SEN virus infection in patients with hepatocellular carcinoma.

Although most cases of hepatocellular carcinoma (HCC) are associated with either the hepatitis B or C viruses (HBV, HCV), about 10-20% of HCCs occur in patients with chronic hepatitis that is aetiologically undefined. The aim of the present study was to determine the prevalence of the transfusion-transmitted SEN virus (SEN-V) in patients with HCC, including those patients who do not otherwise appear to be infected with HBV or HCV. Fragments of SEN-V subtypes D and H were amplified separately by PCR from the sera of 50 patients with HCC (31 from Canada and 19 from Japan) as well as from HCC and adjacent nontumourous liver tissues from eight of the Canadian patients. SEN-V DNA was found in the serum of 10 of 31 (32%) Canadian patients and eight of 19 (42%) Japanese patients [overall, 18 of 50 (36%) HCC patients]. SEN-V DNA was detected in the serum of 10 of 23 (43%) HCC patients with antibody to HCV (anti-HCV), six of 11 (55%) with hepatitis B surface antigen (HBsAg), and two of 16 (12%) without detectable anti-HCV or HBsAg. Twenty-three HCC patients in this study had 'silent HBV,' characterized by the detection of HBV DNA in the absence of HBsAg; eight of these (35%) also had SEN-V infections. SEN-V DNA was detected in HCC patients most typically in those with coexistent HBV or HCV infection. SEN-V was found in only one of seven HCC patients without HBV (without HBsAg or HBV DNA) or HCV and thus does not appear to be an important cause of 'cryptogenic' HCC.

HBsAg-negative hepatitis B virus infections in hepatitis C virus-associated hepatocellular carcinoma.

This study was conducted to evaluate reports that hepatitis B virus (HBV) DNA sequences can be found in the serum and/or tumour tissue from some hepatocellular carcinoma (HCC) patients who have no detectable hepatitis B surface antigen (HBsAg) in their sera. Such HBV infections would be highly atypical, because prospective studies have shown a clear succession of specific serologic markers during and after most HBV infections. As most HBsAg-negative HCC patients in Japan have hepatitis C virus (HCV) infections, the present study was conducted to determine whether some of these patients actually have unrecognized HBV infections. Thirty newly diagnosed HCC patients from Kurume, Japan, with antibody to the hepatitis C virus (anti-HCV) were studied. None of the 30 had HBsAg detectable in their serum. Of 22 for whom test results for antibodies to the hepatitis B core antigen (anti-HBc) and antibodies to HBsAg (anti-HBs) were available, 14 (64%) had anti-HBc and anti-HBs, four (18%) had anti-HBc alone, and four (18%) had no HBV markers. Nested polymerase chain reaction was used to detect the HBV surface (S), core (C), polymerase (P) and core promoter gene sequences in the HCC tissues and in the adjacent nontumorous liver tissues. HBV DNA was detected in HCC and/or adjacent nontumorous liver in 22 of 30 (73%) patients [detected in both HCC and nontumorous liver in 19/30 patients (63%)]. Among the 22 patients with detectable HBV DNA, more than one HBV gene was detected in 10 (46%). Among the four patients whose sera were negative for all HBV markers, three had HBV DNA in either HCC and nontumorous liver (two cases) or only in the nontumorous liver (one case); HBV DNA could not be detected in tissues from the fourth patient. In 18 of 21 (86%) patients with detectable HBV core promoter sequences, mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found. No deletions were detected in the core promoter gene region of the type reported to be associated with some cases of HBsAg-negative HBV infection. Thus, HBV DNA was detectable in 22 (73%) HBsAg-negative, anti-HCV-positive HCCs, including three (10%) who were also negative for anti-HBc and anti-HBs. HBV mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found in the majority of cases, mutations that have previously been reported in HBV that is integrated in HCC DNA. In serologic surveys to determine etiologic associations of HCC, patients such as those in this study would have been incorrectly designated as having 'HCV-associated HCC,' whereas the data in this study suggest that HBV could have played a role in the development of their HCCs.

Integration of hepatitis B virus containing mutations in the core promoter/X gene in patients with hepatocellular carcinoma.

UNLABELLED: Integration of hepatitis B virus is thought to be an essential step in hepatitis B virus associated hepatocarcinogenesis. Mutations at nucleotides 1762 and 1764 in the hepatitis B virus, within a sequence encoding both the core promoter gene and the X gene, have been found frequently in patients with hepatocellular carcinoma. However, integration of these mutant sequences has not been reported to date. METHODS: A 228-base pair segment of the hepatitis B virus core promoter gene was amplified from hepatocellular carcinomas and adjacent non-tumourous liver tissue by nested PCR and sequenced. Integration of hepatitis B virus into human genomic DNA was investigated using the 'genome walking' method. RESULTS: Point mutations were found in both hepatitis B virus nucleotides 1762 and 1764 in 8 of 14 hepatocellular carcinoma tissues (57%) and in 11 of 14 adjacent non-tumourous liver tissues (79%). Three patients were evaluated using the 'genome walking' method; all were found to have hepatitis B virus DNA integrated in their hepatocellular carcinoma (two patients) and/or in their non-tumourous liver tissue (three patients). Integration occurred in all tissues near host genomic sites that are prone to integration. Hepatitis B virus was integrated at or near the hepatitis B virus DR1 site in all samples, and all contained truncated X gene sequences that have been reported to be capable of producing fusion transcripts with transactivation potential. CONCLUSIONS: Integrated hepatitis B virus DNA containing core promoter mutations at nucleotides 1762 and 1764 was found in hepatocellular carcinoma and/or adjacent non-tumourous liver tissue of three patients. These findings leave open the possibility that insertional mutagenesis or transactivation by fusion transcripts resulting from hepatitis B virus integration could play a role in hepatocarcinogenesis in some patients.

The role of the cAMP-PKA system in the short-term regulation of striatal [(14)C]-2-deoxyglucose uptake in freely moving rats.

The cyclic adenosine monophosphate (cAMP)-protein kinase (PK) A system has been shown to have stimulatory effects on glucose utilization in various tissues in vitro. However, little is known about the influence of cAMP on glucose utilization in vivo. In the present study, we examined how cAMP-related compounds affected [(14)C]-2-deoxyglucose (DG) uptake in the striatum of freely moving rats. An intrastriatal injection of dibutyryl-cyclic adenosine monophosphate (db-cAMP), although increasing local cerebral blood flow, was found to decrease the uptake of [(14)C]-2-DG in the striatum. This decrease of [(14)C]-2-DG uptake in the striatum was completely blocked by pretreatment with Rp-adenosine-3',5'-cyclic monophosphorothioate triethylamine (Rp-cAMPS). Moreover, intrastriatal infusion of Rp-cAMPS alone produced a striking increase of [(14)C]-2-DG uptake in the striatum. These results strongly suggest that transient activation of the cAMP-PKA system can depress the glucose phosphorylation process of the rat brain in vivo.

Correlation of immunohistochemical staining and mutations of p53 in human hepatocellular carcinoma.

Mutations of the p53 tumor suppressor gene are common in hepatocellular carcinomas (HCCs). Detection of mutations by sequencing provides more information than immunohistochemical staining, but the equipment needed and the time required make it less practical for use in large-scale studies or in studies in developing countries. The degree of correlation between results obtained with these two methods has been studied in various tumors but has not been well-established in human HCCs. Paraffin sections of HCCs of 28 patients from Qidong, China were immunohistochemically stained using monoclonal antibody to p53. In addition, exons 5-8 of the p53 gene were sequenced in these HCCs. Of the 28 HCCs, nine had 0-9% of nuclei stained for p53, and 19 had 50-95% stained. Mutations in p53 exons 5-8 were found in 17/28 (61%) HCCs, including 15 at codon 249 (exon 7), one at codon 198 (exon 6), and one at codon 175 (exon 5). Among these 17 cases with p53 mutations, 16 cases (94%) had 50-95% of nuclei stained. Among 11 HCCs with no mutations by sequencing, 8 were also negative by immunohistochemistry (0-9% of nuclei stained) (73%) (the five HCCs with no staining whatsoever all had wild-type p53). Immunohistochemical staining to detect p53 mutations in human HCCs detected most mutations that were detected by sequencing (94% sensitivity, 73% specificity), and this method is therefore suitable when sequencing cannot be performed.

A new human hepatocellular carcinoma cell line (HAK-2) forms various structures in collagen gel matrices.

We established a new human hepatocellular carcinoma (HCC) cell line, designated HAK-2, from a surgically resected HCC of a 57-yr-old Japanese man. The patient's tumor consisted of 5 different histological features in a single nodule: well-differentiated HCC with trabecular pattern; and moderately differentiated HCC with 4 different patterns (i.e., trabecular, pseudoglandular, solid, and scirrhous). Morphologically, HAK-2 cells on a plastic dish showed oval-shaped nuclei and large flat, polygonal eosinophilic cytoplasm and proliferated in a monolayered sheet with a population doubling time of 36.8 hours. Meanwhile, various structures, such as compact, trabecular, and tubular arrangements, were induced in HAK-2 cells cultured in type I collagen gel matrix. Also, HAK-2 cells in vitro underwent spontaneous apoptosis more frequently than other HCC cell lines examined. HAK-2 cells secreted various plasma proteins including albumin into the culture medium. Chromosome and flow cytometric analyses revealed that HAK-2 had many structural abnormalities with human karyotype and a single aneuploid cell population with a DNA index of 3.7, respectively. These findings suggest that HAK-2 is a new human HCC cell line representing two morphological characteristics; (1) formation of various structures in the presence of extracellular matrix and (2) frequent spontaneous apoptosis in vitro.

Expression of Fas and anti-Fas-mediated apoptosis in human hepatocellular carcinoma cell lines.

BACKGROUND/AIMS: Fas transduces apoptotic signals upon cross-linking with the Fas ligand, which is experimentally replaced by anti-Fas antibodies. Because little is known about Fas expression and function in hepatocellular carcinoma, these issues are addressed in the current article. METHODS: We examined Fas expressions at protein and mRNA levels, and susceptibility to anti-Fas-mediated apoptosis, on six hepatocellular carcinoma cell lines. RESULTS: Two cell lines constitutively expressed high levels of Fas both on their cell surface and in their cytoplasm, whereas the other four cell lines expressed Fas mainly in their cytoplasm. Fas mRNA of normal size was detected in all cell lines in reverse transcriptase-polymerase chain reaction analyses. Although a Fas mRNA variant, suggesting a soluble Fas molecule, was detected in the two cell lines expressing high levels of Fas, its amount was very small compared to that of normal-sized Fas transcript. Anti-Fas dose-dependently induced apoptosis exclusively in the two cell lines which constitutively express high levels of cell surface Fas. However, after preincubation with interferon-gamma, one cell line with low surface Fas expression became anti-Fas sensitive equivalent to the two cell lines expressing surface Fas at high levels. Studies of two clonally related cell lines showed that dedifferentiated clones had lower Fas expression and resistance to anti-Fas, suggesting deterioration of Fas system after clonal cell dedifferentiation. CONCLUSIONS: These findings suggest sensitivity to anti-Fas is virtually relevant to cell surface Fas, but not to cytoplasmic Fas expression. However, its expression level does not correlate to sensitivity to anti-Fas.

A human combined hepatocellular and cholangiocarcinoma cell line (KMCH-2) that shows the features of hepatocellular carcinoma or cholangiocarcinoma under different growth conditions.

BACKGROUND/AIMS: Combined hepatocellular and cholangiocarcinoma is a rare tumor of the liver, and its histogenesis remains unclear. The authors addressed this issue in the current article. METHODS: A specimen aseptically obtained from the surgically resected combined hepatocellular and cholangiocarcinoma was processed for primary culture. The morphologic features of the established cell line cultured on a plastic dish and in type I collagen gel matrix, and transplanted in nude mice were examined. RESULTS: The authors established a new human combined hepatocellular and cholangiocarcinoma cell line, designated KMCH-2, from a 40-year-old Japanese man. KMCH-2 cells on a plastic dish proliferated in a monolayered sheet with a population doubling time of 32 to 44 h. KMCH-2 expressed functional characteristics of hepatocellular carcinoma, such as albumin synthesis at protein and mRNA levels, but were poorly differentiated in morphology, showing an overlap of features with cholangiocarcinoma. KMCH-2 cells cultured within type I collagen gel matrix proliferated, forming compact to vaguely trabecular and pseudoglandular arrangements, and differentiated to show morphological characteristics of hepatocellular carcinoma unlike the cells on a plastic dish. Mucin production was not detected in KMCH-2 cells in vitro. Subcutaneous tumors which developed in nude mice injected with KMCH-2 cells represented features of adenocarcinoma with mucin production. CONCLUSIONS: The present results revealed the presence of an albumin-producing human hepatic neoplastic cell, such as KMCH-2, that can differentiate to show not only the features of hepatocellular carcinoma but also those of cholangiocarcinoma under certain growth conditions.

Expression of intercellular adhesion molecule 1 in human hepatocellular carcinoma.

We investigated the expression of intercellular adhesion molecule 1 (ICAM-1) in ex vivo human hepatocellular carcinoma (HCC) cells and in vitro in eight liver cancer cell lines, including six HCC cell lines and two combined hepatocholangiocarcinoma (CHC) cell lines. Immunohistochemistry showed the expression of ICAM-1 on the HCC cell surface with honeycomblike appearance in most cases (96.2%). On the other hand, hepatocytes in noncancerous areas did not express ICAM-1, except those hepatocytes in the periportal and intra-acinar areas with inflammation. Immunohistochemical study on cultured cells revealed that four cultured HCC cell lines and one CHC cell line constitutively expressed ICAM-1 on the cell surface and in the cytoplasm. Flow cytometric analysis revealed that immunostain-positive cells expressed surface ICAM-1 with more than a 90% positive cell rate, and their expressions were upregulated by incubation of cells with inflammatory cytokines, such as interferon alfa, interferon gamma, tumor necrosis factor-alpha, and interleukin 1 beta. Soluble ICAM-1 was detected in supernatants of cell lines expressing cell surface ICAM-1 expression, and was increased in amounts 2- to 20-fold by inflammatory cytokines. These findings suggest that liver cancer cells in ex vivo may express not only surface but also a soluble form of ICAM-1, differently from normal hepatocytes, and that both expressions are upregulated by inflammatory cytokines.

Expression of CD44 in human hepatocellular carcinoma cell lines.

CD44 is a glycosylated cell surface adhesion molecule expressed on a diverse range of cells and has several variant forms, some of which are involved in metastasis of cancer cells. Because little is known about CD44 in human hepatocellular carcinoma (HCC), we investigated its expression in tissue specimens from primary lesions (12 cases), in smear specimens from peritoneal effusions (2 cases), and in cell lines (HCC cell lines, KIM-1, KYN-1, KYN-2, KYN-3, HAK-1A, and HAK-1B; combined hepatocholangiocarcinoma cell lines, KMCH-1 and KMCH-2; and bile duct carcinoma cell lines, KMC-1 and KMBC). Immunohistochemical studies using monoclonal antibody recognizing epitope Group 1 of human CD44 molecule showed that HCC cells in all tissue specimens, including the original tumors of one smear specimen and HAK-1A, were negative for CD44; whereas, HCC cells in two-smear specimens, KIM-1, KYN-2, KYN-3, HAK-1A, HAK-1B, KMCH-1, KMC-1, and KMBC, showed positive reactions on the cell membrane. Immunostain-positive cell lines showed a positive cell rate of 51.9% to 99.8% by flow cytometric analysis. Western blotting detected CD44 protein of hemopoietic type in KIM-1, KYN-3, HAK-1A, and HAK-B and epithelial type in KMC-1 and KMBC. Southern blotting of complementary DNA amplified after reverse transcriptase-polymerase chain reaction (RT-PCR) detected hemopoietic type and some variant forms with longer insertion in all cell lines but KMCH-2, whereas hemopoietic type and variants with minor insertion were only detectable in tissue specimens. These findings suggest that HCC cells in ascites and in culture often express CD44, but those in tissue do not at protein level.

Establishment of a human hepatic adenosquamous carcinoma cell line (KMC-2) and its response to cytokines.

A human hepatic adenosquamous carcinoma cell line (KMC-2) was established from a serially transplanted tumor in nude mice (nuKMC-2), which originated from human cholangio-cellular carcinoma and showed histological alteration from adenocarcinoma to squamous cell carcinoma (SCC) along with serial transplantation. KMC-2 cells in monolayer culture proliferated in a sheet-like arrangement with a population doubling time of 29.5 h, whereas the cells in 0.1% collagen gel embedded culture formed a compact and tubular structure with the population doubling time of 35.4 h. The cells secreted carbohydrate antigen 19-9 (CA19-9), tissue polypeptide antigen and SCC-related antigen. The back-transplanted nude mouse tumor exhibited morphologic features of adenosquamous carcinoma resembling those in the original nude mouse tumor. IFN-alpha, IFN-gamma and TNF-alpha suppressed cell proliferation significantly. Functionally, IFN-gamma significantly suppressed CA19-9 secretion, and conversely promoted SCC-related antigen secretion. These findings suggest that KMC-2 is the first human hepatic adenosquamous carcinoma cell line primarily originated from adenocarcinoma; the environmental factors, such as the presence of extracellular matrix and the cytokines influenced the growth, morphology and function of KMC-2.

The herbal medicine sho-saiko-to inhibits proliferation of cancer cell lines by inducing apoptosis and arrest at the G0/G1 phase.

Water-soluble ingredients of the herbal medicine sho-saiko-to dose-dependently inhibited the proliferation of a human hepatocellular carcinoma cell line (KIM-1) and a cholangiocarcinoma cell line (KMC-1). Fifty % effective doses on day 3 of exposure to sho-saiko-to were 353.5 +/- 32.4 micrograms/ml for KIM-1 and 236.3 +/- 26.5 micrograms/ml for KMC-1. However, almost no suppressive effects were detected in normal human peripheral blood lymphocytes or normal rat hepatocytes. Sho-saiko-to suppressed the proliferation of the carcinoma cell lines significantly more strongly than did each of its major ingredients, i.e., saikosaponin a, c, and d, ginsenoside Rb1 and Rg1, glycyrrhizin, baicalin, baicalein, and wogonin, or another herbal medicine, juzen-taiho-to (P < 0.05 or 0.005). Because such ingredients are barely soluble in water, there could be synergistic or additive effects of the ingredients in sho-saiko-to. Morphological, DNA, and cell cycle analyses revealed two possible modes of action of sho-saiko-to to suppress the proliferation of carcinoma cells; (a) it induces apoptosis in the early period of exposure and (b) it induces arrest at the G0/G1 phase in the late period of exposure.