In situ detection of hepatitis B, C, and G virus nucleic acids in human hepatocellular carcinoma tissues from different geographic regions

Abstract

We performed a retrospective study to determine the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis G virus (HGV) genomes in formalinfixed, paraffin-embedded liver tissues from hepatocellular carcinoma (HCC) patients in various geographic areas. Hepatocellular carcinoma (HCC) is increasing in incidence worldwide and is one of the most common malignant tumors in the world. It has been well documented that chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections play a major role in the development of this cancer. In Japan, the incidence of HCC has been increasing over the last 30 years. However, as the prevalence of the HBV infection has been decreasing, this trend for HCC increase might be attributable to chronic hepatitis and cirrhosis caused by HCV. In fact, HCC often occurs in patients with chronic HCV infection, and anti-HCV has been found frequently in affected patients. [1][2][3][4] Since the discovery of the HCV genome in 1989, 5 although knowledge about HCV has been growing rapidly, it still remains uncertain whether HCV plays a direct or indirect role in hepatocarcinogenesis. We have previously reported a highly sensitive method of detecting and identifying sequences of the RNA genome in formalin-fixed, paraffinembedded (FFPE) tissues by polymerase chain reaction (PCR) assay. 6 In the present study, using this method to assess the pathological role of persistent infection of hepatitis viruses, including HBV, HCV, and newly isolated hepatitis G virus (HGV), 7 in the origin of HCC, we performed a retrospective study to determine the prevalence of these hepatitis virus genomes in FFPE specimens from patients with HCC in various geographic areas. PATIENTS AND METHODSPatients. We selected sequential liver samples of all HCC tissues seen at the participating institutions. We analyzed routinely processed FFPE liver specimens of surgical origin from patients consisting of 122 Japanese (89 males and 33 females, ranging in age from 38 to 82 years, collected from 1984 to 1996), 55 Koreans (42 males and 13 females, ranging in age from 33 to 72 years, collected from 1989 to 1995), 65 Americans (40 males and 25 females, ranging in age from 39 to 80 years, collected from 1990 to 1995), 8 Japanese Americans in Hawaii (8 males, ranging in age from 57 to 77 years, collected in 1994), and 15 Spanish (9 males and 6 females, ranging in age from 61 to 72 years, collected in 1994) with HCC. All of them underwent liver surgery and were diagnosed with HCC by histopathological examination. We used paraffin blocks that have nontumor areas other than tumor in a part of cases, although it mainly consists of tumor areas. We also compared a frequency of HCC in patients with primary biliary cirrhosis who were excluded from analysis as hepatitis virus infections in the present study.Nucleic Acids Extraction and PCR. Extraction of the nucleic acids (RNA and DNA) from FFPE liver specimens and PCR was performed as described in detail previously. 6 Briefly, sections were cut and placed into l.5-m...

Potential role of signal transducer and activator of transcription (STAT)3 signaling pathway in inflammation, survival, proliferation and invasion of hepatocellular carcinoma

“…The HBx protein is thought to play a major role in HCC by modifying apoptosis, inhibiting nucleotide excision and repair of damaged cellular DNA, and modulating transcriptional activation of cellular growth regulating genes [20]. Strong epidemiological evidence correlating HCC to HBV infection is demonstrated by the presence of HB surface antigen (HBs Ag) and HB core antibodies (HBc antibodies) in the blood of HCC patients [21]. Hepatocyte transformation may also be indirectly influenced by HBV DNA integration [22].…”

Surface, core, and X genes of hepatitis B virus in hepatocellular carcinoma

“…Our results are in contrast to Western and Japanese studies, which report that the hepatitis C virus (HCV) is associated more frequently and is etiologically implicated with HCC than with HBV. 14,21,22 Active HBV vaccination programs are probably responsible for this change in viral prevalence in Japan both in HCC patients and in the general population. 2 Well differentiated HCCs are permissive to viral growth and replication as substantiated by a Korean study.…”

Prokaryotical expression of structural and non-structural proteins of hepatitis G virus

“…Besides, whether the liver is the replication site of HGV has remained unclear. Saito et al [32] had detected both positive and negative stranded HGV RNA by HGV RT-PCR in the liver tissues of all the six tested HGV infected patients, which indicated that liver might be the primary site of HGV replicatio n, but many other scientists could not repeat these findings in their HGV infected patients by the same METHODS [33][34][35][36] . Recently, Reshetnyak et al reported that patients with HGV monoinfection had demonstrated the increase of the DNA single-stranded breaks peripheral blood lymphocytes (PBL) quantity [37] .…”