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Protein kinase C delta (PKCδ) is a multifunctional PKC family member and has been implicated in many types of cancers, including liver cancer. Recently, we have reported that PKCδ is secreted from liver cancer cells, and involved in cell proliferation and tumor growth. However, it remains unclear whether the extracellular PKCδ directly regulates cell surface growth factor receptors. Here, we identify epidermal growth factor receptor (EGFR) as a novel interacting protein of the cell surface PKCδ in liver cancer cells. Imaging studies showed that secreted PKCδ interacted with EGFR-expressing cells in both autocrine and paracrine manners. Biochemical analysis revealed that PKCδ bound to the extracellular domain of EGFR. We further found that a part of the amino acid sequence on the C-terminal region of PKCδ was similar to the putative EGFR binding site of EGF. In this regard, the point mutant of PKCδ in the binding site lacked the ability to bind to the extracellular domain of EGFR. Upon an extracellular PKCδ-EGFR association, ERK1/2 activation, downstream of EGFR signaling, was apparently induced in liver cancer cells. This study indicates that extracellular PKCδ behaves as a growth factor and provides a molecular basis for extracellular PKCδ-targeting therapy for liver cancer.

Background and Aim Sarcopenia frequently develops in patient with liver cirrhosis (LC). Ethanol reduces muscle protein synthesis and accelerates proteolysis. However, the relationship between heavy alcohol consumption and sarcopenia remains controversial. This study aimed to investigate the characteristics and prevalence of sarcopenia among patients with alcoholic LC (ALC) in real‐world clinical settings. Methods This cross‐sectional study included 181 patients with LC. Heavy alcohol consumption was defined as >60 g/day. Sarcopenia was diagnosed according to the Japan Society of Hepatology criteria. Results Among the 181 patients, 64 (35.4%) were diagnosed with ALC. Patients with ALC were younger (median, 61.5 vs 72.0 years; P, This study aimed to investigate the characteristics and prevalence of sarcopenia among 181 patients with alcoholic liver cirrhosis (ALC). Patients with ALC were younger and had a lower prevalence of sarcopenia, despite advanced disease stage/impaired liver function reserve, compared to those with non‐ALC.

Background and Aim Although tenofovir alafenamide (TAF), as well as entecavir (ETV), is widely used as first‐line treatment for patients with chronic hepatitis B, there are only a few studies comparing sequential therapy from ETV to TAF and continuous ETV monotherapy in patients with maintained virologic response to ETV. Methods In a retrospective multicenter study, we investigated the efficacy and safety of sequential therapy from ETV to TAF (ETV‐TAF group) and compared them with continuous ETV monotherapy (ETV group), using propensity score matching, in chronic hepatitis B patients. Results From 442 patients, we analyzed 142 patients from each group comprising 71 patients matched for several data, including age, HBV genotype, hepatitis B envelope antigen, cirrhosis, alanine aminotransferase, platelet count, prior ETV monotherapy period, and hepatitis B surface antigen (HBsAg) change during prior ETV monotherapy. In the ETV‐TAF group, HBsAg levels significantly decreased from baseline to 48 weeks after switching to TAF (−0.02 log IU/mL, P = 0.038). HBcrAg levels also significantly decreased after switching to TAF (−0.1 log IU/mL, P = 0.004). However, there were no significant differences in the reduction of HBsAg and HBcrAg levels between the ETV‐TAF and ETV groups. There was no significant difference in the change of estimated glomerular filtration rate levels from baseline to 48 weeks between the two groups. Conclusions The present study indicated that the efficacy, especially of the HBsAg‐reducing action, and safety of sequential therapy from ETV to TAF were similar to those of continuous ETV monotherapy among chronic hepatitis B patients with maintained virologic response to ETV., In a retrospective, multicenter study involving 17 institutions, we investigated the efficacy and safety of sequential therapy from entecavir (ETV) to tenofovir alafenamide (TAF) (ETV‐TAF group). The present study indicated that the efficacy, especially of the hepatitis B surface antigen‐reducing action, and safety of sequential therapy from ETV to TAF were similar to those of continuous ETV monotherapy.

BACKGROUND AND AIM Primary biliary cholangitis (PBC) patients who are refractory to ursodeoxycholic acid (UDCA) are at risk for progression to cirrhosis and liver failure. Bezafibrate could be an alternative second-line therapeutic option in these patients. This study aimed to evaluate the long-term outcome(s) of combined UDCA and bezafibrate therapy in UDCA-refractory PBC patients and identify prognostic factors. METHODS Among 445 patients treated with UDCA, 150 patients inadequately responded to UDCA monotherapy and received long-term UDCA plus bezafibrate (median, 15 years). Data from these patients were used for this retrospective analysis. RESULTS Combination therapy resulted in significant improvements in serum biochemistry and liver transplantation risk estimated using the UK-PBC-risk and the GLOBE scores. The cumulative normalization rates of alkaline phosphatase, gamma-glutamyltransferase, and immunoglobulin M (IgM) were significantly higher in patients without cirrhosis-related symptoms or liver-related events than in those with them. Overall, IgM constantly emerged as a significant factor associated with cirrhosis-related symptoms and liver-related events at all time points. Cumulative survival rates were significantly lower in patients with IgM ≥ 240 mg/dL than in patients with IgM

Based on high efficacy and safety demonstrated in clinical trials, treatment with glecaprevir/pibrentasvir (G/P) for 8 weeks is recommended for hepatitis C virus (HCV)-infected patients who are direct-acting antiviral (DAA) naïve, genotype 1 or 2, and noncirrhotic. The aim of this study was to validate real-world experience with 8-week G/P treatment in Japan. We conducted a prospective observational cohort study in 554 patients who underwent 8-week treatment from among 1,022 patients who initiated G/P therapy. The majority (54.5%) were male, with a median age of 66 years, and HCV genotype distribution was genotype 1, 43.8%; genotype 2, 55.3%; and mixed subtype, 0.9%. Overall, the sustained virologic response rate at 12 weeks (SVR12) was 92.8% (530/571) in the intention-to-treat population and 99.3% (526/530) in the per-protocol population. The SVR12 rates by subgroups were as follows: subtype 1a, 100% (6/6); 1b, 100% (189/189); 2a, 99.3% (150/151); 2b, 99.0% (103/104); and mixed subtype, 50% (2/4). Among four patients with virologic failure following 8-week treatment with G/P, none had baseline polymorphisms or treatment-emergent amino acid substitutions in NS3. However, 2 of 4 patients with virologic failure had treatment-emergent amino acid substitutions in NS5A. Adverse events (AEs) were reported in 21.5% of patients and 1.2% of patients discontinued due to drug-related AEs. In conclusion, G/P treatment for 8 weeks was safe and effective for DAA-naïve noncirrhotic genotype 1 or 2 patients in a real-world clinical setting in Japan.

Aim Primary biliary cholangitis (PBC) is an autoimmune liver disease with unknown pathogenesis. In PBC, activation of T-cell receptor (TCR) signaling is associated with inflammatory cytokine production through N-Ras upregulation. Although the CD4+ T cell TCR repertoire could be associated with PBC pathogenesis, it has not been evaluated. Thus, we analyzed the PBC-CD4+ T cell TCR repertoire using next generation sequencing (NGS). Methods Four PBC patients (one treatment-naive and three receiving ursodeoxycholic acid) and three healthy individuals were enrolled. NRAS expression in CD4+ T cells was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). N-Ras dynamics in CD4+ T cells were assessed by qRT-PCR and GTP-N-Ras activation assay. The TCR α- (TRA) and β-chain (TRB) repertoires on CD4+ T cells were analyzed by NGS and profiled using hierarchical analysis. Motif analysis was undertaken to elucidate the structure of PBC-specific TCRs. Results NRAS was upregulated in PBC relative to control CD4+ T cells (P 2). Among them, TRAV29/J22, TRBV6-5/J2-6, and TRBV10-1/J2-1 were expressed in PBC but the expression was negligible in the controls, with more mature and longer forms observed in PBC-CD4+ T cells. Conclusions N-Ras was upregulated in PBC-CD4+ T cells, and it enhanced TCR activation, indicating that PBC-CD4+ T cells were activated by N-Ras upregulation with differentially expressed TCR repertoires on their surfaces.

AIM Serum Mac-2 binding protein (M2BP) and Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+ -M2BP) are used to estimate the liver fibrosis stage in chronic liver diseases. However, few head-to-head studies have been carried out to compare the two biomarkers in non-alcoholic fatty liver disease (NAFLD). METHODS Serum M2BP and WFA+ -M2BP levels were compared against clinical characteristics and liver histological manifestations in the same samples collected from 213 biopsy-proven NAFLD patients. RESULTS Median levels (range) of M2BP and WFA+ -M2BP were 1.58 (0.70-7.75) pg/mL and 0.85 (0.22-11.32) cut-off index (COI), respectively. Fibrosis stages 1, 2, 3, and 4 were determined in 136, 37, 17, and 23 patients, respectively. Median levels of both biomarkers increased stepwise with fibrosis progression. The M2BP and WFA+ -M2BP levels showed a significant positive correlation (r = 0.643, P = 2.91 × 10-26 ), but a marked discrepancy between both biomarkers was noted in five stage 4 and three stage 1 patients, who had high WFA+ -M2BP but relatively low M2BP levels. Most of these outliers had findings suggestive of more advanced fibrosis. For diagnosing any fibrosis severity, WFA+ -M2BP had greater area under the receiver operating characteristic curve (AUC) and predictive accuracy than M2BP. Among eight fibrosis markers/indices, WFA+ -M2BP yielded the second highest AUC (0.832) and the highest predictive accuracy (82.2%) to diagnose cirrhosis. In addition, WFA+ -M2BP showed the second highest predictive accuracy to diagnose severe fibrosis (78.4%) and significant fibrosis (76.1%). CONCLUSION This head-to-head comparison suggests that WFA+ -M2BP is superior to M2BP for distinguishing liver fibrosis stages in NAFLD patients. A marked discrepancy between the two biomarkers may be indicative of advanced NAFLD (UMIN000023286).