Autophagy and microRNA in hepatitis B virus-related hepatocellular carcinoma

Approximately 350 million people worldwide are chronically infected by hepatitis B virus (HBV). HBV causes severe liver diseases including cirrhosis and hepatocellular carcinoma (HCC). In about 25% of affected patients, HBV infection proceeds to HCC. Therefore, the mechanisms by which HBV affects the host cell to promote viral replication and its pathogenesis have been the subject of intensive research efforts. Emerging evidence indicates that both autophagy and microRNAs (miRNAs) are involved in HBV replication and HBV-related hepatocarcinogenesis. In this review, we summarize how HBV induces autophagy, the role of autophagy in HBV infection, and HBV-related tumorigenesis. We further discuss the emerging roles of miRNAs in HBV infection and how HBV affects miRNAs biogenesis. The accumulating knowledge pertaining to autophagy and miRNAs in HBV replication and its pathogenesis may lead to the development of novel strategies against HBV infection and HBV-related HCC tumorigenesis.     

Prevention of hepatocellular carcinoma in chronic viral hepatitis B and C infection

Hepatocellular carcinoma(HCC)is a leading cause of cancer-related mortality worldwide,with the majority of cases associated with persistent infection from hepatitis B virus(HBV)or hepatitis C virus(HCV).Natural history studies have identified risk factors associated with HCC development among chronic HBV and HCV infection.High-risk infected individuals can now be identified by the usage of risk predictive scores.Vaccination plays a central role in the prevention of HBV-related HCC.Treatment of chronic HBV infection,especially by nucleoside analogue therapy,could also reduce the risk of HBV-related HCC.Concerning HCV infection,besides the advocation of universal precautions to reduce the rate of infection,pegylated interferon and ribavirin could also reduce the risk of HCV-related HCC among those achieving a sustained virologic response.Recently there has been mounting evidence on the role of chemopreventive agents in reducing HBV-and HCV-related HCC.The continued advances in the understanding of the molecular pathogenesis of HCC would hold promise in preventing this highly lethal cancer.     

Molecular characteristics and stages of chronic hepatitis B virus infection

Hepatitis B virus （HBV） is a common viral pathogen that causes a substantial health burden worldwide. Remarkable progress has been made in our under- standing of the natural stages of chronic HBV infection. A dynamic balance between viral replication and host immune response is pivotal to the pathogenesis of liver disease. Knowledge of the HBV genome organization and replication cycle can unravel HBV genotypes and molecular variants, which contribute to the heterogeneity in outcome of chronic HBV infection. Most HBV infections are spontaneously resolved in immunocompetent adults, whereas they become chronic in most neonates and infants at a great risk of developing complications such as cirrhosis and hepatocellular carcinoma （HCC）. Those with chronic HBV infection may present in one of the four phases of infection： immune tolerance, immune clearance [hepatitis B e antigen （HBeAg）-positive chronic hepatitis B （CHB）], inactive carrier state, and reactivation （HBeAg-negative CHB）. Understanding the dynamic nature of chronic HBV infection is crucial in the management of HBV carriers. Long-term monitoring and optimal timing of antiviral therapy for chronic HBV infection help to prevent progression of HBV-related liver disease to its later stage, particularly in patients with higher risk markers of HCC, such as serum DNA concentration, HBeAg status, serum aminotransferase, HBV genotypes, and pre-core or core mutants.     

Anti-viral therapy to reduce recurrence and improve survival in hepatitis B virus-related hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is the most common malignancy and the third leading cause of cancer death worldwide.Chronic infection with hepatitis B virus(HBV)and hepatitis C virus accounts for approximately75%-80%of HCC cases worldwide.In particular,chronic HBV infection is a predominant risk factor for HCC in Asia and Africa.Hepatic resection and radiofrequency ablation are increasingly used for the curative treatment of HCC,and good local control can be achieved.However,the high rate of recurrence is a major obstacle to improving prognosis.A high viral load of HBV DNA is the most important correctable risk factor for recurrence.Furthermore,interferon and/or nucleotide analogues may decrease HBV DNA.Therefore,these drugs may decrease recurrence.In this article,treatment strategies for HBV-related HCC are described in order to reduce recurrence and improve survival.     

Hepatitis B virus infection and the risk of hepatocellular carcinoma

Epidemiological studies have provided overwhelming evidence for a causal role of chronic hepatitis B virus(HBV) infection in the development of hepatocellular carcinoma(HCC).However,the pathogenesis of HBV infection and carcinogenesis of HBV-associated HCC are still elusive.This review will summarize the current knowledge on the mechanisms involved in HBV-related liver carcinogenesis.The role of HBV in tumor formation appears to be complex,and may involve both direct and indirect mechanisms.Integration of H...     

Prevention of hepatocellular carcinoma in patients with chronic hepatitis B

Patients with chronic hepatitis B are at significant risk for hepatocellular carcinoma(HCC). Globally,over half a million people each year are diagnosed with HCC,with marked geographical variations. Despite overwhelming evidence for a causal role of hepatitis B virus(HBV) infection in the development of HCC and a well-established relationship between high baseline hepatitis B viral load and cumulative risk of HCC,the molecular basis for this association has not been fully elucidated. In addition,a beneficial role for antiviral therapy in preventing the development of HCC has been difficult to establish. This review examines the biological and molecular mechanisms of HBV-related hepatocarcinogenesis,recent results on the effect of modern nucleos(t)ides on the rate of HCC development in high risk HBV cohorts and the potential mechanisms by which long-term antiviral therapy with potent inhibitors of HBV replication might reduce the risk of HCC in patients with chronic hepatitis B. Although evidence from randomized controlled trials shows the favourable effects of antiviral agentsin achieving profound and durable suppression of HBV DNA levels while improving liver function and histology,robust evidence of other long-term clinical outcomes,such as prevention of HCC,are limited.     

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.     

Roles of micrornas in the Hepatitis B Virus Infection and Related Diseases

The hepatitis B virus (HBV) is a small enveloped DNA virus that belongs to the Hepadnaviridae family. HBV can cause acute and persistent infection which can lead to hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) play a crucial role in the main cellular events. The dysregulation of their expression has been linked to the development of the cancer as well as to viral interference. This chapter will describe the involvement of miRNAs in the case of HBV infection and their implication in the development of the HBV-related diseases.     

Antiviral therapies for hepatitis B virus-related hepatocellular carcinoma

Chronic hepatitis B virus(HBV) infection is a critical risk factor for the carcinogenesis and progression of hepatocellular carcinoma(HCC). It promotes HCC development by inducing liver fibrogenesis, genetic and epigenetic alterations, and the expression of active viral-coded proteins. Effective antiviral treatments inhibit the replication of HBV, reduce serum viral load and accelerate hepatitis B e antigen serum conversion. Timely initiation of antiviral treatment is not only essential for preventing the incidence of HCC in chronic hepatitis B patients, but also important for reducing HBV reactivation, improving liver function, reducing or delaying HCC recurrence, and prolonging overall survival of HBV-related HCC patients after curative and palliative therapies. The selection of antiviral drugs, monitoring of indicators such as HBV DNA and hepatitis B surface antigen, and timely rescue treatment when necessary, are essential in antiviral therapies for HBVrelated HCC.     

High serum adiponectin correlates with advanced liver disease in patients with chronic hepatitis B virus infection

Purpose  Adiponectin possesses anti-inflammatory and insulin-sensitizing properties. Little is known about the role of adiponectin in hepatitis B-related liver disease. Methods  Serum adiponectin and hepatitis B viral factors were cross-sectionally assayed in 280 patients with chronic hepatitis B virus (HBV) infection including 120 patients with chronic HBV infection, 40 patients with cirrhosis, and 120 patients with hepatocellular carcinoma (HCC); 116 healthy adults were used as controls. The dynamics of serum adiponectin level was also studied longitudinally in 25 patients with hepatitis B e antigen (HBeAg) seroconversion (SC). Results  We found that serum adiponectin level in patients with chronic HBV infection was similar to that in healthy controls and was significantly lower than patients with cirrhosis and HCC. In univariate analysis, high serum adiponectin level significantly correlated with the presence of HBV-related cirrhosis or HCC, abnormal serum ALT level, and HBV genotype C. Multivariate analysis revealed that high serum adiponectin level significantly correlated with the development of HCC. Serum adiponectin levels remained stationary in patients experiencing HBeAg SC. Conclusions  Our findings suggest that HBV infection itself does not affect adiponectin levels. Serum adiponectin level correlates with the progression of HBV-related liver diseases but not with the development of HBeAg SC.     

HBV感染自然史研究进展

病毒复制与宿主免疫之间的动态平衡在HBV感染自然史进展和发病机制中起重要作用。多数免疫能力正常的成人感染HBV后呈自限性,而在婴幼儿则多发展成为慢性HBV感染。慢性HBV感染分为4期：免疫耐受期、HBeAg阳性慢性肝炎期、非复制的HBsAg携带期和HBeAg阴性慢性肝炎期。HBVDNA水平、HBeAg的状态以及ALT水平可以预测HBV感染的长期结局如肝硬化或肝细胞癌。本文对HBV感染自然史分期、慢性HBV感染的结局和预后进行了综述。     

乙型肝炎病毒致肝细胞癌发生机制研究进展

肝细胞癌（HCC）的发生与乙型肝炎病毒（HBV）感染密切相关。HBV感染所致的炎症反应、HBV X基因及其产物X蛋白、核心启动子突变、前S2区突变、剪接特异性蛋白等均可能参与HCC的发生发展。     

Association between metabolic factors and chronic hepatitis B virus infection

There are limited data regarding the relationship between chronic hepatitis B virus (HBV) infection and metabolic factors. This article aims to highlight the link of metabolic factors with hepatitis B surface antigen (HBsAg) serostatus, HBV load, and HBV-related hepatocellular carcinoma (HCC). Although HBsAg-positive serostatus was positively correlated with a high risk of metabolic syndrome in students, chronic HBV-infected individuals have high serum adiponectin levels. The androgen pathway in HBV carriers with a low body mass index is more triggered which leads to enhanced HBV replication. High HBV load was inversely associated with obesity in hepatitis B e antigen (HBeAg)-seropositive HBV carriers; while in HBeAg-seronegative HBV carriers, high HBV load was inversely related to hypertriglyceridemia rather than obesity. For overweight and obese HBV-infected patients, high HBV load was positively associated with serum adiponectin levels. Several large cohort studies have revealed a positive link of diabetes with incidence of HBV-related HCC. However, the association between incidence of HCC and metabolic factors other than diabetes is still inconclusive. More long-term prospective studies should elucidate the association of chronic HBV infection and its outcomes with metabolic factors in clinical practice.     

Hepatitis B virus persistent infection-related single nucleotide polymorphisms in HLA regions are associated with viral load in hepatoma families

BACKGROUNDGenome-wide association studies from Asia indicate that HLA-DP and HLA-DQ loci are important in persistent hepatitis B virus (HBV) infections. One of the key elements for HBV-related carcinogenesis is persistent viral replication and inflammation.AIMTo examine genetic and nongenetic factors with persistent HBV infection and viral load in families with hepatocellular carcinoma (HCC).METHODSThe HCC families included 301 hepatitis B surface antigen (HBsAg) carriers and 424 noncarriers born before the nationwide vaccination program was initiated in 1984. Five HBV-related single nucleotide polymorphisms (SNPs) — rs477515, rs9272105, rs9276370, rs7756516, and rs9277535 — were genotyped. Factors associated with persistent HBV infection and viral load were analyzed by a generalized estimating equation.RESULTSIn the first-stage persistent HBV study, all SNPs except rs9272105 were associated with persistent infection. A significantly higher area under the reciprocal operating characteristic curve for nongenetic factors vs genetic factors (P < 0.001) suggests that the former play a major role in persistent HBV infection. In the second-stage viral load study, we added 8 HBsAg carriers born after 1984. The 309 HBsAg carriers were divided into low (n = 162) and high viral load (n = 147) groups with an HBV DNA cutoff of 10⁵ cps/mL. Sex, relationship to the index case, rs477515, rs9272105, and rs7756516 were associated with viral load. Based on the receiver operating characteristic curve analysis, genetic and nongenetic factors affected viral load equally in the HCC family cohort (P = 0.3117).CONCLUSIONIn these east Asian adults, the mechanism of persistent HBV infection-related SNPs was a prolonged viral replication phase.     

Nucleos(t)ide analogs in the prevention of hepatitis B virus related hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is among the most common cancer types and causes of cancer related mortality worldwide.Almost 50% of all HCC cases globally are attributable to chronic hepatitis B virus(HBV) infection.The incidence rates of HCC in untreated Asian subjects with HBV infection was estimated to be 0.2% in inactive carriers,0.6% for those with chronic hepatitis without cirrhosis,and 3.7% for those with compensated cirrhosis.In Western populations,HCC incidences are reported to be 0.02% in inactive carriers,0.3% in subjects with chronic hepatitis without cirrhosis,and 2.2% in subjects with compensated cirrhosis.Despite effective antiviral treatment options which are able to transform chronic hepatitis into an inactive carrier state,the risk of HCC cannot be fully ruled out to exclude those patients from surveillance.Newer nucleos(t)ide analogues(NAs) as entecavir and tenofovir are very potent in terms of sustained virological suppression which leads to improved liver histology.However,they do not have any influence on the ccc DNA or integrated DNA of HBV in the liver.Nonetheless,viral replication is the only modifiable component among the established risk factors for HBV-related HCC with the current treatment options.In this review,it was aimed to summarize cumulative evidence behind the concept of prevention of HBV related HCC by NAs,and to discuss remaining obstacles to eliminate the risk of HCC.     

Viral hepatitis and hepatocellular carcinoma: From molecular pathways to the role of clinical surveillance and antiviral treatment

Hepatocellular carcinoma (HCC) is a global health challenge. Due to the high prevalence in low-income countries, hepatitis B virus (HBV) and hepatitis C virus infections remain the main risk factors for HCC occurrence, despite the increasing frequencies of non-viral etiologies. In addition, hepatitis D virus coinfection increases the oncogenic risk in patients with HBV infection. The molecular processes underlying HCC development are complex and various, either independent from liver disease etiology or etiology-related. The reciprocal interlinkage among non-viral and viral risk factors, the damaged cellular microenvironment, the dysregulation of the immune system and the alteration of gut-liver-axis are known to participate in liver cancer induction and progression. Oncogenic mechanisms and pathways change throughout the natural history of viral hepatitis with the worsening of liver fibrosis. The high risk of cancer incidence in chronic viral hepatitis infected patients compared to other liver disease etiologies makes it necessary to implement a proper surveillance, both through clinical-biochemical scores and periodic ultrasound assessment. This review aims to outline viral and microenvironmental factors contributing to HCC occurrence in patients with chronic viral hepatitis and to point out the importance of surveillance programs recommended by international guidelines to promote early diagnosis of HCC.