Masahiko Yano

Comprehensive Analysis of the Effects of Ordinary Nutrients on Hepatitis C Virus RNA Replication in Cell Culture

ABSTRACT To date, only a limited number of studies have reported finding an influence of ordinary nutrients on hepatitis C virus (HCV) RNA replication. However, the effects of other nutrients on HCV RNA replication remain largely unknown. We recently developed a reporter assay system for genome-length HCV RNA replication in hepatoma-derived HuH-7 cells (OR6). Here, using this OR6 assay system, we comprehensively examined 46 nutrients from four nutrient groups: vitamins, amino acids, fatty acids, and salts. We found that three nutrients—β-carotene, vitamin D2, and linoleic acid—inhibited HCV RNA replication and that their combination caused additive and/or synergistic effects on HCV RNA replication. In addition, combined treatment with each of the three nutrients and interferon alpha or beta or fluvastatin inhibited HCV RNA replication in an additive manner, while combined treatment with cyclosporine synergistically inhibited HCV RNA replication. In contrast, we found that vitamin E enhanced HCV RNA replication and negated the effects of the three anti-HCV nutrients and cyclosporine but not those of interferon or fluvastatin. These results will provide useful information for the treatment of chronic hepatitis C patients who also take anti-HCV nutrients as an adjunctive therapy in combination with interferon. In conclusion, among the ordinary nutrients tested, β-carotene, vitamin D2, and linoleic acid possessed anti-HCV activity in a cell culture system, and these nutrients are therefore considered to be potential candidates for enhancing the effects of interferon therapy.

Inhibition of hepatitis C virus infection and expression in vitro and in vivo by recombinant adenovirus expressing short hairpin RNA

Background and Aim:  We have reported previously that synthetic small interfering RNA (siRNA) and DNA‐based siRNA expression vectors efficiently and specifically suppress hepatitis C virus (HCV) replication in vitro. In this study, we investigated the effects of the siRNA targeting HCV‐RNA in vivo.

Sustained biochemical remission after interferon treatment may closely be related to the end of treatment biochemical response and associated with a lower incidence of hepatocarcinogenesis

Abstract: Clinical background and incidence of hepatocellular carcinoma (HCC) of patients with chronic hepatitis C who obtained biochemical remission without eradication of virus (biochemical response) after interferon (IFN) treatment was retrospectively analyzed for 755 patients. Annual incidence of HCC was significantly lower in the patients with biochemical response and sustained response than that of the patients that did not show these responses. Logistic regression analysis showed that only the normalization of alanine aminotransferase (ALT) value at the end of IFN treatment was a significant factor for biochemical response. Annual incidence of HCC was significantly lower in the patients who obtained normalization of ALT values at the end of treatment than those who did not. Patients who were younger, who had a lower level of activity and fibrosis indices in histology, higher platelet count, and who were given more higher total dose of IFN were more likely to attain normalization of ALT levels at the end of treatment, and this was related to biochemical response. Low incidence of HCC in patients who obtained normalization of ALT values at the end of treatment was likely because they were in the earlier stage of chronic hepatitis. Active treatment of chronic hepatitis C with interferon in the early phase of the disease may bring about a biochemical response in some patients, even if sustained virological response is not obtained.

Blockade of ataxia telangiectasia mutated sensitizes hepatoma cell lines to sorafenib by interfering with Akt signaling

Sorafenib is a multi-kinase inhibitor applicable to hepatocellular carcinoma (HCC), but its limited therapeutic effects are a major problem to be solved. Here, we show that blockade of ataxia telangiectasia mutated (ATM) improves the antitumor effects of sorafenib. When hepatoma cell lines HepG2 and PLC/PRF/5 were treated with sorafenib plus ATM small inhibitory RNAs, ATM inhibitor KU55933 or caffeine, Akt signaling was suppressed and the cytotoxic effects were significantly potentiated. Moreover, ATM inhibition effectively suppressed the sorafenib-induced cell migration. Taken together, manipulation of ATM activity might be a useful strategy for improving sorafenib treatment of HCC.

Multicentric occurrence of hepatocellular carcinoma with nonalcoholic steatohepatitis

AIM To reveal the manner of hepatocellular carcinoma (HCC) development in patients with nonalcoholic steatohepatitis (NASH) focusing on multicentric occurrence (MO) of HCC. METHODS We compared clinicopathological characteristics between patients with and without MO of HCC arising from NASH background. The clinical features were implicated with reference to the literature available. RESULTS MO of HCC was identified with histological proof in 4 out of 12 patients with NASH-related HCC (2 males and 2 females). One patient had synchronous MO; an advanced HCC, two well-differentiated HCCs and a dysplastic nodule, followed by the development of metachronous MO of HCC. The other three patients had multiple advanced HCCs accompanied by a well-differentiated HCC or a dysplastic nodule. Of these three patients, one had synchronous MO, one had metachronous MO and the other had both synchronous and metachronous MO. There were no obvious differences between the patients with or without MO in terms of liver function tests, tumor markers and anatomical extent of HCC. On the other hand, all four patients with MO of HCC were older than 70 years old and had the comorbidities of obesity, type 2 diabetes mellitus (T2DM), hypertension and cirrhosis. Although these conditions were not limited to MO of HCC, all the conditions were met in only one of eight patients without MO of HCC. Thus, concurrence of these conditions may be a predisposing situation to synchronous MO of HCC. In particular, old age, T2DM and cirrhosis were suggested to be prerequisite for MO because these factors were depicted in common among two other cases with MO of HCC under NASH in the literature. CONCLUSION The putative predisposing factors and necessary preconditions for synchronous MO of HCC in NASH were suggested in this study. Further investigations are required to clarify the accurate prevalence and predictors of MO to establish better strategies for treatment and prevention leading to the prognostic improvement in NASH.

Characterization of elevated alanine aminotransferase levels during pegylated-interferon α-2b plus ribavirin treatment for chronic hepatitis C.

Aim:  Elevation of alanine aminotransferase (ALT) levels during pegylated‐interferon (peg‐IFN) plus ribavirin therapy in patients with chronic hepatitis C [CHC] is a problem that cannot be disregarded. The aim of this study is to assess the frequency and to characterize clinical parameters of this phenomenon.

Hepatitis B virus X induces cell proliferation in the hepatocarcinogenesis via up‐regulation of cytoplasmic p21 expression

Hepatitis B virus X protein (HBx) has been shown to induce hepatocarcinogenesis by disrupting the functions of intracellular molecules. Cyclin‐dependent kinase inhibitor p21 (Cip1/WAF1), known as a tumour‐suppressor gene, has been reported to have paradoxical function, that is, acting as an oncogene, particularly when expressed in the cytoplasm. The effects of HBx on the expression and function of p21 also remain controversial.

Very-Low-Dose Pegylated Interferon α2a Plus Ribavirin Therapy for Advanced Liver Cirrhosis Type C: A Possible Therapeutic Alternative without Splenic Intervention

Despite the recent progress in interferon (IFN) therapies for chronic hepatitis C, liver cirrhosis remains refractory. One of the major obstacles to successful IFN therapy is low platelet count. Currently, splenic interventions, such as partial splenic embolization (PSE) or surgical splenectomy, have been applied effectively and make standard IFN therapy possible. However, there may be a group of patients with low platelet counts who can be treated without splenic intervention. We here report two patients with advanced type C liver cirrhosis who were successfully treated using very-low-dose pegylated interferon α2a plus ribavirin. One patient had a very low platelet count (2.5 × 104/µl) due to splenomegaly before treatment. However, pretreatment serum HCV titers were low in both patients and early viral responses were obtained in both. Because PSE or splenectomy may still have some safety concerns, this attenuated IFN treatment protocol can be an alternative therapeutic option for patients with advanced type C liver disease, but good virological factors for sustained virological response.

Progression of hypermethylation of the p16(INK4A) gene from normal liver to nontumorous liver and hepatocellular carcinoma: an evaluation using quantitative PCR analysis.

The aim of this study was to determine to what extent hypermethylation of the p16INK4A (p16) gene promoter is increased in nontumorous liver tissues compared with in normal liver, using two quantitative methylation-specific polymerase chain reaction (MS-PCR) methods and a bisulfite sequencing method. Methylation of the p16 gene was detected more frequently in nontumorous liver than in normal liver using the TaqMan PCR method. Methylation indices also were significantly higher in nontumorous than in normal liver. However, the bisulfite sequencing method did not detect significantly more methylation of the p16 gene in nontumorous than normal liver, nor was there a significant difference in the level of p16 mRNA. There may be a greater proportion of cells which contain methylated p16 in nontumorous than in normal liver. However, the difference was so small that the functional relevance to hepatocarcinogenesis remains elusive.

Development of a hepatitis C virus relapse model using genome-length hepatitis C virus ribonucleic acid-harboring cells possessing the interferon-α-resistance phenotype

Aim:  The cure rate of current interferon (IFN) therapy is limited to approximately 50% and most of the relapses after therapy are caused by genotype‐1. To develop a relapse model in cell culture, we attempted to obtain genome‐length hepatitis C virus ribonucleic acid (HCV RNA) harboring cells possessing the IFN‐α‐resistance phenotype from previously established OR6 cells, which enabled the luciferase reporter assay for monitoring of HCV RNA replication.