Alterations in <scp>NK</scp> 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 TIM3^-NK cells, TIM3⁺NK 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.