乙型肝炎病毒变异与肝细胞癌发生关系

乙型肝炎病毒（hepatitisBvirus,HBV）基因组复制时,以病毒前基因组RNA作为模板合成子代病毒DNA,催化该过程的逆转录酶缺乏校对功能,所以HBV易出现变异。近年来,各国学者通过比较肝细胞癌（hepatocellular carcinoma,HCC）患者和非HCC患者的HBV基因序列,发现HBV基本核心启动子区的A1762T／G1764A变异或T1753V变异、增强子Ⅰ区的G1053A或G1229A变异、前S蛋白的F141L变异、前s2区基因缺失变异和x基因的截短变异,分别是HCC的易患因素,而前c区常见的G1896A变异,与HCC的发生无关。增强子Ⅱ区的C1653T变异在c基因HBV感染中可能与发生HCC有关,而在A基因型可能无关。     

The Survival Benefit of Liver Transplantation for Hepatocellular Carcinoma Patients with Hepatitis B Virus Infection and Cirrhosis

Background

A precise predictive survival model of liver transplantation (LT) with antiviral prophylaxis for hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) and cirrhosis has not been established. The aim of our study was to identify predictors of outcome after LT in these patients based on tumor staging systems, antitumor therapy pre-LT, and antiviral prophylaxis in patients considered to be unfit by Milan or UCSF criteria.

Methods

From 2002 to 2008, 917 LTs with antiviral prophylaxis were performed on patients with HBV-cirrhosis, and 313 had concurrent HCC.

Results

Stratified univariate and multivariate analyses demonstrated that independent predictors for poor survival were tumor size >7.5 cm (P = 0.001), tumor number >1 (P = 0.005), vascular invasion (P = 0.001), pre-LT serum alpha-fetoprotein (AFP) level ≥1000 ng/ml (P = 0.009), and pre-LT aspartate aminotransferase (AST) level ≥120 IU/L (P = 0.044). Pre-LT therapy for HCC was an independent predictor of better survival (P = 0.028). Based on CLIP and TNM tumor staging systems, HCC patients with HBV-cirrhosis who met the following criteria: solitary tumor ≤7.5 cm, or ≤4 multifocal nodules, the largest lesion ≤5 cm and total tumor diameter ≤10 cm, or more nodules with the largest lesion ≤3 cm, and pre-LT serum AFP level <1000 µg/L and AST level <120 IU/L without vascular invasion and lymph node metastasis who were unfit for UCSF, had survival rates of 89% at 5 years. There was a 47% 5-year survival rate for patients with HCC exceeding the revised criteria.

Conclusions

The current criteria for LT based on tumor size, number and levels of AFP and AST may be modestly expanded while still preserving excellent survival after LT. The expanded criteria combined with antiviral prophylaxis and pre-LT adjuvant therapy for HCC may be a rational strategy to prolong survival after LT for HCC patients with HBV-associated cirrhosis.     

HBx Protein Potentiates Hepatitis B Virus Reactivation

Molecular Biology - Hepatitis B virus (HBV) can cause chronic hepatitis B, one of the most prevalent infectious diseases in the world. Global estimates suggest that over 2 billion people are...     

Variants Identified by Hepatocellular Carcinoma and Chronic Hepatitis B Virus Infection Susceptibility GWAS Associated with Survival in HBV-Related Hepatocellular Carcinoma

Recent genome-wide association studies (GWAS) have identified several common susceptibility loci associated with the risk of hepatocellular carcinoma (HCC) or chronic hepatitis B infection (CHB). However, the relationship between these genetic variants and survival of patients with hepatitis B virus (HBV)-related HCC is still unknown. In this study, 22 single nucleotide polymorphisms (SNPs) were genotyped among 330 HBV-related HCC patients using the MassARRAY system from Sequenom. Cox proportional hazards regression was used to examine the effects of genotype on survival time under an additive model with age, sex, smoking status and clinical stage as covariates. We identified four SNPs on 6p21 (rs1419881 T>C, rs7453920 G>A,rs3997872 G>A and rs7768538 T>C), and two SNPs on 8p12 (rs2275959 C>T and rs7821974 C>T) significantly associated with survival time of HBV-related HCC patients. Our results suggest that HCC or CHB susceptibility loci might also affect the prognosis of patients with HBV-related HCC.     

乙肝病毒与原发性肝癌的相关风险研究

为了解慢性乙型肝炎病毒感染与原发性肝癌的关系,本文采用回顾性研究方法对328例原发性肝癌病人与同期收治的340例非肝癌的其他消化道肿瘤病人的乙型肝炎病毒感染血清标志物(HBV M)及肝功能检测结果进行对比分析.结果显示肝癌组乙肝表面抗原(HBsAg)阳性率(63.11%)显著高于非肝癌组(消化道其他肿瘤对照组)(11.47%).肝癌组慢性乙型肝炎病毒感染"HBsAg、抗-HBe和抗-HBc三者均表达为阳性者"(37.2%)显著高于"HBsAg、HBeAg和抗-HBc三者均表达为阳性者"(6.4%).肝功能检测结果,"HBsAg、HBeAg和抗-HBc三者均表达为阳性组"与"HBsAg、HBeAg和抗-HBc三者均表达为阳性组"比较无显著性差异(P＞0.05),而肝癌组与非肝癌组比较,肝癌组肝损害显著高于非肝癌组(P＜0.01).表明慢性乙型肝炎病毒感染在原发性肝癌病因学中起着十分重要的作用,"HBsAg、抗-HBe和抗-HBc三者均表达为阳性者"是原发性肝癌的高危人群.     

乙肝病毒与原发性肝癌的相关风险研究

为了解慢性乙型肝炎病毒感染与原发性肝癌的关系,本文采用回顾性研究方法对 328 例原发性肝癌病人与同期收治的 340 例非肝癌的其他消化道肿瘤病人的乙型肝炎病毒感染血清标志物(HBV M)及肝功能检测结果进行对比分析。结果显示肝癌组乙肝表面抗原(HBsAg)阳性率(63.11%)显著高于非肝癌组(消化道其他肿瘤对照组)(11.47%)。肝癌组慢性乙型肝炎病毒感染“HBsAg、抗-HBe 和抗-HBc 三者均表达为阳性者”(37.2%)显著高于“HBsAg、HBeAg 和抗-HBc 三者均表达为阳性者”(6.4%)。肝功能检测结果,“HBsAg、HBeAg 和抗-HBc三者均表达为阳性组”与“HBsAg、HBeAg 和抗-HBc 三者均表达为阳性组”比较无显著性差异(P>0.05),而肝癌组与非肝癌组比较,肝癌组肝损害显著高于非肝癌组(P<0.01)。表明慢性乙型肝炎病毒感染在原发性肝癌病因学中起着十分重要的作用,“HBsAg、抗-HBe 和抗-HBc 三者均表达为阳性者”是原发性肝癌的高危人群。     

Association of Hepatitis B Virus Pre-S Deletions with the Development of Hepatocellular Carcinoma in Qidong,China

Background/Aim

To investigate the roles of mutations in pre-S and S regions of hepatitis B virus (HBV) on the progression of hepatocellular carcinoma (HCC) in Qidong, China.

Methods

We conducted an age matched case-control study within a cohort of 2387 male HBV carriers who were recruited from August, 1996. The HBV DNA sequence in pre-S/S regions was successfully determined in 96 HCC cases and 97 control subjects. In addition, a consecutive series of samples from 11 HCC cases were employed to evaluate the pre-S deletion patterns before and after the occurrence of HCC.

Results

After adjustment for age, history of cigarette smoking and alcohol consumption, HBeAg positivity, pre-S deletions, pre-S2 start codon mutations, and T53C mutation were significantly associated with HCC, showing adjusted odds ratios (ORs) from 1.914 to 3.199. HCC patients also had a lower frequency of T31C mutation in pre-S2 gene, compared with control subjects (0.524; 95% CI 0.280-0.982). HBV pre-S deletions were clustered mainly in the 5′ end of pre-S2 region. Multivariate analysis showed that pre-S deletions and pre-S2 start codon mutations were independent risk factors for HCC. The OR (95% CI) were 2.434 (1.063–5.573) and 3.065 (1.099–8.547), respectively. The longitudinal observation indicated that the pre-S deletion mutations were not acquired at the beginning of HBV infection, but that the mutations occurred during the long course of liver disease.

Conclusion

Pre-S deletions and pre-S2 start codon mutations were independently associated with the development of HCC. The results also provided direct evidence that pre-S deletion mutations were not acquired from the beginning of infection but arose de novo during the progression of liver disease.     

Evolutionary Changes of Hepatitis B Virus Pre-S Mutations Prior to Development of Hepatocellular Carcinoma

Background and Aims

Deletions/mutations in the hepatitis B virus (HBV) pre-S region have been associated with hepatocellular carcinoma (HCC). We aimed to study the evolutionary changes of pre-S mutations prior to HCC development.

Methods

We studied the HBV pre-S sequences at 1 to 10 years preceding diagnosis of HCC in 74 patients with HBV-related HCC (HCC group). 148 chronic hepatitis B patients matched for sex and age in 2:1 ratio, who had been followed up for at least 3 years without HCC (HCC-free group) were recruited as controls. 56 and 47 patients of HCC and HCC-free groups respectively had serially stored sera for longitudinally examination at 1–3 years, 4–6 years, 7–9 years and ≥10 years prior to the recruitment of the study.

Results

Compared to the HCC-free group, higher frequencies of pre-S deletions and point mutations (at 11 codons) were observed in the HCC group (p<0.05). Multiple logistic regression analysis showed that pre-S deletions, point mutations at codon 51 and 167 were independent factors associated with HCC. Longitudinal observation showed that pre-S deletions and most of the 11 HCC-associated pre-S point mutations existed at least 10 years before HCC development, and were more prevalent preceding HCC development in patients from HCC groups than HCC-free group. The number of HCC-associated pre-S point mutations increased over time preceding HCC development, and correlated positively with the time to HCC diagnosis (r = 0.220, p = 0.005).

Conclusions

High prevalence and cumulative evolution of pre-S mutations preceding HCC development suggested a possible carcinogenic role of pre-S mutations and their potential application in HCC risk prediction.     

Impact of Cigarette Smoking on Outcome of Hepatocellular Carcinoma after Surgery in Patients with Hepatitis B

Background and Objectives

Cigarette smoking is a potential risk factor for hepatocellular carcinoma (HCC) initiation, partially through interaction with hepatitis B virus (HBV). We examined the hypothesis that cigarette smoking might be associated with HBV-related HCC recurrence and patient survival after curative surgery.

Patients and Methods

Data of 302 patients with HBV infection who had undergone curative resection for HCC were prospectively collected from 2008 to 2011. Smoking status and smoking quantity (pack-years, PY) were asked at admission. Factors affecting recurrence-free survival (RFS) were examined. RFS and liver-specific mortality (LSM) stratified by risk factors were compared with log-rank test.

Results

109 were current smokers. Current smokers were not different from non-smokers in tumor burden and surgical procedure. Univariate and multivariate analysis identified that heavy smoking (PY ≥20) was the most significant factor associated with HBV-related HCC recurrence after curative surgical resection (p = 0.001), followed by anti-HBV treatment (p<0.01), current smoking (p = 0.028), surgical margin <1 cm (p = 0.048) and blood transfusion >600 ml (p = 0.028). The median RFS in non-smokers, ex-smokers and current smokers was 34 months, 24 months and 26 months, respectively (p = 0.033). Current smokers had significantly worse RFS rate and increased 5-year cumulative LSM than non-smokers (p = 0.024, and p<0.001, respectively). Heavy smokers had significantly worse RFS than non- and light smokers (0<PY<20) (p<0.001, respectively) and higher cumulative LSM than non-smokers and light smokers (p = 0.003 and 0.001, respectively). Furthermore, in current smokers, continuing smoking postoperatively was strongly associated with poorer RFS and higher LSM than those who quit smoking postoperatively (p = 0.016 and p = 0.003, respectively).

Conclusions

Smoking history and quantity appears to be risk factors for HBV-related HCC recurrence and LSM of patients after surgery. For smokers, continued smoking postoperatively might accelerate tumor recurrence and patient death. Therefore, smoking abstinence should be strongly recommended to patients pre- and postoperatively.     

Hepatitis B Virus X Protein-Induced Aberrant Epigenetic Modifications Contributing to Human Hepatocellular Carcinoma Pathogenesis

Hepatocellular carcinoma (HCC) remains one of the most prevalent malignant diseases worldwide, and the majority of cases are related to hepatitis B virus (HBV) infection. Interactions between the HBV-encoded X (HBx) protein and host factors are known to play major roles in the onset and progression of HBV-related HCC. These dynamic molecular mechanisms are extremely complex and lead to prominent changes in the host genetic and epigenetic architecture. This review summarizes the current knowledge about HBx-induced epigenetic changes, including aberrations in DNA methylation, histone modifications, and microRNA expression, and their roles in HBV-infected liver cells and HBV-related HCC. Moreover, the HBx-mediated epigenetic control of HBV covalently closed circular DNA (cccDNA) is also discussed. Although this field of study is relatively new, the accumulated evidence has indicated that the epigenetic events induced by HBx play important roles in the development of HBV-related HCC. Ongoing research will help to identify practical applications of the HBV-related epigenetic signatures as biomarkers for early HCC detection or as potential targets to prevent and treat HBV-related HCC.     

乙型肝炎病人重叠感染丙型肝炎的评价

应用ＥＬＩＳＡ和ＰＣＲ法检测５０２例乙肝病人血清,４０１例ＨＢｓＡｇ阳性血清中,有１１４例（２８．４％）抗－ＨＣＶ和ＨＣＶＲＮＡ双项阳性,２５例（６．２％）ＨＣＶＲＮＡ单项阳性;２１例（５．２％）抗－ＨＣＶ单项阳性。将ＨＢｓＡｇ乙肝病人分成ＨＢＶＤＮＡ,ＨＢｅＡｇ阳性组和ＨＢＶＤＮＡ,ＨＢｅＡｇ阴性组。前者抗－ＨＣＶ阳性率为１１．６％～２０．５％,ＨＣＶＲＮＡ阳性率为１６．２％～２０．５％。后者抗－ＨＣＶ阳性率为２０．２％～５５．６％,ＨＣＶＲＮＡ阳性率为２３％～６０．３％。结果说明长期携带ＨＢＶ者和慢性乙肝病人均可重叠ＨＣＶ感染。ＨＢＶＤＮＡ阳性组抗－ＨＣＶ和ＨＣＶＲＮＡ阳性率明显高于ＨＢＶＤＮＡ阳性组     

Predictability of Liver-Related Seromarkers for the Risk of Hepatocellular Carcinoma in Chronic Hepatitis B Patients

Background

Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is a major global health problem. A few risk calculators have been developed using mainly HBV seromarkers as predictors. However, serum HBV DNA level, HBV genotype, and mutants are not routinely checked in regular health examinations. This study aimed to assess the predictability of HCC risk in chronic hepatitis B patients, using a combination of liver-related seromarkers combined with or without HBV seromarkers.

Methods

A prospective cohort of 1,822 anti-HCV-seronegative chronic HBV carriers was included in this study. Liver-related seromarkers including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alpha-fetoprotein (AFP), gamma-glutamyltransferase (GGT), total bilirubin, total protein, albumin, serum globulins, apolipoprotein A1, and apolipoprotein B were examined. Hazard ratios of HCC with 95% confidence intervals were estimated using Cox proportional hazards regression models. Regression coefficients of seromarkers significantly associated with HCC risk in multivariate analyses were used to create integer risk scores. The predictability of various risk models were assessed by area under receiver operating characteristic curves (AUROCs).

Results

During a median follow-up of 5.9 years, 48 newly-developed HCC cases were ascertained. Elevated serum levels of ALT (≥28 U/L), AFP (≥5 ng/mL), and GGT (≥41 U/L), an increased AST/ALT ratio (AAR, ≥1), and lowered serum levels of albumin (≤4.1 g/dL) and alpha-1 globulin (≤0.2 g/dL) were significantly associated with an increased HCC risk (P<0.05) in multivariate analysis. The risk model incorporating age, gender, AAR, and serum levels of ALT, AFP, GGT, albumin, and alpha-1 globulin had an AUROC of 0.89 for predicting 6-year HCC incidence. The AUROC was 0.91 after the addition of HBV seromarkers into the model, and 0.83 for the model without liver-related seromarkers, with the exception of ALT.

Conclusion

Liver-related seromarkers may be combined into useful risk models for predicting HBV-related HCC risk.     

Hepatitis B Virus HBx Activates Notch Signaling via Delta-Like 4/Notch1 in Hepatocellular Carcinoma

Hepatitis virus B (HBV) infection is one of the major causes of hepatocellular carcinomas (HCC). HBx protein encoded in HBV genome is one of the key viral factors leading to malignant transformation of infected cells. HBx functions by interfering with cellular functions, causing aberration in cellular behaviour and transformation. Notch signalling is a well-conserved pathway involved in cellular differentiation, cell survival and cell death operating in various types of cells. Aberration in the Notch signalling pathways is linked to various tumors, including HCC. The role of HBx on the Notch signalling in HCC, however, is still controversial. In this study, we reported that HBV genome-containing HCC cell line HepG2 (HepG2.2.15) expressed higher Notch1 and Delta-like 4 (Dll4), compared to the control HepG2 without HBV genome. This upregulation coincided with increased appearance of the cleavage of Notch1, indicating constitutively activated Notch signalling. Silencing of HBx specifically reduced the level of Dll4 and cleaved Notch1. The increase in Dll4 level was confirmed in clinical specimens of HCC lesion, in comparison with non-tumor lesions. Using specific signalling pathway inhibitors, we found that MEK1/2, PI3K/AKT and NF-κB pathways are critical for HBx-mediated Dll4 upregulation. Silencing of HBx clearly decreased the level of phosphorylation of Akt and Erk1/2. Upon silencing of Dll4 in HepG2.2.15, decreased cleaved Notch1, increased apoptosis and cell cycle arrest were observed, suggesting a critical role of HBx-Dll4-Notch1 axis in regulating cell survival in HCC. Furthermore, clonogenic assay confirmed the important role of Dll4 in regulating cell survival of HBV-genome containing HCC cell line. Taken together, we reported a link between HBx and the Notch signalling in HCC that affects cell survival of HCC, which can be a potential target for therapy.     

High Risk of Hepatitis B Reactivation among Patients with Acute Myeloid Leukemia

BackgroundHepatitis B virus (HBV) infections are common and associated with significant morbidity and mortality in cancer patients. However, the incidence and risk factors of HBV reactivation in patients with acute myeloid leukemia (AML) are rarely investigated.MethodsAML patients followed-up at the National Taiwan University Hospital between 2006 and 2012 were analyzed. The clinical characteristics and laboratory data were retrospectively reviewed.ResultsFour hundred and ninety patients comprising 265 men and 225 women were studied. The median age was 52 years (range, 18 - 94). Chronic HBV carriage was documented at the time of leukemia diagnosis in 57 (11.6%) patients. Forty-six (80.7%) of the 57 HBV carriers received prophylaxis with anti-HBV agents. Sixteen HBV carriers (28.1%) developed hepatitis B reactivation during or after chemotherapy, including 7 patients who had discontinued antiviral therapy. The incidence of hepatitis B reactivation among AML patients with HBV carriage was 9.5 per 100 person-years. Prophylaxis with anti-HBV agents significantly decreased the risk of hepatitis B reactivation among HBV carriers (13% vs. 61%, p<0.001). Four (2.8%) of 142 patients with initial positive anti-HBsAb and anti-HBcAb experienced hepatitis B reactivation and lost their protective anti-HBsAb. Multivariate analysis revealed that diabetes mellitus (p=0.008, odds ratio (OR) = 2.841, 95% confident interval (CI): 0.985-8.193) and carriage of HBsAg (p<0.001, OR=36.878, 95% CI: 11.770-115.547) were independent risk factors for hepatitis B reactivation in AML patients.ConclusionsHepatitis B reactivation is not uncommon in the HBsAg positive AML patients. Prophylaxis with anti-HBV agent significantly decreased the risk of hepatitis B reactivation.     

丙型肝炎病毒诱发肝细胞癌的分子机制

丙型肝炎是由丙型肝炎病毒(hepatitis C virus,HCV)引起的一种肝脏疾病。肝细胞癌(hepatocellular carcinoma,HCC)是人类最常见的恶性肿瘤之一。大量实验和临床研究表明,HCV的感染是导致肝细胞癌的主要因素之一。尽管目前可以通过直接抗病毒药物治疗HCV感染,但是患肝细胞癌的风险仍然存在。HCV诱发肝细胞癌是一个多步骤过程,其可能是通过病毒因子直接作用和/或通过引起慢性炎症诱发肝癌。因此,需要更好地了解HCV诱发肝细胞癌的分子机制,为肝细胞癌的防治提供研究基础。本文就近年来国内外对丙型肝炎病毒直接作用诱发肝细胞癌的分子机制进行综述,具体从血管生成、细胞凋亡、细胞增殖、上皮 间质转化、脂肪变性和氧化应激6个方面进行阐述,以期更好地了解HCV诱发肝细胞癌的分子机制,为肝细胞癌的防治提供研究基础。     

丙型肝炎病毒诱发肝细胞癌的分子机制

丙型肝炎是由丙型肝炎病毒(hepatitis C virus,HCV)引起的一种肝脏疾病。肝细胞癌(hepatocellular carcinoma,HCC)是人类最常见的恶性肿瘤之一。大量实验和临床研究表明,HCV的感染是导致肝细胞癌的主要因素之一。尽管目前可以通过直接抗病毒药物治疗HCV感染,但是患肝细胞癌的风险仍然存在。HCV诱发肝细胞癌是一个多步骤过程,其可能是通过病毒因子直接作用和/或通过引起慢性炎症诱发肝癌。因此,需要更好地了解HCV诱发肝细胞癌的分子机制,为肝细胞癌的防治提供研究基础。本文就近年来国内外对丙型肝炎病毒直接作用诱发肝细胞癌的分子机制进行综述,具体从血管生成、细胞凋亡、细胞增殖、上皮 间质转化、脂肪变性和氧化应激6个方面进行阐述,以期更好地了解HCV诱发肝细胞癌的分子机制,为肝细胞癌的防治提供研究基础。     

Hepatitis C Virus Protein Interaction Network Analysis Based on Hepatocellular Carcinoma

Epidemiological studies have validated the association between hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). An increasing number of studies show that protein-protein interactions (PPIs) between HCV proteins and host proteins play a vital role in infection and mediate HCC progression. In this work, we collected all published interaction between HCV and human proteins, which include 455 unique human proteins participating in 524 HCV-human interactions. Then, we construct the HCV-human and HCV-HCC protein interaction networks, which display the biological knowledge regarding the mechanism of HCV pathogenesis, particularly with respect to pathogenesis of HCC. Through in-depth analysis of the HCV-HCC interaction network, we found that interactors are enriched in the JAK/STAT, p53, MAPK, TNF, Wnt, and cell cycle pathways. Using a random walk with restart algorithm, we predicted the importance of each protein in the HCV-HCC network and found that AKT1 may play a key role in the HCC progression. Moreover, we found that NS5A promotes HCC cells proliferation and metastasis by activating AKT/GSK3β/β-catenin pathway. This work provides a basis for a detailed map tracking new cellular interactions of HCV and identifying potential targets for HCV-related hepatocellular carcinoma treatment.