From biomarkers to drug delivery: advances in extracellular vesicles in cancer diagnosis and targeted therapy

Extracellular vesicles (EVs), lipid-bilayer nanoparticles secreted by diverse cell types, have emerged as pivotal mediators in cancer progression through intercellular communication. These vesicles encapsulate oncogenic biomolecules—including proteins, nucleic acids, and metabolites—enabling the reprogramming of recipient cells to foster tumor initiation, angiogenesis, immune evasion, and metastatic niche formation. Tumor-derived EVs (TDEVs) reflect parental cell molecular profiles, offering non-invasive biomarkers for cancer diagnosis. Their stability in bodily fluids and enrichment of tumor-specific markers, such as mutant DNA, oncogenic miRNAs, and immunosuppressive ligands, surpass conventional circulating biomarkers in sensitivity and specificity, positioning EVs as promising tools for liquid biopsy. In addition to their diagnostic potential, EVs have dual roles as therapeutic targets and drug delivery vehicles. TDEVs promote chemoresistance by transferring drug efflux pumps, pro-survival RNAs, and immunosuppressive factors, but their inherent biocompatibility and targeting capabilities make them ideal nanocarriers. In preclinical models, engineered EVs loaded with chemotherapeutics, siRNA, or CRISPR-Cas9 components exhibit enhanced tumor accumulation and reduced off-target toxicity. Surface modifications, such as peptide conjugation or antibody integration, further improve their homing specificity. This review synthesizes advances in EV biology, diagnostic applications, and therapeutic innovations, highlighting their translational potential in oncology. By combining mechanistic insights with translational opportunities, we highlight the evolving promise of EVs as versatile platforms for cancer management.