Concurrent expression of glucose-6-phosphate dehydrogenase and secreted phosphoprotein 1 characterizes an aggressive and immunosuppressive tumor state in hepatocellular carcinoma

Abstract

Introduction Despite improved outcomes with combined hepatic arterial infusion chemotherapy (HAIC) and systemic therapy in hepatocellular carcinoma (HCC), therapeutic resistance is frequently driven by the tumor microenvironment. We aimed to explore biological features associated with therapeutic resistance in HCC. Methods We integrated single-cell transcriptomics of a therapy-progressive lesion with large-scale bulk transcriptomic modeling and independent clinical validation. We performed immunohistochemistry in an independent retrospective cohort of 114 treatment-naïve patients to clinically validate the computational findings. Results Single-cell analysis revealed concurrent upregulation of glucose-6-phosphate dehydrogenase (G6PD) and secreted phosphoprotein 1 (SPP1) in tumor hepatocytes from an index therapy-progressive lesion. A metabolic-transcriptional risk signature effectively stratified overall survival in the TCGA-LIHC and ICGC LIRI-JP cohorts. This signature was associated with an “inflamed-yet-suppressed” tumor microenvironment, characterized by concurrent upregulation of multiple immune checkpoints and defective cytotoxic capacity. Exploratory intercellular communication modeling inferred that surviving hepatocytes were major senders of SPP1-related signaling. In the clinical validation cohort, tissue G6PD H-score was significantly associated with shorter recurrence-free survival in univariable analysis (HR = 1.086 per 10-point increase, 95% CI 1.015–1.162, P = 0.017) and exploratory stratified analyses. G6PD was positively correlated with SPP1 at both the bulk transcriptomic and tissue protein levels (protein Spearman r = 0.571, P < 0.0001). Discussion These findings suggest that concurrent G6PD and SPP1 expression characterizes an aggressive and immunosuppressive tumor state in HCC. Although this association may provide biological insight into treatment refractoriness, its predictive value for modern combination therapies requires prospective validation in treated cohorts.