Hisamitsu Miyaaki

Lens culinaris agglutinin-reactive α-fetoprotein and protein induced by vitamin K absence II are potential indicators of a poor prognosis: a histopathological study of surgically resected hepatocellular carcinoma

BackgroundWe histopathologically examined Lens culinaris agglutinin-reactive α-fetoprotein (AFP-L3)-positive hepatocellular carcinoma (HCC) and protein induced by vitamin K absence (PIVKA) II-positive HCC to clarify the efficacy of these markers for predicting a poor prognosis.MethodsSerum AFP-L3 and PIVKA II was measured in 110 HCC patients. AFP-L3 was measured by lectin-affinity electrophoresis coupled with antibody-affinity blotting, and PIVKA II by using a high-sensitivity kit. The growth type, capsule formation, capsule infiltration, portal vein invasion, intrahepatic metastasis and histological tumor grade were evaluated pathologically.ResultsThirty-eight (35%) HCC patients were AFP-L3-positive, and 63 (57%) were PIVKA II-positive. In AFP-L3-positive HCC, the frequencies of an infiltrative growth type (positive : negative = 66% : 42%, P = 0.027) and a poorly differentiated type (positive : negative = 32% : 6%, P < 0.001) were significantly higher than in AFP-L3-negative HCC. In PIVKA II-positive HCC, the frequencies of an infiltrative growth type (positive : negative = 62% : 28%, P < 0.001), vascular invasion (positive : negative = 63% : 26%, P < 0.001), and intrahepatic metastasis (positive : negative = 38% : 4%, P < 0.001) were significantly higher than in PIVKA II-negative HCC. In both AFP-L3- and PIVKA II-positive HCC, the frequency of a poorly differentiated growth type was significantly higher than in HCC positive for either AFP-L3 or PIVKA II or HCC negative for both AFP-L3 and PIVKA II (both positive : either positive : both negative = 37% : 12% : 0%; P = 0.014, P < 0.001, respectively).ConclusionsAFP-L3 was related to progression from moderately differentiated to poorly differentiated HCC, whereas PIVKA II was more specific to vascular invasion. PIVKA II is therefore likely to be a useful indicator of vascular invasion.

Significance of serum and hepatic microRNA-122 levels in patients with non-alcoholic fatty liver disease.

Non‐alcoholic fatty liver disease (NAFLD) is believed to be a type of metabolic syndrome. MicroRNA‐122 (miR‐122) is the most abundant microRNA in the liver and is an important factor for the metabolism of glucose and lipids. In the present study, we examined the correlation between the hepatic and serum miR‐122 expression levels and the clinicopathological factors of patients with NAFLD.

Clinicopathological study of nonalcoholic fatty liver disease in Japan: the risk factors for fibrosis.

Background/Aims: We evaluated patients with nonalcoholic fatty liver disease (NAFLD) and compared the clinical and pathological features to identify the risk factors for NAFLD with severe fibrosis.

Differential effects of calcineurin inhibitors, tacrolimus and cyclosporin a, on interferon-induced antiviral protein in human hepatocyte cells†

The premise of our study is that selective inhibition of interferon (IFN) by calcineurin inhibitors contribute to the increased severity of hepatitis C virus (HCV) posttransplantation. Therefore, we examined the influence of calcineurin inhibitors in the human hepatocyte cell line on IFN‐α‐induced phosphorylation of Janus kinase (Jak) and signal transducers and activators of transcription (STAT), nuclear translocation of IFN‐stimulated gene factor 3 (ISGF‐3), IFN‐stimulated regulatory element (ISRE)‐contained promoter activity, and the expressions of antiviral proteins. Tacrolimus (Tac), but not cyclosporin A (CyA), had an inhibitory effect on IFN‐α‐induced double‐stranded ribonucleic acid (RNA)‐dependent protein kinase (PKR) in a dose‐dependent manner. STAT‐1 also acted in a similar fashion to PKR. IFN‐α combined with Tac attenuated the ISRE‐containing promoter gene activity as compared with IFN‐α alone. In contrast, its expression in pretreated CyA was slightly attenuated. In pretreated Tac, but not CyA, the levels of IFN‐α‐induced tyrosine phosphorylated STAT‐1 and ‐2 were clearly lower than those induced by IFN‐α alone. Tac and CyA did not decrease the IFN‐α‐induced JAK‐1 phosphorylation. The nuclear translocation rate of tyrosine phosphorylated STAT‐1 was inhibited by pretreatment of both Tac and CyA by western blotting and immunohistochemistry. In an HCV replicon system, pretreated Tac diminished the replication inhibitory effect of IFN‐α. In this study, we show that calcineurin inhibitors, especially Tac, are the negative regulators of IFN signaling in the hepatocyte; the greatest cause of such inhibition is the phosphorylation disturbance of STAT‐1, next to inhibition of the nuclear translocation of STAT‐1. In conclusion, disturbance of tyrosine phosphorylation of STAT‐1 resulted in diminished ISRE‐containing promoter activity and a decline in antiviral protein expression. Moreover, the replication of HCV was activated. This phenomenon is detrimental to IFN therapy after liver transplantation, and the selection of calcineurin inhibitors may warrant further discussion depending on the transplant situation. Liver Transpl 14:292–298, 2008.

Antitumor function of microRNA-122 against hepatocellular carcinoma

MicroRNA-122 (miR-122), a highly abundant and liver-specific miRNA, acts as a tumor suppressor against hepatocellular carcinoma (HCC). Decreased expression of miR-122 in HCC is frequently observed and is associated with poor differentiation, larger tumor size, metastasis and invasion, and poor prognosis. Mutant mice with knockout (KO) of the miR-122 locus developed steatohepatitis due to increased triglyceride (TG) synthesis and decreased TG secretion from hepatocytes, and eventually developed HCC. Exogenic miR-122 introduction into miR-122 KO mice inhibited the development of HCC. Target genes of miR-122, including cyclin G1, a disintegrin and metalloprotease (ADAM)10, serum response factor, insulin-like growth factor-1 receptor, ADAM17, transcription factor CUTL1, the embryonic isoform of pyruvate kinase (Pkm2), Wnt1, pituitary tumor-transforming gene 1 binding factor, Cut-like homeobox 1, and c-myc, are involved in hepatocarcinogenesis, epithelial mesenchymal transition, and angiogenesis. MiR-122 expression is regulated by liver-enriched transcription factors such as hepatocyte nuclear factor (HNF)1α, HNF3β, HNF4α, HNF6, and CCAAT/enhancer-binding protein (C/EBP)α. A positive feedback loop exists between C/EBPα and miR-122 and between HNF6 and miR-122, whereas a negative feedback loop exists between c-myc and miR-122. Since cotreatment of 5-Aza-Cd and histone deacetylase inhibitor restored miR-122 expression in HCC cells, epigenetic modulation of miR-122 expression is involved in the suppression of miR-122 in HCC. Several experiments suggest that increasing miR-122 levels in HCC with or without antitumor agents may be a promising strategy for HCC treatment.

Baseline Serum Cholesterol Is Associated with a Response to Pegylated Interferon Alfa-2b and Ribavirin Therapy for Chronic Hepatitis C Genotype 2

Background. HCV infection is associated with lipid disorders because this virus utilizes the host lipid metabolism to sustain its life cycle. Several studies have indicated that higher concentrations of serum cholesterol and LDL before treatment are important predictors of higher rates of sustained virological response (SVR). However, most of these studies involved patients infected with HCV genotype 1. Thus, we performed a multi-institutional clinical study to evaluate the impact of lipid profiles on SVR rates in patients with HCV genotype 2. Methods. A total of 100 chronic hepatitis C patients with HCV genotype 2 who received peg-IFN alfa-2b and ribavirin therapy were consecutively enrolled. The significance of age, sex, BMI, AST level, ALT level, WBC, hemoglobin, platelet count, gamma-glutamyltransferase, total cholesterol level (TC), LDL level, HCV RNA, and histological evaluation was examined for SVR using logistic regression analysis. Results. The 100 patients infected with HCV genotype 2 were divided into 2 groups, an SVR group and a non-SVR group. Characteristics of each group were subsequently compared. There was no significant difference in the level of HCV RNA, BMI, platelet, TG, or stage of fibrosis between the groups. However, there were significant differences in the levels of TC and LDL-C. In multivariate logistic regression analysis using baseline characteristics, high TC level was an independent and significant risk factor (relative risk 18.59, P = 0.015) for SVR. Conclusion. Baseline serum total cholesterol levels should be considered when assessing the likelihood of sustained treatment response following the course of peg-IFN and ribavirin therapy in patients with chronic HCV genotype 2 infection.

A snack enriched with oral branched-chain amino acids prevents a fall in albumin in patients with liver cirrhosis undergoing chemoembolization for hepatocellular carcinoma

Nutritional support may play an important role in management of liver cirrhosis (LC) associated with unresectable hepatocellular carcinoma (HCC). Total protein and albumin deteriorate in patients with LC undergoing trans-arterial chemoembolization (TACE). Therefore, in this study, we examined the hypothesis that short-term administration of branched-chain amino acids (BCAA) will prevent a fall in total protein and albumin in the perioperative period. The subjects were 56 patients who underwent TACE for HCC between 2004 and 2005 at Nagasaki University Hospital. The patients were randomly placed in the BCAA group (n = 28) or a control group (n = 28). The patients in the BCAA group consumed a snack containing 50 g of BCAA once a day at 10:00 pm starting 1 day before TACE and continuing until 2 weeks after TACE. A comparison of baseline and end point data showed greater decreases in the concentrations of total protein, albumin, cholinesterase, and total cholesterol and in the red blood cell count in the control group compared to the BCAA group. Ammonia levels decreased in the BCAA group and increased in the control group. Our findings indicate that a BCAA supplement taken orally as a late evening snack prevents suppression of liver function by TACE in patients with LC complicated with HCC during the 2-week period after TACE.

Predictive value of suppressor of cytokine signal 3 (SOCS3) in the outcome of interferon therapy in chronic hepatitis C

Aims:  Suppressor of cytokine signaling 3 (SOCS3) can suppress Janus kinase (JAK)‐signal transducers and activators of transcription (STAT) signaling by blocking an IFN‐induced protein. In this study, the relationship between SOCS3 and phosphorylation of STAT1 in the liver and outcome of interferon therapy were examined.

Significance of hepatitis B virus core‐related antigen and covalently closed circular DNA levels as markers of hepatitis B virus re‐infection after liver transplantation

Currently, hepatitis B virus (HBV) re‐infection after liver transplantation (LT) can be almost completely suppressed by the administration of HBV reverse transcriptase inhibitors and hepatitis B immunoglobulins. However, after transplantation, there is no indicator of HBV replication because tests for the serum hepatitis B surface antigen and HBV‐DNA are both negative. Therefore, the criteria for reducing and discontinuing these precautions are unclear. In this study, we examined the serum HBV core‐related antigen (HBcrAg) and intrahepatic covalently closed circular DNA (cccDNA) in order to determine if these could be useful markers for HBV re‐infection.

Interferon-α-induced mTOR activation is an anti-hepatitis C virus signal via the phosphatidylinositol 3-kinase-Akt-independent pathway

ObjectThe interferon-induced Jak-STAT signal alone is not sufficient to explain all the biological effects of IFN. The PI3-K pathways have emerged as a critical additional component of IFN-induced signaling. This study attempted to clarify that relationship between IFN-induced PI3-K-Akt-mTOR activity and anti-viral action.ResultWhen the human normal hepatocyte derived cell line was treated with rapamycin (rapa) before accretion of IFN-α, tyrosine phosphorylation of STAT-1 was diminished. Pretreatment of rapa had an inhibitory effect on the IFN-α-induced expression of PKR and p48 in a dose dependent manner. Rapa inhibited the IFN-α inducible IFN-stimulated regulatory element luciferase activity in a dose-dependent manner. However, wortmannin, LY294002 and Akt inhibitor did not influence IFN-α inducible luciferase activity. To examine the effect of PI3-K-Akt-mTOR on the anti-HCV action of IFN-α, the full-length HCV replication system, OR6 cells were used. The pretreatment of rapa attenuated its anti-HCV replication effect in comparison to IFN-α alone, whereas the pretreatment with PI3-K inhibitors, wortmannin and LY294002 and Akt inhibitor did not influence IFN-induced anti-HCV replication.ConclusionIFN-induced mTOR activity, independent of PI3K and Akt, is the critical factor for its anti-HCV activity. Jak independent mTOR activity involved STAT-1 phosphorylation and nuclear location, and then PKR is expressed in hepatocytes.