Analysis of the optimal psoas muscle mass index cut-off values, as measured by computed tomography, for the diagnosis of loss of skeletal muscle mass in Japanese people

This study aimed to determine the optimal psoas muscle mass index (PMI) cut-off values for diagnosis of skeletal muscle mass loss.

METHODS

We evaluated PMI in two groups of normal controls: a medical check-up group and a liver donation candidate group. We analyzed two novel PMI cut-off values, one based on the mean - two standard deviations (2SD) and one based on the lower 5%. Skeletal muscle mass index (SMI) evaluations using computed tomography (sliceOmatic; TomoVision) and bioelectrical impedance analysis and PMI evaluation were undertaken simultaneously. We analyzed the correlation between our PMI cut-off values and the Japan Society of Hepatology-defined SMI cut-off values. The prevalence of skeletal muscle mass loss in patients with liver disease was assessed using the novel PMI cut-off values.

RESULTS

In 504 normal controls aged ≤50 years, the PMI cut-off values based on mean -2SD and the lower 5% were set at 3.30 cm² /m² for men and 1.69 cm² /m² for women and 3.74 cm² /m² for men and 2.29 cm² /m² for women, respectively. The PMI cut-off values based on the lower 5% alone showed that skeletal muscle mass loss increased with age. Furthermore, they correlated well with Japan Society of Hepatology-defined SMI (sliceOmatic) cut-off values and showed a significantly higher prevalence of skeletal muscle mass loss in patients with liver cirrhosis than those without liver cirrhosis.

CONCLUSIONS

We propose the following PMI cut-off values: 3.74 cm² /m² for male individuals and 2.29 cm² /m² for female individuals. These cut-off values can facilitate accurate diagnosis and management of sarcopenia in patients with chronic liver disease.

High serum angiopoietin-2 level predicts non-regression of liver stiffness measurement-based liver fibrosis stage after direct-acting antiviral therapy for hepatitis C

AIM

Factors associated with improvement of liver fibrosis after successful hepatitis C virus (HCV) eradication by interferon (IFN)-free direct-acting antiviral agents (DAAs) have been not clarified well. Angiopoietin-2 (Ang2) is reported to be associated with vascular leak and inflammation observed in patients with advanced liver fibrosis.

METHODS

In this retrospective study, patients treated with IFN-free DAAs who underwent transient elastography before and at 24-weeks post-treatment and achieved sustained viral response were enrolled. Baseline serum Ang2 was measured, and its relationship with other clinical factors was analyzed. Liver fibrosis stage was defined based on liver stiffness according to a previous report. Predictive factors for regression of liver fibrosis stage after DAA therapy were evaluated.

RESULTS

Overall, 116 patients were analyzed. Baseline serum Ang2 levels were significantly associated with liver stiffness, spleen index, and liver stiffness-based liver fibrosis stage. Moreover, 75% of patients experienced regression of liver fibrosis stage after DAA therapy. Multivariate analysis revealed that advanced liver fibrosis stage and Ang2 levels were significantly associated with regression of liver fibrosis stage after DAA therapy. In patients with advanced liver fibrosis (F3/4), baseline Ang2 level alone could predict regression of liver fibrosis stage. A baseline Ang2 cut-off value (354 pg/ML) could predict regression of liver fibrosis stage after DAA therapy with high accuracy (sensitivity 0.882, specificity 0.733).

CONCLUSIONS

Evaluation of serum Ang2 levels before DAA therapy is important. Our results provide a novel mechanistic insight into non-regression of liver stiffness after DAA therapy. Long-term and larger studies are required.

Baseline angiopoietin-2 and FGF19 levels predict treatment response in patients receiving multikinase inhibitors for hepatocellular carcinoma

Background

Sorafenib and lenvatinib are first‐line systemic therapies for unresectable hepatocellular carcinoma (HCC). However, the criteria for their selection remain unclear.

Methods

We identified patients with unresectable HCC who were treated with sorafenib or lenvatinib between August 2009 and January 2019 at the Hokkaido University Hospital. Patients who continued treatment for >2 months, underwent evaluation by computed tomography every 2–3 months, and had complete clinical data were included. Responders were patients with objective response (OR) for lenvatinib and patients with stable disease (SD) exceeding 6 months (long‐SD) or OR for sorafenib. The predictive factors for treatment response, including fibroblast growth factor (FGF)19 and 21, angiopoietin 2 (ANG2), hepatocyte growth factor, and vascular endothelial growth factor, were evaluated.

Results

Overall, 27 and 29 patients treated with lenvatinib and sorafenib, respectively, were included. The responders for lenvatinib and sorafenib were 63% (17/27) and 38% (11/29), respectively. No significant predictive factors for treatment response were identified in patients treated with sorafenib. However, baseline serum FGF19 and ANG2 levels were significantly associated with treatment response to lenvatinib. All (9/9) patients with low baseline ANG2 and FGF19 levels who received lenvatinib achieved OR. Conversely, the OR was low (13%; 1/9) in patients with high baseline ANG2 and FGF19 levels. Responder rate was 40% (2/5) in patients with high baseline ANG2 and FGF19 levels who received sorafenib.

Conclusion

This study is, to our knowledge, the first to demonstrate that baseline ANG2 and FGF19 levels may aid in selecting optimal systemic therapy for patients with unresectable HCC.

Effects of resistance-associated variants in genotype 2 hepatitis C virus on viral replication and susceptibility to antihepatitis C virus drugs

AIMS

Development of direct-acting antivirals (DAAs) has made antihepatitis C virus (HCV) treatment highly safe and effective. However, the emergence of resistant-associated variants (RAVs) after failure of DAA therapy affects retreatment outcomes. In particular, genotype 1 HCV with P32 deletion has been reported to be highly resistant to all approved non-structural protein (NS)5A inhibitors. However, analysis of RAVs in genotype 2 HCV has been limited. Accordingly, in this study, we evaluated the roles of genotype 2 HCV variants in antiviral drug efficacy.

METHODS

We utilized HCV-2b/2a (JFH-1) chimeric virus (genotype 2a), which replicates more robustly than JFH-1. We constructed various genotype 2a JFH-1-based HCV cell culture systems with NS3 (D168E), NS5A (F28S, F28S/M31I, P32 deletion, and Y93H), and NS5B (S282 T) RAVs and analyzed the replication ability and sensitivity to various anti-HCV reagents.

RESULTS

Genotype 2a-based HCV with NS5A-P32 deletion could not replicate even in long-term cultures. Genotype 2a-based HCV with NS5A-F28S/M31I showed significantly higher replication ability than the wild-type strain, and replication could not be suppressed, even with high concentrations of NS5A inhibitors, including pibrentasvir and velpatasvir (<1000-10 000 fold-resistance compared with the wild-type strain). However, genotype 2a-based HCV with NA5A-F28S/M31I was sensitive to HCV protease inhibitor, NS5B inhibitor, interferon-α, and ribavirin. Genotype 2a-based HCV with NS5B-S282 T was resistant to sofosbuvir, but was highly sensitive to ribavirin compared with the control.

CONCLUSIONS

When undertaking retreatment for genotype 2a HCV-infected patients who fail to respond to DAAs, the optimized retreatment should be chosen according to the sensitivity of the emerging RAVs to anti-HCV drugs.

Entecavir treatment of hepatitis B virus-infected patients with severe renal impairment and those on hemodialysis

AIM

Entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) are first-line nucleos(t)ide analogues for hepatitis B virus (HBV)-infected patients. However, consecutive TDF treatment causes renal dysfunction, and the safety and efficacy of TAF have not been established in severe renal dysfunction patients, including hemodialysis patients. The efficacy and safety of ETV in these populations has not been clarified. The study aimed to clarify this.

METHODS

In this retrospective multicenter study, between 2006 and 2018, a total of 567 HBV-infected patients treated with ETV monotherapy were screened. Patients were included if >20 years old, treated with ETV monotherapy for >1 year, and had proper clinical information. The efficacy of ETV and changes in renal function were evaluated according to renal function.

RESULTS

A total of 273 patients were included: 9.2% (25/273), 1.8% (5/273), and 3.7% (10/273) had chronic kidney disease (CKD) stage G3, CKD stage G4/5, and were on hemodialysis, respectively. Overall, 84.2%, 94.0%, and 96.2% of patients experienced serum HBV-DNA disappearance at 1, 2, and 3 years, respectively, after treatment initiation. In patients with CKD stage G3-5, estimated glomerular filtration rate tended to restore with time, which was in contrast to patients without renal dysfunction. The rate of disappearance in serum HBV-DNA, alanine transaminase normalization, and virological breakthrough was similar between patients with or without renal dysfunction. ETV showed high efficacy for all 10 hemodialysis patients without virological breakthrough.

CONCLUSIONS

Entecavir for HBV-infected patients with severe renal dysfunction, including hemodialysis patients, is highly effective and does not affect renal function.

Assessing the risk of hepatocellular carcinoma by combining liver stiffness and the controlled attenuation parameter

AIM

Ultrasound technology can now be used for liver stiffness measurement (LSM) and for evaluating the amount of hepatic fat quantitatively known as the controlled attenuation parameter (CAP). This study aimed to determine the applicable cut-off values of LSM and the CAP for primary hepatocellular carcinoma (HCC), and to investigate their clinical usefulness for assessing HCC risk in patients with chronic liver disease.

METHODS

A total of 1054 patients (88 with primary HCC and 966 without HCC) whose LSM and the CAP were measured by transient elastography with clinically evident hepatitis C virus (419 patients), hepatitis B virus (377 patients), and non-alcoholic fatty liver disease (258 patients) were enrolled in this study. Subsequently, a total of 966 patients who did not have HCC initially were followed, and the usefulness of the cut-off values of LSM and CAP for HCC development were evaluated.

RESULTS

In hepatitis C virus patients, the incidence of HCC development was significantly higher among those with a combination of LSM ≥8.0 kPa and CAP ≤221 dB/m than among those with other values (log-rank test 0.0239, hazard ratio 2.66, 95%CI 1.07-6.47, P = 0.0362). In non-alcoholic fatty liver disease patients, the incidence of HCC development was significantly higher among those with a combination of LSM ≥5.4 kPa and CAP ≤265 dB/m than among others (log-rank test 0.0040, hazard ratio 8.91, 95% CI 1.47-67.97, P = 0.0192).

CONCLUSION

In the hepatitis C virus and non-alcoholic fatty liver disease groups, a combination of LSM and the CAP cut-off values would be useful for screening to identify the high-risk group for primary HCC development.

Early response and safety of lenvatinib for patients with advanced hepatocellular carcinoma in a real-world setting

Background and Aim

Lenvatinib has been recently approved as a first‐line systematic therapy for patients with advanced hepatocellular carcinoma (HCC) based on the results of the phase 3 clinical trial REFLECT. This trial excluded patients with a history of systemic chemotherapy, bile duct invasion, and Child‐Pugh grade B. We aimed to investigate the efficacy and safety of lenvatinib for these patients and in the real‐world setting.

Methods

Among patients who were administered lenvatinib for advanced HCC between April and October 2018 in Hokkaido University Hospital and related hospitals, we evaluated those who were followed for more than 2 months and whose treatment response was evaluated via dynamic computed tomography at baseline and 2 months after treatment initiation. Meanwhile, patients were excluded if they had decompensated liver cirrhosis, were followed up less than 2 months, or were not evaluated at 2 months. Patients were also stratified according to compliance with the REFLECT inclusion criteria for further analysis.

Results

A total of 41 patients were included; more than 50% did not meet the REFLECT inclusion criteria. In total, 5 (12.2%), 20 (48.8%), 12 (29.3%), and 4 (9.3%) showed complete response, partial response, stable disease, and progressive disease, respectively. The objective response rate was 61.2%. The objective response rate and disease control rate were similar between patients who did and did not meet the REFLECT inclusion criteria. Moreover, the safety profile was also similar between the two patient groups.

Conclusion

Lenvatinib showed high early response rate and tolerability in patients with advanced HCC. Favorable outcomes were similarly observed in patients who did not meet the REFLECT inclusion criteria.

Metformin Regulates the Expression of CD133 Through the AMPK-CEBPβ Pathway in Hepatocellular Carcinoma Cell Lines

CD133 is a cellular surface protein, which has been reported to be a cancer stem cell marker, and thus is considered a potential target for cancer treatment. Metformin, one of the biguanides used for the treatment of diabetes, is also known to reduce the risk of cancer development and cancer stem-like cells (CSCs), including the expression of CD133. However, the mechanism underlying the reduction of the expression of CD133 by metformin is not yet understood. This study shows that metformin suppressed CD133 expression mainly by affecting the CD133 P1 promoter via adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling but not the mammalian target of rapamycin (mTOR). AMPK inhibition rescued the reduction of CD133 by metformin. Further experiments demonstrated that CCAAT/enhancer-binding protein beta (CEBPβ) was upregulated by metformin and that two isoforms of CEBPβ reciprocally regulated the expression of CD133. Specifically, the liver-enriched activator protein (LAP) isoform increased the expression of CD133 by directly binding to the P1 promoter region, whereas the liver-enriched inhibitory protein (LIP) isoform suppressed the expression of CD133. Consistent with these findings, a three dimensional (3D) culture assay and drug sensitivity assay demonstrated that LAP-overexpressing cells formed large spheroids and were more resistant to 5-fluorouracil (5-FU) treatment, whereas LIP-overexpressing cells were more sensitive to 5-FU and showed combined effects with metformin. Our results indicated that metformin-AMPK-CEBPβ signaling plays a crucial role in regulating the gene expression of CD133. Additionally, regulating the ratio of LAP/LIP may be a novel strategy for targeting CSCs for the treatment of cancer.

The Successful Retreatment with Glecaprevir and Pibrentasvir of Genotype 1 or 2 HCV-infected Hemodialysis Patients who Failed to Respond to NS5A and Protease Inhibitor Treatment

Clinical trials and real-world data have proven that hepatitis C virus (HCV) in most infected patients can be eradicated by direct-acting antivirals (DAAs). However, the proper retreatment regimen for hemodialysis patients with HCV infection who have previously failed to respond to DAAs has not been clarified. We herein report, for the first time, the successful retreatment with glecaprevir and pibrentasvir, of three hemodialysis patients with genotype 1 or 2 HCV infection, who had previously failed to respond to combination therapy with an HCV-NA5A inhibitor (daclatasvir) and an HCV protease inhibitor (asunaprevir).

Glecaprevir and Pibrentasvir for Japanese Patients with Human Immunodeficiency Virus and Genotype 3 Hepatitis C Virus Coinfection: A Report of Three Cases

The efficacy and safety of glecaprevir and pibrentasvir in Japanese patients with human immunodeficiency virus (HIV) and/or genotype 3 hepatitis C virus (HCV) infection is yet to be clarified. This is because no or only a few patients have been included in Japanese phase 3 trials. We herein report for the first time the successful treatment of glecaprevir and pibrentasvir in three Japanese patients with HIV and genotype 3 HCV coinfection as well as hemophilia. Glecaprevir and pibrentasvir treatment is safe and effective for Japanese patients with genotype 3 HCV and HIV coinfection.

Safety and efficacy of elbasvir and grazoprevir in Japanese hemodialysis patients with genotype 1b hepatitis C virus infection

BACKGROUND

The prevalence of hepatitis C virus (HCV) infection in hemodialysis patients is high and results in a poor prognosis. Thus, safer and more effective treatment regimens are required. In this prospective multicenter study, we investigated the efficacy and safety of the novel HCV-NS5A-inhibitor, elbasvir, and protease inhibitor, grazoprevir in Japanese hemodialysis patients with genotype 1b HCV infection.

METHODS

This study is registered at the UMIN Clinical Trials Registry as UMIN00002578. A total of 23 Japanese dialysis patients with genotype 1b HCV infection who were treated with elbasvir and grazoprevir between January 2017 and March 2018 and followed for more than 12 weeks after treatment completion were included. We evaluated the sustained virologic response at 12 weeks after treatment completion (SVR12) and safety during treatment.

RESULTS

Of the 23 patients, 7 had advanced liver fibrosis and 2 had a signature resistance-associated variant of NS5A (NS5A RAVs)-L31M/V or Y93H at baseline. All patients completed therapy, and 96.7% (22/23) of the patients achieved SVR12. All patients with advanced liver fibrosis and signature NS5A RAVs at baseline achieved SVR12 with a high safety profile. No patient experienced lethal or severe adverse events during therapy, and the most common adverse event was anemia. One patient, who was a non-responder to this therapy, had a history of failure with daclatasvir and asunaprevir therapies and had NS5A RAVs of A92K at baseline, but not signature NS5A RAVs.

CONCLUSIONS

Grazoprevir and elbasvir combination is highly effective and safe for hemodialysis patients with genotype 1b HCV infection.

Liver steatosis and dyslipidemia after HCV eradication by direct acting antiviral agents are synergistic risks of atherosclerosis

Aim

We comprehensively analyzed how hepatitis C virus (HCV) eradication by interferon (IFN)-free direct-acting-antiviral-agents (DAAs) affects liver steatosis and atherogenic risk.

Methods

Patients treated with IFN-free-DAAs who underwent transient elastography before and at 24-weeks post-treatment, including controlled attenuation parameter (CAP), and achieved sustained viral response (SVR) were enrolled. The association between changes in liver steatosis, lipid-metabolism, and genetic and clinical factors was analyzed.

Results

A total of 117 patients were included. The mean CAP and low-density lipoprotein cholesterol (LDL-C) levels were significantly elevated at SVR24. However, baseline LDL-C and CAP values were significantly negatively correlated with changes in these values after HCV eradication, indicating that in patients with high baseline values, the values generally decreased after HCV eradication. Mean small-dense LDL-C (sdLDL-C), which has greater atherogenic potential, was significantly elevated only in patients with both dyslipidemia (LDL-C >140 mg/dL) and liver steatosis (CAP >248 dB/m) at SVR24. Those patients had significant higher baseline BMI, LDL-C, and total-cholesterol levels.

Conclusions

Generally, successful HCV eradication by IFN-free-DAAs decreases CAP and LDL-C in patients with high baseline values. However, elevated LDL-C was accompanied with elevated sdLDL-C only in patients with liver steatosis and dyslipidemia at SVR24; therefore, those patients may require closer monitoring.

L-Carnitine Suppresses Loss of Skeletal Muscle Mass in Patients With Liver Cirrhosis

Liver cirrhosis (LC) is a major cause of secondary sarcopenia. Sarcopenia makes the prognosis worse; thus, novel therapeutic options for sarcopenia in patients with LC are urgently required as they are currently limited. In this retrospective study, 158 patients with LC were screened, and 35 of those patients who were treated with L‐carnitine for more than 6 months and for whom skeletal muscle mass changes could be evaluated by computer tomography were enrolled. Of the 158 patients, 79 patients who did not receive L‐carnitine supplementation served as controls. Cases and controls were propensity score matched for age, sex, presence of hepatocellular carcinoma, and branched chain amino acid administration, and changes in skeletal muscle mass and clinical data were compared. The 35 patients who received L‐carnitine supplementation and 35 propensity score‐matched patients who did not receive carnitine supplementation comprised the final enrollment. Compared with control patients, patients who received L‐carnitine had significantly worse liver function, which is associated with rapid progress of skeletal muscle depletion. However, loss of skeletal muscle mass was significantly suppressed in patients receiving L‐carnitine, and a significant effect was observed in patient subgroups stratified by age, sex, presence of hepatocellular carcinoma, and branched chain amino acid administration. The change ratios of most laboratory data, including vitamin D and insulin‐like growth factor 1 levels, were similar in the two groups, but ammonia levels were significantly less in those receiving L‐carnitine. However, even in patients receiving L‐carnitine but not showing an ammonia decrease, loss of skeletal muscle was significantly suppressed. Conclusion: L‐carnitine suppresses loss of skeletal muscle mass and may therefore be a novel therapeutic option for sarcopenia in patients with LC. (Hepatology Communications 2018; 00:000‐000)

Safety and efficacy of sofosbuvir and ribavirin for genotype 2 hepatitis C Japanese patients with renal dysfunction

AIM

The safety and efficacy of sofosbuvir (SOF) and ribavirin (RBV) have not been well clarified in patients with renal dysfunction because clinical trials have not included such patients. We evaluated the safety and efficacy of SOF and RBV for genotype 2 hepatitis C virus (HCV)-infected patients with renal dysfunction.

METHODS

The study included genotype 2 HCV-infected patients who received SOF and RBV between July 2014 and May 2017. The sustained virologic response (SVR) after the treatment and safety during the therapy were evaluated according to renal function.

RESULTS

A total of 231 patients were included in this study. The median age was 62 years old, and 45.9% (106/231) were men. Of the 231 patients, 191 (82.8%) and 40 (17.2%) were classified as having chronic kidney disease (CKD) stages G1/2 and G3, respectively. The overall SVR rate was 97% (224/231). The SVR rates in patients with CKD stages G1, 2, G3a, and G3b were 98.1%, 98.6%, 87.9%, and 100%, respectively, and this therapy was tolerated. Multivariate analysis indicated that renal dysfunction was significantly associated with a non-SVR (odds ratio, 6.963; 95% confidence interval, 1.494-32.41; P = 0.013). The patients with renal dysfunction were older, had advanced liver fibrosis, lower baseline platelet and hemoglobin levels, and a higher rate of RBV dose reduction.

CONCLUSIONS

Sofosbuvir and RBV therapy is highly effective and safe for genotype 2 HCV-infected Japanese patients. However, attention should be paid to baseline renal function when SOF- and RBV-containing regimens are used for patients with renal dysfunction.

Add-on effects of fluvastatin in simeprevir/pegylated-interferon/ribavirin combination therapy for patients with genotype 1 hepatitis C virus infection: A randomized controlled study

BACKGROUND

The Japan Society of Hepatology guidelines indicate that hepatitis C virus (HCV) protease inhibitor combination therapy with simeprevir (SMV), pegylated-interferon (Peg-IFN), and ribavirin (RBV) is a therapeutic option for patients who fail to respond to a direct direct-acting antiviral-containing regimen. However, treatment outcomes have room for improvement. Fluvastatin (FLV) add-on treatment in Peg-IFN and RBV combination therapy for HCV-infected patients significantly improved the sustained virologic response (SVR), but the add-on effect of FLV on SMV combination therapy is not well understood.

METHODS

This was a prospective, randomized, multicenter study in which a total of 61 HCV genotype 1b-infected patients were recruited and 60 eligible patients were randomly allocated to two groups that received 12 weeks of SMV/Peg-IFN/RBV followed by 12 weeks of Peg-IFN/RBV with or without 24 weeks of FLV. The SVR rate and adverse events were compared between the two groups.

RESULTS

Thirty-one patients were allocated to the FLV add-on group and 29 patients were allocated to the control group. Baseline clinical factors, including median age, baseline platelet count, alanine aminotransferase level, HCV RNA titer, Fibrosis-4 index, and rate of IL28B minor genotype, were all similar between the two groups. The rapid virologic response, end-of-treatment response rates, SVR rates at 24 weeks after treatment, and safety profiles were also similar between the two groups.

CONCLUSIONS

This prospective, randomized, multicenter study indicated that FLV had no add-on effect when given with SMV/Peg-IFN/RBV combination therapy for genotype 1b HCV-infected patients.

Comparing the risk of hepatitis B virus reactivation between direct-acting antiviral therapies and interferon-based therapies for hepatitis C

Hepatitis B virus (HBV) reactivation has been reported during antihepatitis C treatment in patients with hepatitis C virus (HCV) and HBV co-infection. We aimed to evaluate the frequency and risk factors of HBV reactivation during anti-HCV therapy and compared those between interferon (IFN)-free direct-acting antiviral (DAA) therapies and IFN-based therapies. Three hundred and twenty-two patients with HCV infection receiving anti-HCV therapy were retrospectively screened. The baseline HBV infection statuses of all eligible patients and the HBV-DNA level of all patients with current or previous HBV infection were examined at the end of treatment. In patients with baseline anti-HBs positivity, changes in anti-HBs titre were evaluated. Of 287 patients who met the inclusion criteria, 157 had current (n=4) or previous (n=153) HBV infection; 85 were treated with IFN-free DAA therapies and 72 were treated with IFN-based therapies. Six patients experienced HBV reactivation (n=2) or HBV reappearance (n=4) after IFN-free DAA therapies, while no patient developed HBV reactivation after IFN-based therapies. The risk factors of HBV reactivation or reappearance were DAA therapies and a reduction in anti-HBs titre to <12 mIU mL^-1 by the end of treatment. The decline changes of anti-HBs titre were significantly higher in patients treated with DAA therapies. Although HBV reactivation hepatitis was not observed, three of four patients with HBV reactivation or reappearance after achieving HCV eradication had viremia 8 weeks after completion of therapy. A significant proportion of patients develop HBV reactivation or reappearance without hepatitis after IFN-free DAA therapies. Low levels of anti-HBs and their decrease to <12 mIU mL^-1 after treatment are significant risk factors for HBV reactivation or reappearance.

Interplay between Notch1 and Notch3 promotes EMT and tumor initiation in squamous cell carcinoma

Notch1 transactivates Notch3 to drive terminal differentiation in stratified squamous epithelia. Notch1 and other Notch receptor paralogs cooperate to act as a tumor suppressor in squamous cell carcinomas (SCCs). However, Notch1 can be stochastically activated to promote carcinogenesis in murine models of SCC. Activated form of Notch1 promotes xenograft tumor growth when expressed ectopically. Here, we demonstrate that Notch1 activation and epithelial–mesenchymal transition (EMT) are coupled to promote SCC tumor initiation in concert with transforming growth factor (TGF)-β present in the tumor microenvironment. We find that TGFβ activates the transcription factor ZEB1 to repress Notch3, thereby limiting terminal differentiation. Concurrently, TGFβ drives Notch1-mediated EMT to generate tumor initiating cells characterized by high CD44 expression. Moreover, Notch1 is activated in a small subset of SCC cells at the invasive tumor front and predicts for poor prognosis of esophageal SCC, shedding light upon the tumor promoting oncogenic aspect of Notch1 in SCC.

Notch receptors can exert different roles in cancer. In this manuscript, the authors reveal that Notch1 activation and EMT promote tumor initiation and cancer cell heterogeneity in squamous cell carcinoma, while the repression of Notch3 by ZEB1 limits Notch1-induced differentiation, permitting Notch1-mediated EMT.

Fibroblast growth factor-2-mediated FGFR/Erk signaling supports maintenance of cancer stem-like cells in esophageal squamous cell carcinoma

In esophageal squamous cell carcinoma (ESCC), a subset of cells defined by high expression of CD44 and low expression of CD24 has been reported to possess characteristics of cancer stem-like cells (CSCs). Novel therapies directly targeting CSCs have the potential to improve prognosis of ESCC patients. Although fibroblast growth factor-2 (FGF-2) expression correlates with recurrence and poor survival in ESCC patients, the role of FGF-2 in regulation of ESCC CSCs has yet to be elucidated. We report that FGF-2 is significantly upregulated in CSCs and significantly increases CSC content in ESCC cell lines by inducing epithelial-mesenchymal transition (EMT). Conversely, the FGFR inhibitor, AZD4547, sharply diminishes CSCs via induction of mesenchymal-epithelial transition. Further experiments revealed that MAPK/Erk kinase (Mek)/extracellular signal-regulated kinases (Erk) pathway is crucial for FGF-2-mediated CSC regulation. Pharmacological inhibition of FGF receptor (FGFR)-mediated signaling via AZD4547 did not affect CSCs in Ras mutated cells, implying that Mek/Erk pathway, downstream of FGFR signaling, might be an important regulator of CSCs. Indeed, the Mek inhibitor, trametinib, efficiently suppressed ESCC CSCs even in the context of Ras mutation. Consistent with these findings in vitro, xenotransplantation studies demonstrated that inhibition of FGF-2-mediated FGFR/Erk signaling significantly delayed tumor growth. Taken together, these findings indicate that FGF-2 is an essential factor regulating CSCs via Mek/Erk signaling in ESCC. Additionally, inhibition of FGFR and/or Mek signaling represents a potential novel therapeutic option for targeting CSCs in ESCC.

Safety and efficacy of daclatasvir and asunaprevir in hepatitis C virus-infected patients with renal impairment

AIM

Hepatitis C virus (HCV) infection is a risk factor for end-stage renal disease, renal graft failure, and hemodialysis patient mortality. However, the efficacy of direct-acting antiviral therapy for HCV-infected patients with renal impairment is unclear. Additionally, the promising NS5B inhibitor sofosbuvir has not been recommended for patients with severe renal impairment. In this prospective, multicenter study, we evaluated the efficacy and safety of daclatasvir and asunaprevir combination therapy, with a focus on patients with renal impairment.

METHODS

The study included 322 genotype 1 HCV-infected patients who received daclatasvir and asunaprevir combination therapy. The safety and sustained virological response was examined at 12 weeks after the end of treatment and safety was evaluated according to renal function.

RESULTS

Of 322 patients, 5% (16/322) and 2.5% (8/322) had chronic kidney disease stage G3b (estimated glomerular filtration rate [eGFR], 30-44 mL/min/1.73 m² ) and stage G4/5 (eGFR, 15-29/<15 mL/min/1.73 m² ), respectively. Baseline presence of the NS5A resistance-associated variant, previous simeprevir treatment, and HCV RNA titers, which were predictors of a sustained viral response, were similar between patients with eGFR <45 mL/min/1.73 m² and eGFR >45 mL/min/1.73 m² . Notably, the 12-week sustained viral response rate was comparable in patients with eGFR <45 mL/min/1.73 m² (100%, 24/24) and those with eGFR >45 mL/min/1.73 m² (88.9%, 265/298; P = 0.07). Treatment discontinuation rates and adverse events, including alanine aminotransferase elevation, anemia, and renal disorders, were similar between the two groups.

CONCLUSION

Daclatasvir and asunaprevir combination therapy for patients with renal dysfunction was highly effective and safe.

Autophagy supports generation of cells with high CD44 expression via modulation of oxidative stress and Parkin-mediated mitochondrial clearance

High CD44 expression is associated with enhanced malignant potential in esophageal squamous cell carcinoma (ESCC), amongst the deadliest of all human carcinomas. Although alterations in autophagy and CD44 expression are associated with poor patient outcomes in various cancer types, the relationship between autophagy and cells with high CD44 expression remains incompletely understood. In transformed esophageal keratinocytes, CD44^Low-CD24^High (CD44L) cells give rise to CD44^High-CD24^−/Low (CD44H) cells via epithelial-mesenchymal transition (EMT) in response to transforming growth factor (TGF)-β. We couple patient samples and xenotransplantation studies with this tractable in vitro system of CD44L to CD44H cell conversion to investigate the functional role of autophagy in generation of cells with high CD44 expression. We report that high expression of the autophagy marker cleaved LC3 expression correlates with poor clinical outcome in ESCC. In ESCC xenograft tumors, pharmacological autophagy inhibition with chloroquine derivatives depletes cells with high CD44 expression while promoting oxidative stress. Autophagic flux impairment during EMT-mediated CD44L to CD44H cell conversion in vitro induces mitochondrial dysfunction, oxidative stress and cell death. During CD44H cell generation, transformed keratinocytes display evidence of mitophagy, including mitochondrial fragmentation, decreased mitochondrial content and mitochondrial translocation of Parkin, essential in mitophagy. RNA interference-mediated Parkin depletion attenuates CD44H cell generation. These data suggest that autophagy facilitates EMT-mediated CD44H generation via modulation of redox homeostasis and Parkin-dependent mitochondrial clearance. This is the first report to implicate mitophagy in regulation of tumor cells with high CD44 expression, representing a potential novel therapeutic avenue in cancers where EMT and CD44H cells have been implicated, including ESCC.

Prevalence and characteristics of naturally occurring sofosbuvir resistance-associated variants in patients with hepatitis C virus genotype 1b infection

AIM

Sofosbuvir (SOF), a nucleotide analog pro-drug, targets hepatitis C virus (HCV) NS5B polymerase and shows potential for treating HCV infection, given its high efficacy and good barrier to resistance. However, in addition to the rare resistant-associated variant (RAV) of non-structural protein NS5B S282T, several new potential RAVs of SOF have been reported, especially related to HCV genotype 1b. However, the prevalence and characteristics of these RAVs have not been clarified.

METHODS

We analyzed the prevalence of variants in the NS3/NS5A/NS5B regions in 96 patients treated with simeprevir (SMV) combination therapy, and the prevalence of RAVs in patients showing treatment failure was determined by direct- or deep-sequencing methods. Associations between these potential RAVs and clinical factors were also analyzed.

RESULTS

Prevalence of NS5B RAV C316N was high (46.9%, 45/96), whereas that of NS5B L159F was relatively low (1.04%, 1/96); however, deep sequencing showed that 30.0% of patients with C316N also had NS5B RAV L159F. Additionally, there was no significant relationship between the existence of potential NS5B and NS5A or NS3 RAVs. However, the presence of NS5B C316N was significantly associated with an HCV core amino acid 91 substitution. No significant difference was detected between each RAV and sustained virological response in simeprevir combination therapy.

CONCLUSION

We provide clear evidence of the high prevalence of two potential naturally occurring NS5B RAVs (C316N and L159F) in Japan. It may be important to pay particular attention to these new potential RAVs, especially when using SOF-based therapy in patients with RAVs due to previous direct-acting antiviral therapy failure.

Anti-adipogenic and antiviral effects of l-carnitine on hepatitis C virus infection

Hepatitis C virus (HCV) has been reported to hijack fatty acid metabolism in infected hepatocytes, taking advantage of lipid droplets for virus assembly. In this study, we analyzed the anti-HCV activity of l-carnitine, a substance involved in the transport of fatty acids into mitochondria. JFH-1 or HCV replicon-transfected Huh7.5.1 cells were treated with or without l-carnitine to examine its anti-HCV effects. The effects of l-carnitine on HCV entry, HCV-induced adipogenesis and lipid droplet formation, and HCV-induced oxidative stress were examined. Treatment of JFH-1-infected cells with l-carnitine inhibited HCV propagation in a concentration-dependent manner. In contrast, l-carnitine had no anti-HCV activity in the HCV replicon system, which is lacking viral assembly. In addition, l-carnitine did not affect HCV entry. However, l-carnitine treatment decreased intracellular lipid droplets, which are crucial for HCV assembly in JFH-1-infected cells. The expression level of CPT-1 was decreased in JFH-1-infected cells, and l-carnitine treatment restored this expression. HCV-infected cells exhibited increased production of reactive oxygen species and glutathione oxidation. l-carnitine decreased oxidative stress induced by JFH-1-infection, as shown by glutathione/glutathione disulfide assays and MitoSOX staining. l-carnitine exhibited anti-HCV activity, possibly by inhibiting HCV assembly and through its anti-adipogenic activity in HCV-infected cells. Moreover, l-carnitine has antioxidant properties in HCV-infected hepatocytes. Overall, these results indicated that l-carnitine may be an effective adjunctive agent in antiviral therapies to treat chronic hepatitis C. J. Med. Virol. 89:857-866, 2017. © 2016 Wiley Periodicals, Inc.

Abstract 2678: Notch1 regulates epithelial-mesenchymal transition and tumor-initiating capability in esophageal squamous-cell carcinoma

Introduction: Notch signaling may act as a tumor suppressor during the development of squamous cell carcinomas (SCCs); yet, Notch activation promotes tumor growth in a subset of SCC cells. The roles of Notch in the pathogenesis of esophageal squamous cell carcinoma (ESCC) remain elusive.

Methods: Notch1 activation and epithelial-mesenchymal transition (EMT) were determined in an esophageal epithelium-targeted cell-lineage traceable (K5CreERT2-Rosa26tdTomatolsl) mouse model of ESCC induced by 4-nitroquinoline 1-oxide (4NQO), which was coupled with flow cytometry and single cell-derived ESCC organoid formation assays. Tumor-initiating capability was assessed in xenograft transplantation experiments with TE11 human ESCC cells carrying either Crispr-Cas9-deleted Notch1 loci or tetracycline-inducible expression of the activated form of Notch1 (ICN1). Surgically resected primary tumors and adjacent normal mucosa from ESCC patients (n = 152) were analyzed by immunohistochemistry for Notch1 activation and the EMT marker ZEB1.

Results: 4NQO-treated mice developed tdTomato-positive primary and metastatic ESCC tumors with EpCAM-negative ESCC cells displaying traits compatible with EMT. Notch1 activation and ZEB1 expression were co-localized in ESCC cells at the stromal interface, a finding that was further recapitulated in ESCC tumor organoids. Interestingly, Cre-mediated ex vivo Notch1 deletion in a single cell suspension from Notch1loxP/loxP mouse-derived ESCC tumors decreased organoid formation rate. TE11 xenograft tumors appeared to contain a unique ESCC cell fraction containing EpCAM-negative cells, where ICN1 conferred tumorigenicity upon serial transplantation. This population displayed upregulation of Notch1 target genes and the ESCC-lineage survival factor/oncogene SOX2. Moreover, Notch1 deletion in TE11 not only limited tumor formation, but also decreased EMT in culture. A subset of ESCC patients (49/140, 33%) showed ICN1-positive ESCC cells with concurrent ZEB1 expression at the tumor invasive front. The presence of such ESCC cells was associated with poor 5-year survival (P = 0.001), tumor depth (P = 0.01), lymphatic and venous invasion (P = 0.003) and distant metastasis (P = 0.002). Moreover, such ICN1-expressing cells were increased in ESCC patients (7/12, 58%) who received pre-surgical neoadjuvant therapy.

Conclusions: Cell-lineage tracing experiments validate for the first time Notch1 activation and EMT in the 4NQO-induced mouse model of ESCC. Analyses of single cell-derived ESCC tumor organoids, xenograft and primary ESCC tumors reveal that Notch1 activation may be associated with tumor initiating capability, EMT and chemotherapy resistance, implicating Notch1 activation in the pathogenesis of ESCC and potentially other SCCs.

Citation Format: Koji Tanaka, Kelly A. Whelan, Naryan L. Rustgi, Prasanna M. Chandramouleeswaran, Seiji Naganuma, Shingo Kagawa, Mitsuteru Natsuizaka, Yoshiaki Kita, Shoji Natsugoe, Que Jianwen, Devraj Basu, Andres J. Klein-Szanto, Adam Bass, J. Alan Diehl, Hiroshi Nakagawa. Notch1 regulates epithelial-mesenchymal transition and tumor-initiating capability in esophageal squamous-cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2678.

Fluorescent imaging of superficial head and neck squamous cell carcinoma using a γ-glutamyltranspeptidase-activated targeting agent: a pilot study

Background

Detecting superficial head and neck squamous cell carcinoma (HNSCC) by endoscopy is challenging because of limited morphological hallmarks, and iodine cannot be applied to head and neck lesions due to severe mucosal irritation. γ-glutamyltranspeptidase (GGT), a cell surface enzyme, is overexpressed in several cancers, and it has been reported that γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG), a fluorescent targeting agent which can be enzymatically activated and becomes fluorescent after cleavage of a GGT-specific sequence, can be activated within a few minutes after application to animal models. We investigated whether early HNSCC can be detected by applying gGlu-HMRG to clinical samples.

Methods

gGlu-HMRG was applied to four HNSCC cell lines, and fluorescence was observed by fluorescence microscopy and flow cytometry. Immunohistological examination was performed in three recent cases of endoscopic submucosal dissection (ESD) to investigate GGT expression. Fluorescence imaging with gGlu-HMRG in eight clinical samples resected by ESD or surgery was performed, and fluorescence intensity of tumor and normal mucosa regions of interest (ROI) was prospectively measured.

Results

All four gGlu-HMRG-applied cell lines emitted green fluorescence. Immunohistological examination demonstrated that GGT was highly expressed in HNSCC of the recent three ESD cases but barely in the normal mucosa. Fluorescence imaging showed that iodine-voiding lesions became fluorescent within a few minutes after application of gGlu-HMRG in all eight resected tumors. Tumor ROI fluorescence intensity was significantly higher than in the normal mucosa five minutes after gGlu-HMRG application.

Conclusions

Fluorescence imaging with gGlu-HMRG would be useful for early detection of HNSCC.