Radiogenomic identification of NET score-associated immune regulatory candidates in hepatocellular carcinoma

Neutrophil extracellular traps (NETs), chromatin-based structures released by activated neutrophils, have been implicated in inflammation, antimicrobial defense, and tumor progression. However, the transcriptional features associated with NET-related programs and their immunological relevance in hepatocellular carcinoma (HCC) remain incompletely understood. To investigate the prognostic and immunological significance of literature-derived NET-related genes (NETRGs) in HCC, identify NET score-associated candidate genes, and explore their potential association with the tumor immune microenvironment through transcriptomic, radiogenomic, and functional analyses. Transcriptomic and clinical data from TCGA-LIHC were analyzed. A NET enrichment score was calculated using ssGSEA based on literature-derived NETRGs. Weighted gene co-expression network analysis (WGCNA) was performed to identify co-expression modules associated with the NET score. NET score-associated candidate genes were identified by integrating high-/low-NET score differentially expressed genes, tumor-normal differentially expressed genes, and WGCNA-derived co-expression hub genes. A radiogenomic model based on HGF expression was developed using random forest and LASSO algorithms. Functional experiments, including LPS stimulation, tumor-bearing mouse models, and co-culture systems, were used to evaluate the roles of Cathepsin C and HGF in immune regulation. NETRGs were dysregulated in HCC and stratified patients into subgroups with distinct prognostic and immune microenvironmental features. A high NET score was associated with better prognosis and an immune-inflamed tumor microenvironment characterized by higher immune and stromal scores, lower tumor purity, and increased immune cell enrichment. HGF showed the highest diagnostic performance among the candidate genes and was used to construct an exploratory radiogenomic model with moderate discriminatory performance (AUC = 0.751). Experimentally, LPS-induced inflammatory stimulation was associated with activation of the NF-κB–Cathepsin C/HGF axis. Cathepsin C was associated with reduced CD8⁺ T-cell infiltration and effector function and increased Treg infiltration, whereas HGF was associated with impaired dendritic cell maturation. NF-κB knockdown attenuated these immunosuppressive effects. This study identifies a tumor-intrinsic inflammatory signaling axis involving NF-κB–Cathepsin C/HGF that is associated with immune-regulatory features in HCC. The integrative transcriptomic, radiogenomic, and experimental analyses suggest that NET score-associated inflammatory and immunosuppressive programs may contribute to immune evasion in HCC, but direct therapeutic targeting of this axis requires further validation.