KIR and HLA loci are associated with hepatocellular carcinoma development in patients with hepatitis B virus infection: a case-control study

Background

Natural killer (NK) cells activation has been reported to contribute to inflammation and liver injury during hepatitis B virus (HBV) infection both in transgenic mice and in patients. However, the role of NK cells in the process of HBV-associated hepatocellular carcinoma (HCC) development has not been addressed. Killer cell immunoglobulin-like receptors (KIRs) are involved in regulating NK cell activation through recognition of specific human leukocyte antigen (HLA) class I allotypes.

Methodology/Principal Findings

To investigate whether KIR and HLA genes could influence the risk of HBV-associated HCC development, 144 HBV-infected patients with HCC and 189 well-matched HBV infectors with chronic hepatitis or cirrhosis as non-HCC controls were enrolled in this study. The presence of 12 loci of KIR was detected individually. HLA-A, -B, -C loci were genotyped with high-resolution. HLA-C group 1 homozygote (OR = 2.02; p = 0.005), HLA-Bw4-80I (OR = 2.67; p = 2.0E-04) and combination of full-length form and 22 bp-deleted form of KIR2DS4 (KIR2DS4/1D) (OR = 1.89; p = 0.017) were found associated with HCC incidence. When the combined effects of these three genetic factors were evaluated, more risk factors were observed correlating with higher odds ratios for HCC incidence (P trend = 7.4E-05). Because all the risk factors we found have been reported to result in high NK cell functional potential by previous studies, our observations suggest that NK cell activation may contribute to HBV-associated HCC development.

Conclusions/Significance

In conclusion, this study has identified significant associations that suggest an important role for NK cells in HCC incidence in HBV-infected patients. Our study is useful for HCC surveillance and has implications for novel personalized therapy strategy development aiming at HCC prevention in HBV-infected patients.     

Analysis of a cellular model to account for the natural history of infection by the hepatitis B virus and its role in the development of primary hepatocellular carcinoma.

Infection with the hepatitis B virus (HBV) can have many different outcomes. Transient infection may result in acute hepatitis or may remain subclinical. Persistent infection may also be subclinical, or may involve chronic active hepatitis, and can finally lead to the development of primary hepatocellular carcinoma. A mathematical model is given to account for the many different outcomes of HBV pathogenesis. The model is based on the assumption that the liver contains two cell populations with differing abilities to support active HBV replication and/or viral integration into the genome. The model helps account for the relationship of the different clinical courses of HBV infection to the age when the disease is acquired, together with the state of the immune system of the patient.     

IL-23 production of liver inflammatory macrophages to damaged hepatocytes promotes hepatocellular carcinoma development after chronic hepatitis B virus infection

Liver inflammation after chronic hepatitis B virus (HBV) infection is essential for hepatocellular carcinoma (HCC) development. We did a nested case-control study based on QBC chronic HBV infection cohort to identify HCC-related inflammatory cytokines. Serum levels of distinct Th-cell representative cytokines at varied periods before HCC diagnosis were determined in 50 HCC cases and 150 age- and gender-matched controls who did not develop HCC in 8–10?years. The individuals with HCC outcome had statistically higher serum levels of IL-23 than controls (P?<?0.01). Further analysis in HCC tissues showed that CD14⁺ inflammatory macrophages were the major IL-23 producers. Monocytes-derived macrophages generated more amount of IL-23 after being stimulated with cell-associated HBV core antigen from damaged HBV-infected hepatocytes than the cells being stimulated with HBV-S and HBV e antigen, which are secreted from infected hepatocytes. IL-23 upregulated IL-23 receptor expressions on macrophages, enhanced macrophage-mediated angiogenesis. In HBV-transgenic (Alb1HBV) mice, administration of diethylnitrosamine induced more liver tumors than in wild-type mice. The livers of Alb1HBV mice had higher concentrations of IL-23 and vascular endothelial growth factor (VEGF) than the wild-type mice. Neutralizing IL-23 activity, diethylnitrosamine-treated Alb1HBV mice developed significantly less tumors and produced less VEGF, tumor angiogenesis was inhibited with dramatically decreased CD31⁺ cells within tumor mass (all P?<?0.01).

The role of hepatitis B virus x gene in development of primary hepatocellular carcinoma

Primary hepatocellular carcinoma (HCC) is one of the most common cancers occurring in human, and there is strong epidemiological evidence suggesting that persistent hepatitis B virus (HBV) infection is the most important risk factor for its development. HBx gene was found to be a transactivator recently. Its continuous expression in hepatocytes may transactivate cellular genes which can play a certain role in development of HCC. The HBx gene fragment was used to construct a recombinant eukaryotic expression vector pCEP4 and introduced into HepG2 cells. The effect of HBx gene on HCC cells growth and its molecular mechanism in HCC cells regulation were investigated.     

The role of hepatitis B virus × gene in development of primary hepatocellular carcinoma

Primary hepatocellular carcinoma (HCC) is one of the most common cancers occurring in human, and there is strong epidemiological evidence suggesting that persistent hepatitis B virus (HBV) infection is the most important risk factor for its development.HBx gene was found to be a transactivator recently. Its continuous expression in hepatocytes may transactivate cellular genes which can play a certain role in development of HCC. TheHBx gene fragment was used to construct a recombinant eukaryotic expression vector pCEP4 and introduced into HepG2 cells. The effect ofHBx gene on HCC cells growth and its molecular mechanism in HCC cells regulation were investigated.     

Integrated structures of duck hepatitis B virus DNA in hepatocellular carcinoma.

The structure of integrated viral DNA in a hepatocellular carcinoma of a duck from Chi-tung county in China was analyzed. Three different clones of integrated viral DNA, lambda DHS 6-1, lambda DHS 6-2, and lambda DHE 6-2, were obtained from the neoplastic portion of the liver by molecular cloning. One of the three clones, lambda DHS 6-1, showed inverted repetition of integrated viral DNA with chromosomal flanking sequences. Another clone, lambda DHS 6-2, showed a head-to-head configuration of the core and surface gene regions of duck hepatitis B virus (DHBV) DNA. The virus-chromosome junctions were often located near direct repeat 1 or 2 of DHBV DNA in three independent clones. Nucleotide sequences at the virus-virus junctions in two clones, lambda DHS 6-1 and 6-2, indicated the possible rearrangement of chromosomal DNA and recombination of viral DNA. DHBV DNA appears to be integrated into the genome of hepatocytes in a manner similar to that of human and woodchuck hepatitis viruses. Thus, the duck system may serve as a useful animal model for the study of human hepatocarcinogenesis.     

The role of hepatitis B virus x gene in development of primary hepatocellular carcinoma

Primary hepatocellular carcinoma (HCC) is one of the most common cancers occurring in human,and there is strong epidemiological evidence suggesting that persistent hepatitis B virus (HBV) infection is the most important risk factor for its development.HBx gene was found to be a transactivator recently.Its continuous expression in hepatocytes may transactivate cellular genes which can play a certain role in development of HCC.The HBx gene fragment was used to construct a recombinant eukaryotic expression vector pCEP4 and introduced into HepG2 cells.The effect of HBx gene on HCC cells growth and its molecular mechanism in HCC cells regulation were investigated.     

Analysis of hepatocellular carcinoma associated with hepatitis B virus

The hepatitis B virus (HBV) is considered one of the main driving forces in the development of hepatocellular carcinoma (HCC). Human HBV is a partially double-stranded DNA (dsDNA) virus consisting of approximately 3.2 kbp. HBV predominantly infects hepatocytes via the receptor sodium taurocholate cotransporting polypeptide (NTCP) and coreceptor hepatic proteoglycan. The replication of HBV in hepatocytes leads to apoptosis while simultaneously leading to cirrhosis and cancer. Although the integration of dsDNA into the hepatocyte genome seems to be the main cause of mutation, since the discovery of their function, viral proteins have been shown to regulate the P53 pathway or P13K/AKT pathway to prevent host cell apoptosis, causing uncontrolled proliferation of liver cells leading to the formation of solid tumours. The most common treatments involve nucleo(s)tide analogue (NA) and polyethylene glycol (PEG)ylated interferon-alpha (PegIFN-α). NA treatment has been found to be effective for the majority of patients and induces few side effects. Nevertheless, the rate of seroconversion is relatively low. PegIFN treatment is contraindicated during pregnancy and leads to a higher morbidity rate, but the seroconversion rate is high. Since medicines and vaccines have been developed, the incidence and mortality of HBV related to HCC have profoundly decreased compared to those in 2000. This review investigates what can be the potential mechanism that HBV can cause HBV and the treatment used in chronic and acute infection.     

Chromosomal sites for hepatitis B virus integration in human hepatocellular carcinoma.

The discovery that hepatitis B virus (HBV) integrates into host chromosomes raises the question of whether such viral DNA integration correlates directly with the activation of specific oncogenes or the inactivation of anti-oncogenes. To obtain insight into this problem, we randomly collected HBV integrant samples from different human hepatocellular carcinomas and identified the site of chromosomal integration by using in situ hybridization and/or linkage analysis with the flanking cellular DNAs as probes. Our findings did not specifically identify particular HBV DNA integration sites in chromosomes, although chromosomes 11 and 17 seemed to have more than the average number of integrants.     

Hepatocellular carcinoma in urban born blacks: frequency and relation to hepatitis B virus infection.

Chronic hepatitis B virus infection is far less common in urban born than in rural born southern African blacks, who also have a high incidence of hepatocellular carcinoma. A case-control study was carried out to determine the relative frequency of hepatocellular carcinoma and its relation to hepatitis B virus infection in urban born blacks. Three hundred and ninety two black patients with hepatocellular carcinoma and matched controls seen at two city hospitals were classified by questioning as urban born or rural born. The ratio of rural born to urban born blacks among the controls was 1.1:1.0 (207/185), whereas in the patients with cancer the ratio was 4.8:1.0 (324/68) (p less than 0.0001). Analysis of the prevalence of hepatitis B markers in 62 urban born and matched rural born blacks with hepatocellular carcinoma showed no differences in the frequency of current or past hepatitis B virus infection. It is concluded that urban born blacks are less likely than rural born blacks to develop hepatocellular carcinoma, but when they do the tumour is equally likely to be related to infection with hepatitis B virus. The findings lend further support to an important role for chronic hepatitis B virus infection in the aetiology of hepatocellular carcinoma.     

Interaction of aflatoxin and hepatitis B virus in the pathogenesis of hepatocellular carcinoma

Aflatoxin-B1 (AFB) and chronic hepatitis B virus (HBV) infection epidemiologically correlate with the geographic distribution of hepatocellular carcinoma (HCC). Integration of HBV DNA into the cellular genome of HCCs and the in vivo formation of adducts between AFB and nucleic acids lead us to suggest that hepatocytes with integrated HBV DNA preferentially accumulate AFB; the AFB-adducts formed may then initiate cell transformation by modifying the expression of critical host genes. The altered molecular biology of liver cells in HCC is evidenced by the fact that HBV does not replicate in HCC tissues or cell lines. The effect of AFB on the expression of cellular genes such as endogenous retrovirus(es) and possibly cellular oncogene(s) can be analyzed in HCC cell lines with and without integrated HBV DNA. In addition, human HCC tissues can be probed for HBV sequences and AFB-DNA adducts at the single-cell level. The presence of HBV and AFB can be correlated with the expression of putative transforming genes, providing a new insight into the interaction between liver cells, HBV and AFB in the pathogenesis of HCC.     

Serum microRNAs as biomarkers for hepatocellular carcinoma in Chinese patients with chronic hepatitis B virus infection

Background

MicroRNAs (miRNAs) have been shown to anticipate great cancer diagnostic potential. Recently, circulating miRNAs have been reported as promising biomarkers for various pathologic conditions. The objective of this study was to investigate the potential of serum miRNAs as novel biomarkers for hepatocellular carcinoma (HCC).

Methodology/Principal Findings

This study was divided into four phases: (I) Ten candidate serum miRNAs were detected by using real-time RT-PCR, corresponding 10 HCC patients with chronic hepatitis B virus (HBV) infection and 10 age- and sex-matched healthy subjects. (II) Marker validation by real-time RT-PCR on HBV patients with (n = 48) or without HCC (n = 48), and healthy subjects (n = 24). (III) Marker detection by real-time RT-PCR in sera from another 14 HCC patients before and 1 month after surgical resection. (IV) We examined the correlation between the expressions of candidate serum miRNAs with clinical parameters of HCC patients. Although miR-222, miR-223 or miR-21 were significantly up- or down-regulated between HCC patients and healthy controls, no significant difference was observed in the levels of these miRNAs between HBV patients without and with HCC. MiR-122 in serum was significantly higher in HCC patients than healthy controls (p<0.001). More importantly, it was found that the levels of miR-122 were significantly reduced in the post-operative serum samples when compared to the pre-operative samples. Although serum miR-122 was also elevated in HBV patients with HCC comparing with those without HCC, the difference was at the border line (p = 0.043).

Conclusions/Significance

Our results suggest that serum miR-122 might serve as a novel and potential noninvasive biomarker for detection of HCC in healthy subjects, moreover, it might serve as a novel biomarker for liver injury but not specifically for detection of HCC in chronic HBV infection patients.     

CDC25B is associated with the risk of hepatocellular carcinoma,but not related to persistent infection of hepatitis B virus in a Chinese population

The cell division cycle 25 (CDC25) gene members, including CDC25A, CDC25B and CDC25C, are reported to be associated with several human cancers. Here, we aim to investigate the association of functional polymorphisms of CDC25 gene family with the risk of hepatocellular carcinoma (HCC) and persistent infection of Hepatitis B virus (HBV) in a Chinese HBV-related population. First, we used bioinformatics tools to systematically screen functional polymorphisms within CDC25 gene family. Second, we evaluated the effects of candidate polymorphisms by recruiting 790 HCC cases, 709 persistent HBV carriers (PHC), and 741 subjects with HBV natural clearance (SHNC). MassARRAY platform was used for genotyping. At last, we conducted functional prediction and assay to further explore the pathogenic mechanism of the identified polymorphism. Our results demonstrated that CDC25B rs2295348 played a protective role in HCC risk in a HBV-related Chinese population (adjusted odds ratio [OR]?=?0.77, 95% confidence interval [CI] 0.65–0.93, P?=?0.006). It showed a more significantly reduced HCC risk in the SHNC population (adjusted OR?=?0.73, 95% CI 0.59–0.89, P?=?0.002). However, we did not observe the association between CDC25B rs2295348 and the risk of persistent HBV infection. Further functional prediction and assay demonstrated that the mutant A allele of CDC25B rs2295348 might significantly decrease gene expression to modify the HCC risk. Our results suggest that CDC25B rs2295348 may confer a protective effect on HCC risk in a HBV-related Chinese population, but do not influence the susceptibility to persistent HBV infection.