Evaluation of the effectiveness of drug-eluting transarterial chemoebolization in hepatocellular carcinoma

Background and Aim

Transarterial Chemoembolization (TACE) therapy is currently considered as first option therapy in the intermediate stage HCC. The purpose of our study is to assess the efficacy and prognostic factors related to the DEB- TACE therapy.

Materials and Methods

The data from 133 patients with unresecetable HCC who were treated with DEB-TACE and followed between January 2011-March 2018 were retrospectively evaluated. To assess the efficacy of therapy, control imagings were performed at 30^th and 90^th days after the procedure. Response rates, survival outcomes, and prognostic factors were investigated.

Results

According to the Barcelona staging system, 16 patients (13%) were in the early stage, 58 patients (48%) were in the intermediate stage and 48 patients (39%) were in the advanced stage. There were complete response (CR) in 20 patients (17%), partial response (PR) in 36 patients (32%), stable disease (SD) in 24 patients (21%) and progressed disease (PD) in 35 (30%) patients. Median follow-up time was 14 months (range 1-77 months). Median PFS and OS were 4 months and 11 months, respectively. In multivariate analysis, posttreatment AFP ≥400 ng/ml was found to be an independent prognostic factor on both PFS and OS. Child-Pugh classification and tumor size >7 cm were independent prognostic factors on OS.

Conclusion

DEB-TACE is effective and a tolerable treatment method for unresectable HCC patients.

Proposal and Validation of a Novel Scoring System for Hepatocellular Carcinomas Beyond Curability Borders

Optimal scoring system for clinical prognostic factors in patients with unresectable hepatocellular carcinoma (HCC) is currently uncertain. We aimed to develop and externally validate an easy to use tool, particularly for this population, and named it the "unresectable hepatocellular carcinoma prognostic index" (UHPI). We evaluated the data of patients with treatment-naive unresectable HCC who were diagnosed in the training center from 2010 to 2019 (n = 209). A simple prognostic model was developed by assigning points for each covariate in proportion to the beta coefficients in the Cox multivariable model. Predictive performance and distinction ability of the UHPI were further evaluated in an independent European validation cohort (n = 147) and compared with 11 other available models. A simple scoring system was derived, assigning 0.5/1/2 scores for six independent covariates including, the Child-Pugh score, Eastern Cooperative Oncology Group performance status, maximum tumor size, vascular invasion or extrahepatic metastasis, lymph node involvement, and alpha-fetoprotein. The UHPI score, ranging from 0 to 6, showed superior performance in prognosis prediction and outperformed 11 other staging or prognostic models, giving the highest homogeneity (c-index, 6-month and 1-year area under the receiver operator characteristic curves), lowest Akaike information criterion, and -2 log-likelihood ratio values. The UHPI score allocated well the risk of patients with unresectable HCC for mortality within the first year, using two cut-off values (low-risk, <0.5; intermediate-risk, 0.5-2; high-risk, >2). Conclusion: The UHPI score can predict prognosis better than other systems in subjects with unresectable HCC and can be used in clinical practice or trials to estimate the 6-month and 1-year survival probabilities for this group.

Surveillance Strategies for Hepatocellular Carcinoma: Recent Advances and the Shifting Paradigm

Currently, international liver societies recommend screening at-risk individuals for HCC (patients with cirrhosis regardless of etiology, and/or chronic hepatitis B virus, and/or advanced liver fibrosis) with biannual abdominal ultrasound (USG) with or without alpha-fetoprotein (AFP). The global acceptance of USG in surveillance relies on the absence of risks, non-invasiveness, and lower costs. However, the suboptimal performance of USG ± AFP in reaching direct and indirect goals of HCC surveillance highlights the need for alternative surveillance strategies. Several studies targeted contrast-enhanced magnetic resonance imaging techniques, but the main barriers for their entrance to surveillance programs have been concerns about cost-effectivity and long scan times. Overall, the HCC risk stratification appears at hand by several validated multiple score systems, but their optimal performance is obtained only in populations who show highly homogenous clinical, pathological, epidemiologic, etiologic, and therapeutic characteristics, and this limitation poses a major drawback to their sustainable use in clinical practice. We need globally validated and molecular integrated risk stratification tools to shape the future tailored HCC surveillance decision algorithms. A dynamic process for HCC surveillance algorithms awaits us owing to the expected further prospective studies focusing on risk-stratified screening strategy.

Characteristics of Newly Diagnosed Hepatocellular Carcinoma Patients Across Turkey: Prospective Multicenter Observational 3K Registry Study

AIMS

To evaluate patient profile for epidemiological and clinicopathological characteristics and potential risk/prognostic factors in newly diagnosed hepatocellular carcinoma (HCC) patients across Turkey.

METHODS

A total of 547 patients (mean (SD) age 62.6 (10.3) years, 81.9% were males) were included in this registry study. Data on patient characteristics, etiologies of HCC, laboratory values, and tumor characteristics and stages were recorded at study enrollment.

RESULTS

HBV infection (68.2%) was the leading etiology, followed by HCV infection (17.2%), HDV infection (5.5%), alcohol (6.4%), and NAFLD (3.5%), as the major etiologies. Considering that 51.6% of the patients had >5 cm HCC, 44% were Child-Pugh B/C and 57% were BCLC B-D, it appears that a significant group of HCC patients were diagnosed at advanced stages. Of 540 patients, 271 (50.2%) were referred or applied with the diagnosis of HCC. Patients with HCC at presentation had larger tumor size (median (min-max) 6.6 (0-30) vs. 4.8 (0-90) cm, P < .001) and more advanced BCLC stage (Stage C-D in 40.8% vs. 26.4%, respectively, P = .005), compared to patients who were diagnosed during follow-up.

CONCLUSIONS

Our findings revealed that HBV infection was the leading etiology and a moderate-to-advanced disease was evident in more than half of patients at the time of diagnosis. HCC patients diagnosed at follow-up had smaller tumor size and earlier BCLC stage.

Evaluation of the Association between Programmed Cell Death-1 Gene Polymorphisms and Hepatocellular Carcinoma Susceptibility in Turkish Subjects. A Pilot Study

BACKGROUND AND AIMS

Programmed cell death-1 (PD-1) has a vital role in regulating T-cell function, and immune escape mechanism of cancer cells. It was shown that there could be a relationship between single nucleotide polymorphisms (SNPs) in the PD-1 gene and susceptibility to hepatocellular carcinoma (HCC) based on various studies. We aimed to investigate the role of three SNPs within the PD-1 gene in susceptibility to HCC in the Turkish population.

METHODS

Single nucleotide polymorphisms of PD-1.1, 1.5, and 1.6 were genotyped by using TaqMan Allelic Discrimination Assays in blood samples of 137 HCC and 136 control subjects, matched for age and gender. The genotype, allele and haplotype frequencies were compared in HCC and control groups using logistic regression analysis.

RESULTS

Genotype distributions of PD-1.1, PD-1.5 and PD-1.6 SNPs were in Hardy-Weinberg equilibrium. No significant difference was observed in the genotype distribution of PD-1.1, PD-1.5 and PD-1.6 polymorphisms among gender and age-matched HCC (M/F: 96/41; mean age: 61.4 ±11.7 years) and control group (M/F: 94/42; mean age: 61.4±10.1). In the haplotype analysis of PD-1.1/PD-1.5/PD-1.6, no significant difference was found among HCC and control group adjusted for sex and age (all p values>0.1).

CONCLUSION

Our findings, firstly reporting the association of PD-1.5 polymorphism with HCC, and PD-1.1 and PD-1.6 with HCC in the Turkish population, suggest that PD-1 polymorphisms are not predisposing factors for HCC development. Future studies with larger sample sizes and different ethnic populations are required to validate our findings.

Low recurrence rate of hepatocellular carcinoma following ledipasvir and sofosbuvir treatment in a real-world chronic hepatitis C patients cohort

The aims of the present study were to evaluate the efficacy and tolerability of ledipasvir/sofosbuvir (LDV/SOF) with or without ribavirin in the treatment of chronic hepatitis C (CHC) in patients with advanced liver disease and to analyse whether the use of LDV/SOF treatment is associated with a new occurrence of hepatocellular carcinoma (HCC) during and after LDV/SOF treatment. The Turkish Early Access Program provided LDV/SOF treatment to a total of 200 eligible CHC patients with advanced liver disease. The median follow-up period was 22 months. All patients were Caucasian, 84% were infected with genotype 1b, and 24% had a liver transplantation before treatment. The sustained virological response (SVR12) was 86.0% with ITT analysis. SVR12 was similar among patients with Child-Pugh classes A, B and C disease and transplant recipients. From baseline to SVR12, serum ALT level and MELD score were significantly improved (P < 0.001). LDV/SOF treatment was generally well tolerated. Only one patient developed a new diagnosed HCC. Seventeen of the 35 patients, who had a history of previous HCC, developed HCC recurrence during the LDV/SOF treatment or by a median follow-up of 6 months after treatment. HCC recurrence was less commonly observed in patients who received curative treatment for HCC compared with those patients who received noncurative treatment (P = 0.007). In conclusion, LDV/SOF with or without ribavirin is an effective and tolerable treatment in CHC patients with advanced liver disease. Eradication is associated with improvements in liver function and a reduced risk of developing a new occurrence of HCC.

High treatment modification rates with lamivudine therapy in HBV-infected patients with low baseline viremia and early virological response: A multicenter study

OBJECTIVE

Low baseline viremia and an early treatment response predict the best outcomes in hepatitis B virus (HBV)-infected patients treated with nucleoside analogues with low barriers to resistance. The aim of this study was to assess the long-term results and effectiveness of lamivudine in patients with low baseline viremia and early virological treatment response.

METHODS

In this multicenter, real-life setting study, 111 antiviral-naive patients with low baseline viremia (HBV DNA <10(7) copies/mL) plus an early virological response (HBV DNA <300 copies/mL at week 24) treated with lamivudine were enrolled. The primary end-point was treatment failure, defined as the re-emergence of detectable viremia or at least a 1 log increase in HBV DNA, resulting in a titer of ≥ 300 copies/mL with lamivudine treatment after week 24, which required treatment modification.

RESULTS

Altogether 111 patients, including 78 non-cirrhotic and 33 cirrhotic patients, were included in the study. Treatment failure occurred in 30.8% of the non-cirrhotic patients over a median follow-up period of 32.5 months, and the 1-, 2-, 3-, 4- and 5-year treatment failure rates were 6.5%, 14.0%, 31.4%, 39.6% and 43.1%, respectively. Treatment failure occurred in 28.8% of the whole group. There were no differences between the cirrhotic and non-cirrhotic patients.

CONCLUSIONS

Lamivudine treatment had a high treatment modification rate in patients with low baseline viremia and early virological response over a long-term follow-up in a real-life setting. The pretreatment and on-treatment favorable characteristics found in the studies with telbivudine appeared to be inapplicable to lamivudine.

Impaired expression of type I and type II interferon receptors in HCV-associated chronic liver disease and liver cirrhosis

PURPOSE

Chronic Hepatitis C Virus (HCV)-infected patients with liver cirrhosis (LC) respond poorly to interferon-alpha (IFN-α) and ribavirin (RBV) combination therapy, but the reason for this is unclear. We previously reported that HCV-infection induces endoplasmic reticulum (ER) stress and autophagy response that selectively down regulates the type I IFN-α receptor-1 (IFNAR1) and RBV transporters (CNT1 and ENT1), leading to IFN-α/RBV resistance. The goal of this study is to verify whether an increase in ER stress and autophagy response is also associated with the reduced expression of IFNAR1 and RBV transporters in chronic HCV-infected patients.

METHODS

Primary human hepatocytes (PHH) were infected with cell culture grown HCV particles (JFH-ΔV3-Rluc). HCV replication was confirmed by the detection of viral RNA by RT-qPCR and HCV-core protein by Western blotting. The ER stress and autophagy response and expression of IFN receptors and RBV transporters in HCV infected PHH and liver tissues derived from patients were measured by Western blotting.

RESULT

HCV infection of PHH showed impaired expression of IFNAR1, IFNγR1 (Type II IFN receptor) and RBV transporters but not IL10Rβ (Type III IFN-λ receptor). ER stress markers (BiP, IRE1α and peIF2α) and autophagy response (LC3II, Beclin 1 and ATG5) were induced in HCV infected chronic liver disease (CLD) and LC patients. Liver biopsies (CLD) show a 50% reduced expression of IFNAR1 and RBV transporters. Furthermore, the expression of IFNAR1 and RBV transporters was impaired in almost all LC patients.

CONCLUSION

HCV infection induces ER stress and autophagy response in infected PHH and chronically infected liver tissues. The expression of IFNAR1, IFNγR1 and RBV transporters were significantly impaired in CLD and cirrhotic livers. Our study provides a potential explanation for the reduced response rate of IFN-α and RBV combination therapy in HCV infected patients with liver cirrhosis.

Interferon alpha induced intrahepatic pSTAT1 inversely correlate with serum HCV RNA levels in chronic HCV infection

BACKGROUND

The Jak-STAT signaling of hepatitis C virus (HCV) infected hepatocyte is critical for the antiviral action of endogenously produced interferon (IFN) as well as exogenously administered interferon alpha (IFN-α). The activation of cellular Jak-STAT signaling by IFN-α results in the phosphorylation and nuclear translocation of pSTAT1 and pSTAT2 proteins to induce antiviral gene transcription. Clinical studies show that chronic HCV patients with high viral load show poor response to interferon alpha and ribavirin combination therapy.

AIM

We seek to determine whether the IFN-α induced activation of pSTAT1 and pSTAT2 in hepatocytes isolated from liver biopsy of patients chronically infected with hepatitis C virus could be related to the viral load.

METHOD

Hepatocytes were isolated from liver biopsies of 18 chronic HCV patients using the collagen digestion method. Induction of pSTAT1 protein in the isolated hepatocyte was measured after IFN-α treatment. The fold change in the levels of pStat1 in the cell lysates due to IFN-treatment was measured by Western blot analysis followed by densitometry analysis.

RESULTS

Results of our study indicate that IFN-α induced pSTAT1 levels vary in chronically infected hepatocytes from chronic HCV patients. Semi-quantitative analysis of the pSTAT1 bands revealed a median induction of 7.4-fold in non-infected primary hepatocytes and 2.3-fold in chronic hepatitis C patients (p < 0.001). Total STAT1 levels were not significantly different between treated and untreated primary hepatocytes. We also found a significantly inverse correlation between the intrahepatic pSTAT1 inductions with the serum HCV RNA levels.

CONCLUSION

We have developed an antibody based Western blot detection method to measure intrahepatic pStat1 and pStat2 levels to assess the cellular response to exogenous IFN-alpha. Our results indicate that pStat1 activation is a good indicator to assess the level of HCV replication in chronic HCV patients.

Free fatty acids induce ER stress and block antiviral activity of interferon alpha against hepatitis C virus in cell culture

Background

Hepatic steatosis is recognized as a major risk factor for liver disease progression and impaired response to interferon based therapy in chronic hepatitis C (CHC) patients. The mechanism of response to interferon-alpha (IFN-α) therapy under the condition of hepatic steatosis is unexplored. We investigated the effect of hepatocellular steatosis on hepatitis C virus (HCV) replication and IFN-α antiviral response in a cell culture model.

Methods

Sub-genomic replicon (S3-GFP) and HCV infected Huh-7.5 cells were cultured with a mixture of saturated (palmitate) and unsaturated (oleate) long-chain free fatty acids (FFA). Intracytoplasmic fat accumulation in these cells was visualized by Nile red staining and electron microscopy then quantified by microfluorometry. The effect of FFA treatment on HCV replication and IFN-α antiviral response was measured by flow cytometric analysis, Renilla luciferase activity, and real-time RT-PCR.

Results

FFA treatment induced dose dependent hepatocellular steatosis and lipid droplet accumulation in the HCV replicon cells was confirmed by Nile red staining, microfluorometry, and by electron microscopy. Intracellular fat accumulation supports replication more in the persistently HCV infected culture than in the sub-genomic replicon (S3-GFP) cell line. FFA treatment also partially blocked IFN-α response and viral clearance by reducing the phosphorylation of Stat1 and Stat2 dependent IFN-β promoter activation. We show that FFA treatment induces endoplasmic reticulum (ER) stress response and down regulates the IFNAR1 chain of the type I IFN receptor leading to defective Jak-Stat signaling and impaired antiviral response.

Conclusion

These results suggest that intracellular fat accumulation in HCV cell culture induces ER stress, defective Jak-Stat signaling, and attenuates the antiviral response, thus providing an explanation to the clinical observation regarding how hepatocellular steatosis influences IFN-α response in CHC.

Preliminary evidence of an association between the functional c-kit rs6554199 polymorphism and achalasia in a Turkish population

BACKGROUND

C-kit-positive interstitial cells of Cajal (ICC) of the lower esophageal sphincter are reduced in achalasia. Two functional gene polymorphisms (rs2237025 and rs6554199) within the c-kit gene may affect its transcriptional activity. In this pilot study, we hypothesized that these polymorphisms would be associated with achalasia.

METHODS

Genomic DNA was extracted and real-time PCR reactions were used to determine the rs2237025 and rs6554199 c-kit polymorphisms in 88 Turkish patients with achalasia and 101 healthy controls.

KEY RESULTS

The frequency of the T allele of rs6554199 was significantly higher in patients with achalasia [odds ratio (OR): 1.55; 95% confidence interval (CI), 1.03-2.34; P = 0.038] compared with the G allele. Under a dominant model of inheritance, the carriage of at least one T allele was significantly more frequent in patients with achalasia (80.7%) than in controls (65.3%; OR: 2.21; 95% CI, 1.13-4.33; P = 0.022). No association of the c-kit rs2237025 polymorphism with achalasia was detected.

CONCLUSIONS & INFERENCES

Despite the small sample size and the possibility of a false positive finding, our preliminary data support the hypothesis that the T allele of the c-kit rs6554199 polymorphism may be associated with achalasia in the Turkish population. These findings need to be replicated in other racial-ethnically diverse populations.

Vitamin E has a dual effect of anti-inflammatory and antioxidant activities in acetic acid-induced ulcerative colitis in rats

BACKGROUND

Increased free radical production, decreased antioxidant capacity and excessive inflammation are well-known features in the pathogenesis of inflammatory bowel disease. Vitamin E is a powerful antioxidant and a scavenger of hydroxyl radicals, and it has been shown to have anti-inflammatory activities in tissues. We investigated the effects of vitamin E on inflammatory activities using an acetic acid (AA)-induced ulcerative colitis model in rats.

METHODS

Wistar rats were divided into 4 groups. Acetic acid was given to 2 groups of animals to induce colitis while the other 2 groups received saline intrarectally. One AA-induced colitis group and 1 control group received vitamin E (30 U/kg/d) intraperitoneally and the pair groups received saline. After 4 days, we evaluated colonic changes biochemically by measuring proinflammatory cytokine levels in tissue homogenates and by histopathologic examination.

RESULTS

Acetic acid caused colonic mucosal injury, whereas vitamin E administration suppressed these changes in the AA-induced colitis group (p < 0.001). Administration of AA resulted in increased levels of tumour necrosis factor-α, interleukin-1β, interleukin-6, myeloperoxidase and malondialdehyde, and decreased levels of glutathione and superoxide dismutase; vitamin E reversed these effects (all p < 0.001).

CONCLUSION

Our study proposes that vitamin E is an effective anti-inflammatory and antioxidant and may be a promising therapeutic option for ulcerative colitis.

Vitamin E has a dual effect of anti-inflammatory and antioxidant activities in acetic acid-induced ulcerative colitis in rats

BACKGROUND

Increased free radical production, decreased antioxidant capacity and excessive inflammation are well-known features in the pathogenesis of inflammatory bowel disease. Vitamin E is a powerful antioxidant and a scavenger of hydroxyl radicals, and it has been shown to have anti-inflammatory activities in tissues. We investigated the effects of vitamin E on inflammatory activities using an acetic acid (AA)-induced ulcerative colitis model in rats.

METHODS

Wistar rats were divided into 4 groups. Acetic acid was given to 2 groups of animals to induce colitis while the other 2 groups received saline intrarectally. One AA-induced colitis group and 1 control group received vitamin E (30 U/kg/d) intraperitoneally and the pair groups received saline. After 4 days, we evaluated colonic changes biochemically by measuring proinflammatory cytokine levels in tissue homogenates and by histopathologic examination.

RESULTS

Acetic acid caused colonic mucosal injury, whereas vitamin E administration suppressed these changes in the AA-induced colitis group (p < 0.001). Administration of AA resulted in increased levels of tumour necrosis factor-α, interleukin-1β, interleukin-6, myeloperoxidase and malondialdehyde, and decreased levels of glutathione and superoxide dismutase; vitamin E reversed these effects (all p < 0.001).

CONCLUSION

Our study proposes that vitamin E is an effective anti-inflammatory and antioxidant and may be a promising therapeutic option for ulcerative colitis.

Mechanism of HCV's resistance to IFN-α in cell culture involves expression of functional IFN-α receptor 1

The mechanisms underlying the Hepatitis C virus (HCV) resistance to interferon alpha (IFN-α) are not fully understood. We used IFN-α resistant HCV replicon cell lines and an infectious HCV cell culture system to elucidate the mechanisms of IFN-α resistance in cell culture. The IFN-α resistance mechanism of the replicon cells were addressed by a complementation study that utilized the full-length plasmid clones of IFN-α receptor 1 (IFNAR1), IFN-α receptor 2 (IFNAR2), Jak1, Tyk2, Stat1, Stat2 and the ISRE- luciferase reporter plasmid. We demonstrated that the expression of the full-length IFNAR1 clone alone restored the defective Jak-Stat signaling as well as Stat1, Stat2 and Stat3 phosphorylation, nuclear translocation and antiviral response against HCV in all IFN-α resistant cell lines (R-15, R-17 and R-24) used in this study. Moreover RT-PCR, Southern blotting and DNA sequence analysis revealed that the cells from both R-15 and R-24 series of IFN-α resistant cells have 58 amino acid deletions in the extracellular sub domain 1 (SD1) of IFNAR1. In addition, cells from the R-17 series have 50 amino acids deletion in the sub domain 4 (SD4) of IFNAR1 protein leading to impaired activation of Tyk2 kinase. Using an infectious HCV cell culture model we show here that viral replication in the infected Huh-7 cells is relatively resistant to exogenous IFN-α. HCV infection itself induces defective Jak-Stat signaling and impairs Stat1 and Stat2 phosphorylation by down regulation of the cell surface expression of IFNAR1 through the endoplasmic reticulum (ER) stress mechanisms. The results of this study suggest that expression of cell surface IFNAR1 is critical for the response of HCV to exogenous IFN-α.

Hepatocellular carcinoma xenograft supports HCV replication: A mouse model for evaluating antivirals

AIM: To develop a hepatocellular carcinoma (HCC) xenograft model for studying hepatitis C virus (HCV) replication in a mice, and antiviral treatment.

METHODS: We developed a stable S3-green fluorescence protein (GFP) cell line that replicated the GFP-tagged HCV sub-genomic RNA derived from a highly efficient JFH1 virus. S3-GFP replicon cell line was injected subcutaneously into γ-irradiated SCID mice. We showed that the S3-GFP replicon cell line formed human HCC xenografts in SCID mice. Cells were isolated from subcutaneous tumors and then serially passaged multiple times in SCID mice by culturing in growth medium supplemented with G-418. The mouse-adapted S3-GFP replicon cells were implanted subcutaneously and also into the liver of SCID mice via intrasplenic infusion to study the replication of HCV in the HCC xenografts. The tumor model was validated for antiviral testing after intraperitoneal injection of interferon-α (IFN-α).

RESULTS: A highly tumorigenic S3-GFP replicon cell line was developed that formed subcutaneous tumors within 2 wk and diffuse liver metastasis within 4 wk in SCID mice. Replication of HCV in the subcutaneous and liver tumors was confirmed by cell colony assay, detection of the viral RNA by ribonuclease protection assay and real-time quantitative reverse transcription polymerase chain reaction. High-level replication of HCV sub-genomic RNA in the tumor could be visualized by GFP expression using fluorescence microscopy. IFN-α cleared HCV RNA replication in the subcutaneous tumors within 2 wk and 4 wk in the liver tumor model.

CONCLUSION: A non-infectious mouse model allows us to study replication of HCV in subcutaneous and metastatic liver tumors. Clearance of HCV by IFN-α supports use of this model to test other anti-HCV drugs.

Intracellular expression of IRF9 Stat fusion protein overcomes the defective Jak-Stat signaling and inhibits HCV RNA replication

Interferon alpha (IFN-α) binds to a cell surface receptor that activates the Jak-Stat signaling pathway. A critical component of this pathway is the translocation of interferon stimulated gene factor 3 (a complex of three proteins Stat1, Stat2 and IRF9) to the nucleus to activate antiviral genes. A stable sub-genomic replicon cell line resistant to IFN-α was developed in which the nuclear translocation of Stat1 and Stat2 proteins was prevented due to the lack of phosphorylation; whereas the nuclear translocation of IRF9 protein was not affected. In this study, we sought to overcome defective Jak-Stat signaling and to induce an antiviral state in the IFN-α resistant replicon cell line by developing a chimera IRF9 protein fused with the trans activating domain (TAD) of either a Stat1 (IRF9-S1C) or Stat2 (IRF9-S2C) protein. We show here that intracellular expression of fusion proteins using the plasmid constructs of either IRF9-S1C or IRF9-S2C, in the IFN-α resistant cells, resulted in an increase in Interferon Stimulated Response Element (ISRE) luciferase promoter activity and significantly induced HLA-1 surface expression. Moreover, we show that transient transfection of IRF9-S1C or IRF9-S2C plasmid constructs into IFN-α resistant replicon cells containing sub-genomic HCV1b and HCV2a viruses resulted in an inhibition of viral replication and viral protein expression independent of IFN-α treatment. The results of this study indicate that the recombinant fusion proteins of IRF9-S1C, IRF9-S2C alone, or in combination, have potent antiviral properties against the HCV in an IFN-α resistant cell line with a defective Jak-Stat signaling.

SH2 modified STAT1 induces HLA-I expression and improves IFN-γ signaling in IFN-α resistant HCV replicon cells

Background

We have developed multiple stable cell lines containing subgenomic HCV RNA that are resistant to treatment with interferon alpha (IFN-α. Characterization of these IFN-α resistant replicon cells showed defects in the phosphorylation and nuclear translocation of STAT1 and STAT2 proteins due to a defective Jak-STAT pathway.

Methodology/Principal Findings

In this study, we have developed an alternative strategy to overcome interferon resistance in a cell culture model by improving intracellular STAT1 signaling. An engineered STAT1-CC molecule with double cysteine substitutions in the Src-homology 2 (SH2) domains of STAT1 (at Ala-656 and Asn-658) efficiently phosphorylates and translocates to the nucleus of IFN-resistant cells in an IFN-γ dependent manner. Transfection of a plasmid clone containing STAT1-CC significantly activated the GAS promoter compared to wild type STAT1 and STAT3. The activity of the engineered STAT1-CC is dependent upon the phosphorylation of tyrosine residue 701, since the construct with a substituted phenylalanine residue at position 701 (STAT1-CC-Y701F) failed to activate GAS promoter in the replicon cells. Intracellular expression of STAT1-CC protein showed phosphorylation and nuclear translocation in the resistant cell line after IFN-γ treatment. Transient transfection of STAT1-CC plasmid clone into an interferon resistant cell line resulted in inhibition of viral replication and viral clearance in an IFN-γ dependent manner. Furthermore, the resistant replicon cells transfected with STAT1-CC constructs significantly up regulated surface HLA-1 expression when compared to the wild type and Y to F mutant controls.

Conclusions

These results suggest that modification of the SH2 domain of the STAT1 molecule allows for improved IFN-γ signaling through increased STAT1 phosphorylation, nuclear translocation, HLA-1 surface expression, and prolonged interferon antiviral gene activation.

Intracytoplasmic stable expression of IgG1 antibody targeting NS3 helicase inhibits replication of highly efficient hepatitis C Virus 2a clone

Background

Hepatitis C virus (HCV) infection is a major public health problem with more than 170 million cases of chronic infections worldwide. There is no protective vaccine currently available for HCV, therefore the development of novel strategy to prevent chronic infection is important. We reported earlier that a recombinant human antibody clone blocks viral NS3 helicase activity and inhibits replication of HCV 1b virus. This study was performed further to explore the mechanism of action of this recombinant antibody and to determine whether or not this antibody inhibits replication and infectivity of a highly efficient JFH1 HCV 2a virus clone.

Results

The antiviral effect of intracellular expressed antibody against the HCV 2a virus strain was examined using a full-length green fluorescence protein (GFP) labeled infectious cell culture system. For this purpose, a Huh-7.5 cell line stably expressing the NS3 helicase gene specific IgG1 antibody was prepared. Replication of full-length HCV-GFP chimera RNA and negative-strand RNA was strongly inhibited in Huh-7.5 cells stably expressing NS3 antibody but not in the cells expressing an unrelated control antibody. Huh-7.5 cells stably expressing NS3 helicase antibody effectively suppressed infectious virus production after natural infection and the level of HCV in the cell free supernatant remained undetectable after first passage. In contrast, Huh-7.5 cells stably expressing an control antibody against influenza virus had no effect on virus production and high-levels of infectious HCV were detected in culture supernatants over four rounds of infectivity assay. A recombinant adenovirus based expression system was used to demonstrate that Huh-7.5 replicon cell line expressing the intracellular antibody strongly inhibited the replication of HCV-GFP RNA.

Conclusion

Recombinant human anti-HCV NS3 antibody clone inhibits replication of HCV 2a virus and infectious virus production. Intracellular expression of this recombinant antibody offers a potential antiviral strategy to inhibit intracellular HCV replication and production.

Sertraline hepatotoxicity: report of a case and review of the literature

Sertraline is a commonly prescribed selective serotonin reuptake inhibitor drug. Hepatotoxicity caused by sertraline is rare. Asymptomatic elevations in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels have been rarely reported and shortly normalize after discontinuation of the agent. We present a case of severe drug-induced hepatitis in a patient receiving sertraline. To our knowledge, this is the seventh case in the medical literature as being associated with severe hepatotoxicity. Since it is extremely rare, we do not suggest a strict laboratory monitoring. However, sertraline should be discontinued in cases with symptoms implying hepatotoxicity and the patients should be informed of the potential of this side effect.