) discrimination method using assay-on-demand TaqMan real-time PCR assays. For IL-6 rs1474347, the AA genotype was more frequent in CHC, HCV-LC, and HCV-HCC compared to controls. Also, the IL-6 rs1474347 AC genotype was favorable for the progression of HCV chronic infection to cirrhosis and HCC. On the other hand, the IL-10 rs1800896 TT genotype was found to be prominent in the HCC group. Additionally, the IL-10 rs180096 TT genotype was favorable for the progression of chronic HCV infection to cirrhosis and HCC. Furthermore, higher levels of AFP were observed in HCC patients with IL-6 rs1474347 AA genotype and HCC patients with IL-10 rs1800896 CC and TT genotypes. Screening for IL-6 rs 1474347 AC genotype and IL-10 rs180096 TT genotype as well as the determination of AFP level showed to be good markers for examining the susceptibility of HCV Egyptian patients to develop cirrhosis and HCC.

Correlation Between Vascular Endothelial Growth Factor and Long-Term Occurrence of HCV-Related Hepatocellular Carcinoma After Treatment with Direct-Acting Antivirals

We aimed to evaluate the correlation between vascular endothelial growth factor (VEGF) and long-term occurrence of hepatocellular carcinoma after HCV treatment with direct-acting antivirals (DAAs) and the HCC stage. Two groups with HCV-related liver cirrhosis and HCC were included: group 1, HCC following DAAs; group 2, HCC did not receive DAAs. The serum level of VEGF and HCC staging was evaluated. The duration between DAAs and HCC was 21.81 ± 11.66 months. Portal vein thrombosis (PVT) was observed more in group 1 (31%). VEGF was relatively elevated in group 1 compared to group 2. HCC patients after DAAs, showed elevated VEGF with frequent PVT.

Prognostic Accuracy of the ADV Score Following Resection of Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis

BACKGROUND

We assessed the prognostic accuracy of ADV score (α-fetoprotein [AFP]-des-γ-carboxyprothrombin [DCP]-tumor volume [TV] score) following resection of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT).

METHODS

This was a retrospective observational study. This study included 147 patients who underwent hepatic resection for HCC with PVTT. They were followed up for ≥ 66 months or until patient death.

RESULTS

The grades of PVTT were Vp1 in 121 (14.3%), Vp2 in 41 (27.9%), Vp3 in 71 (48.3%), and Vp4 in14 (9.5%) cases. Preoperative HCC treatment was performed in 48 (32.7%) patients. R0 and R1 resections were performed in 119 (81.0%) and 28 (19.0%) cases, respectively. The 5-year tumor recurrence, HCC-specific survival, and post-recurrence survival rates were 79.2%, 43.5%, and 25.4%, respectively. Neither PVTT grade nor history of preoperative HCC treatment was a significant prognostic indicator. Stratification in accordance with ADV scores of 1log- and 3log-intervals resulted in high prognostic accuracy in predicting tumor recurrence and patient survival. Following cluster analysis, the cutoff for ADV score was determined at 9log and was more prognostically significant in terms of tumor recurrence and patient survival than surgical curability or microvascular invasion. Further comparisons revealed that prognostic prediction with an ADV score cutoff at 9log was more accurate than that using the Eastern Hepatobiliary Surgery Hospital-PVTT score.

CONCLUSIONS

ADV score is an integrated surrogate biomarker for post-resection prognosis in HCC with PVTT. Our prognostic prediction model using ADV scores provides reliable post-resection prognosis for patients with various grades of these tumors.

Characterization of Antigen Escape Mutations in Chronic HBV-Infected Patients in Upper Egypt

Background

Mutations within the “a” determinant region (position 124–147) that is present in the major hydrophilic region (MHR, position 99–160) of the hepatitis B surface antigen (HBsAg) are associated with vaccine-escape, lack of diagnosis, and failure to hepatitis B immunoglobulin (HBIG) therapy. Data regarding the amino acid changes of “a” determinant region of HBsAg are limited in Egypt. The prevalence and mutations in this region among chronic HBV (CHB)-infected patients in Upper Egypt are not known.

Material and Methods

Blood samples were collected from HBsAg-positive CHB-infected patients (n=123) admitted to Assiut University Hospitals. Serum samples were screened for HBsAg, HBeAg, anti-HBs and anti-HBe antibodies using commercially available ELISA kits. Viral load was determined by qPCR. In addition, mutational analysis was carried out targeting the HBV surface gene to determine the HBV genotype and vaccine escape mutations.

Results

Sequencing analysis of HBV DNA revealed that genotype D is the major circulating type (81.3%), followed by genotype E (18.7%). Analysis of the HBV genome revealed that 103/123 (83.7%) patients showed wild-type sequences and 20/123 (16.3%) showed mutations in the HBsAg gene. Mutation in seventeen patients (17/20, 85%) showed only one mutation, and three patients showed two mutations (3/20, 15%) in the “a” determinant region. The observed mutations were T115S (3/20, 15%), P120T/S (3/20, 15%), T126S (1/20, 5%), Q129R (2/20, 10%), M133T (2/20, 10%), S143L (5/20, 25%), D144E/A (3/20, 15%), and G145R/A (4/20, 20%). Mutations in the “a” determinant region were detected in genotype D isolates only.

Conclusion

We described for the first time the prevalence and characterization of vaccine escape mutants in CHB patients in Upper Egypt. Mutational analysis of the “a” determinant region revealed the presence of a wide spectrum of mutants in the circulating HBV isolates that could be a potential threat to HBV diagnosis, therapy success, and HBV vaccination program in Upper Egypt.

Manipulation of Cellular Processes via Nucleolus Hijaking in the Course of Viral Infection in Mammals

Due to their exceptional simplicity of organization, viruses rely on the resources, molecular mechanisms, macromolecular complexes, regulatory pathways, and functional compartments of the host cell for an effective infection process. The nucleolus plays an important role in the process of interaction between the virus and the infected cell. The interactions of viral proteins and nucleic acids with the nucleolus during the infection process are universal phenomena and have been described for almost all taxonomic groups. During infection, proteins of the nucleolus in association with viral components can be directly used for the processes of replication and transcription of viral nucleic acids and the assembly and transport of viral particles. In the course of a viral infection, the usurpation of the nucleolus functions occurs and the usurpation is accompanied by profound changes in ribosome biogenesis. Recent studies have demonstrated that the nucleolus is a multifunctional and dynamic compartment. In addition to the biogenesis of ribosomes, it is involved in regulating the cell cycle and apoptosis, responding to cellular stress, repairing DNA, and transcribing RNA polymerase II-dependent genes. A viral infection can be accompanied by targeted transport of viral proteins to the nucleolus, massive release of resident proteins of the nucleolus into the nucleoplasm and cytoplasm, the movement of non-nucleolar proteins into the nucleolar compartment, and the temporary localization of viral nucleic acids in the nucleolus. The interaction of viral and nucleolar proteins interferes with canonical and non-canonical functions of the nucleolus and results in a change in the physiology of the host cell: cell cycle arrest, intensification or arrest of ribosome biogenesis, induction or inhibition of apoptosis, and the modification of signaling cascades involved in the stress response. The nucleolus is, therefore, an important target during viral infection. In this review, we discuss the functional impact of viral proteins and nucleic acid interaction with the nucleolus during infection.

How SARS-CoV-2 and Other Viruses Build an Invasion Route to Hijack the Host Nucleocytoplasmic Trafficking System

The host nucleocytoplasmic trafficking system is often hijacked by viruses to accomplish their replication and to suppress the host immune response. Viruses encode many factors that interact with the host nuclear transport receptors (NTRs) and the nucleoporins of the nuclear pore complex (NPC) to access the host nucleus. In this review, we discuss the viral factors and the host factors involved in the nuclear import and export of viral components. As nucleocytoplasmic shuttling is vital for the replication of many viruses, we also review several drugs that target the host nuclear transport machinery and discuss their feasibility for use in antiviral treatment.

Hepatitis B virus X protein promotes vimentin expression via LIM and SH3 domain protein 1 to facilitate epithelial-mesenchymal transition and hepatocarcinogenesis

BACKGROUND

Hepatitis B virus (HBV) X protein (HBX) has been reported to be responsible for the epithelial-mesenchymal transition (EMT) in HBV-related hepatocellular carcinoma (HCC). Vimentin is an EMT-related molecular marker. However, the importance of vimentin in the pathogenesis of HCC mediated by HBX has not been well determined.

METHODS

The expression of vimentin induced by HBX, and the role of LIM and SH3 domain protein 1 (LASP1) in HBX-induced vimentin expression in hepatoma cells were examined by western blot and immunohistochemistry analysis. Both the signal pathways involved in the expression of vimentin, the interaction of HBX with vimentin and LASP1, and the stability of vimentin mediated by LASP1 in HBX-positive cells were assessed by western blot, Co-immunoprecipitation, and GST-pull down assay. The role of vimentin in EMT, proliferation, and migration of HCC cells mediated by HBX and LASP1 were explored with western blot, CCK-8 assay, plate clone formation assay, transwell assay, and wound healing assay.

RESULTS

Vimentin expression was increased in both HBX-positive hepatoma cells and HBV-related HCC tissues, and the expression of vimentin was correlated with HBX in HBV-related HCC tissues. Functionally, vimentin was contributed to the EMT, proliferation, and migration of hepatoma cells mediated by HBX. The mechanistic analysis suggested that HBX was able to enhance the expression of vimentin through LASP1. On the one hand, PI3-K, ERK, and STAT3 signal pathways were involved in the upregulation of vimentin mediated by LASP1 in HBX-positive hepatoma cells. On the other hand, HBX could directly interact with vimentin and LASP1, and dependent on LASP1, HBX was capable of promoting the stability of vimentin via protecting it from ubiquitination mediated protein degradation. Besides these, vimentin was involved in the growth and migration of hepatoma cells mediated by LASP1 in HBX-positive hepatoma cells.

CONCLUSION

Taken together, these findings demonstrate that, dependent on LASP1, vimentin is crucial for HBX-mediated EMT and hepatocarcinogenesis, and may serve as a potential target for HBV-related HCC treatment. Video abstract.

Phosphorylation of Phylogenetically Conserved Amino Acid Residues Confines HBx within Different Cell Compartments of Human Hepatocarcinoma Cells

Hepatitis B virus (HBV) is a circular, and partially double-stranded DNA virus. Upon infection, the viral genome is translocated into the cell nucleus, generating the covalently closed circular DNA (cccDNA) intermediate, and forming a mini chromosome. HBV HBx is a small protein displaying multiple roles in HBV-infected cells, and in different subcellular locations. In the nucleus, the HBx protein is required to initiate and maintain viral transcription from the viral mini chromosome. In contrast, HBx also functions in the cytoplasm, where it is able to alter multiple cellular functions such as mitochondria metabolism, apoptosis and signal transduction pathways. It has been reported that in cultured cells, at low expression levels, the HBx protein is localized in the nucleus, whereas at high expression levels, it accumulates in the cytoplasm. This dynamic subcellular distribution of HBx might be essential to exert its multiple roles during viral infection. However, the mechanism that regulates different subcellular localizations of the HBx protein is unknown. We have previously taken a bioinformatics approach to investigate whether HBx might be regulated via post-translational modification, and we have proposed that the multiple nucleocytoplasmic functions of HBx might be regulated by an evolutionarily conserved mechanism via phosphorylation. In the current study, phylogenetically conserved amino acids of HBx with a high potential of phosphorylation were targeted for site-directed mutagenesis. Two conserved serine (Ser25 and Ser41), and one conserved threonine (Thr81) amino acids were replaced by either alanine or aspartic acid residues to simulate an unphosphorylated or phosphorylated state, respectively. Human hepatoma cells were transfected with increasing amounts of the HBx DNA constructs, and the cells were analyzed by fluorescence microscopy. Together, our results show that the nucleocytoplasmic distribution of the HBx protein could be regulated by phosphorylation since some of the modified proteins were mainly confined to distinct subcellular compartments. Remarkably, both HBx Ser41A, and HBx Thr81D proteins were predominantly localized within the nuclear compartment throughout the different expression levels of HBx mutants.

Characterization of Hepatitis B Virus Integrations Identified in Hepatocellular Carcinoma Genomes

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality. Almost half of HCC cases are associated with hepatitis B virus (HBV) infections, which often lead to HBV sequence integrations in the human genome. Accurate identification of HBV integration sites at a single nucleotide resolution is critical for developing a better understanding of the cancer genome landscape and of the disease itself. Here, we performed further analyses and characterization of HBV integrations identified by our recently reported VIcaller platform in recurrent or known HCC genes (such as TERT, MLL4, and CCNE1) as well as non-recurrent cancer-related genes (such as CSMD2, NKD2, and RHOU). Our pathway enrichment analysis revealed multiple pathways involving the alcohol dehydrogenase 4 gene, such as the metabolism pathways of retinol, tyrosine, and fatty acid. Further analysis of the HBV integration sites revealed distinct patterns involving the integration upper breakpoints, integrated genome lengths, and integration allele fractions between tumor and normal tissues. Our analysis also implies that the VIcaller method has diagnostic potential through discovering novel clonal integrations in cancer-related genes. In conclusion, although VIcaller is a hypothesis free virome-wide approach, it can still be applied to accurately identify genome-wide integration events of a specific candidate virus and their integration allele fractions.

Transcriptomic identification of HBx-associated hub genes in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies around the world. Among the risk factors involved in liver carcinogenesis, hepatitis B virus (HBV) X protein (HBx) is considered to be a key regulator in hepatocarcinogenesis. Whether HBx promotes or protects against HCC remains controversial, therefore exploring new HBx-associated genes is still important.

METHODS

HBx was overexpressed in HepG2, HepG2.2.15 and SMMC-7721 cell lines, primary mouse hepatocytes and livers of C57BL/6N mice. High-throughput RNA sequencing profiling of HepG2 cells with HBx overexpression and related differentially-expressed genes (DEGs), pathway enrichment analysis, protein-protein interaction networks (PPIs), overlapping analysis were conducted. In addition, Gene Expression Omnibus (GEO) and proteomic datasets of HBV-positive HCC datasets were used to verify the expression and prognosis of selected DEGs. Finally, we also evaluated the known oncogenic role of HBx by oncogenic array analysis.

RESULTS

A total of 523 DEGs were obtained from HBx-overexpressing HepG2 cells. Twelve DEGs were identified and validated in cells transiently transfected with HBx and three datasets of HBV-positive HCC transcription profiles. In addition, using the Kaplan-Meier plotter database, the expression levels of the twelve different genes were further analyzed to predict patient outcomes.

CONCLUSION

Among the 12 identified HBx-associated hub genes, HBV-positive HCC patients expressing ARG1 and TAT showed a good overall survival (OS) and relapse-free survival (RFS). Thus, ARG1 and TAT expression could be potential prognostic markers.

HBXIP drives metabolic reprogramming in hepatocellular carcinoma cells via METTL3-mediated m6A modification of HIF-1α

Cancer cells sustain high levels of glycolysis and glutaminolysis via reprogramming of intracellular metabolism, which represents a driver of hepatocellular carcinoma (HCC) progression. Understanding the mechanisms of cell metabolic reprogramming may present a new basis for liver cancer treatment. Herein, we collected HCC tissues and noncancerous liver tissues and found hepatitis B virus X-interacting protein (HBXIP) was found to be upregulated in HCC tissues and associated with poor prognosis. The N6-methyladenosine (m6A) level of hypoxia-inducible factor-1α (HIF-1α) in HCC cells was evaluated after the intervention of METTL3. The possible m6A site of HIF-1α was queried and the binding relationship between METTL3 and HIF-1α was verified. The interference of HBXIP suppressed HCC malignant behaviors and inhibited the Warburg effect in HCC cells. METTL3 was upregulated in HCC tissues and positively regulated by HBXIP. Overexpression of METTL3 restored cell metabolic reprogramming in HCC cells with partial loss of HBXIP. HBXIP mediated METTL3 to promote the metabolic reprogramming and malignant biological behaviors of HCC cells. The levels of total m6A in HCC cells and m6A in HIF-1α were increased. METTL3 had a binding relationship with HIF-1α and mediated the m6A modification of HIF-1α. In conclusion, HBXIP drives metabolic reprogramming in HCC cells via METTL3-mediated m6A modification of HIF-1α.

Cytotoxic Chemotherapy as an Alternative for Systemic Treatment of Advanced Hepatocellular Carcinoma in Developing Countries

Systemic therapy options nowadays for advanced hepatocellular carcinoma (HCC) are either immunotherapy with immune checkpoint inhibitors or targeted therapy. As the incidence of liver cancer is much higher in developing countries, these new medications are not readily accessible for most of the patients. Cytotoxic chemotherapy agents are more available and affordable in developing countries. We are trying to explore the effectiveness of the newer cytotoxic agents in the systematic treatment for advanced HCC. This is a systematic review of all randomized controlled trials since 1997 that utilized systemic cytotoxic chemotherapy agents in the systemic treatment for advanced HCC using Scopus, PubMed, and Cochrane library up to February 2020. Six randomized trials were found. Different drugs and dosages were used, so it was statistically inappropriate to conduct a meta-analysis. No Phase III trial showed statistically significant overall survival (OS) benefit for cytotoxic chemotherapy, except subgroup analysis of Chinese patients in one study who had leucovorin, fluorouracil, and oxaliplatin (FOLFOX) regimen. There was no significant progression-free survival (PFS) or response rate in the Phase II trials. There are not enough data to infer the actual benefits of systemic cytotoxic chemotherapy in advanced HCC. However, oxaliplatin-based regimens may give feasible results. Health systems with limited access to targeted therapy and immunotherapy agents may use oxaliplatin-based regimens in clinical trials for advanced HCC. These results should be confirmed in multiple future randomized clinical trials.

Using Quasispecies Patterns of Hepatitis B Virus to Predict Hepatocellular Carcinoma With Deep Sequencing and Machine Learning

BACKGROUND

Hepatitis B virus (HBV) infection is one of the main leading causes of hepatocellular carcinoma (HCC) worldwide. However, it remains uncertain how the reverse-transcriptase (rt) gene contributes to HCC progression.

METHODS

We enrolled a total of 307 patients with chronic hepatitis B (CHB) and 237 with HBV-related HCC from 13 medical centers. Sequence features comprised multidimensional attributes of rt nucleic acid and rt/s amino acid sequences. Machine-learning models were used to establish HCC predictive algorithms. Model performances were tested in the training and independent validation cohorts using receiver operating characteristic curves and calibration plots.

RESULTS

A random forest (RF) model based on combined metrics (10 features) demonstrated the best predictive performances in both cross and independent validation (AUC, 0.96; accuracy, 0.90), irrespective of HBV genotypes and sequencing depth. Moreover, HCC risk scores for individuals obtained from the RF model (AUC, 0.966; 95% confidence interval, .922-.989) outperformed α-fetoprotein (0.713; .632-.784) in distinguishing between patients with HCC and those with CHB.

CONCLUSIONS

Our study provides evidence for the first time that HBV rt sequences contain vital HBV quasispecies features in predicting HCC. Integrating deep sequencing with feature extraction and machine-learning models benefits the longitudinal surveillance of CHB and HCC risk assessment.

Bioinformatics analysis of LINC01554 and its co‑expressed genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related morbidity and mortality globally. Despite the remarkable improvements in comprehensive HCC treatment, the underlying mechanistic details of HCC remain elusive. We screened HCC patients for differentially expressed genes (DEGs) using the Gene Expression Omnibus (GSE113850) and The Cancer Genome Atlas (TCGA) datasets. LINC01554 expression in 40 paired samples was determined by quantitative reverse transcription polymerase chain reaction (RT-qPCR), and its clinical significance was assessed. LINC01554 was found to have a gain-of-function role in HCC in vitro. Additionally, the bioinformatics analysis of the genes co-expressed with LINC01554 was performed using the Co-LncRNA website, and potential molecular mechanisms were investigated using the Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes resources and validated by in vitro experiments. A total of 229 DEGs were identified from the GSE113850 dataset. Among the identified DEGs, three long non-coding RNAs (lncRNAs) (DIO3OS, LINC01554, and LINC01093) with |logFC| ≥2 and P<0.05 were screened. A total of 148 lncRNAs with |logFC| ≥1 and P<0.05 were identified from TCGA dataset. Low LINC01554 expression levels were significantly correlated with overall survival, pathological stage, hepatitis B infection, tumour size, portal vein tumour thrombus, and TNM stage. Using gain-of-function assays, we further showed that LINC01554 inhibited the proliferation, migration, and invasion of the HCCLM9 and SK-Hep1 cells and promoted G0/G1 arrest, but it did not significantly affect apoptosis. Western blotting revealed that LINC01554 overexpression resulted in increased ZO-1 and E-cadherin expression levels, but decreased N-cadherin and vimentin expression levels. Moreover, LINC01554 overexpression inhibited Akt, p-Akt, β-catenin, and p-Gsk3β expression. Our results showed that LINC01554 repressed HCC cell invasiveness and epithelial-to-mesenchymal transition partly by inhibiting Wnt and PI3K-Akt signalling in vitro. Taken together, our findings provide new insights into the molecular mechanisms underlying HCC tumourigenesis and implicate LINC01554 as a potential target for HCC therapy.

Regulatory B Cells and Their Cytokine Profile in HCV-Related Hepatocellular Carcinoma: Association with Regulatory T Cells and Disease Progression

Although regulatory B cells (Bregs) have been proven to play a suppressive role in autoimmune diseases, infections and different tumors, little is known regarding hepatocellular carcinoma (HCC), especially in hepatitis C-related settings. Herein, we analyzed the frequency of circulating Bregs, serum levels of IL-10, IL-35 and B-cell activating factor (BAFF) and investigated their association with regulatory T cells (Tregs) and disease progression in HCV-related HCC. For comparative purposes, four groups were enrolled; chronic HCV (CHC group, n = 35), HCV-related liver cirrhosis (HCV-LC group, n = 35), HCV-related HCC (HCV-HCC group, n = 60) and an apparently healthy control (Control-group, n = 20). HCC diagnosis and staging were in concordance with the Barcelona Clinic Liver Cancer (BCLC) staging system. Analysis of the percentage of Breg cells and peripheral lymphocyte subsets (Treg) was performed by flow cytometry. Serum cytokine levels of IL-10, IL-35 and B-cell activating factor (BAFF) were measured by ELISA. The frequency of Bregs was significantly higher in the HCV-HCC group compared to the other groups and controls. A significant increase was noted in late-HCC versus those in the early stages. The frequency of Bregs was positively correlated with Tregs, serum IL-10, IL-35 and BAFF. In conclusion, Peripheral Bregs were positively correlated with the frequency of Tregs, IL-10, IL-35 and BAFF, and may be associated with HCV-related HCC progression.

Classification and mutation prediction based on histopathology H&E images in liver cancer using deep learning

Hepatocellular carcinoma (HCC) is the most common subtype of liver cancer, and assessing its histopathological grade requires visual inspection by an experienced pathologist. In this study, the histopathological H&E images from the Genomic Data Commons Databases were used to train a neural network (inception V3) for automatic classification. According to the evaluation of our model by the Matthews correlation coefficient, the performance level was close to the ability of a 5-year experience pathologist, with 96.0% accuracy for benign and malignant classification, and 89.6% accuracy for well, moderate, and poor tumor differentiation. Furthermore, the model was trained to predict the ten most common and prognostic mutated genes in HCC. We found that four of them, including CTNNB1, FMN2, TP53, and ZFX4, could be predicted from histopathology images, with external AUCs from 0.71 to 0.89. The findings demonstrated that convolutional neural networks could be used to assist pathologists in the classification and detection of gene mutation in liver cancer.

Evaluation of the immune memory response to routine HBV vaccine in Egyptian patients with Type 1 diabetes

We aimed to evaluate the immune memory response to HBV vaccine in diabetic patients who had received the full HBV vaccination during infancy and to assess the need for booster doses. Blood samples were collected from children (93 diabetics and 105 controls) and university students (22 diabetics and 20 controls). Anti-HBs titer in serum and after in vitro stimulation of peripheral blood mononuclear cells with HBV vaccine was measured by ELISA. Diabetic groups had significantly lower anti-HBs levels after 10 years of the last HBV vaccine dose. The percentage of diabetic patients having protective anti-HBs titers was significantly lower than controls. In conclusion, diabetic patients had lower immune response to HBV vaccine over time, emphasizing the need for a booster dose.

Differential expression of Tim-3, PD-1, and CCR5 on peripheral T and B lymphocytes in hepatitis C virus-related hepatocellular carcinoma and their impact on treatment outcomes

BACKGROUND AND OBJECTIVE

Activation of the immune checkpoints and expression of chemokines and chemokine receptors have been reported to promote HCC progression. This study aimed to assess the differential expression of Tim-3, PD-1, and CCR5 on peripheral blood lymphocytes from patients with HCV-related HCC and correlate their expression with the treatment outcomes.

PATIENTS AND METHODS

The study incorporated 40 patients with chronic HCV-related HCC and 40 healthy controls. Patients were radiologically assessed for hepatic focal lesions and portal vein thrombosis. Response to HCC treatment and overall survival (OS) outcomes were determined. The expression of Tim-3, PD-1, and CCR5 among CD19⁺, CD4⁺, and CD8⁺ lymphocytes was assessed by flow cytometry.

RESULTS

Higher frequencies of CD4⁺ and CD8⁺ cells expressing each of Tim-3 and PD-1 and PD-1⁺CD19⁺ cells were observed in the HCV-related HCC patients in comparison with controls. The highest expression of Tim-3 and PD-1 was by the CD8⁺ cells. Strong relations were detected among PD-1⁺CD19⁺, PD-1⁺CD4⁺ and PD-1⁺CD8⁺ cells. Elevated levels of PD-1⁺ lymphocytes were significantly associated with poor treatment response and shorter OS.

CONCLUSION

Modulation of the expression of immune checkpoints as Tim-3 and PD-1, and of CCR5 on T cells is somehow related to HCC. CD8⁺ T cells expressing PD-1 were the most relevant to HCC prognosis (OS and treatment response) and could represent a promising target for immune therapy against HCC. Future studies need to focus on exploring PD-1⁺ B cells and Tim-3⁺CD4⁺ cells, which seem to play a significant role in the pathogenesis of HCC.

Research Progress in Liver-Regenerating Microenvironment and DNA Methylation in Hepatocellular Carcinoma: The Role of Traditional Chinese Medicine

The development, progression, recurrence, and metastasis of hepatocellular carcinoma (HCC) are closely associated with an abnormal liver-regenerating microenvironment (LRM). Therefore, preventing and reversing an abnormal LRM is a potential therapeutic strategy against HCC. Studies are increasingly focusing on the impact of regeneration, fibrosis, angiogenesis, inflammation, immunomodulation, and hepatic stem cells on HCC development and progression. As a key epigenetic mechanism, DNA methylation is extensively involved in regulating physiological and pathological pathways. In this review, we summarize recent findings on the role of DNA methylation in the fibrotic, angiogenic, inflammatory/immune, and stem cell microenvironments of HCC, and discuss new advances in Traditional Chinese Medicine (TCM) on influencing the abnormal LRM, so as to gain new insights into alleviating the abnormal LRM via regulating DNA methylation by TCM.

Recent Advances in Molecular Mechanisms of the NKG2D Pathway in Hepatocellular Carcinoma

Hepatocellular carcinoma is a common malignant tumor with high mortality. Its malignant proliferation, invasion, and metastasis are closely related to the cellular immune function of the patients. NKG2D is a key activated and type II membrane protein molecule expressed on the surface of almost all NK cells. The human NKG2D gene is 270 kb long, located at 12p12.3-p13.1, and contains 10 exons and 9 introns. The three-dimensional structure of the NKG2D monomeric protein contains two alpha-helices, two beta-lamellae, and four disulfide bonds, and its' signal of activation is transmitted mainly by the adaptor protein (DAP). NKG2D ligands, including MICA, MICB, and ULBPs, can be widely expressed in hepatoma cells. After a combination of NKG2D and DAP10 in the form of homologous two polymers, the YxxM motif in the cytoplasm is phosphorylated and then signaling pathways are also gradually activated, such as PI3K, PLCγ2, JNK-cJunN, and others. Activated NK cells can enhance the sensitivity to hepatoma cells and specifically dissolve by releasing a variety of cytokines (TNF-α and IFN-γ), perforin, and high expression of FasL, CD16, and TRAIL. NK cells may specifically bind to the over-expressed MICA, MICB, and ULBPs of hepatocellular carcinoma cells through the surface activating receptor NKG2D, which can help to accurately identify hepatoma, play a critical role in anti-hepatoma via the pathway of cytotoxic effects, and obviously delay the poor progress of hepatocellular carcinoma.

Integrative analysis of highly mutated genes in hepatitis B virus-related hepatic carcinoma

Gene mutation is responsible for the development of hepatocellular carcinoma (HCC) with hepatitis B virus (HBV) infection; however, the characteristics and associated biological functions of highly mutated genes, in which the mutation frequencies are at least 5% in HCC patients with HBV infection, are not clearly evaluated. In the study, we analyzed the information regarding somatic mutation obtained by whole‐exome sequencing in 280 HBV‐related HCC tissues from public databases and published studies. Via integrative analysis, 78 genes, including TP53, TTN, MUC16, CTNNB1, and PCLO were summarized as highly mutated genes, and some of these mutated genes were further identified as cancer driver genes. Besides, we discovered that the highly mutated genes were enriched with various biological functions and pathways. The expression of many of highly mutated genes was found to be significantly altered in HBV‐related HCC, and several highly mutated genes were related to a variety of clinical factors and associated with the poor survival of the disease. Taken together, these results could enrich our understanding of highly mutated genes and their relationships with HBV‐related HCC. Some of the identified highly mutated genes might be used as novel biomarkers of disease prognosis, or as molecular targets for the treatment of HCC with HBV infection.

Prognostic impact of toll-like receptors 2 and 4 expression on monocytes in Egyptian patients with hepatocellular carcinoma

Toll-like receptors (TLRs) have a role in chronic inflammation. Still, little is known about the expression of TLRs in hepatocellular carcinoma (HCC). Herein, we tried to assess the prognostic value of TLR2 and TLR4 expression on circulating monocytes in HCC patients and correlate their levels with some clinical, laboratory data, and treatment outcomes. Forty patients with hepatic focal lesions diagnosed radiologically as HCC by triphasic multislice CT pelviabdominal and chest, and in some patients MRI diffusion and 38 age and sex matching healthy controls were enrolled in the study. Subjects were evaluated for liver functions, alpha-fetoprotein (AFP), imaging, response to different treatments, and overall survival. TLR2 and TLR4 expression by monocytes was detected by flow cytometry. The expression of both TLR2 and TLR4 on monocytes was significantly increased in HCC patients than the controls, in patients with more progressive HCC than those with lower progression and in patients with poor response to treatment than patients with better treatment response. Moreover, their levels showed positive correlations with ALT, AST, and AFP and inverse correlations with the overall survival of HCC patients. The results of the current study suggest that increased expression ofTLR2 and TLR4 on peripheral monocytes might reflect the development and progression of HCC and can be used to indicate poor prognosis. In addition, high expression of TLR2 correlated significantly with poor response to treatment, while high expression of both TLR2 and TLR4 were associated with poor survival. Our findings will help to design more studies on the role of TLRs in HCC pathogenesis and prognosis which may provide new therapeutic targets for HCC.

Effects of MACC1 polymorphisms on hepatocellular carcinoma development and clinical characteristics

Hepatocellular carcinoma (HCC) is a major malignancy of cancer-related mortality worldwide. Metastasis-associated in colon cancer-1 (MACC1) was suggested as a marker for vascular invasive HCC. This study investigated the MACC1 single-nucleotide polymorphisms (SNPs) to evaluate HCC susceptibility and clinicopathological characteristics. In this study, real-time polymerase chain reaction was applied to analyze five SNPs of MACC1 rs1990172, rs975263, rs3095007, rs4721888, and rs3735615 in 378 patients with HCC and 1199 cancer-free controls. The results showed that in 151 HCC patients among smokers who carried MACC1 rs1990172 "CA + AA" variants had a lower risk of developing a large tumor (odds ratio [OR] = 0.375, p = 0.026), more advanced clinical stage ([OR] = 0.390, p=0.032), and vascular invasion ([OR] = 0.198, p = 0.034). In 137 HCC patients among drinkers who carried MACC1 rs4721888 "GC + CC" variants had a higher risk to develop vascular invasion ([OR] = 3.780, p = 0.009). Further analyses revealed a statistical significance of aberrant AST/ALT ratio in HCC patients with MACC1 rs975263 "AG+GG" variants before adjustment of age and alcohol drinking. In conclusion, our results suggested that the MACC1 SNPs rs1990172, rs4721888, and rs975263 are involved in HCC progression and clinical characteristics. MACC1 polymorphisms may serve as a marker or a predictor to evaluate HCC progression and prognosis.