Extracellular vesicles as biomarkers and therapeutic nanocarriers in cancer

Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, are lipid bilayer-bound nanoparticles secreted by various cell types. EVs mediate intercellular communication by selectively transporting bioactive molecules including proteins, lipids, and nucleic acids. This review comprehensively analyzes EVs biogenesis, classification, and cargo diversity, emphasizing their multifaceted roles in physiological processes and cancer. EVs exhibit intrinsic dual regulatory roles in tumor biology. On the one hand, they promote malignant tumor progression by delivering pro-tumorigenic cargoes and mediating immunosuppressive responses; on the other hand, they can induce anti-tumor immune responses through antigen presentation and immune activation. Beyond these endogenous functions, EVs serve as reliable liquid biopsy biomarkers and versatile therapeutic nanocarriers. Furthermore, engineered EVs enable precise drug delivery in immunotherapy and targeted therapy approaches. Despite their promising clinical potential, major challenges, including the lack of standardized isolation methods and concerns regarding the safety of engineered modifications, remain to be addressed. Future studies should focus on elucidating subtype-specific mechanisms, optimizing therapeutic strategies, and validating clinical efficacy in large-scale trials. EVs represent a promising platform bridging basic research and clinical applications, ushering in a new paradigm of precision medicine for cancer diagnosis and treatment.