Tumor-educated platelets: from molecular mechanisms to liquid biopsy and therapeutic applications.

Platelets, once regarded solely as mediators of hemostasis and thrombosis, are now recognized as active participants in tumor biology. A growing body of evidence indicates that tumors can reprogram circulating platelets into tumor-educated platelets (TEPs) through molecular cargo exchange, intraplatelet RNA processing, and receptor remodeling. These processes reshape platelet transcriptomic and proteomic profiles and endow TEPs with functional properties that support tumor progression. This review critically examines the molecular mechanisms underlying platelet education, including extracellular vesicle-mediated biomolecule transfer, spliceosome-associated RNA reprogramming, and tumor-induced alterations in platelet surface receptors. We then analyze how these molecular changes translate into key pro-tumorigenic functions, such as promotion of angiogenesis, induction of anoikis resistance via the RhoA-MYPT1-PP1-YAP1 axis, facilitation of immune evasion, and enhancement of metastatic dissemination. Beyond mechanistic insights, we evaluate the translational relevance of TEPs as a liquid biopsy biosource and as a potential therapeutic target. Particular attention is given to current limitations, including the specificity of TEP RNA signatures across cancer types, methodological heterogeneity in platelet isolation and profiling, and the unresolved distinction between causal reprogramming and passive biomolecule uptake. Collectively, this review positions TEPs as a biologically informative but methodologically challenging interface between tumor biology and clinical oncology, highlighting both their diagnostic promise and the critical barriers that must be overcome for their integration into precision cancer management.