HBx mutations promote hepatoma cell migration through the Wnt/β-catenin signaling pathway

Metabolic reprogramming of glucose: the metabolic basis for the occurrence and development of hepatocellular carcinoma

Primary liver cancer is a common malignant tumor of the digestive system, with hepatocellular carcinoma (HCC) being the most prevalent type. It is characterized by high malignancy, insidious onset, and a lack of specific early diagnostic and therapeutic markers, posing a serious threat to human health. The occurrence and development of HCC are closely related to its metabolic processes. Similar to other malignant tumors, metabolic reprogramming occurs extensively in tumor cells, with glucose metabolism reprogramming being particularly prominent. This is characterized by abnormal activation of glycolysis and inhibition of oxidative phosphorylation and gluconeogenesis, among other changes. Glucose metabolism reprogramming provides intermediates and energy for HCC to meet its demands for rapid growth, proliferation, and metastasis. Additionally, various enzymes and signaling molecules involved in glucose metabolism reprogramming play irreplaceable roles. Therefore, regulating key metabolic enzymes and pathways in these processes is considered an important target for the diagnosis and treatment of HCC. This paper reviews the current status and progress of glucose metabolism reprogramming in HCC, aiming to provide new insights for the diagnosis, detection, and comprehensive treatment strategies of HCC involving combined glucose metabolism intervention in clinical settings.

Current updates on the molecular and genetic signals as diagnostic and therapeutic targets for hepatitis B virus-associated hepatic malignancy

Liver cancer caused by the hepatitis B virus (HBV) is the third most common cancer-related cause of death worldwide. Early detection of HBV-caused hepatic tumors increases the likelihood of a successful cure. Molecular and genetic signals are becoming more and more recognized as possible indicators of HBV-associated hepatic malignancy and of how well a treatment is working. As a result, we have discussed the current literature on molecular and genetic sensors, including extracellular vesicle microRNAs (EV-miRNAs), long non-coding circulating RNAs (lncRNAs), extracellular vesicles (EVs), and cell free circulating DNA (cfDNA), for the diagnosis and forecasting of HBV-related hepatic cancer. Extracellular vesicle microRNAs such as miR-335-5p, miR-172-5p, miR-1285-5p, miR-497-5p, miR-636, miR-187-5p, miR-223-3p, miR-21, miR-324-3p, miR-210-3p, miR-718, miR-122, miR-522, miR-0308-3p, and miR-375 are essential for the posttranscriptional regulation of oncogenes in hepatic cells as well as the epigenetic modulation of many internal and external signaling pathways in HBV-induced hepatic carcinogenesis. LncRNAs like lnc01977, HULC (highly up-regulated in liver cancer), MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), and HOTAIR (hox transcript antisense intergenic RNA) have been demonstrated to control hepatic-tumors cell growth, relocation, encroachment, and cell death resiliency. They are also becoming more and more involved in immune tracking, hepatic shifting, vasculature oversight, and genomic destabilization. EVs are critical mediators involved in multiple aspects of liver-tumors like angiogenesis, immunology, tumor formation, and the dissemination of malignant hepatocytes. Furthermore, cfDNA contributes to signals associated with tumors, including mutations and abnormal epigenetic changes during HBV-related hepatic tumorigenesis.

The dynamic variation position and predominant quasispecies of hepatitis B virus: Novel predictors of early hepatocarcinoma

To find the predictors of early HCC based on the dynamic changes of HBV quasispecies, this study utilizing the second-generation sequencing (NGS) and high-order multiplex droplet digital PCR (ddPCR) technology to examine the HBV quasispecies in serum of total 247 subjects recruited from high-incidence area of HCC. In the discovery stage, 15 non-synonymous Single Nucleotide Polymorphisms (SNPs) with higher variant proportion in HCC case group were founded (all P<0.05). Furthermore, the variant proportions in some of these SNPs were observed changing regularly within 5 years before the onset of HCC, and 5 of them located in HBX, 2 in HBS and 2 in HBC. The HBV predominant quasispecies and their consensus sequences were identified by genetic evolution analysis, in which the high HBS and HBC quasispecies heterogeneity were found associated with the forming of multifarious quasispecies clones, and the HBX gene had the highest proportion of predominant quasispecies (46.7 % in HBX vs 12.7 % and 13.8 % in HBS and HBC respectively) with the key variations (G1512A, A1630G, T1753C/G/A, A1762T and G1764A) determined. In the validation stage, we confirmed that the combined double mutations of G1512A+A1630G, A1762T+G1764A, and the combined triple mutations of T1753C/G/A + A1762T+G1764A, all expressed higher in early HCC cases when comparing with control group (all P<0.05). We also demonstrated the advantages of ddPCR using in multi-variations detection in large-sample for early HCC surveillance and screening. So we think that the dynamic of key HBV variation positions and their different combinations determined by quasispecies anlysis in this study can act as the novel predictors of early hepatocarcinoma and suitable to popularize and apply in HCC screening.

CRISPR/Cas9 as a New Antiviral Strategy for Treating Hepatitis Viral Infections

Hepatitis is an inflammatory liver disease primarily caused by hepatitis A (HAV), B (HBV), C (HCV), D (HDV), and E (HEV) viruses. The chronic forms of hepatitis resulting from HBV and HCV infections can progress to cirrhosis or hepatocellular carcinoma (HCC), while acute hepatitis can lead to acute liver failure, sometimes resulting in fatality. Viral hepatitis was responsible for over 1 million reported deaths annually. The treatment of hepatitis caused by viral infections currently involves the use of interferon-α (IFN-α), nucleoside inhibitors, and reverse transcriptase inhibitors (for HBV). However, these methods do not always lead to a complete cure for viral infections, and chronic forms of the disease pose significant treatment challenges. These facts underscore the urgent need to explore novel drug developments for the treatment of viral hepatitis. The discovery of the CRISPR/Cas9 system and the subsequent development of various modifications of this system have represented a groundbreaking advance in the quest for innovative strategies in the treatment of viral infections. This technology enables the targeted disruption of specific regions of the genome of infectious agents or the direct manipulation of cellular factors involved in viral replication by introducing a double-strand DNA break, which is targeted by guide RNA (spacer). This review provides a comprehensive summary of our current knowledge regarding the application of the CRISPR/Cas system in the regulation of viral infections caused by HAV, HBV, and HCV. It also highlights new strategies for drug development aimed at addressing both acute and chronic forms of viral hepatitis.

Histomolecular characterisation of hepatitis B virus induced liver cancer

Hepatitis B virus (HBV)-associated liver cancer is the third most prevalent cancer-related cause of death worldwide. Different studies have been done on the histomolecular analysis of HBV induced-liver cancer including epigenetics which are dynamic molecular mechanisms to control gene expression without altering the host deoxyribonucleic acid, genomics characterise the integration of the viral genome with host genome, proteomics characterise how gene modifies and results overexpression of proteins, glycoproteomics discover different glyco-biomarker candidates and show glycosylation in malignant hepatocytes, metabolomics characterise how HBV impairs a variety of metabolic functions during hepatocyte immortalisation, exosomes characterise immortalised liver cells in terms of their differentiation and proliferation, and autophagy plays a role in the development of hepatocarcinogenesis linked to HBV infection.

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.

The role of regulatory T cells and follicular T helper cells in HBV infection

Hepatitis B has become one of the major global health threats, especially in developing countries and regions. Hepatitis B virus infection greatly increases the risk for liver diseases such as cirrhosis and cancer. However, treatment for hepatitis B is limited when considering the huge base of infected people. The immune response against hepatitis B is mediated mainly by CD8+ T cells, which are key to fighting invading viruses, while regulatory T cells prevent overreaction of the immune response process. Additionally, follicular T helper cells play a key role in B-cell activation, proliferation, differentiation, and formation of germinal centers. The pathogenic process of hepatitis B virus is generally the result of a disorder or dysfunction of the immune system. Therefore, we present in this review the critical functions and related biological processes of regulatory T cells and follicular T helper cells during HBV infection.

Insights into the impact of hepatitis B virus on hepatic stellate cell activation

During chronic hepatitis B virus (HBV) infection, hepatic fibrosis is a serious pathological condition caused by virus-induced liver damage. The activation of hepatic stellate cells (HSCs) is a central event in the occurrence and progression of liver fibrosis. Although accumulating evidence has shown that HBV directly stimulates HSC activation, whether the virus infects and replicates in HSCs remains controversial. Inflammation is one of the obvious characteristics of chronic HBV infection, and it has been demonstrated that persistent inflammation has a predominant role in triggering and maintaining liver fibrosis. In particular, the regulation of HSC activation by HBV-related hepatocytes via various inflammatory modulators, including TGF-β and CTGF, in a paracrine manner has been reported. In addition to these inflammation-related molecules, several inflammatory cells are essential for the progression of HBV-associated liver fibrosis. Monocytes, macrophages, Th17 cells, NK cells, as well as NKT cells, participate in the modulation of HBV-related liver fibrosis by interacting with HSCs. This review summarizes current findings on the effects of HBV and the relevant molecular mechanisms involved in HSC activation. Because HSC activation is essential for liver fibrosis, targeting HSCs is an attractive therapeutic strategy to prevent and reverse hepatic fibrosis induced by HBV infection. Video abstract.

When Viruses Cross Developmental Pathways

Aberrant regulation of developmental pathways plays a key role in tumorigenesis. Tumor cells differ from normal cells in their sustained proliferation, replicative immortality, resistance to cell death and growth inhibition, angiogenesis, and metastatic behavior. Often they acquire these features as a consequence of dysregulated Hedgehog, Notch, or WNT signaling pathways. Human tumor viruses affect the cancer cell hallmarks by encoding oncogenic proteins, and/or by modifying the microenvironment, as well as by conveying genomic instability to accelerate cancer development. In addition, viral immune evasion mechanisms may compromise developmental pathways to accelerate tumor growth. Viruses achieve this by influencing both coding and non-coding gene regulatory pathways. Elucidating how oncogenic viruses intersect with and modulate developmental pathways is crucial to understanding viral tumorigenesis. Many currently available antiviral therapies target viral lytic cycle replication but with low efficacy and severe side effects. A greater understanding of the cross-signaling between oncogenic viruses and developmental pathways will improve the efficacy of next-generation inhibitors and pave the way to more targeted antiviral therapies.

Current impact of viral hepatitis on liver cancer development: The challenge remains

Chronic infections due to hepatitis B and hepatitis C viruses are responsible for most cases of hepatocellular carcinoma (HCC) worldwide, and this association is likely to remain during the next decade. Moreover, viral hepatitis-related HCC imposes an important burden on public health in terms of disability-adjusted life years. In order to reduce such a burden, some major challenges must be faced. Universal vaccination against hepatitis B virus, especially in the neonatal period, is probably the most relevant primary preventive measure against the development of HCC. Moreover, considering the large adult population already infected with hepatitis B and C viruses, it is also imperative to identify these individuals to ensure their access to treatment. Both hepatitis B and C currently have highly effective therapies, which are able to diminish the risk of development of liver cancer. Finally, it is essential for individuals at high-risk of HCC to be included in surveillance programs, so that tumors are detected at an early stage. Patients with hepatitis B or C and advanced liver fibrosis or cirrhosis benefit from being followed in a surveillance program. As hepatitis B virus is oncogenic and capable of leading to liver cancer even in individuals with early stages of liver fibrosis, other high-risk groups of patients with hepatitis B are also candidates for surveillance. Considerable effort is required concerning these strategies in order to decrease the incidence and the mortality of viral hepatitis-related HCC.

Potential of HBx Gene for Hepatocarcinogenesis in Noncirrhotic Liver

Current treatments for hepatitis B virus (HBV) using nucleos(t)ide analogs cannot eliminate the risk of hepatocellular carcinoma (HCC) development. As HBV-associated HCC can develop even in the absence of liver cirrhosis, HBV is regarded to possess direct oncogenic potential. HBV regulatory protein X (HBx) has been identified as a primary mediator of HBV-mediated hepatocarcinogenesis. A fragment of the HBV genome that contains the coding region of HBx is commonly integrated into the host genome, resulting in the production of aberrant proteins and subsequent hepatocarcinogenesis. Besides, HBx interferes with the host DNA or deoxyribonucleic acid damage repair pathways, signal transduction, epigenetic regulation of gene expression, and cancer immunity, thereby promoting carcinogenesis in the noncirrhotic liver. However, numerous molecules and pathways have been implicated in the development of HBx-associated HCC, suggesting that the mechanisms underlying HBx-mediated hepatocarcinogenesis remain to be elucidated.

CCN Family Proteins in Cancer: Insight Into Their Structures and Coordination Role in Tumor Microenvironment

The crosstalk between tumor cells and the tumor microenvironment (TME), triggers a variety of critical signaling pathways and promotes the malignant progression of cancer. The success rate of cancer therapy through targeting single molecule of this crosstalk may be extremely low, whereas co-targeting multiple components could be complicated design and likely to have more side effects. The six members of cellular communication network (CCN) family proteins are scaffolding proteins that may govern the TME, and several studies have shown targeted therapy of CCN family proteins may be effective for the treatment of cancer. CCN protein family shares similar structures, and they mutually reinforce and neutralize each other to serve various roles that are tightly regulated in a spatiotemporal manner by the TME. Here, we review the current knowledge on the structures and roles of CCN proteins in different types of cancer. We also analyze CCN mRNA expression, and reasons for its diverse relationship to prognosis in different cancers. In this review, we conclude that the discrepant functions of CCN proteins in different types of cancer are attributed to diverse TME and CCN truncated isoforms, and speculate that targeting CCN proteins to rebalance the TME could be a potent anti-cancer strategy.

Promotion of epithelial-mesenchymal transformation by hepatocellular carcinoma-educated macrophages through Wnt2b/β-catenin/c-Myc signaling and reprogramming glycolysis

Background

Tumour-associated macrophages (TAMs) in the tumour microenvironment (TME) can promote the progression of hepatocellular carcinoma (HCC). Some tumours can be suppressed by targeting Wnt2b in tumour cells. However, the role of Wnt2b in HCC is still unknown. In particular, the role of Wnt2b-mediated signal activation in macrophage polarization in the HCC microenvironment, and the regulatory effect between Wnt and glycolysis in TAMs has not been described.

Methods

The expression of Wnt2b in TAMs was detected by qPCR and immunofluorescence. Wnt2b/β-catenin interference in HCC-TAMs was performed by lentivirus carrying targeted shRNA or TLR9 agonist. Markers related to macrophage polarization and the changes of key glycolytic enzymes expression were detected by flow cytometry and qPCR. ECAR was analysed by Seahorse analyser. MTT assay, wound healing assay, western blotting were used to evaluate the promoting effect of different HCC-TAMs on the proliferation, migration and EMT of HCC in vitro. Tumour cells and different HCC-TAMs were injected via subcutaneously into immunodeficient mice to assess the effects of CpG ODN, Wnt2b, or β-catenin on HCC-TAMs in tumour growth in vivo.

Results

Polarization-promoting factors derived from HCC cells upregulated the expression of Wnt2b in macrophages, which promoted the polarization of TAMs to M2-like macrophages by activating Wnt2b/β-catenin/c-Myc signalling. Furthermore, this process was associated with the activation of glycolysis in HCC-TAMs. These HCC-TAMs could promote the development of EMT, proliferation, and migration of HCC. In addition to silencing Wnt2b or β-catenin expression, TLR9 agonist CpG ODN downregulated the level of glycolysis and inhibited the M2 polarization of HCC-TAMs, reversing the tumour-promoting effects of TAMs in vitro and vivo.

Conclusions

As a potential target for HCC therapy, Wnt2b may play an important regulatory role for the functions of TAMs in the TME. Moreover, the TLR9 agonist CpG ODN might act as a Wnt2b signal inhibitor and can potentially be employed for HCC therapy by disturbing Wnt2b/β-catenin/c-Myc and inhibiting glycolysis in HCC-TAMs.

Tumor-Linked Macrophages Promote HCC Development by Mediating the CCAT1/Let-7b/HMGA2 Signaling Pathway

BACKGROUND

The role of high mobility group A2 (HMGA2) in the progression of hepatocellular carcinoma (HCC) is yet to be investigated, though tumor-associated macrophages (TAMs) are known to mediate the process.

METHODS

Immunohistochemistry (IHC), Western blot, and real-time PCR assays were performed to identify HMGA2 and TAMs markers. The TAMs-like macrophages (TAMs-Mφs) were triggered with the help of 25 ng/mL hM-CSF and 50% NBCM. EdU assay wound healing assay, transwell assay, and TUNEL assay, as well as flow cytometry, were carried out to study the effect of HMGA2 or TAMs on the functioning of HCC cells.

RESULTS

HCC tumor tissues were detected with upregulated HMGA2 and TAMs markers (CD68, CD163, and CD204); in addition, HMGA2 was positively correlated with TAMs markers. The proliferation, migration, and invasion of HepG2 cells were also observed to be stimulated by HMGA2. Remarkably, cell apoptosis was not affected by upregulated HMGA2, but HMAG2 inhibition was observed to intensify it. Also, the release of CSF1 was observed to be amplified by HMGA2. HMGA2-overexpressed-HepG2 cells promoted the migrating abilities of both M0-Mφs and TAMs-Mφs but were suppressed by HMGA2 down-regulated HepG2 cells. In addition, TAMs-Mφs supernatant regulated the CCAT1/let-7b/HMGA2 signaling pathway by intensifying the malignant biological behaviors.

CONCLUSION

HMGA2 stimulated TAMs-induced HCC progression, mediated by the CCAT1/let-7b/HMGA2 signaling pathway, TAMs aggravated HCC development.

Downregulation of GSK3β and Upregulation of URG7 in Hepatitis B-Related Hepatocellular Carcinoma

: Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC). The exact molecular contributors to the development of HBV-related HCC are not yet completely understood. Recent studies demonstrated that the deregulation of the Wnt pathway is highly associated with the development of HCC. Besides, HBV is known to have roles in the deregulation of this pathway. The present study evaluated the molecular aspects of the Wnt pathway in HBV-related HCC in liver tissue samples. Viral characterization was done by identifying the HBx mutations and the assessment of intrahepatic viral load. The expression of Wnt pathway genes was assessed using real-time PCR and methylation-specific PCR. The intrahepatic viral load was significantly higher in tumor samples than in normal tissues (P = 0.0008). Aberrant expression was observed in Wnt-1, Wnt-7a, FZD2, FZD7, β-catenin, URG7, c-Myc, SFRP5, and GSK3β, among which Wnt1, FZD2, SFRP5, Gsk3β, and URG7 were associated with HBV. HBx mutations at positions I88, L116, and I127 + F132 were associated with the decreased expression of GSK3β and overexpression of URG7 and Wnt1. Alterations in the expression level of β-catenin, as well as some mutants of HBx, were correlated with the level of c-Myc. HBV-related HCC seems to be mostly coordinated with epigenetic behaviors of HBx, such a multi-functional peptide with suppressing/trans-activating functions.

Investigation of CTNNB1 gene mutations and expression in hepatocellular carcinoma and cirrhosis in association with hepatitis B virus infection

Hepatitis B virus (HBV), along with Hepatitis C virus chronic infection, represents a major risk factor for hepatocellular carcinoma (HCC) development. However, molecular mechanisms involved in the development of HCC are not yet completely understood. Recent studies have indicated that mutations in CTNNB1 gene encoding for β-catenin protein lead to aberrant activation of the Wnt/ β-catenin pathway. The mutations in turn activate several downstream genes, including c-Myc, promoting the neoplastic process. The present study evaluated the mutational profile of the CTNNB1 gene and expression levels of CTNNB1 and c-Myc genes in HBV-related HCC, as well as in cirrhotic and control tissues. Mutational analysis of the β-catenin gene and HBV genotyping were conducted by direct sequencing. Expression of β-catenin and c-Myc genes was assessed using real-time PCR. Among the HCC cases, 18.1% showed missense point mutation in exon 3 of CTNNB1, more frequently in codons 32, 33, 38 and 45. The frequency of mutation in the hotspots of exon 3 was significantly higher in non-viral HCCs (29.4%) rather than HBV-related cases (12.7%, P = 0.021). The expression of β-catenin and c-Myc genes was found upregulated in cirrhotic tissues in association with HBV infection. Mutations at both phosphorylation and neighboring sites were associated with increased activity of the Wnt pathway. The results demonstrated that mutated β-catenin caused activation of the Wnt pathway, but the rate of CTNNB1 gene mutations was not related to HBV infection. HBV factors may deregulate the Wnt pathway by causing epigenetic alterations in the HBV-related HCC.

GSK-3 in liver diseases: Friend or foe?

Liver diseases, including hepatitis due to hepatitis B or C virus infection, non-alcoholic fatty liver disease, and hepatocellular carcinoma pose major challenges for overall health due to limited curative treatment options. Thus, there is an urgent need to develop new therapeutic strategies for the treatment of these diseases. A better understanding of the signaling pathways involved in the pathogenesis of liver diseases can help to improve the efficacy of emerging therapies, mainly based on pharmacological approaches, which influence one or more specific molecules involved in key signal transduction pathways. These emerging therapies are very promising for the prevention and treatment of liver diseases. One promising druggable molecular target is the multifunctional serine/threonine kinase, glycogen synthase kinase 3 (GSK-3). In this review, we discuss conditions in which GSK-3 is implicated in liver diseases. In addition, we explore newly emerging drugs that target GSK-3β, as well as their potential use in and impact on the management of liver diseases.

HBx mediated Increase of SIRT1 Contributes to HBV-related Hepatocellular Carcinoma Tumorigenesis

Objective: Hepatocellular carcinoma (HCC) is one of the main causes of cancer-related deaths worldwide, and chronic hepatitis B virus (HBV) infection is strongly associated with HCC development, but the pathogenesis of HBV-related HCC remains obscure. Sirtuin 1 (SIRT1) has been implicated to enhance the replication of HBV and to promote the tumorigenesis of HCC. In this study, we aim to investigate the functional role of SIRT1 on HBV viral protein and HBV-induced HCC. Methods: Tumorous liver tissues from patient diagnosed with HBV-related HCC were collected and further divided into two groups (with or without metastasis). Then, the mRNA and protein level of SIRT1 in those tissues were detected by real time PCR and Western blot, respectively. Meanwhile, the protein level of epithelial-mesenchymal transition (EMT) relative markers in those tissues was determined by Western blot. Furthermore, the expression of SIRT1 in HBV-expressing HCC cells was examined. Next, the relationship between viral proteins and SIRT1 expression were determined by real time PCR and Western blot. In addition, the potential role of HBx-upregulated SIRT1 in HCC proliferation, migration and invasion were analyzed by cell viability assays, cell proliferation assay, wound healing assay, transwell assay and Western blot. Results: In this study, we found that the expression of SIRT1 was obviously increased in patients with metastasis compared to the patients without metastasis. Consistently, the expression of SIRT1 was also upregulated in HBV-expressing HCC cells compared to the controls. Further investigation showed that viral protein HBx was responsible for the elevated SIRT1 in HBV-expressing HCC cells. Meanwhile, the expression of HBx could be upregulated by SIRT1. Additionally, functional studies showed that HBx-elevated SIRT1 could promote HCC cell proliferation, migration and invasion. Importantly, HBx induced HCC proliferation and migration could be suppressed by Nicotinamide in a dose dependent manner. Conclusions: Our findings uncovered the positive role of SIRT1 in HBx-mediated tumorigenesis which implicated the potential role of SIRT1 in HBV-related HCC treatment.

Oncogenic Wnt3a: A Candidate Specific Marker and Novel Molecular Target for Hepatocellular Carcinoma

Background and aim: It is of the utmost importance for the specific diagnosis and effective therapy of hepatocellular carcinoma (HCC). Abnormality of oncogenic Wingless-type MMTV integration site family member 3a (Wnt3a) has been associated with progression of HCC. In this study, we aimed to evaluate Wnt3a as a novel biomarker and target for HCC. Methods: Circulating Wnt3a levels were quantitatively detected in a cohort of chronic liver diseases by an enzyme-linked immune-absorbent assay (ELISA). Hepatic Wnt3a expression in HCC and para-cancerous tissues was analyzed by immunohistochemistry. Prognostic value of Wnt3a for HCC was discovered in the cohort from the Cancer Genome Atlas (TCGA). Dynamic alterations of Wnt3a levels were detected in the hepatocarcinogenesis model induced by 2-acetylaminofluorene. Effects of Wnt3a on biological behaviors were evaluated in vitro and in vivo based on Crispr/Cas9. Results: Up-regulated Wnt3a levels were observed in serum of HCC patients with high specificity and sensitivity for HCC diagnosis. Combination of Wnt3a and AFP could improve sensitivity to 93.9% in serological detection. In addition, Wnt3a expression in HCC tissues was significantly higher than that in para-cancerous tissues. The cohort of TCGA demonstrated that high Wnt3a expression led to a poor survival of HCC patients, especially in cases at advanced stages. Furthermore, the hepatocarcinogenesis model showed that Wnt3a dynamically increased in the development of HCC. Functionally, silencing Wnt3a by Crispr/Cas9 suppressed the proliferation, colony formation, induced cell cycle arrest of HCC cells by de-activating Wnt/β-catenin pathway in vitro, and inhibited xenograft tumor growth in vivo. Conclusions: Oncogenic Wnt3a could be considered as a candidate biomarker and novel target for HCC.

HBV-related hepatocarcinogenesis: the role of signalling pathways and innovative ex vivo research models

BACKGROUND

Hepatitis B virus (HBV) is the leading cause of liver cancer, but the mechanisms by which HBV causes liver cancer are poorly understood and chemotherapeutic strategies to cure liver cancer are not available. A better understanding of how HBV requisitions cellular components in the liver will identify novel therapeutic targets for HBV associated hepatocellular carcinoma (HCC).

MAIN BODY

The development of HCC involves deregulation in several cellular signalling pathways including Wnt/FZD/β-catenin, PI3K/Akt/mTOR, IRS1/IGF, and Ras/Raf/MAPK. HBV is known to dysregulate several hepatocyte pathways and cell cycle regulation resulting in HCC development. A number of these HBV induced changes are also mediated through the Wnt/FZD/β-catenin pathway. The lack of a suitable human liver model for the study of HBV has hampered research into understanding pathogenesis of HBV. Primary human hepatocytes provide one option; however, these cells are prone to losing their hepatic functionality and their ability to support HBV replication. Another approach involves induced-pluripotent stem (iPS) cell-derived hepatocytes. However, iPS technology relies on retroviruses or lentiviruses for effective gene delivery and pose the risk of activating a range of oncogenes. Liver organoids developed from patient-derived liver tissues provide a significant advance in HCC research. Liver organoids retain the characteristics of their original tissue, undergo unlimited expansion, can be differentiated into mature hepatocytes and are susceptible to natural infection with HBV.

CONCLUSION

By utilizing new ex vivo techniques like liver organoids it will become possible to develop improved and personalized therapeutic approaches that will improve HCC outcomes and potentially lead to a cure for HBV.

Hepatocellular carcinoma: Mechanisms of progression and immunotherapy

Liver cancer is one of the most common malignancies, and various pathogenic factors can lead to its occurrence and development. Among all primary liver cancers, hepatocellular carcinoma (HCC) is the most common. With extensive studies, an increasing number of molecular mechanisms that promote HCC are being discovered. Surgical resection is still the most effective treatment for patients with early HCC. However, early detection and treatment are difficult for most HCC patients, and the postoperative recurrence rate is high, resulting in poor clinical prognosis of HCC. Although immunotherapy takes longer than conventional chemotherapy to produce therapeutic effects, it persists for longer. In recent years, the emergence of many new immunotherapies, such as immune checkpoint blockade and chimeric antigen receptor T cell therapies, has given new hope for the treatment of HCC.

Hepatitis B virus X protein promotes proliferation of hepatocellular carcinoma cells by upregulating miR-181b by targeting ING5

Hepatitis B virus X protein (HBx) played a key role in the development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Emerging evidence has demonstrated that miR-181b and the inhibitor of growth protein 5 (ING5) participated in the pathophysiological process. However, the regulatory mechanism of HBx remained unknown. The expression of miR-181b and ING5 in HCC tissues and cell lines were examined using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Cell viability was determined using the MTT method following HCC cell lines transfection. The interaction between miR-181b and ING5 was assessed by luciferase reporter assay. The nude mice tumor model was well established to evaluate the role and biological functions of HBx on the progression of HBV-related HCC in vivo. MiR-181b was upregulated and ING5 was downregulated in HCC tissues and cell lines. As suggested by the results from in vitro and in vivo experiments, HBx downregulates the expression of the miR-181b target gene ING5, resulting in the promotion of HCC cell proliferation. HBx accelerates proliferation activity of HCC cells by increasing miR-181b expression via targeting ING5, thereby influencing the progression of HBV-related HCC.

WISP2 exhibits its potential antitumor activity via targeting ERK and E-cadherin pathways in esophageal cancer cells

Backgrounds

Emerging evidence has demonstrated that WISP2 is critically involved in cell proliferation, migration, invasion and metastasis in cancers. However, the function of WISP2 in esophageal squamous cell carcinoma (ESCC) is largely unclear. Therefore, we aim to explore the effects and the potential mechanism of WISP2 on proliferation and motility and invasion of ESCC cells.

Methods

Cell proliferation was detected by MTT assay and apoptosis was measured by FACS in ESCC cells after WISP2 downregulation and overexpression. Cell migration and invasion were analyzed by wound healing assay and transwell migration assay, respectively. The expression of ERK-1/2, Slug and E-cadherin was measured by Western blot respectively. IHC was performed to measure the expression of WISP2 in ESCC tissues.

Results

WISP2 overexpression is associated with survival in ESCC patients. WISP2 overexpression inhibited cell growth and induced cell apoptosis, suppressed cell migration and invasion in ESCC cells. Moreover, WISP overexpression retarded tumor growth in mouse model. WISP2 downregulation enhanced cell growth, inhibited apoptosis, promoted cell migration and invasion in ESCC cells. Mechanistically, WISP2 exerts its tumor suppressive functions via regulation of ERK1/2, Slug, and E-cadherin in ESCC cells.

Conclusions

Our findings suggest that activation of WISP2 could be a useful therapeutic strategy for the treatment of ESCC.

The emerging role of WISP proteins in tumorigenesis and cancer therapy

Accumulated evidence has demonstrated that WNT1 inducible signaling pathway protein (WISP) genes, which belong to members of the CCN growth factor family, play a pivotal role in tumorigenesis and progression of a broad spectrum of human cancers. Mounting studies have identified that WISP proteins (WISP1-3) exert different biological functions in various human malignancies. Emerging evidence indicates that WISP proteins are critically involved in cell proliferation, apoptosis, invasion and metastasis in cancers. Because the understanding of a direct function of WISP proteins in cancer development and progression has begun to emerge, in this review article, we describe the physiological function of WISP proteins in a variety of human cancers. Moreover, we highlight the current understanding of how the WISP protein is involved in tumorigenesis and cancer progression. Furthermore, we discuss that targeting WISP proteins could be a promising strategy for the treatment of human cancers. Hence, the regulation of WISP proteins could improve treatments for cancer patients.

Yes-associated protein promotes early hepatocyte cell cycle progression in regenerating liver after tissue loss

The ability of the liver to restore its original volume following tissue loss has been associated with the Hippo‐YAP1 pathway, a key controller of organ size. Yes‐associated protein 1 (YAP1)—a growth effector usually restrained by Hippo signaling—is believed to be of particular importance; however, its role in liver regeneration remains ill‐defined. To explore its function, we knocked down YAP1 prior to standard 70%‐hepatectomy (sHx) using a hepatocyte‐specific nanoformulation. Knockdown was effective during the major parenchymal growth phase (S‐phase/M‐phase peaks at 32 hours/48 hours post‐sHx). Liver weight gain was completely suppressed by the knockdown at 32 hours, but was reaccelerated toward 48 hours. Likewise, proliferative markers, Ccna2/b2 and YAP1 target gene expression were downregulated at 32 hours, but re‐elevated at 48 hours post‐sHx. Nonetheless, knockdown slightly compromised survival after sHx. When assessing a model of resection‐induced liver failure (extended 86%‐hepatectomy, eHx) featuring deficient S‐ and M‐phase progression, YAP1 was not induced at 32 hours, but upregulated at 48 hours post‐eHx, confirming its dissociation from M‐phase regulation. Therefore, YAP1 is vital to push hepatocytes into cycle and through the S‐phase, but is not required for further cell cycle progression during liver regeneration. The examination of YAP1 in human livers suggested its function is conserved in the regenerating mammalian liver.

Hepatitis B virus X protein promotes epithelial-mesenchymal transition and metastasis in hepatocellular carcinoma cell line HCCLM3 by targeting HMGA2

Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC), and HBV X protein (HBx) serves an essential role in the development of HCC. However, its mechanism remains to be elucidated. The aim of the present study was to investigate the role and mechanism of the HBx protein in the epithelial-mesenchymal transition (EMT) and metastasis of HCC. The HCCLM3 cell line was transfected with a HBx-expressing vector. The effects of HBx overexpression on proliferation, migration, invasion and EMT capacities of the HCCLM3 cell line were evaluated using MTT, migration and invasion assays, and western blotting, respectively. Furthermore, the impact of High mobility group AT-hook 2 (HMGA2) knockdown on HBx-mediated metastasis was investigated in the HCC cell line HCCLM3. The results demonstrated that HBx significantly upregulated HMGA2 expression, and enhanced the proliferation, EMT, invasion and migration in HCC cells. Furthermore, HMGA2 knockdown almost abolished HBx-induced EMT and metastasis in HCC. The results of the present study suggest that HBx promotes the proliferation, EMT, invasion and migration of HCC cells by targeting HMGA2. HMGB2 may serve as a potential therapeutic target for HBV-associated HCC.

Applications of next-generation sequencing analysis for the detection of hepatocellular carcinoma-associated hepatitis B virus mutations

BACKGROUND

Next-generation sequencing (NGS) is a powerful and high-throughput method for the detection of viral mutations. This article provides a brief overview about optimization of NGS analysis for hepatocellular carcinoma (HCC)-associated hepatitis B virus (HBV) mutations, and hepatocarcinogenesis of relevant mutations.

MAIN BODY

For the application of NGS analysis in the genome of HBV, four noteworthy steps were discovered in testing. First, a sample-specific reference sequence was the most effective mapping reference for NGS. Second, elongating the end of reference sequence improved mapping performance at the end of the genome. Third, resetting the origin of mapping reference sequence could probed deletion mutations and variants at a certain location with common mutations. Fourth, using a platform-specific cut-off value to distinguish authentic minority variants from technical artifacts was found to be highly effective. One hundred and sixty-seven HBV single nucleotide variants (SNVs) were found to be studied previously through a systematic literature review, and 12 SNVs were determined to be associated with HCC by meta-analysis. From comprehensive research using a HBV genome-wide NGS analysis, 60 NGS-defined HCC-associated SNVs with their pathogenic frequencies were identified, with 19 reported previously. All the 12 HCC-associated SNVs proved by meta-analysis were confirmed by NGS analysis, except for C1766T and T1768A which were mainly expressed in genotypes A and D, but including the subgroup analysis of A1762T. In the 41 novel NGS-defined HCC-associated SNVs, 31.7% (13/41) had cut-off values of SNV frequency lower than 20%. This showed that NGS could be used to detect HCC-associated SNVs with low SNV frequency. Most SNV II (the minor strains in the majority of non-HCC patients) had either low (< 20%) or high (> 80%) SNV frequencies in HCC patients, a characteristic U-shaped distribution pattern. The cut-off values of SNV frequency for HCC-associated SNVs represent their pathogenic frequencies. The pathogenic frequencies of HCC-associated SNV II also showed a U-shaped distribution. Hepatocarcinogenesis induced by HBV mutated proteins through cellular pathways was reviewed.

CONCLUSION

NGS analysis is useful to discover novel HCC-associated HBV SNVs, especially those with low SNV frequency. The hepatocarcinogenetic mechanisms of novel HCC-associated HBV SNVs defined by NGS analysis deserve further investigation.

Impact of wild-type and carboxyl-terminal truncated hepatitis B virus X on hepatocyte proliferation

AIM

To construct lentiviral vectors expressing human wild-type HBx (wt-HBx) and truncated HBx (tHBx^Δ35) and study the effect of wt-HBx and tHBx^Δ35 on the proliferation and apoptosis of normal liver cell lines.

METHODS

Lentiviral vectors TOPO3.1-wt-HBx and TOPO3.1-tHBx^Δ35 were constructed and transfected into 293T cells with three packaging plasmids. The supernatants were collected to infect LO2 and MIHA cells, respectively. The expression of wt-HBx and tHBx^Δ35 was detected by fluorescence microscopy and western blot analysis. The effect of HBx and tHBx^Δ35 on the proliferation, cell cycle, and apoptosis was analyzed by cell counting, MTS, and flow cytometry, respectively.

RESULTS

The recombinant lentiviral vectors were successfully constructed. The proliferation of liver cells infected with tHBx^Δ35 was significantly increased, compared with HBx or CTRL infected cells, while the proliferation of liver cells infected with HBx was decreased compared with tHBx^Δ35 or CTRL infected cells (P < 0.05). tHBx^Δ35 improved the number of cells in S phase, while HBx induced G0/G1-S cell cycle arrest. The effect of tHBx^Δ35 or HBx on apoptosis was mild.

CONCLUSION

HBx can inhibit the proliferation of hepatocytes, while tHBx^Δ35 can improve the proliferation of liver cells.

Deregulation of Frizzled Receptors in Hepatocellular Carcinoma

G protein-coupled receptors (GPCRs) have a substantial role in tumorigenesis and are described as a “cancer driver”. Aberrant expression or activation of GPCRs leads to the deregulation of downstream signaling pathways, thereby promoting cancer progression. In hepatocellular carcinoma (HCC), the Wnt signaling pathway is frequently activated and it is associated with an aggressive HCC phenotype. Frizzled (FZD) receptors, a family member of GPCRs, are known to mediate Wnt signaling. Accumulating findings have revealed the deregulation of FZD receptors in HCC and their functional roles have been implicated in HCC progression. Given the important role of FZD receptors in HCC, we summarize here the expression pattern of FZD receptors in HCC and their corresponding functional roles during HCC progression. We also further review and highlight the potential targeting of FZD receptors as an alternative therapeutic strategy in HCC.

HBV infection potentiates resistance to S-phase arrest-inducing chemotherapeutics by inhibiting CHK2 pathway in diffuse large B-cell lymphoma

A considerable number of diffuse large B-cell lymphoma (DLBCL) patients are infected with hepatitis B virus (HBV), which is correlated with their poor outcomes. However, the role of HBV infection in DLBCL treatment failure remains poorly understood. Here, our data demonstrated that HBV infection was closely associated with poorer clinical prognosis independent of its hepatic dysfunction in germinal center B-cell type (GCB type) DLBCL patients. Interestingly, we found that DLBCL cells expressing hepatitis B virus X protein (HBX) did not exhibit enhanced cell growth but did show reduced sensitivity to methotrexate (MTX) and cytarabine (Ara-C), which induced S-phase arrest. Mechanism studies showed that HBX specifically inhibited the phosphorylation of checkpoint kinase 2 (CHK2, a key DNA damage response protein). CHK2 depletion similarly conferred resistance to the S-phase arrest-inducing chemotherapeutics, consistent with HBX overexpression in DLBCL cells. Moreover, overexpression of wild-type CHK2 rather than its unphosphorylated mutant (T68A) significantly restored the reduced chemosensitivity in HBX-expressing cells, suggesting that HBV infection conferred resistance to chemotherapeutics that induced S-phase arrest by specifically inhibiting the activation of CHK2 response signaling in DLBCL.

HBx induces expression of CTGF in the transfected hepatoma cell line HepG2

Aim: To investigate the effect of HBx on CTGF expression by hepatocytes. Materials & methods: HepG2 cells were transfected with the full-length gene of HBV, HBV protein-expressing plasmids, rhTGFβ1, LY2109761 or Smad2 siRNA, respectively, using Lipofectamine 3000. CTGF expression was detected by real-time PCR, ELISA, respectively. Then the effect of IL-32 on CTGF promoter was assayed by the Dual Luciferase® Reporter Assay System. Results: We found that HBx could induce CTGF expression by HepG2 cells in a concentration-dependent manner. CTGF expression induced by HBx employed the activation of TGFβ1-Smad2 signal pathway. Inhibition of TGFβ1 or Smad2 decreased CTGF expression induced by HBx. Conclusion: HBV might be involved in the pathogenesis of liver fibrosis through the HBx-induced CTGF expression.

Modulation of Wnt signaling pathway by hepatitis B virus

Hepatitis B virus (HBV) has a global distribution and is one of the leading causes of hepatocellular carcinoma. The precise mechanism of pathogenicity of HBV-associated hepatocellular carcinoma (HCC) is not yet fully understood. Viral-related proteins are known to take control of several cellular pathways like Wnt/β-catenin, TGF-β, Raf/MAPK and ROS for the virus's own replication. This affects cellular persistence, multiplication, migration, alteration and genomic instability. The Wnt/FZD/β-catenin signaling pathway plays a significant role in the pathology and physiology of the liver and has been identified as a main factor in HCC development. The role of β-catenin is linked mainly to the canonical pathway of the signaling system. Progression of liver diseases is known to be accompanied by disturbances in β-catenin expression (mainly overexpression), with its cytoplasmic or nuclear translocation. In recent years, studies have documented that the HBV X protein and hepatitis B surface antigen (HBsAg) can act as pathogenic factors that are involved in the modulation and induction of canonical Wnt signaling pathway. In the present review we explore the interaction of HBV genome products with components of the Wnt/β-catenin signaling pathway that results in the enhancement of the pathway and leads to hepatocarcinogenesis.

HBx protein-mediated ATOH1 downregulation suppresses ARID2 expression and promotes hepatocellular carcinoma

Hepatitis B virus X protein plays a crucial role in the pathogenesis of hepatocellular carcinoma. We previously showed that the tumor suppressor ARID2 inhibits hepatoma cell cycle progression and tumor growth. Here, we evaluated whether hepatitis B virus X protein was involved in the modulation of ARID2 expression and hepatocarcinogenesis associated with hepatitis B virus infection. ARID2 expression was downregulated in HBV‐replicative hepatoma cells, HBV transgenic mice, and HBV‐related clinical HCC tissues. The expression levels of HBx were negatively associated with those of ARID2 in hepatocellular carcinoma tissues. Furthermore, HBx suppressed ARID2 at transcriptional level. Mechanistically, the promoter region of ARID2 gene inhibited by HBx was located at nt‐1040/nt‐601 and contained potential ATOH1 binding elements. In addition, ectopic expression of ATOH1 or mutation of ATOH1 binding sites within ARID2 promoter partially abolished HBx‐triggered ARID2 transcriptional repression. Functionally, ARID2 abrogated HBx‐enhanced migration and proliferation of hepatoma cells, whereas depletion of ATOH1 enhanced tumorigenecity of HCC cells. Therefore, our findings suggested that deregulation of ARID2 by HBx through ATOH1 may be involved in HBV‐related hepatocellular carcinoma development.

Secreted frizzled-related protein 2-mediated cancer events: Friend or foe?

Secreted frizzled-related protein (SFRP)2, an identified member of the SFRPs family of molecules, is often methylated in human cancers and its down-regulation is closely related to Wnt signaling activity and tumor progression. Although the blocker of the Wnt signaling has not been fully used in clinical trial, interest has been further enhanced by the realization of SFRPs' potential as targets to modulate Wnt signaling and cancer cell growth. Emerging evidence showed that SFRP2 was an anti-oncogene, however, a steady flow of research has indicated that it may also have tumor promotion effects in some cancer types. Furthermore, SFRP2 methylation was shown to accelerate cancer cell invasion and growth in tumor progression. In this review, we define recent understanding of the diverse roles of SFRP2 in tumorigenesis, and it might promote the development of novel drugs for curing cancer by targeting SFRP2.

HBx mutations promote hepatoma cell migration through the Wnt/β-catenin signaling pathway

HBx mutations (T1753V, A1762T, G1764A, and T1768A) are frequently observed in hepatitis B virus (HBV)‐related hepatocellular carcinoma (HCC). Aberrant activation of the Wnt/β‐catenin signaling pathway is involved in the development of HCC. However, activation of the Wnt/β‐catenin signaling pathway by HBx mutants has not been studied in hepatoma cells or HBV‐associated HCC samples. In this study, we examined the effects of HBx mutants on the migration and proliferation of HCC cells and evaluated the activation of Wnt/β‐catenin signaling in HBx‐transfected HCC cells and HBV‐related HCC tissues. We found that HBx mutants (T, A, TA, and Combo) promoted the migration and proliferation of hepatoma cells. The HBx Combo mutant potentiated TOP‐luc activity and increased nuclear translocation of β‐catenin. Moreover, the HBx Combo mutant increased and stabilized β‐catenin levels through inactivation of glycogen synthase kinase‐3β, resulting in upregulation of downstream target genes such as c‐Myc,CTGF, and WISP2. Enhanced activation of Wnt/β‐catenin was found in HCC tissues with HBx TA and Combo mutations. Knockdown of β‐catenin effectively abrogated cell migration and proliferation stimulated by the HBx TA and Combo mutants. Our results indicate that HBx mutants, especially the Combo mutant, allow constitutive activation of the Wnt signaling pathway and may play a pivotal role in HBV‐associated hepatocarcinogenesis.