Hypoxic migrasomes drive colorectal cancer liver metastasis by mediating CD5L(+) macrophage efferocytosis via NRP2/PROX1 axis.

OBJECTIVE: Migrasomes are a newly discovered class of extracellular vesicles, yet their roles in colorectal cancer (CRC) metastasis remain poorly understood. This study aimed to investigate the functional significance of CRC-derived migrasomes, particularly under hypoxic conditions, in promoting liver metastasis and modulating the tumor immune microenvironment. METHODS: Migrasomes in CRC tissues and cells were characterized using transmission electron microscopy or immunofluorescence. A mouse liver metastasis model and single-cell RNA sequencing (scRNA-seq) were employed to explore functional outcomes and cellular interactions. RESULTS: Migrasome structures were observed in both primary CRC and metastatic liver tissues, and live-cell imaging revealed hypoxic CRC cells released increased numbers of migrasomes. In vivo imaging demonstrated hepatic accumulation of hypoxic migrasomes and enhanced liver metastasis in mice. ScRNA-seq of liver metastases revealed that hypoxic migrasomes reprogrammed the tumor microenvironment, notably expanding a Tmem45a⁺ fibroblast subset with myofibroblast features and promoting CD5L⁺ macrophage differentiation with elevated efferocytic capacity. Mechanistically, NRP2, enriched in migrasomes derived from hypoxic CRC cells, was transferred to macrophages, binding with PROX1 to drive CD5L expression and upregulate of efferocytosis receptors. NRP2 knockdown in CRC cells abrogated migrasome-induced CD5L⁺ macrophage polarization and impaired apoptotic tumor cell clearance. CONCLUSION: These findings demonstrate that hypoxic CRC-derived migrasomes facilitate liver metastasis by reprogramming stromal and immune compartments, particularly through NRP2/PROX1-mediated education of macrophages toward a pro-efferocytic CD5L⁺ phenotype. Our study reveals a previously unrecognized intercellular communication axis involving migrasomes in CRC progression and provides a potential therapeutic target for metastatic disease.