Spatial transcriptome and single-cell reveal the role of sorbitol metabolism in hepatocellular carcinoma progression and tumor microenvironment.

BACKGROUND: Metabolic reprogramming represents a hallmark feature of hepatocellular carcinoma (HCC). As a crucial branch of the polyol pathway, the biological functions and clinical implications of sorbitol metabolism in HCC progression remain to be fully elucidated. METHODS: This study integrated single-cell transcriptomic data from 67 HCC patients to establish a sorbitol metabolism scoring system. Pseudotime trajectory analysis was employed to investigate the differentiation patterns of cells with aberrant sorbitol metabolism, while spatial transcriptomics was utilized to characterize their spatial distribution. Using machine learning approaches on HCC cohort transcriptomic data, we developed a prognostic prediction model, complemented by CIBERSORT-based immune infiltration analysis and CellMiner-derived drug sensitivity predictions. In addition, in vitro gain- and loss-of-function experiments were conducted to validate the biological role of SQSTM1 in HCC cells. RESULTS: Our findings demonstrate that ALDH3A1+ malignant cells with high sorbitol metabolism scores exhibit dysregulated cell adhesion, enhanced immune evasion capacity, and activated hypoxia signaling pathways. These cells were predominantly localized at the tumor invasive front. The ALDH3A1+-based predictive model identified a high-risk group with significantly poorer prognosis, characterized by increased TP53 mutation frequency and a distinct immunosuppressive microenvironment. Drug sensitivity analysis suggested Irofulven as a potential therapeutic agent targeting sorbitol metabolism-active tumor cells. Furthermore, in vitro experiments demonstrated that SQSTM1 promoted HCC cell proliferation and migration, supporting its functional involvement in HCC progression. CONCLUSION: This study uncovers the mechanistic role of sorbitol metabolism in driving HCC progression through shaping an immunosuppressive microenvironment. The sorbitol metabolism scoring system may serve as a novel prognostic biomarker and provides a theoretical foundation for precision treatment strategies, such as Irofulven-targeted therapy, in HCC management. Moreover, SQSTM1 may act as an important downstream functional mediator and represents a potential therapeutic target in hepatocellular carcinoma.