Tolloid-like 1 genetic variants determine fibrosis regression in chronic hepatitis C patients with curative antivirals

A literature review of genetics and epigenetics of HCV-related hepatocellular carcinoma: translational impact

Background and Objective

Hepatocellular carcinoma (HCC) poses a significant global health burden and ranks as the fifth most prevalent cancer on a global scale. Hepatitis C virus (HCV) infection remains one of the major risk factors for HCC development. HCC is a heterogeneous disease, and the development of HCC caused by HCV is intricate and involves various factors, including genetic susceptibility, viral factors, immune response due to chronic inflammation, alcohol abuse, and metabolic dysfunction associated with fatty liver disease. In this review, we provide a comprehensive and updated review of research on the genetics and epigenetic mechanisms implicated in developing HCC associated with HCV infection. We also discuss the potential translational implications, including novel biomarkers and drugs for treatment.

Methods

A comprehensive literature search was conducted in June 2023 in PubMed and Embase databases.

Key Content and Findings

Recent findings indicate that a variety of genetic and epigenetic processes are involved in the pathogenesis and continue to exist even after the complete elimination of HCV. The deregulation of the epigenome has been identified as a significant factor in the deletrious effects of liver disease, especially during the initial stages when genetic alterations are uncommon. The enduring "epigenetic memory" of gene expression is believed to be regulated by epigenetic mechanisms, indicating that alterations caused by HCV infection continue to exist and are linked to the risk of development of liver cancer even after successful treatment. Systems biology analytical methods will be required to delineate the magnitude and significance of both genetic and epigenomic alterations in tumor evolution.

Conclusions

By facilitating a more profound understanding of these aspects, this will ultimately foster the advancement of novel therapies and ultimately improve outcomes for patients.

The impact of single-nucleotide polymorphisms on liver stiffness and controlled attenuation parameter in patients treated with direct-acting antiviral drugs for hepatitis C infection

Single-nucleotide polymorphisms (SNPs) of patatin-like phospholipase domain-containing 3 (PNPLA3), tolloid-like protein 1 (TLL1) and interleukin-28 (IL28) have been identified as susceptibility factors for liver steatosis, inflammation and fibrosis in patients with hepatitis C virus (HCV) infection. Here, whether these polymorphisms affected predispositions to changes in liver stiffness (LS) and controlled attenuation parameter (CAP) following direct-acting antiviral (DAA) therapy was assessed. The changes in LS and steatosis in 77 HCV-infected patients receiving DAA therapy were compared with PNPLA3, TLL1 and IL28 genotypes, using CAP, FibroScan and Virtual Touch tissue quantification (VTTQ) before treatment and 12 weeks after the end of the treatment. VTTQ results showed that LS significantly decreased in PNPLA3 CC (P=0.035), TLL1 AA (P=0.011) and IL28B TT (P=0.005) genotypes; no significant differences were observed in PNPLA3 CG/GG, TLL1 AT/TT and IL28B TG/GG. FibroScan results showed that LS significantly decreased in TLL1 AA (P=0.028) and IL28B TT (P=0.032), with no significant difference in PNPLA3 CC. No significant differences were observed in PNPLA3 CG/GG, TLL1 AT/TT and IL28B TG/GG groups. CAP was significantly increased in PNPLA3 CG/GG (P=0.039 and P<0.05) and IL28B TT (P=0.014); no significant difference was observed in PNPLA3 CC and all genotypes of TLL1 and IL28B TG/GG. Therefore, these results indicated that SNPs could predict changes in LS and steatosis after DAA therapy.

Omics-derived hepatocellular carcinoma risk biomarkers for precision care of chronic liver diseases

Precise hepatocellular carcinoma (HCC) risk prediction will play increasingly important roles with the contemporary HCC etiologies, that is, non-alcoholic fatty liver disease and resolved hepatitis C virus infection. Because the HCC incidence rate in this emerging patient population is relatively low (~1% per year), identification of a subset of patients at the highest risk is critical to concentrate the effort and resources of regular HCC screening to those who most need it. Omics profiling has been derived using several candidate HCC risk biomarkers, which could refine HCC screening by enabling individual risk-based personalized or risk-stratified patient management. Various types of biomolecules have been explored as sources of information to predict HCC risk at various time horizons. Germline DNA polymorphisms likely reflect race/ethnicity- and/or etiology-specific susceptibility to HCC development or chronic liver disease progression toward carcinogenesis. Transcriptomic dysregulations in the diseased liver capture functional molecular status supporting oncogenesis such as inflammatory pathway and myofibroblast activation. Circulating nucleic acids, proteins, and metabolites could serve as less-invasive measures of molecular HCC risk. Characterization of gut microbiota could also inform HCC risk estimation. Each biomarker could have its niche of clinical application depending on logistics of use, performance, and costs with a goal to eventually improve patient prognosis as a part of the whole algorithm of chronic liver disease management.

TLL1 variants do not predict hepatocellular carcinoma development in HCV cirrhotic patients treated with direct-acting antivirals

Tolloid-like 1 gene (TLL1) variant rs17047200 has been associated with hepatocellular carcinoma (HCC) in Japanese hepatitis C virus (HCV) patients with sustained virological response (SVR) to interferon or direct-acting antiviral (DAA)-based regimens. We investigated whether this holds true also in Caucasian cirrhotic patients cured by DAAs. Consecutive Caucasian HCV cirrhotics receiving DAA between December 2014 and December 2016 in a single centre were enrolled. Cirrhosis was defined histologically (METAVIR F4) or by liver stiffness measurement (LSM > 11.9 kPa). TLL1 rs17047200 was analysed by TaqMan SNP genotyping assay. 452 patients were enrolled: median age 63 (28-87) years, 58% males, 47% HCV-1b, LSM 19.1 (12.0-75.0) kPa and Fibrosis-4 (FIB-4) score 4.9 (0.3-46.0). 96% patients achieved an SVR. TLL1 genotype was AA in 329 (73%) and AT/TT in 123 (27%) (MAF = 0.14, HWE P > 0.05). Patients' clinical features were similar across TLL1 genotypes. After 33 (3-47) months from DAA start, 31 patients developed HCC, with a 3-year estimated cumulative probability being 7.5% (95% CI: 5%-10%). The cumulative incidence of HCC was 9% in TLL1 AA vs 7% in AT/TT patients (P = 0.55). Male sex (HR: 3.78, 95% CI: 1.4-10.1, P = 0.008), diabetes (HR: 3.5, 95% CI: 1.68-7.27, P = 0.001) and FIB-4 (HR: 1.09, 95% CI: 1.03-1.14, P = 0.001) were baseline-independent predictors of HCC. The incidence of HCC was not influenced by TLL1 genotypes even when considering an additional group of 348 noncirrhotic patients, being 2% in AA vs 1% AT/TT patients (P = 0.58). In a large cohort of Caucasian HCV cirrhotics treated with DAA, TLL1 variants do not predict HCC development.