Direct-acting antivirals and interferon-based therapy on hepatocellular carcinoma risk in chronic hepatitis-C patients

Aim: It was controversial whether direct-acting antiviral (DAA) is better than interferon-based therapy (IBT) in preventing HCV-related hepatocellular carcinoma (HCC). Therefore, we accomplished this large, stepwise meta-analysis. Materials & methods: The PubMed, Cochrane and ScienceDirect were searched for studies published during January 2009-March 2019. Antiviral type, number of chronic hepatitis C (CHC) patients, number of HCC cases from CHC patients, sustained virological response (SVR) status and important covariate data were extracted from each study. Results & conclusion: It is demonstrated that antiviral treatment reduces the occurrence of HCC in patients with CHC; achieving SVR to antiviral treatment reduces HCC; DAA treatment is not better than IBT in the prophylaxis of HCC; DAA treatment and cirrhosis are independently associated with a higher incidence of HCC than IBT in middle-aged CHC patients who achieve SVR.

Impact of HCV core gene quasispecies on hepatocellular carcinoma risk among HALT-C trial patients

Mutations at positions 70 and/or 91 in the core protein of genotype-1b, hepatitis C virus (HCV) are associated with hepatocellular carcinoma (HCC) risk in Asian patients. To evaluate this in a US population, the relationship between the percentage of 70 and/or 91 mutant HCV quasispecies in baseline serum samples of chronic HCV patients from the HALT-C trial and the incidence of HCC was determined by deep sequencing. Quasispecies percentage cut-points, ≥42% of non-arginine at 70 (non-R⁷⁰) or ≥98.5% of non-leucine at 91 (non-L⁹¹) had optimal sensitivity at discerning higher or lower HCC risk. In baseline samples, 88.5% of chronic HCV patients who later developed HCC and 68.8% of matched HCC-free control patients had ≥42% non-R⁷⁰ quasispecies (P = 0.06). Furthermore, 30.8% of patients who developed HCC and 54.7% of matched HCC-free patients had quasispecies with ≥98.5% non-L⁹¹ (P = 0.06). By Kaplan-Meier analysis, HCC incidence was higher, but not statistically significant, among patients with quasispecies ≥42% non-R⁷⁰ (P = 0.08), while HCC incidence was significantly reduced among patients with quasispecies ≥98.5% non-L⁹¹ (P = 0.01). In a Cox regression model, non-R⁷⁰ ≥42% was associated with increased HCC risk. This study of US patients indicates the potential utility of HCV quasispecies analysis as a non-invasive biomarker of HCC risk.

Efficacy of interferon-beta plus ribavirin combination treatment on the development of hepatocellular carcinoma in Japanese patients with chronic hepatitis C

AIM

Although there is much evidence of an antitumor effect of pegylated interferon (IFN)-α-based treatment, limited data is available about that of IFN-β-based treatment. Our goal was to evaluate the impact of IFN-β plus ribavirin (RBV) treatment on the suppression of hepatocellular carcinoma (HCC).

METHODS

This retrospective, multicenter study consisted of 124 chronic hepatitis C patients who were treated with IFN-β plus RBV treatment, including 61 with advanced fibrosis and five with pretreatment HCC. All participants were followed for a median of 2.8 years (range, 2.2-3.2) after the end of their antiviral treatment. The data of 112 patients who finished the treatment were available for analysis. Cox proportional hazard analyses were performed to determine factors significantly associated with HCC development. Cumulative incidence curves for HCC were plotted using the Kaplan-Meier method and differences between groups were assessed using the log-rank test.

RESULTS

The 2.9% rate of HCC development of patients with sustained virological response (SVR) was significantly lower (P = 0.027) than the 15.9% of non-SVR patients. Interestingly, no significant difference was observed between the rates of HCC development of patients with and without advanced fibrosis (P = 0.733), even though the SVR rate of patients with advanced fibrosis was significantly lower than that of those without advanced fibrosis (P < 0.001). Stepwise multivariable Cox analysis extracted that only SVR was significantly associated with HCC development (hazard ratio, 0.20; 95% confidence interval, 0.03-0.84, P = 0.027).

CONCLUSION

SVR was significantly associated with a lower risk of HCC development after IFN-β plus RBV treatment.

A cell culture system for distinguishing hepatitis C viruses with and without liver cancer-related mutations in the viral core gene

BACKGROUND & AIMS

Although patients infected by genotype 1b hepatitis C virus (HCV) with Q(70) and/or M(91)core gene mutations have an almost five-fold increased risk of developing hepatocellular carcinoma (HCC) and increased insulin resistance, the absence of a suitable experimental system has precluded direct experimentation on the effects of these mutations on cellular gene expression.

METHODS

HuH7 cells were treated long-term with human serum to induce differentiation and to produce a model system for testing high-risk and control HCV. For clinical validation, profiles of infected cells were compared to each other and to those of liver biopsies of patients with early-stage HCV-related cirrhosis followed prospectively for up to 23 years (n=216).

RESULTS

Long-term culture in human serum produced growth-arrested, hepatocyte-like cells whose gene profile overlapped significantly with that of primary human hepatocytes. High-risk (Q(70)/M(91)) and control (R(70)/L(91)) viruses had dramatically different effects on gene expression of these cells. The high-risk virus enhanced expression of pathways associated with cancer and type II diabetes, while the control virus enhanced pathways associated with oxidative phosphorylation. Of special clinical relevance, the transcriptome of cells replicating the high-risk virus correlated significantly with an HCC high-risk profile in patients (Bonferroni-corrected p=0.03), whereas no such association was observed for non-HCC-related clinical outcomes.

CONCLUSIONS

The cell-based system allowed direct head-to-head comparison of HCV variants, and provided experimental support for previous clinical data indicating an oncogenic effect of core gene mutations. This simple experimental system distinguished HCV variants and will enable future mechanistic analysis and exploration of interventional approaches.

STK4 regulates TLR pathways and protects against chronic inflammation-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is frequently associated with pathogen infection-induced chronic inflammation. Large numbers of innate immune cells are present in HCCs and can influence disease outcome. Here, we demonstrated that the tumor suppressor serine/threonine-protein kinase 4 (STK4) differentially regulates TLR3/4/9-mediated inflammatory responses in macrophages and thereby is protective against chronic inflammation-associated HCC. STK4 dampened TLR4/9-induced proinflammatory cytokine secretion but enhanced TLR3/4-triggered IFN-β production via binding to and phosphorylating IL-1 receptor-associated kinase 1 (IRAK1), leading to IRAK1 degradation. Notably, macrophage-specific Stk4 deletion resulted in chronic inflammation, liver fibrosis, and HCC in mice treated with a combination of diethylnitrosamine (DEN) and CCl4, along with either LPS or E. coli infection. STK4 expression was markedly reduced in macrophages isolated from human HCC patients and was inversely associated with the levels of IRAK1, IL-6, and phospho-p65 or phospho-STAT3. Moreover, serum STK4 levels were specifically decreased in HCC patients with high levels of IL-6. In STK4-deficient mice, treatment with an IRAK1/4 inhibitor after DEN administration reduced serum IL-6 levels and liver tumor numbers to levels similar to those observed in the control mice. Together, our results suggest that STK4 has potential as a diagnostic biomarker and therapeutic target for inflammation-induced HCC.

FoxO3a nuclear localization and its association with β-catenin and Smads in IFN-α-treated hepatocellular carcinoma cell lines

Interferon-α2b (IFN-α2b) reduces proliferation and increases apoptosis in hepatocellular carcinoma cells by decreasing β-catenin/TCF4/Smads interaction. Forkhead box O-class 3a (FoxO3a) participates in proliferation and apoptosis and interacts with β-catenin and Smads. FoxO3a is inhibited by Akt, IκB kinase β (IKKβ), and extracellular-signal-regulated kinase (Erk), which promote FoxO3a sequestration in the cytosol, and accumulates in the nucleus upon phosphorylation by c-Jun N-terminal kinase (JNK) and p38 mitogen-activated kinase (p38 MAPK). We analyzed FoxO3a subcellular localization, the participating kinases, FoxO3a/β-catenin/Smads association, and FoxO3a target gene expression in IFN-α2b-stimulated HepG2/C3A and Huh7 cells. Total FoxO3a and Akt-phosphorylated FoxO3a levels decreased in the cytosol, whereas total FoxO3a levels increased in the nucleus upon IFN-α2b stimulus. IFN-α2b reduced Akt, IKKβ, and Erk activation, and increased JNK and p38 MAPK activation. p38 MAPK inhibition blocked IFN-α2b-induced FoxO3a nuclear localization. IFN-α2b enhanced FoxO3a association with β-catenin and Smad2/3/7. Two-step coimmunoprecipitation experiments suggest that these proteins coexist in the same complex. The expression of several FoxO3a target genes increased with IFN-α2b. FoxO3a knockdown prevented the induction of these genes, suggesting that FoxO3a acts as mediator of IFN-α2b action. Results suggest a β-catenin/Smads switch from TCF4 to FoxO3a. Such events would contribute to the IFN-α2b-mediated effects on cellular proliferation and apoptosis. These results demonstrate new mechanisms for IFN-α action, showing the importance of its application in antitumorigenic therapies.

Prevention of hepatitis C virus infection and liver cancer

Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer and the third leading cause of cancer-related death, and its incidence is increasing. The majority of HCC cases are associated with chronic viral hepatitis. With over 170 million individuals chronically infected with hepatitis C virus (HCV) worldwide, HCV is currently a serious global health concern, leading to chronic hepatitis, cirrhosis and HCC, thereby causing significant morbidity and mortality. With the incidence of HCV infection increasing, the problem of HCV-associated HCC is expected to worsen as well, with the majority of HCCs developing in the setting of cirrhosis. Thus, it is imperative to provide antiviral therapy to infected individuals prior to the development of established cirrhosis in order to reduce the risk of subsequent HCC. Indeed, the successful eradication of HCV is associated with clinical and histological improvement as well as a greatly reduced risk of subsequent HCC development. Even after the development of cirrhosis, successful viral clearance is still associated with reduced HCC risk. Current standard of care antiviral treatment consists of pegylated interferon-α and ribavirin, but viral clearance rates are suboptimal with this regimen, especially in difficult to treat cohorts. However, there is a myriad of different classes of HCV-specific direct-acting antiviral agents currently in development, which can be used in combination with one another or with standard of care treatment to improve HCV cure rates. Preventative and therapeutic vaccines against HCV remain an area of ongoing research with good progress towards developing an effective vaccine in the future.