Small but mighty: microparticles as mediators of tumor progression.

A wide spectrum of both normal and diseased cell types shed extracellular vesicles that facilitate intercellular communication without direct cell-to-cell contact. Microparticles (MPs) are a subtype of extracellular vesicles that participate in multiple biological processes. They carry abundant bioactive molecules including different forms of nucleic acids and proteins that can markedly modulate cellular behavior. MPs are involved in several hallmarks of cancer such as drug resistance, thrombosis, immune evasion, angiogenesis, tumor invasion and metastasis. Such MPs originate from either cancer or other host cells. As MPs are secreted and can be detected in various body fluids, they can be used as potential diagnostic and prognostic biomarkers as well as vehicles for delivery of cytotoxic drugs. This review summarizes accumulating evidence on the biological properties of MPs in cancer, with reference to their potential usage in clinical settings.