Objective: To investigate whether aurora kinase A (AURKA) in hepatocellular carcinoma (HCC) cells drives M2 polarization of macrophages via exosomes, and to clarify its underlying molecular mechanism.

Methods: The correlations between AURKA expression level in HCC tissues and M2 macrophage infiltration as well as prognosis of HCC patients were analyzed using the GEPIA (Gene Expression Profiling Interactive Analysis) and TIMER (Tumor Immune Estimation Resource) public databases. Based on the human HCC cell line MHCC-97H, AURKA stably overexpressed (97H-AKAOE) and knockdown (97H-AKAKD) cells were constructed. Exosomes were isolated by ultracentrifugation and characterized by transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. Exosomes derived from 97H-AKAOE and 97H-AKAKD cells were co-cultured with M0 macrophages, and the expression levels of M2 macrophage marker proteins CD163 and Arg-1 were assessed by real-time quantitative reverse transcription PCR (RT-qPCR) and Western blotting to evaluate the effect of AURKA on M2 polarization of macrophages. Liquid chromatography-mass spectrometry (LC-MS) was used to identify key differentially expressed proteins regulated by AURKA in exosomes, and functional rescue experiments were performed to validate their roles on M2 polarization of macrophages.

Results: AURKA was highly expressed in HCC tissues, and its expression level positively correlated with poor prognosis of HCC patients and M2 macrophage infiltration abundance (all P < 0.05). AURKA overexpression significantly enhanced the exosome-induced M2 polarization of macrophages, as evidenced by the upregulated CD163 and Arg-1, whereas AURKA knockdown suppressed this effect. Proteomic analysis revealed that lectin galactoside-binding soluble 3-binding protein (LGALS3BP) was significantly enriched in exosomes from AURKA-overexpressing HCC cells. Knockdown of LGALS3BP partially reversed the AURKA-mediated M2 polarization of macrophages.

Conclusion: AURKA in HCC cells drives M2 polarization of macrophages by upregulating exosomal LGALS3BP expression, thereby promoting the formation of an immunosuppressive tumor microenvironment in HCC. Elucidation of this mechanism provides a potential novel target for HCC immunotherapy.