Persistence of Hepatitis B and Hepatitis C Viral Genomes in Primary Liver Cancers from HBsAg-Negative Patients: A Study of a Low-endemic Area

Abstract

The role of HBV and HCV in the course of primary liver cancer in patients who are negative for HBsAg has been debated. Using a combination of serological and polymerase chain reaction assays, we investigated the association between HCV and HBV infections and primary liver cancer in 24 HBsAg-negative patients living in France. The presence of HCV RNA and HBV DNA sequences was tested for in serum and in tumorous and nontumorous liver samples. Twelve patients had anti-HCV, and 11 patients had anti-HBs and/or anti-HBc. HCV RNA sequences were found in the serum samples of all anti-HCV-positive patients and none of the patients who were negative. Patients with HCV viremia had HCV RNA genomic sequences and presumed replicative intermediates in both tumorous and nontumorous specimens. Sequence analysis of a hypervariable region in the E2/NS1 gene of HCV showed significant variations between the viral molecules isolated from the nontumorous, tumorous and serum samples. This eliminated the hypothesis of the contamination of the tumor by nontumorous cells and serum particles and assessed that liver tumor cells did contain HCV RNA genomes. Eleven of 22 patients tested had HBV DNA in the serum; 5 patients were anti-HBc positive and anti-HBs positive. Patients with HBV viremia had HBV DNA sequences in both tumorous and nontumorous liver specimens. Selective loss of part of the HBV genome in the tumorous tissue of two of these patients suggested HBV DNA persistence in clonally expanded malignant cells. Only 4 of the 22 patients were negative for both viruses. Our results show that HBsAg-negative hepatocellular cancer in France is associated with chronic HBV or HCV infection and, in some cases, both; these findings are consistent with an etiological role for HBV and HCV in HCC that develops in cirrhotic patients living in areas of low prevalence.

Hepatitis B virus-related hepatocellular carcinoma: paradigms for viral-related human carcinogenesis

“…However, using PCR tests and distinct primers distributed on the S, PreS/S, C and X HBV genes, we and others have been able to demonstrate the presence of defective HBV DNA in the tumor cells; interestingly, defective HBV genomes have been identified more frequently in tumors than in nontumor tissues and the PCR profiles were consistent with the clonal expansion of cells containing defective and integrated HBV DNA (Paterlini et al, 1993;Bre´chot, 1998). In this view, it is interesting that some cases of HBV-related cis-activation, such as that involving the SERCA1 encoding gene (see sections above), has been in fact shown in an HBsAg-negative, anti-HBc-positive individual (Chami et al, 2000).…”

Risk Factors for Hepatocellular Carcinoma in India

“…The p53 tumor suppressor gene can be altered in HCC under the transactivating potential of the HBx protein. [4][5][6] Chronic Hepatitis C virus infection is now considered an important etiologic factor in HCC. 7 HCV-related carcinogenesis is possibly related to chronic inflammation and cirrhosis.…”

“…5 Alcohol seems to be a cocarcinogen in the pathogenesis of HCC, by inducing cirrhosis, and by increasing the risk of viral infections (HBV and HCV), as well as via its effects on P450 mixed function oxidase system, thus causing enhanced activation of chemical carcinogens. 5 Ozturk et al 1991 23 described Aflatoxin has been shown to cause hepatocarcinogenesis by a guanine-to-thymidine mutation at the third base of codon 249 in the p53 tumor suppressor gene. The risk of HCC is highest when Aflatoxin exposure is associated with the presence of HBsAg, suggesting a viral-chemical interaction.…”

Structure and expression of Tg737, a putative tumor suppressor gene, in human hepatocellular carcinomas

“…DNA was extracted following a previously reported method. 32 RNA was extracted with the TRIzol B solution according to the supplied protocol (Life Technologies, Gibco BRL, Bethesda, MD) and resuspended in diethyl pyrocarbonate-treated water.…”

“…32,33 Northern Blot Analysis. For Northern blots, polyA ϩ RNA was isolated from total RNA using Dynabeads Oligo (dT) 25 (Dynal, Oslo, Norway) according to the manufacturer' s instruction.…”