Tsutomu Tamai

Serum manganese superoxide dismutase and thioredoxin are potential prognostic markers for hepatitis C virus-related hepatocellular carcinoma.

AIM To evaluate the clinical significance of oxidative stress markers in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). METHODS Sixty-four consecutive patients who were admitted to Kagoshima University Medical and Dental Hospital were enrolled in this retrospective study. All patients had chronic liver disease (CLD) due to infection with HCV. Thirty patients with HCV-related HCC, 34 with HCV-related CLD without HCC (non-HCC), and 20 healthy volunteers (HVs) were enrolled. Possible associations between serum manganese superoxide dismutase (MnSOD) and thioredoxin (TRX) levels and clinical parameters or patient prognosis were analyzed over a mean follow-up period of 31.7 mo. RESULTS The serum MnSOD levels were significantly higher in patients with HCV-related HCC than in patients without HCC (P = 0.03) or HVs (P < 0.001). Similarly, serum TRX levels were also significantly higher in patients with HCV-related HCC than in patients without HCC (P = 0.04) or HVs (P < 0.01). However, serum levels of MnSOD and TRX were not correlated in patients with HCC. Among patients with HCC, the overall survival rate (OSR) was lower in patients with MnSOD levels ≥ 110 ng/mL than in patients with levels < 110 ng/mL (P = 0.01), and the OSR tended to be lower in patients with TRX levels < 80 ng/mL (P = 0.05). In addition, patient prognosis with HCC was poorest with serum MnSOD levels ≥ 110 ng/mL and serum TRX levels < 80 ng/mL. Furthermore, a multivariate analysis using a Cox proportional hazard model and serum levels of five factors (MnSOD, prothrombin time, serum albumin, serum α-fetoprotein (AFP), and serum des-γ-carboxy prothrombin) revealed that MnSOD levels ≥ 110 ng/mL (risk ratio: 4.12, 95% confidential interval: 1.22-13.88, P = 0.02) and AFP levels ≥ 40 ng/mL (risk ratio: 6.75; 95% confidential interval: 1.70-26.85, P < 0.01) were independent risk factors associated with a poor patient prognosis. CONCLUSION Serum MnSOD and TRX levels are potential clinical biomarkers that predict patient prognosis in HCV-related HCC.

Highly sensitive lens culinaris agglutinin-reactive α-fetoprotein is useful for early detection of hepatocellular carcinoma in patients with chronic liver disease

The fucosylated fraction of α-fetoprotein (AFP-L3) is a specific marker for hepatocellular carcinoma (HCC). However, conventional AFP-L3% (c-AFP-L3%) has not always been reliable in cases with low serum α-fetoprotein (AFP) levels. In this study, we evaluated the clinical utility of a newly developed assay, highly sensitive AFP-L3% (hs-AFP-L3%). Subjects included 74 patients with benign liver disease (BLD), including chronic hepatitis and cirrhosis, and 94 with HCC. Serum hs-AFP-L3% was significantly higher than c-AFP-L3% in patients with early-stage HCC (solitary or <20 mm in diameter). Additionally, hs-AFP-L3% was significantly increased in patients with well-differentiated HCC. In patients with serum AFP <20 ng/ml, the sensitivities of c-AFP-L3% and hs-AFP-L3% were 12.5 and 44.6%, respectively, at a cut-off value of 5%. In 59 BLD patients with serum AFP <20 ng/ml, the HCC-positive rate in patients with hs-AFP-L3% ≥ 5% was significantly higher compared to those with hs-AFP-L3% <5% during the follow-up period (median, 35 months; range, 5-48 months). Importantly, none of the BLD patients with both serum AFP <20 ng/ml and hs-AFP-L3% <5% developed HCC. These results indicated that hs-AFP-L3% is useful for early detection of HCC in BLD patients, even for those with serum AFP <20 ng/ml. Furthermore, since hs-AFP-L3% increases before HCC is detectable by various advanced imaging modalities, this assay may help identify BLD patients with a higher risk of HCC.

Identification of a novel biomarker for oxidative stress induced by hydrogen peroxide in primary human hepatocytes using the 2‐nitrobenzenesulfenyl chloride isotope labeling method

Aim:  Oxidative stress is involved in the progression of non‐alcoholic steatohepatitis (NASH). However, there are few biomarkers that are easily measured and accurately reflect the disease states. The aim of this study was to identify novel oxidative stress markers using the 2‐nitrobenzenesulfenyl (NBS) stable isotope labeling method and to examine the clinical utility of these diagnostic markers for NASH.

Glycoprotein Nonmetastatic Melanoma B (Gpnmb)-Positive Macrophages Contribute to the Balance between Fibrosis and Fibrolysis during the Repair of Acute Liver Injury in Mice.

Background and aims Glycoprotein nonmetastatic melanoma B (Gpnmb), a transmembrane glycoprotein that is expressed in macrophages, negatively regulates inflammation. We have reported that Gpnmb is strongly expressed in the livers of rats fed a choline-deficient, L-amino acid-defined (CDAA) diet. However, the role of macrophage-expressed Gpnmb in liver injury is still unknown. This study aimed to clarify the characteristics of infiltrating macrophages that express Gpnmb, and the involvement of Gpnmb in the repair process in response to liver injury. Methods C57BL/6J, DBA/2J [DBA] and DBA/2J-Gpnmb+ [DBA-g+] mice were treated with a single intraperitoneal injection of carbon tetrachloride (CCl4) at a dose of 1.0 mL/kg body weight. Mice were sacrificed at predetermined time points, followed by measurement of serum alanine aminotransferase (ALT) levels and histological examination. Expression of Gpnmb, pro-/anti-inflammatory cytokines, and profibrotic/antifibrotic factors were examined by quantitative RT-PCR and/or Western blotting. Immunohistochemistry, fluorescent immunostaining and flow cytometry were used to determine the expression of Gpnmb, CD68, CD11b and α-SMA, phagocytic activity, and the presence of apoptotic bodies. We used quantitative RT-PCR and ELISA to examine TGF-β and MMP-13 expression and the concentrations and supernatants of isolated infiltrating hepatic macrophages transfected with siGpnmb. Results In C57BL/6J mice, serum ALT levels increased at two days after CCl4 injection and decreased at four days. Gpnmb expression in the liver was stimulated four days after CCl4 injection. Histological examination and flow cytometry showed that Gpnmb-positive cells were almost positive for CD68-positive macrophages, contained engulfed apoptotic bodies and exhibited enhanced phagocytic activity. Isolated infiltrating hepatic macrophages transfected with siGpnmb showed high MMP-13 secretion. There was no significant difference in the magnitude of CCl4-induced liver injury between DBA-g+ and DBA mice. However, hepatic MMP-13 expression, as well as α-SMA expression and collagen production, increased significantly in DBA-g+ compared with DBA mice. Conclusions Gpnmb-positive macrophages infiltrate the liver during the recovery phase of CCl4–induced acute liver injury and contribute to the balance between fibrosis and fibrolysis in the repair process following acute liver injury.

The incidence of hepatocellular carcinoma associated with hepatitis C infection decreased in Kyushu area

Summary Background The incidence of hepatocellular carcinoma (HCC) in Japan has still been increasing. The aim of the present study was to analyze the epidemiological trend of HCC in the western area of Japan, Kyushu. Material/Methods A total of 10,010 patients with HCC diagnosed between 1996 and 2008 in the Liver Cancer study group of Kyushu (LCSK), were recruited for this study. Cohorts of patients with HCC were categorized into five year intervals. The etiology of HCC was categorized to four groups as follows; B: HBsAg positive, HCV-RNA negative, C: HCV-RNA positive, HBsAg negative, B+C: both of HBsAg and HCV-RNA positive, nonBC: both of HBsAg and HCV-RNA negative. Results B was 14.8% (1,485 of 10,010), whereas 68.1% (6,819 of 10,010) had C, and 1.4% (140 of 10,010) had HCC associated with both viruses. The remaining 1,566 patients (15.6%) did not associate with both viruses. Cohorts of patients with HCC were divided into six-year intervals (1996–2001 and 2002–2007). The ratio of C cases decreased from 73.1% in 1996–2001 to 64.9% in 2002–2007. On the other hand, B and -nonBC cases increased significantly from 13.9% and 11.3% in 1996–2001 to 16.2% and 17.6% in 2002–2007, respectively. Conclusions The incidence of hepatocellular carcinoma associated with hepatitis C infection decreased after 2001 in Kyushu area. This change was due to the increase in the number and proportion of the HCC not only nonBC patients but also B patients.

Hepatocyte growth factor ameliorates mucosal injuries leading to inhibition of colon cancer development in mice

Hepatocyte growth factor (HGF), which facilitates the repair of injured mucosa, has the potential to be a new therapeutic agent for inflammatory bowel disease (IBD). However, given that the incidence of colorectal cancer increases continuously with disease duration in patients with IBD, the fact that HGF is a potent mitogen for intestinal epithelial cells may further heighten the risk of bowel cancer in this patient population. In this study, we examined the effects of recombinant HGF on colorectal cancer development in mice with or without experimentally induced colitis. Although HGF stimulated proliferation of colonic epithelial cells in normal mucosa, the development of colorectal cancer induced by repeated injection of azoxymethane (AOM) was significantly inhibited by HGF treatment. In a mouse model of colitis-associated cancer, colorectal cancer frequently developed despite only a single injection of AOM prior to three cycles of dextran sulfate sodium administration. However, HGF treatment significantly facilitated the repair of injured mucosa, leading to inhibition of colorectal cancer development in a dose-dependent manner. Thus, HGF-induced repair of injured mucosa inhibits rather than accelerates the development of colorectal cancer, and these results also suggest the importance of blocking the cycles of mucosal injury and repair to prevent colitis-associated colorectal cancer.

Repeated enemas with hepatocyte growth factor selectively stimulate epithelial cell proliferation of injured mucosa in rats with experimental colitis.

AIMS Hepatocyte growth factor (HGF) modulates intestinal epithelial cell proliferation and migration. We previously reported that systemic administration of recombinant human HGF (rh-HGF) ameliorated experimental colitis. However, an increase in serum HGF concentrations may induce undesired systemic effects, limiting the use of rh-HGF. To avoid possible side effects, we investigated the safety and efficacy of rectally administered rh-HGF as a treatment for experimental colitis. MAIN METHODS We measured serum human HGF concentration following a single rectal enema of rh-HGF. Rats with 2,4,6-trinitrobenzene sulfonic acid (TNBS)- or dextran sulfate sodium (DSS)-induced colitis were treated with rectal enemas of rh-HGF once a day for seven days. The degree of mucosal injuries and the proliferative activity of the colon epithelium were examined. KEY FINDINGS Rats administered a rectal enema of rh-HGF at a dose of 0.1 mg/ml or less had no detectable rh-HGF in the serum. Repeated enemas of rh-HGF at this dose significantly reduced mucosal injuries, both with respect to lesion size and inflammatory cell infiltration. This regimen also stimulated proliferation of epithelial cells surrounding injured mucosa; however, the cell proliferation of uninjured mucosa was not affected by this local treatment. SIGNIFICANCE Rectally administered rh-HGF selectively accelerates the repair of injured mucosa in rat experimental colitis without systemic exposure to HGF. Rectal enemas of HGF are thus a potential novel and safe therapy for IBD.

Hepatitis C virus NS3/4A protease inhibits complement activation by cleaving complement component 4.

Background It has been hypothesized that persistent hepatitis C virus (HCV) infection is mediated in part by viral proteins that abrogate the host immune response, including the complement system, but the precise mechanisms are not well understood. We investigated whether HCV proteins are involved in the fragmentation of complement component 4 (C4), composed of subunits C4α, C4β, and C4γ, and the role of HCV proteins in complement activation. Methods Human C4 was incubated with HCV nonstructural (NS) 3/4A protease, core, or NS5. Samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then subjected to peptide sequencing. The activity of the classical complement pathway was examined using an erythrocyte hemolysis assay. The cleavage pattern of C4 in NS3/4A-expressing and HCV-infected cells, respectively, was also examined. Results HCV NS3/4A protease cleaved C4γ in a concentration-dependent manner, but viral core and NS5 did not. A specific inhibitor of NS3/4A protease reduced C4γ cleavage. NS3/4A protease–mediated cleavage of C4 inhibited classical pathway activation, which was abrogated by a NS3/4A protease inhibitor. In addition, co-transfection of cells with C4 and wild-type NS3/4A, but not a catalytic-site mutant of NS3/4A, produced cleaved C4γ fragments. Such C4 processing, with a concomitant reduction in levels of full-length C4γ, was also observed in HCV-infected cells expressing C4. Conclusions C4 is a novel cellular substrate of the HCV NS3/4A protease. Understanding disturbances in the complement system mediated by NS3/4A protease may provide new insights into the mechanisms underlying persistent HCV infection.

Human neutrophil peptide-1 promotes alcohol-induced hepatic fibrosis and hepatocyte apoptosis

Background and aims Neutrophil infiltration of the liver is a typical feature of alcoholic liver injury. Human neutrophil peptide (HNP)-1 is an antimicrobial peptide secreted by neutrophils. The aim of this study was to determine if HNP-1 affects ethanol-induced liver injury and to examine the mechanism of liver injury induced by HNP-1. Methods Transgenic (TG) mice expressing HNP-1 under the control of a β-actin-based promoter were established. Ethanol was orally administered to HNP-1 TG or wild-type C57BL/6N (WT) mice. SK-Hep1 hepatocellular carcinoma cells were used to investigate the effect of HNP-1 on hepatocytes in vitro. Results After 24 weeks of ethanol intake, hepatic fibrosis and hepatocyte apoptosis were significantly more severe in TG mice than in WT mice. Levels of CD14, TLR4, and IL-6 in liver tissues were higher in TG mice than in WT mice. Apoptosis was accompanied by higher protein levels of caspase-3, caspase-8, and cleaved PARP in liver tissue. In addition, phosphorylated ASK1, ASK1, phosphorylated JNK, JNK1, JNK2, Bax, Bak and Bim were all more abundant in TG mice than in WT mice. In contrast, the level of anti-apoptotic Bcl2 in the liver was significantly lower in TG mice than in WT mice. Analysis of microRNAs in liver tissue showed that miR-34a-5p expression was significantly higher in TG mice than in WT mice. Furthermore, in the presence of ethanol, HNP-1 increased the apoptosis with the decreased level of Bcl2 in a concentration-dependent manner in vitro. Conclusions HNP-1 secreted by neutrophils may exacerbate alcohol-induced hepatic fibrosis and hepatocyte apoptosis with a decrease in Bcl2 expression and an increase in miR-34a-5p expression.

Utility of percutaneous radiofrequency ablation alone or combined with transarterial chemoembolization for early hepatocellular carcinoma

Percutaneous radiofrequency ablation (RFA) combined with transarterial chemoembolization (TACE) is an effective, standard therapy against small hepatocellular carcinoma (HCC). However, there is debate regarding the effectiveness of RFA combined with TACE (RFA/TACE) compared with RFA alone. These two approaches were compared for the treatment of early HCC. The present study examined 83 HCC tumors in 83 patients treated with RFA between April 2007 and August 2014 at three medical institutions. All HCCs were single hypervascular tumors, with a median diameter of 16 mm (range, 6-30 mm). The overall survival (OS) rate of all patients (n=83) was 97.5% at 1 year, 82.8% at 3 years and 48.6% at 5 years, and the local recurrence rate of all patients was 14.3% at 1 year, 32.3% at 3 years and 36.5% at 5 years. The tumor-free survival (TFS) rate of all patients was 95.1% at 1 year, 56.3% at 3 years and 23.4% at 5 years. Compared with RFA alone, RFA/TACE significantly improved OS (P<0.001), intrahepatic distant recurrence (IDR; P=0.038) and TFS (P=0.010). A univariate analysis of prognostic indicators revealed that age <70 years (P=0.008), aspartate transaminase <40 IU/l (P=0.003), alanine aminotransferase <40 IU/l (P=0.006) and platelet count >10×104/µl (P=0.05) were associated with a high survival rate. Multivariate analysis identified RFA/TACE [hazard ratio (HR), 0.108; P=0.001] as an independent prognostic indicator. RFA/TACE was identified as the only independent indicator of IDR (HR: 0.467; P=0.042) and TFS (HR: 0.452; P=0.012). RFA/TACE improved OS rate, IDR and TFS compared with RFA alone. The data suggested that RFA/TACE should be considered for the treatment of single hypervascular HCC.