Background & Aims In vitro studies suggest that hepatitis C virus (HCV) may have a direct oncogenic effect, independent of the well-established indirect mechanism of hepatocarcinogenesis driven by chronic necroinflammation, compensatory regeneration, and fibrosis. However, evidence supporting such mechanisms in human liver tissue remains limited. This study aimed to determine whether HCV contributes directly to hepatocarcinogenesis in human liver samples.Methods We conducted a nested case-control study within a prospective liver biopsy biobank at the University Hospital Basel. Patients with chronic hepatitis C (CHC) who developed hepatocellular carcinoma (HCC) during follow-up (index cases, CHC-HCC) were identified and 1:2 propensity score-matched to CHC controls without HCC (controls, CHC-nonHCC). Matching included clinical, demographic, and virological risk factors for HCC. Liver biopsies were analyzed using RNA- and whole-exome sequencing. We constructed an ensemble of linear regression models based on HCV-induced persistent transcriptomic features.Results We identified baseline biopsies from 16 CHC-HCC patients and 32 matched CHC-nonHCC controls. Principal component analysis of transcriptomic data significantly separated the two groups (Mann-Whitney U Test, p-value 0.009). Differential expression analysis revealed dysregulation of MYC target genes, the unfolded protein response, and oxidative phosphorylation in CHC-HCC samples. Notably, 615 baseline differentially expressed genes (DEGs) also differed from normal HCV-negative livers and remained dysregulated in non-tumor liver tissue collected years later at HCC diagnosis (t-test, FDR < 0.05). From this persistently altered gene set, we trained an ensemble of linear regression models that that identified a 19-gene signature predictive of HCC risk.Conclusions Our findings provide direct evidence from human liver biopsies that HCV contributes to hepatocarcinogenesis not only through indirect mechanisms such as inflammation and regeneration, but also through long-lasting, hepatocyte-intrinsic molecular reprogramming.Impact And Implications Hepatitis C virus (HCV) has long been known to promote liver cancer through chronic inflammation and regeneration, but whether it induces durable oncogenic changes in human hepatocytes in vivo remained unclear. Our study demonstrates that HCV leaves a persistent, hepatocyte-intrinsic molecular imprint detectable years before HCC diagnosis, even after viral cure. We also provide proof-of-concept for transcriptomic predictive features that can identify patients at higher risk for HCC development, which could help refine surveillance and enable targeted chemoprevention strategies.
Boldanova et al. (Fri,) studied this question.