Hepatitis B immunization and hepatocellular carcinoma: The Gambia Hepatitis Intervention Study

The Gambia Hepatitis Intervention Study (GHIS) was initiated by the International Agency for Research on Cancer (IARC) in 1986. It consisted of a randomized trial in the Gambian population, aiming to evaluate the protection provided by HBV vaccination administered during the first year of life against primary infection, the development of chronic carriage, and primary liver cancer. The results, reported at 9 years from the introduction of the vaccine as conferring a high degree of protection (83% against primary infection and 95% against chronic carriage), are briefly discussed. It is expected that HBV vaccination will result in a reduction of mortality from hepatocellular carcinoma, the most frequent cancer in males in sub-Sahara Africa.     

Hepatitis B virus infection and primary hepatocellular carcinoma.

For many years, epidemiological studies have demonstrated a strong link between chronic hepatitis B virus (HBV) infection and the development of primary hepatocellular carcinoma (PHC). Other hepatocarcinogens such as hepatitis C virus and aflatoxin also contribute to hepatocarcinogenesis either in conjunction with HBV infection or alone. Cellular and molecular biological studies are providing explanations for the HBV-PHC relationship, and models are now being formulated to further test the relative importance of various factors such as viral DNA integration, activation of oncogenes, genetic instability, loss of tumor suppressor genes, and trans-activating properties of HBV to the pathogenesis of PHC. Further research will probably define more than a single mechanism whereby chronic HBV infection results in PHC.     

Hepatitis B surface antigen and hepatocellular carcinoma in Southern Africa

Summary Most series in Africa show a high percentage of hepatitis B surface Hepatitis antigen in hepatocellular carcinoma. Two groups of cases were investigated in this study. The one was derived from the autopsy material at Baragwanath hospital from subjects who had lived in Soweto, a large Black urban town. The second group consisted of male Black mineworkers generally originating from rural areas. A combination of the aldehydefuchsin stain and immunoperoxidase technique was used. The two groups showed totally different results. The Baragwanath series consisted of 24 hepatocellular carcinomas of which only 4 (17%) were HBsAg positive. Of the 24 cases, 14 had cirrhosis of which 9 were macronodular and 5 micronodular. Ten of these cases showed heavy iron overload. The series of male Black mineworkers comprised 22 cases of which 16 (72%) were HBsAg positive. Twelve of the 22 cases showed a macronodular cirrhosis and there were no micronodular cirrhoses. Only one case showed severe iron overload. These findings delineate two different populations of hepatocellular carcinoma in Southern Africa.     

Hepatitis B virus DNA in primary hepatocellular carcinoma tissue.

Tumour, cirrhotic, and metastatic tissues from four patients with primary hepatocellular carcinoma have been investigated for the presence of hepatitis B viral DNA by nucleic acid hybridization. Tumours from two of three patients with a current HBV infection contained 1--2 genomes per cell of unintegrated viral DNA, while tumours from the third HBs antigen-positive patient contained less than one genome equivalent per ten cells. A tumour from one patient with anti-HBs contained no detectable HBV DNA. A variety of models involving HBV as an etiologic agent may be advanced to explain the statistical correlation of HBV infection with primary hepatocellular carcinoma (PHC). The data presented here argue against the model that HBV DNA integrated into every cell is required to maintain the oncogenic transformation of hepatocytes, but they do not rule out other models.     

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 × 10⁵ copies/ml and 87.1% >1 × 10⁴ 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 × 10⁵ copies/ml and 49.6% >1 × 10⁴ 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. J. Med. Virol. 81:1525–1530, 2009. © 2009 Wiley‐Liss, Inc.     

Hepatitis B antigen in the liver cells in cirrhosis and hepatocellular carcinoma.

The demonstration of hepatitis B antigen in the liver cells in formalin fixed paraffin embedded tissues by Shikata's orcein staining method affords an opportunity to conduct retrospective studies on necrospy materials. Such a study in Singapore showed orcein-positive liver cells in 22 out of 52 (42.3%) and 37 out of 50 (74.0%) cases of cirrhosis of the liver and hepatocellular carcinoma respectively, while only 5 out of 113 (4.4%) 'normal' livers gave positive results. There is a significant difference in the frequency of hepatocellular carcinoma in orcein-positive and orcein-negative cirrhotic livers (28 out of 50, 10 out of 40 respectively). These results suggest a possible aetiological relationship between hepatitis B antigen and hepatocellular carcinoma.     

Hepatitis B virus antigens in liver resections from patients with hepatocellular carcinoma

A high rate of hepatitis B virus (HBV) antigen carriers among patients with hepatocellular carcinoma (HCC) has been recorded from areas of endemic HBV infections in Africa and Asia, but there are only rare and contradictory data for Europe. 12 specimens of resected liver tissue were immunohistologically investigated for hepatitis B surface antigen (HBsAg) as well as for hepatitis B core antigen (HBcAg). HBsAg was contained in non-tumorous liver tissue in 66 per cent of these cases. In two cases detection of HBcAg in the liver provided evidence to replication of the virus. HBcAg plus HBsAg were present in tumour tissue in one case. All of the HBV antigen carriers did not have chronic hepatitis. On the other hand, all patients with chronic hepatitis had HBV antigens in their liver tissue. HBV antigens were detectable in 7 non-cirrhotic livers, but were contained in only one of two cirrhotic livers. These results are likely to suggest a possible relevance of HBV infection to the aetiology of HCC even in central Europe without customary liver cirrhosis.     

Hepatitis B surface antigen, hepatocellular carcinoma and cirrhosis in south India--an autopsy study

This study is aimed at finding the association of hepatocellular carcinoma and cirrhosis with hepatitis B surface antigen in a particular geographical area, Andhra Pradesh State in South India. In total, 206 cases of autopsy livers were studied for the presence of hepatitis B surface antigen by orcein staining. Of the 114 cases of cirrhosis 67.54% were positive for the antigen. There were 13 cases of macronodular, 55 cases of mixed and 46 cases of micronodular cirrhosis. The antigen positivity was 100%, 98.7% and 21.74% respectively. The difference in positivity between micronodular and the other two types of cirrhosis was statistically significant (P less than 0.01). Of the 58 cases of hepatocellular carcinoma, 50 were associated with cirrhosis. In 80% of these cases, hepatitis B surface antigen was demonstrated, whereas 75% of cases of hepatocellular carcinoma not associated with cirrhosis, were positive for hepatitis B surface antigen. The geographical importance of these findings was discussed.     

Hepatitis B surface antigen containing immune complexes occur in seronegative hepatocellular carcinoma patients

IgG, IgM and hepatitis B surface antigen (HBsAg) containing immune complexes (IC) were detected by the Clq and conglutinin solid phase assays in both HBsAg+ and HBsAg- groups of patients with primary hepatocellular carcinoma (HCC). No differences were observed between the two patient groups either in the levels of antigen non-specific and HBsAg specific complexes or in the immunoglobulin isotype in the complexes. The results show that HBsAg can occur in an IC form in the sera of patients classified as HBsAg- by sensitive commercial assays and provides evidence of a further association of hepatitis B virus (HBV) and HCC in antigen negative patients. Furthermore, the HBsAg IC in HCC patients differ from those in other HBV infected subjects in that they are preferentially detected by the Clq assay.     

Hepatitis B virus X protein boosts hepatocellular carcinoma progression by downregulating microRNA-137

BackgroundHepatocellular carcinoma (HCC) is a frequent diagnosed malignancy. microRNAs (miRs) are involved in various cellular processes during cancer development. This study attempted to probe the miR-based mechanism in hepatitis B virus X protein (HBx) small interfering RNA (siRNA)-treated HCC cells.MethodsHBx expression in hepatocyte and HCC cells was detected, and cells with highest HBx expression were screened out and transfected with HBx-siRNAs. Then the effect of HBx on HCC cell proliferation was detected. miRs differentially expressed in HBx-siRNA-transfected MHCC97H cells were analyzed and verified. miR-137 methylation was analyzed by bioinformatics, and miR-137 restoration was detected after Aza treatment. Furthermore, miR-137 methylation in MHCC97H cells with HBx knockdown or HBx overexpression was detected by methylation specific PCR. The targeting relationship between miR-137 and Notch1 was verified. Then the gain-and-loss functions of miR-137 or/and Notch1 were performed to estimate their roles in HCC cell proliferation. The effects of HBx-siRNA and overexpressed miR-137 in vivo were observed by tumor xenograft in nude mice and immunohistochemistry.ResultsHBx-siRNA weakened MHCC97H cell proliferation and tumor growth. miR-137 was highly expressed in HBx-siRNA-treated HCC cells and targeted Notch1. HBx knockdown decreased miR-137 methylation and restored miR-137 expression. miR-137 overexpression prevented HCC cell proliferation and tumor growth, while miR-137 downregulation reversed the repressing effects of HBx-siRNA on HCC cell proliferation. Inhibition of Notch1 reversed HCC cell proliferation induced by miR-137 downregulation.ConclusionOverexpression of miR-137 blocks HCC cell proliferation in HBx-siRNA-treated MHCC97H cells by targeting Notch1. This study may offer novel target for HCC treatment.     

Hepatitis C virus-induced hepatocellular carcinoma

Hepatitis C virus (HCV) is a leading etiology of hepatocellular carcinoma (HCC). The interaction of HCV with its human host is complex and multilayered; stemming in part from the fact that HCV is a RNA virus with no ability to integrate in the host''s genome. Direct and indirect mechanisms of HCV-induced HCC include activation of multiple host pathways such as liver fibrogenic pathways, cellular and survival pathways, interaction with the immune and metabolic systems. Host factors also play a major role in HCV-induced HCC as evidenced by genomic studies identifying polymorphisms in immune, metabolic, and growth signaling systems associated with increased risk of HCC. Despite highly effective direct-acting antiviral agents, the morbidity and incidence of liver-related complications of HCV, including HCC, is likely to persist in the near future. Clinical markers to selectively identify HCV subjects at higher risk of developing HCC have been reported however they require further validation, especially in subjects who have experienced sustained virological response. Molecular biomarkers allowing further refinement of HCC risk are starting to be implemented in clinical platforms, allowing objective stratification of risk and leading to individualized therapy and surveillance for HCV individuals. Another role for molecular biomarker-based stratification could be enrichment of HCC chemoprevention clinical trials leading to smaller sample size, shorter trial duration, and reduced costs.     

Hepatitis B virus X gene variability in French-born patients with chronic hepatitis and hepatocellular carcinoma

The polymorphism of the hepatitis B virus (HBV) X gene from patients born in Lorraine has been studied in serum samples from 22 HBV infected patients, 14 presenting with chronic hepatitis and 8 with hepatocellular carcinoma (HCC). Subtypes adw and ayw represented 21 of the 22 sequenced isolates. The sequence of the X gene of HBV strains from these patients differed from the ones of Far East origin by A to T(1678) and G to A(1759) changes for subtype ayw and C to T(1792) for adw. The expression of the preC region, as indicated by the detection of HBe antigen (HBeAg), was not observed in 11 patients. In 6 patients (3 HCC and 3 non HCC), the absence of HBeAg could be related to a stop codon at position 28. For the 5 remaining patients, the precore stop mutation at codon 28 was not evidenced but 3 out these 5 patients had mutations at nt 1764 and nt 1766 in the promoter of the preC/C gene. These two mutations were also observed in 2 patients with HBeAg, indicating that they are not implicated in the suppression of expression of this gene. Independently of the serotype, two main differences were noted between aminoacid (aa) sequences of chronic hepatitis and HCC related strains: first, twice as many aa changes were found in HCC patients than in chronic hepatitis B carriers (mean of aa changes per patient 4.1 vs. 2.0) and second, we found apparition of polar aa in HCC patients. Most mutations already described in patients from the Far East with HCC have been found in strains of patients from Lorraine. The changes K130M and V131I, considered as "hot spot mutations," were found in strains of HCC patients carrying an ayw subtype of the HBV genome but not in the ones of chronically infected patients. In contrast, strains of the adw subtype had these two changes in the two groups of patients. However when considering the 22 sequenced genes, these hot spot mutations were associated with HCC (P = 0.034).     

Hepatitis B virus (HBV)-DNA-positive hepatocellular carcinoma following hepatitis B virus infection in a child

Integrated hepatitis B virus (HBV) DNA sequences were found in neoplastic liver tissue of a hepatitis B surface antigen (HBsAg)-negative child who had previously suffered from HBsAg-positive chronic active hepatitis and was anti-HBs and anti-hepatitis B core (HBc) positive at the time of tumor development. Reintegration pattern was consistent with the presence of a single integration site of the HBV genome into cellular DNA, and clonal proliferation of such infected cells. A normal liver, tested in the same experiment with the same amount of total DNA, was negative for viral DNA sequences. These findings support the possible oncogenic role of HBV in the development of liver cancer, not only in adults, but also in children, even in patients who are negative for HBsAg at the time of tumor diagnosis.