Alterations in NK Cell Function and Glucose Metabolism Characteristics in Patients With Progressive Hepatocellular Carcinoma.

Natural killer (NK) cell immunosuppression represents a critical factor in patients with progressive hepatocellular carcinoma (HCC), yet its underlying characteristics at the single-cell level remain poorly defined. This study investigates the functional and metabolic alterations in NK cells associated with progressive HCC. We performed single-cell RNA sequencing (scRNA-seq) on peripheral blood samples from six treatment-naïve HCC patients, categorised into progressive and stable disease groups based on a 3-year follow-up. This was complemented by multicolor flow cytometry of peripheral blood, alongside multicolor fluorescence analyses of paired tumour and adjacent tissues. Our analyses revealed a significant reduction in NK cell proportion and a marked downregulation of immune-related genes in patients with progressive HCC. scRNA-seq further identified a distinct NK cell characterised by high expression of HAVCR2 (TIM3). Compared to TIM3NK cells, TIM3NK cells exhibited an exhausted phenotype, evidenced by upregulated CD39 and TIGIT, impaired functional capacity (reduced CD107a and IFN-γ) and downregulated key glycolytic enzymes (HK2, ATP5a). Clinically, high TIM3 expression correlated with shorter progression-free survival and an increased risk of tumour progression. Collectively, our findings delineate a state of NK cell immunosuppression and metabolic impairment in progressive HCC, potentially driven by glycolytic reprogramming and establish TIM3 as a critical marker and potential therapeutic target.