Platelet-derived mitochondrial transfer in cancer metastasis: mechanisms, functional consequences, and translational...

Cancer metastasis is a multistep and highly inefficient process that depends on reciprocal interactions between tumor cells and the host microenvironment. Among the most important host contributors, platelets have emerged as active facilitators of metastatic dissemination, supporting the survival of circulating tumor cells, immune evasion, endothelial arrest, extravasation, and early colonization. More recently, platelet-derived mitochondrial transfer has been recognized as a novel mechanism by which platelets may enhance tumor aggressiveness through metabolic reprogramming. This review critically synthesizes the current literature on platelet-mediated mitochondrial transfer in cancer, with emphasis on its biological mechanisms, functional consequences, and translational implications. Emerging evidence in selected osteosarcoma and triple-negative breast cancer models indicates that activated platelets can donate functional mitochondria to cancer cells through direct contact and microparticle-mediated pathways, potentially increasing oxidative phosphorylation, ATP production, redox adaptability, proliferative capacity, and migratory behavior. Mechanistically, platelet mitochondrial transfer may involve pathways linked to mitochondrial quality control and trafficking, including PINK1/Parkin-MFN2 signaling, while also intersecting with broader platelet-tumor crosstalk that promotes epithelial-mesenchymal transition, anoikis resistance, and immune escape. In parallel, platelet-derived mitochondrial cargo and related extracellular vesicle signatures may offer new opportunities for liquid biopsy-based biomarker development. However, major challenges remain, including the need for rigorous in vivo validation, discrimination of intact mitochondria from fragmented mitochondrial material, and clarification of context-dependent effects across tumor types. Collectively, platelet-derived mitochondrial transfer represents an emerging layer of intercellular communication that may link thrombosis, metabolism, and metastasis, and it offers promising avenues for both biomarker discovery and therapeutic intervention.