A case-control study of the relationship between hepatitis B virus DNA level and risk of hepatocellular carcinoma in Qidong, China

Association Between Alcohol Consumption and Risk of Nasopharyngeal Carcinoma: A Comprehensive Meta-Analysis of Epidemiological Studies

BACKGROUND

Alcohol consumption is increasing all over the world, but whether it is an independent factor affecting the occurrence of nasopharyngeal carcinoma (NPC) is inconsistent in many studies. We aimed to explore the association between alcohol consumption and NPC risk by integrating existing evidence in a meta-analysis.

METHODS

We searched for relevant articles published up to August 2018 in PubMed, Cochrane Library, Web of Science, and China National Knowledge infrastructure (CNKI). The Newcastle-Ottawa scale was used to assess the quality of the included studies. Odds ratios (ORs) or relative risks were pooled to estimate the associations between alcohol consumption and NPC risk.

RESULTS

The meta-analysis of cohort studies showed no significant association between alcohol consumption and NPC, but pooled results from case-control studies indicated that ever drinking increased the probability of NPC versus nondrinking (OR = 1.10; 95% confidence interval [CI]: 1.01, 1.19). As compared with nondrinkers, high-frequency drinking (≥7 times/wk) increased the NPC probability (OR = 1.29; 95% CI: 1.05, 1.53) and low-frequency drinking (<7 times/wk) decreased the probability (OR = 0.77; 95% CI: 0.60, 0.94), as did shorter duration of drinking (<20 years) (OR = 0.64; 95% CI: 0.49, 0.79). On subgroup analyses, significant pooled results were observed for studies with high quality, with hospital-based controls and with adjustment for confounding factors, smoking, age, and sex.

CONCLUSIONS

The risk of NPC may increase with alcohol consumption. Ever drinking increased the risk versus nondrinking. Additionally, high-frequency drinking increased the risk, but low-frequency drinking decreased it to some extent. Further intensive studies based on well-designed methods are needed to examine the association.

Individual and combined effects of hepatitis B surface antigen level and viral load on liver cancer risk

BACKGROUND

Hepatitis B surface antigen (HBsAg) and viral load are both hallmarks of hepatitis B virus (HBV) infection and have potential to stratify liver cancer risk.

METHODS

We carried out a nested case-control study including 211 liver cancer cases and 221 controls who were seropositive for HBsAg within two population-based cohorts in Shanghai. Logistic regression was performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Risk of liver cancer was positively related to increasing levels of HBV-DNA and HBsAg in dose-response manners. Compared with subjects with HBV-DNA < 2000 IU/ml, the adjusted ORs increased from 2.11 (95%CI: 0.99-4.50) to 10.47 (95%CI: 5.06-21.68) for those with HBV-DNA level at 2000-19 999 to ≥ 20 000 IU/ml. Compared with subjects at a low level of HBsAg (0.05-99 IU/ml), the adjusted ORs increased from 1.82 (95%CI: 0.90-3.68) to 2.21 (95%CI: 1.10-4.43) for those with HBsAg level at 100-999 to ≥ 1000 IU/ml. Compared with subjects with HBV-DNA < 2000 IU/ml and HBsAg < 100 IU/ml, the adjusted ORs were increased from 2.20 (95%CI: 1.07-4.49) for those with HBV-DNA < 2000 and HBsAg ≥ 100 IU/ml to 6.94 (95%CI: 3.39-14.23) for those with HBV-DNA ≥ 2000 IU/ml and HBsAg < 1000 IU/ml, and 16.15 (95%CI: 7.60-34.32) for those with HBV-DNA ≥ 2000 IU/ml and HBsAg ≥ 1000 IU/ml.

CONCLUSION

Elevated levels of HBV-DNA and HBsAg are associated with increased risks of liver cancer. Chronic HBsAg carriers may be suggested to simultaneously lower the viral load to < 2000 IU/ml and HBsAg level to < 100 IU/ml to lower their liver cancer risk.

Hyper-Expression of PD-1 Is Associated with the Levels of Exhausted and Dysfunctional Phenotypes of Circulating CD161++TCR iVα7.2+ Mucosal-Associated Invariant T Cells in Chronic Hepatitis B Virus Infection

Mucosal-associated invariant T (MAIT) cells, defined as CD161⁺⁺TCR iVα7.2⁺ T cells, play an important role in the innate defense against bacterial infections, and their functionality is impaired in chronic viral infections. Here, we investigated the frequency and functional role of MAIT cells in chronic hepatitis B virus (HBV) infection. The peripheral CD3⁺CD161⁺⁺TCR iVα7.2⁺ MAIT cells in chronic HBV-infected patients and healthy controls were phenotypically characterized based on CD57, PD-1, TIM-3, and CTLA-4, as well as HLA-DR and CD38 expression. The frequency of MAIT cells was significantly decreased among chronic HBV-infected individuals as compared to controls. Expression of CD57, PD-1, CTLA-4, as well as HLA-DR and CD38 on MAIT cells was significantly elevated in chronic HBV-infected individuals relative to controls. The percentage of T cell receptor (TCR) iVα7.2⁺ CD161⁺ MAIT cells did not correlate with HBV viral load but inversely with HLA-DR on CD4⁺ T cells and MAIT cells and with CD57 on CD8⁺ T cells suggesting that decrease of MAIT cells may not be attributed to direct infection by HBV but driven by HBV-induced chronic immune activation. The percentage and expression levels of PD-1 as well as CTLA-4 on MAIT cells inversely correlated with plasma HBV-DNA levels, which may suggest either a role for MAIT cells in the control of HBV infection or the effect of HBV replication in the liver on MAIT cell phenotype. We report that decrease of TCR iVα7.2⁺ MAIT cells in the peripheral blood and their functions were seemingly impaired in chronic HBV-infected patients likely because of the increased expression of PD-1.

Qidong hepatitis B virus infection cohort: a 25-year prospective study in high risk area of primary liver cancer

Qidong hepatitis B virus (HBV) infection cohort (QBC) is a prospective community-based study designed to investigate causative factors of primary liver cancer (PLC) in Qidong, China, where both PLC and HBV infection are highly endemic. Residents aged 20-65 years, living in seven townships of Qidong, were surveyed using hepatitis B surface antigen (HBsAg) serum test and invited to participate in QBC from June 1991 to December 1991. A total of 852 and 786 participants were enrolled in HBsAg-positive and HBsAg-negative sub-cohorts in May 1992, respectively. All participants were actively followed up in person, received HBsAg, alanine aminotransferase (ALT), alpha-fetoprotein (AFP) tests and upper abdominal ultrasonic examination, and donated blood and urine samples once or twice a year. The total response rate was 99.6%, and the number of incident PLC was 201 till the end of February 2017. The ratio of incidence rates was 12.32 (95% confidence interval[CI]=7.16-21.21, P < 0.0001) in HBsAg-positive arm compared with HBsAg-negative arm. The relative risk of PLC was 13.25 (95% CI=6.67-26.33, P < 0.0001) and 28.05 (95% CI=13.87-56.73, P < 0.0001) in the HBsAg+/HBeAg- group and the HBsAg+/HBeAg+ group, respectively, as compared to the HBsAg-/HBeAg- group. A series of novel PLC-related mutations including A2159G, A2189C and G2203W at the C gene, A799G, A987G and T1055A at the P gene of HBV genome were identified by using samples from the cohort. The mutation in hepatitis B virus (HBV) basal core promoter region of HBV genome has an accumulative effect on the occurrence of PLC. In addition, the tripartite relationship of aflatoxin exposure, P53 mutation and PLC was also investigated. Dynamic prediction model for PLC risk by using its long-term follow-up information and serial blood samples for QBC was developed. This model is expected to improve the efficiency of PLC screening in HBV infection individuals.

The contribution of serum hepatitis B virus load in the carcinogenesis and prognosis of hepatocellular carcinoma: evidence from two meta-analyses

BACKGROUND AND AIM

The meta-analysis aimed to quantify and summarize the contribution of serum hepatitis B virus (HBV) DNA load in the carcinogenesis and prognosis of hepatocellular carcinoma (HCC).

RESULTS

Nine independent studies with a total of 1162 cases and 9365 participants on risk of HCC and seventeen studies with 1342 cases and 2891 participants on recurrence of HCC were finally included. The non-liner dose-response association between HBV DNA level and HCC risk was observed, with P value equal to 0.02 for linear test. Compared with 2 log10copies/ml HBV DNA level carriers, the summary relative risk of HCC were 1.65(95% CI: 0.94-2.92) for 4.5 log10copies/ml, 2.20(95% CI: 1.00-4.85) for 5.5 log10copies/ml, 3.06(95% CI: 1.11-8.44) for 6.5 log10copies/ml. Moreover, individuals with high viral load (HBV DNA levels > 105copies/ml) presented significant association with increased risk of HCC recurrence, with the pooled RR of 1.69 (95% CI: 1.49-1.92).

MATERIALS AND METHODS

Pertinent studies were identified by searching PubMed, Embase and ISI Web of science databases up to January 2016 and by reviewing the references of retrieved articles. The dose-response meta-analysis was precisely performed to calculate the summary relative risks (RRs) by quantizing the association between HBV load and risk of HCC. Besides, the contribution of HBV load on recurrence of HCC was further clarified by general meta-analysis.

CONCLUSIONS

These findings indicated a non-linear dose-response relationship between serum HBV DNA level and risk of HCC, and confirmed the significant contribution of serum HBV DNA level in the prognosis of HCC.

Analysis of Risk Factors Associated with the Development of Hepatocellular Carcinoma in Chronic HBV-Infected Chinese: A Meta-Analysis

Hepatitis B virus (HBV) infection is a major risk factor for the development of hepatocellular carcinoma (HCC) in China. At present, there still are 9.3 million chronic HBV-infected Chinese. Numerous studies have explored the association between possible factors and hepatocellular carcinoma risk, however, the results remains inconsistent. Therefore, we did this pooled analysis so as to get a precise result. Here, we took the chronic HBV-infected Chinese as the object. We systematically searched for studies evaluating whether the proposed factors changed HCC risk in PubMed, Chinese National Knowledge Infrastructure, VIP database and Wanfang data. Odds ratios (OR) with 95% confidence intervals (CI) were calculated by Review Manager 5.0 and publication bias was determined by Begg’s test and Egger’s test. In total, 3165 cases and 10,896 controls from 27 studies were included in this meta-analysis. Our results showed that pooled OR with 95% CI for each of the factors investigated were: non-antiviral treatment 2.70 (2.01, 3.62), high HBV DNA levels 2.61 (1.73, 3.94), alcohol consumption 2.19 (1.53, 3.13), a family history of HCC 3.58 (2.53, 5.06) and male gender 2.14 (1.68, 2.73), respectively. Our meta-analysis supports that high HBV DNA levels, non-antiviral treatment, alcohol consumption, a family history of HCC and male gender contributed to the risk of hepatocellular carcinoma in chronic HBV-infected Chinese from currently available evidence. Given the high prevalence of the non-antiviral treatment and alcohol drinking, behavior interventions for the two factors should be tackled first.

Cancer prevention and control: alarming challenges in China

China is geographically the third largest country in the world and the most populated low-to-middle-income country. Cancer incidence and mortality rates for some cancers in the USA and European countries have steadily decreased over the last decades, whereas the incidence and mortality of certain cancers in China have been increasing at an alarming speed. Rapid industrialization and urbanization in China have been accompanied by incredible changes in lifestyle and environment combined with an aging population. Mortality caused by lung, colorectal and breast cancers has been steadily increasing, whereas cancer mortality from gastric, esophageal and cervical tumors has tended to decrease. Similar to what has occurred in the United States, unhealthy lifestyles in China, including heavy smoking and poor diet combined with pollution, have contributed to increased cancer risk. China is facing many challenges in cancer treatment and prevention for the general population. The major areas that need to be addressed in the control of cancer in China include cancers associated with environmental pollution, tobacco use, occupational carcinogens, infection, excessive alcohol consumption, dietary deficiencies and obesity. In this perspective, we review the problems in each area and suggest ideas for future directions in cancer research and strategies and actions to reduce the incidence of cancer in China.

Potential mechanisms of hepatitis B virus induced liver injury

Chronic active hepatitis (CAH) is acknowledged as an imperative risk factor for the development of liver injury and hepatocellular carcinoma. The histological end points of CAH are chronic inflammation, fibrosis and cirrhosis which are coupled with increased DNA synthesis in cirrhotic vs healthy normal livers. The potential mechanism involved in CAH includes a combination of processes leading to liver cell necrosis, inflammation and cytokine production and liver scaring (fibrosis). The severity of liver damage is regulated by Hepatitis B virus genotypes and viral components. The viral and cellular factors that contribute to liver injury are discussed in this article. Liver injury caused by the viral infection affects many cellular processes such as cell signaling, apoptosis, transcription, DNA repair which in turn induce radical effects on cell survival, growth, transformation and maintenance. The consequence of such perturbations is resulted in the alteration of bile secretion, gluconeogenesis, glycolysis, detoxification and metabolism of carbohydrates, proteins, fat and balance of nutrients. The identification and elucidation of the molecular pathways perturbed by the viral proteins are important in order to design effective strategy to minimize and/or restore the hepatocytes injury.

Significance of viral status on occurrence of hepatitis B-related hepatocellular carcinoma

Hepatitis B virus (HBV) infection remains a challenging global health problem, with more than 350 million people chronically infected and at risk of developing hepatocellular carcinoma (HCC). Interactions that occur among host, environmental, and viral factors determine the natural course and predict the prognosis of patients with chronic HBV infection. In the past decades, several important viral factors of predictive of HCC have been identified, such as high hepatitis B surface antigen level, seropositivity of hepatitis B e antigen, high viral load, viral genotype, and specific viral sequence mutations. Identification of certain viral risk factors for HCC development and stratification of patient risk are very important to perform future surveillance programs. In this article, we thus reviewed the risk of viral factors involved in hepatocarcinogenesis.

Novel natural mutations in the hepatitis B virus reverse transcriptase domain associated with hepatocellular carcinoma

BACKGROUND/AIM

Hepatitis B Virus (HBV) mutations play a role in the development of hepatocellular carcinoma (HCC). However, the association between HBV polymerase gene mutations and HCC has not been reported. In this study, we conducted a multi-stage study to identify HCC-related mutations in the reverse transcriptase (RT) domain of the HBV polymerase gene.

METHODS

A total of 231 HCCs and 237 non-HCC controls from Qidong, China, were included in this study. The entire sequence of HBV RT was first compared between 29 HCC and 35 non-HCC cases, and candidate mutations were then evaluated in two independent validation sets.

RESULTS

There were 15 candidate mutations identified from the discovery set, with A799G and T1055A being consistently associated with HCC across all studies. A pooled analysis of samples revealed that A799G, A987G, and T1055A were independent risk factors for HCC, with adjusted odds ratios of 5.53 [95% confidence interval (CI), 1.69-18.10], 4.20 (95%CI, 1.15-15.35), and 3.78 (95%CI, 1.45-9.86), respectively. A longitudinal study showed that these mutations were detectable 4-5 years prior to HCC diagnosis.

CONCLUSIONS

Our study provides evidence the first that HBV RT contains naturally occurring mutations that can be used as predictive markers for HCC.

Prospective cohort studies of association between family history of liver cancer and risk of liver cancer

Uncertainty remains on the relationship between a family history of liver cancer and liver cancer risk in prospective cohort studies in a general population. Thus, we examined this association in 133,014 participants in the Shanghai Women's and Men's Health Studies. Family history of liver cancer was categorized through dichotomous and proportional score approaches. Hazard ratios (HRs) and 95% confidence intervals (CIs) were derived using the Cox proportional hazards models with adjustment for potential confounders. A meta-analysis of observational studies through December 2013 on liver cancer risk in relation to family history of liver cancer was also performed. Study-specific risk estimates were combined using fixed or random effects models depending on whether significant heterogeneity was detected. For the Shanghai Women's and Men's Health Studies, 299 liver cancer cases were identified during follow-up through 2010. Family history of liver cancer was associated with liver cancer risk using both binary indicator (HR = 2.60, 95% CI: 1.77-3.80) and proportional score (high-risk vs. minimal-risk category: HR = 3.03, 95% CI: 1.73-5.31), with increasing HRs for increasing score categories. The meta-analysis also showed an increased risk for those with a family history of liver cancer (relative risk = 2.55, 95% CI: 2.05-3.16). Family history of liver cancer was related to increased risk of liver cancer in Chinese population. This risk is particularly high for those with an affected mother. The "dose-response" of risk with an increasing family history score of liver cancer might further facilitate future cancer prevention programs on identifying individuals with the highest potential liver cancer risk.

Family history of hepatocellulcar carcinoma is not associated with its patients' prognosis after hepatectomy

BACKGROUND

Family history of liver cancer is a major risk factor for hepatocellular carcinoma (HCC). In this study, we investigated the prognosis of patients with HCC with or without family history.

METHODS

Data for 1,313 patients who underwent hepatectomy as initial treatment for HCC between 2000 and 2008 at a tertiary cancer center hospital were retrieved from a prospective database. A positive family history was defined as a self-reported history of HCC in first-degree relatives. Clinicopathologic characteristics were compared by family history. Kaplan-Meier method and Cox proportional hazards regressions were applied for overall survival (OS) and disease-free survival (DFS).

RESULTS

Of 1,313 patients, 169 patients (12.9%) had first-degree relatives with a history of HCC. There were no significant differences between patients with or without family history in basic clinicopathologic characteristics. In either whole group or each stage according to the TNM staging system, first-degree family history was not associated with survival in all patients, hepatitis B virus-positive patients, as well as male patients. Multivariate analysis revealed that first-degree family history was not a prognostic factor, either for OS or DFS.

CONCLUSION

A first-degree family history of HCC is not associated with its patients' prognosis after hepatectomy.

Molecular characterization of hepatitis B virus in liver disease patients and asymptomatic carriers of the virus in Sudan

Background

Hepatitis B virus is hyperendemic in Sudan. Our aim was to molecularly characterize hepatitis B virus from Sudanese individuals, with and without liver disease, because genotypes play an important role in clinical manifestation and treatment management.

Methods

Ninety-nine patients - 30 asymptomatic, 42 cirrhotic, 15 with hepatocellular carcinoma, 7 with acute hepatitis and 5 with chronic hepatitis- were enrolled. Sequencing of surface and basic core promoter/precore regions and complete genome were performed.

Results

The mean ± standard deviation, age was 45.7±14.8 years and the male to female ratio 77:22. The median (interquartile range) of hepatitis B virus DNA and alanine aminotransferase levels were 2.8 (2.2-4.2) log IU/ml and 30 (19–49) IU/L, respectively. Using three genotyping methods, 81/99 (82%) could be genotyped. Forty eight percent of the 99 patients were infected with genotype D and 24% with genotype E, 2% with putative D/E recombinants and 7% with genotype A. Patients infected with genotype E had higher frequency of hepatitis B e antigen-positivity and higher viral loads compared to patients infected with genotype D. Basic core promoter/precore region mutations, including the G1896A in 37% of HBeAg-negative individuals, could account for hepatitis B e antigen-negativity. Pre-S deletion mutants were found in genotypes D and E. Three isolates had the vaccine escape mutant sM133T.

Conclusion

Sudanese hepatitis B virus carriers were mainly infected with genotypes D or E, with patients infected with genotype E having higher HBeAg-positivity and higher viral loads. This is the first study to molecularly characterize hepatitis B virus from liver disease patients in Sudan.

Treatment of HBV related cirrhosis

Until very recently, hepatitis B virus (HBV)-associated cirrhosis was often regarded as an irreversible condition. It is associated with strongly increased mortality and a high risk of the development of hepatocellular carcinoma (HCC). Indeed, the incidence of HCC per 100 person years was shown to be 2-3.7 in patients with cirrhosis compared with only 0.3-0.6 in patients with active hepatitis B without cirrhosis and 0.02-0.2 in asymptomatic carriers. Liver transplantation was considered to be the only medical intervention, which could resolve this condition and which could improve the general condition of these patients. However, it is now becoming increasingly evident that long-term suppression of viral replication allows the regenerative potential of the liver to reverse even high grade liver fibrosis. For the management of HBV-related cirrhosis, it is therefore important to provide effective treatment and to identify and avoid risk factors for the development of cirrhosis and hepatic decompensation.

Pathogenic mechanisms in HBV- and HCV-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly lethal cancer, with increasing worldwide incidence, that is mainly associated with chronic hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections. There are few effective treatments partly because the cell- and molecular-based mechanisms that contribute to the pathogenesis of this tumour type are poorly understood. This Review outlines pathogenic mechanisms that seem to be common to both viruses and which suggest innovative approaches to the prevention and treatment of HCC.

Functional Aspects of PARP1 in DNA Repair and Transcription

Poly (ADP-ribose) polymerase 1 (PARP1) is an ADP-ribosylating enzyme essential for initiating various forms of DNA repair. Inhibiting its enzyme activity with small molecules thus achieves synthetic lethality by preventing unwanted DNA repair in the treatment of cancers. Through enzyme-dependent chromatin remodeling and enzyme-independent motif recognition, PARP1 also plays important roles in regulating gene expression. Besides presenting current findings on how each process is individually controlled by PARP1, we shall discuss how transcription and DNA repair are so intricately linked that disturbance by PARP1 enzymatic inhibition, enzyme hyperactivation in diseases, and viral replication can favor one function while suppressing the other.

Family history of liver cancer and hepatocellular carcinoma

Familial clustering of hepatocellular carcinoma (HCC) has been frequently reported in eastern Asiatic countries, where hepatitis B infection is common. Little is known about the relationship between family history of liver cancer and HCC in Western populations. We carried out a case-control study in Italy, involving 229 HCC cases and 431 hospital controls. Data on family history were summarized through a binary indicator (yes/no) and a family history score (FHscore), considering selected family characteristics. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were obtained from unconditional multiple logistic regression models, including terms for age, sex, study center, education, tobacco smoking, alcohol drinking, hepatitis B surface antigen, and/or anti-hepatitis C virus positivity. We also performed a meta-analysis on family history of liver cancer and liver cancer updated to April 2011 using random-effects models. After adjustment for chronic infection with hepatitis B/C viruses, family history of liver cancer was associated with HCC risk, when using both the binary indicator (OR, 2.38; 95% CI, 1.01-5.58) and the FHscore, with increasing ORs for successive score categories. Compared to subjects without family history and no chronic infection with hepatitis B/C viruses, the OR for those exposed to both risk factors was 72.48 (95% CI, 21.92-239.73). In the meta-analysis, based on nine case-control and four cohort studies, for a total of approximately 3,600 liver cancer cases, the pooled relative risk for family history of liver cancer was 2.50 (95% CI, 2.06-3.03).

CONCLUSION

A family history of liver cancer increases HCC risk, independently of hepatitis. The combination of family history of liver cancer and hepatitis B/C serum markers is associated with an over 70-fold elevated HCC risk.

High hepatitis B virus load is associated with hepatocellular carcinomas development in Chinese chronic hepatitis B patients: a case control study

Background

Persistent hepatitis B virus (HBV) infection is a risk factor for hepatocellular carcinoma (HCC) development. This study aimed to clarify whether the high HBV DNA level is associated with HCC development by comparing HBV DNA levels between HBV infected patients with and without HCC.

Results

There were 78 male and 12 female patients in each group and there was no statistical difference between these two group patients' average ages. The HBV DNA level in the HCC patients was 4.73 ± 1.71 Log₁₀ IU/ml while 3.90 ± 2.01 Log₁₀ IU/ml in non-HCC patients (P < 0.01). The HBeAg positive rate was 42.2% (38/90) in the HCC group while 13.3% (12/90) in the non-HCC group (P < 0.001). Compared with patients with HBV DNA level of < 3 Log₁₀ IU/ml, the patients with level of 3 to < 4, 4 to < 5, 5 to < 6, or ≥ 6 Log₁₀ IU/ml had the odds ratio for HCC of 1.380 (95% CI, 0.544-3.499), 3.671 (95% CI, 1.363-9.886), 5.303 (95% CI, 1.847-15.277) or 3.030 (95% CI, 1.143-8.036), respectively.

Conclusions

HBV-related HCC patients had higher HBV DNA level than non-HCC counterparts. Our findings imply that active HBV replication is associated with the HCC development.

Novel poly (ADP-ribose) polymerase 1 binding motif in hepatitis B virus core promoter impairs DNA damage repair

It is well-established that hepatitis B virus (HBV) infection is associated with the development of hepatocellular carcinoma (HCC), but patients with high viral DNA load have significantly higher risk. As host factors are required for efficient viral replication and may, therefore, contribute to high viral DNA load, we screened for host factors that can transcriptionally activate the HBV core promoter (HBVCP). We report here that poly (ADP-ribose) polymerase 1 (PARP1), which is known for its DNA repair activity, binds prominently to an octamer motif in the HBVCP and increases transcriptional efficiency. By utilizing a series of single base substitutions at each nucleotide position of the octamer, the PARP1 binding motif can be defined as "RNNWCAAA." Intriguingly, introduction of a vector construct bearing tandem repeats of the octamer motif was able to impair the DNA repair function of PARP1. This finding suggests that HBV viral DNA contains specific sequence motifs that may play a role in disrupting the DNA repair pathways of infected hepatocytes.

CONCLUSION

This study has identified a novel octamer motif in the HBVCP that binds PARP1, and this interaction increases the replication efficiency of HBV. The presence of this octamer motif in hepatocytes was shown to inhibit the DNA repair capacity of PARP1, potentially contributing to the development of HCC.

Management of chronic hepatitis B

Chronic hepatitis B continues to be a major global health burden. It accounts for a substantial impact on health care resources and finances in many parts of the world including Europe. Natural history and disease spectrum are varied, depending on when and how the infection is acquired. The chronic infective state increases patients' risk of progression to liver cirrhosis or hepatocellular carcinoma. Several treatment options are currently available, but their use depends on the stage of the patient's infection, which is influenced by both host and viral factors. The ultimate goals in hepatitis B treatment are to prevent disease progression, hepatic decompensation, hepatocellular carcinoma, and death. Patients with decompensated liver cirrhosis should be referred to specialized transplant centers in a timely manner.

The G1613A mutation in the HBV genome affects HBeAg expression and viral replication through altered core promoter activity

Infection of hepatitis B virus (HBV) causes acute and chronic hepatitis and is closely associated with the development of cirrhosis and hepatocellular carcinoma (HCC). Previously, we demonstrated that the G1613A mutation in the HBV negative regulatory element (NRE) is a hotspot mutation in HCC patients. In this study, we further investigated the functional consequences of this mutation in the context of the full length HBV genome and its replication. We showed that the G1613A mutation significantly suppresses the secretion of e antigen (HBeAg) and enhances the synthesis of viral DNA, which is in consistence to our clinical result that the G1613A mutation associates with high viral load in chronic HBV carriers. To further investigate the molecular mechanism of the mutation, we performed the electrophoretic mobility shift assay with the recombinant RFX1 protein, a trans-activator that was shown to interact with the NRE of HBV. Intriguingly, RFX1 binds to the G1613A mutant with higher affinity than the wild-type sequence, indicating that the mutation possesses the trans-activating effect to the core promoter via NRE. The trans-activating effect was further validated by the enhancement of the core promoter activity after overexpression of RFX1 in liver cell line. In summary, our results suggest the functional consequences of the hotspot G1613A mutation found in HBV. We also provide a possible molecular mechanism of this hotspot mutation to the increased viral load of HBV carriers, which increases the risk to HCC.

Association between alcohol consumption and cancers in the Chinese population--a systematic review and meta-analysis

BACKGROUND

Alcohol consumption is increasing worldwide and is associated with numerous cancers. This systematic review examined the role of alcohol in the incidence of cancer in the Chinese population.

METHODS

Medline/PubMed, EMBASE, CNKI and VIP were searched to identify relevant studies. Cohort and case-control studies on the effect of alcohol use on cancers in Chinese were included. Study quality was evaluated using the Newcastle-Ottawa Scale. Data were independently abstracted by two reviewers. Odds ratios (OR) or relative risks (RR) were pooled using RevMan 5.0. Heterogeneity was evaluated using the Q test and I-squared statistic. P<.01 was considered statistically significant.

RESULTS

Pooled results from cohort studies indicated that alcohol consumption was not associated with gastric cancer, esophageal cancers (EC) or lung cancer. Meta-analysis of case-control studies showed that alcohol consumption was a significant risk factor for five cancers; the pooled ORs were 1.79 (99% CI, 1.47-2.17) EC, 1.40 (99% CI, 1.19-1.64) gastric cancer, 1.56 (99% CI, 1.16-2.09) hepatocellular carcinoma, 1.21 (99% CI, 1.00-1.46) nasopharyngeal cancer and 1.71 (99% CI, 1.20-2.44) oral cancer. Pooled ORs of the case-control studies showed that alcohol consumption was protective for female breast cancer and gallbladder cancer: OR 0.76 (99% CI, 0.60-0.97) and 0.70 (99% CI, 0.49-1.00) respectively. There was no significant correlation between alcohol consumption and lung cancer, colorectal cancer, pancreatic cancer, cancer of the ampulla of Vater, prostate cancer or extrahepatic cholangiocarcinoma. Combined results of case-control and cohort studies showed that alcohol consumption was associated with 1.78- and 1.40-fold higher risks of EC and gastric cancer but was not significantly associated with lung cancer.

CONCLUSIONS

Health programs focused on limiting alcohol intake may be important for cancer control in China. Further studies are needed to examine the interaction between alcohol consumption and other risk factors for cancers in Chinese and other populations.

Hepatocellular carcinoma in African Blacks: Recent progress in etiology and pathogenesis

Occult hepatitis B virus (HBV) infection was shown to be present in 75% of Black Africans with hepatocellular carcinoma (HCC) in whom the tumor was hitherto not thought to be caused by chronic HBV infection. The association between chronic HBV infection and the development of the tumor is thus even closer than was originally thought. HBV viral load was found to be significantly higher in patients with HCC than in Black African controls. As in other populations, HBV e antigen-positive patients with hepatocellular carcinoma had significantly higher viral loads than patients negative for this antigen. The significance of this finding is discussed. The risk for HCC development with genotype A of HBV, the predominant genotype in African isolates, has not been investigated. Genotype A was shown to be 4.5 times more likely than other genotypes to cause HCC in Black Africans, and tumours occurred at a significantly younger age. Increasing numbers of patients with human immunodeficiency virus (HIV) and HBV co-infection are being reported to develop HCC. A preliminary case/control comparison supports the belief that HIV co-infection enhances the hepatocarcinogenic potential of HBV. A study from The Gambia provides the first evidence that dietary exposure to aflatoxin B(1) may cause cirrhosis and that this may play a contributory role in the pathogenesis of aflatoxin-induced HCC. An animal model has provided experimental support for the clinical evidence that dietary iron overload in the African is directly hepatocarcinogenic, in addition to causing the tumor indirectly through the development of cirrhosis.

Hepatitis B viral loads in southern African Blacks with hepatocellular carcinoma

Although viral loads are known to influence the development of hepatitis B virus-induced hepatocellular carcinoma in a number of populations, little information is available in the Black African population. Black African patients with hepatocellular carcinoma differ from those in other populations in having a lower frequency of e antigen-positivity and in other respects that might affect viral loads. Hepatitis B viral loads were measured using real-time polymerase chain reaction assay in 124 Black Africans with hepatocellular carcinoma and compared with those in 125 Black adult asymptomatic viral carriers. The geometric mean viral load in the cancer patients was 553,618 copies/ml (95% CI 301,953-1,015,033 copies/ml), with 62.1% having loads >1 x 10(5) copies/ml and 87.1% >1 x 10(4) copies/ml, whereas that in the carriers was 16,084 copies/ml (95% CI 9,184-28,168 copies/ml), with only 15.2% having values >1 x 10(5) copies/ml and 49.6% >1 x 10(4) copies/ml (P < 0.001 in each instance). Mean viral load was significantly higher in e antigen-positive than e antigen-negative cancer patients (5,905,357 copies/ml [1,362,847-25,588,520] cf 238,173 copies/ml [97,200-685,730]: P < 0.001) after adjusting for age and sex. No statistically significant difference existed between patients in different age groups, in men and women, or in patients infected with genotype A or D after adjusting for the other variables.

CONCLUSION

Black Africans with hepatocellular carcinoma have high hepatitis B viral loads in spite of the relative infrequency of e antigen-positivity.

Hepatitis B virus DNA levels and outcomes in chronic hepatitis B

Serum hepatitis B virus (HBV) DNA levels can fluctuate markedly during the course of chronic HBV infection. Both case-control and cohort studies have shown a significant, dose-response association between serum HBV DNA levels measured at the time of initial evaluation and the subsequent risk of cirrhosis. A similar direct relationship has been shown for the risk of hepatocellular carcinoma (HCC) in cross-sectional, case-control, and cohort studies. Interventional studies have shown a strong correlation between the indices of disease activity seen on liver biopsy and levels of serum HBV DNA. These studies have also shown that reduction in HBV DNA levels correlate strongly with improvements in liver histology. For patients with HCC, prognosis (including risk of death, metastasis, and recurrence following surgery) is worse with higher serum HBV DNA levels. The preponderance of the evidence in the published literature demonstrates that serum HBV DNA level is an important and independent risk factor for disease progression in chronic hepatitis B. The relative importance of serial HBV DNA measurements, the loss of hepatitis B e and surface antigens, as well as the emergence of HBV mutants in the progression of chronic hepatitis B, especially in young patients, is an important need for future research.

Programmed death-1 expression is associated with the disease status in hepatitis B virus infection

AIM: To define the potential role of programmed death-1/programmed death-ligand (PD-1/PD-L) pathway in different hepatitis B virus (HBV) infection disease status; we examined the expression of PD-1 on antigen specific CD8+ T cells in peripheral blood of patients with chronic hepatitis B (CHB) and acute exacerbation of hepatitis B (AEHB) infection.

METHODS: The PD-1 level on CD8+ T lymphocytes and the number of HBV specific CD8+ T lymphocytes in patients and healthy controls (HCs) were analyzed by staining with pentameric peptide-human leukocyte antigen2 (HLA2) complexes combined with flow cytometry. Real-time quantitative polymerase chain reaction (PCR) was used to measure the serum HBV-DNA levels.

RESULTS: The level of PD-1 expression on total CD8+ T cells in CHB patients (13.86% ± 3.38%) was significantly higher than that in AEHB patients (6.80% ± 2.19%, P < 0.01) and healthy individuals (4.63% ± 1.23%, P < 0.01). Compared to AEHB patients (0.81% ± 0.73%), lower frequency of HBV-specific CD8+ T cells was detected in chronic hepatitis B patients (0.37% ± 0.43%, P < 0.05). There was an inverse correlation between the strength of HBV-specific CD8+ T-cell response and the level of PD-1 expression. Besides, there was a significant positive correlation between HBV viral load and the percentage of PD-1 expression on CD8+ T cells in CHB and AEHB subjects (R = 0.541, P < 0.01). However, PD-1 expression was not associated with disease flare-ups as indicated by alanine aminotransferase (ALT) levels (R = 0.066, P > 0.05).

CONCLUSION: Our results confirm previous reports that HBV specific CD8+ T-cell response in the peripheral blood is more intense in patients with AEHB than in chronic hepatitis B with persistent viral infection. Moreover, there is a negative correlation between the level of PD-1 and the intensity of virus specific CD8+ T cell response.