Small Extracellular Vesicle-Associated microRNA in Cancer: Biology and Applications in Translational Research and Precision Oncology

Small extracellular vesicles (sEVs) are extracellular vesicles that mediate intercellular communication through the transfer of bioactive molecules, including proteins, lipids, and nucleic acids. Among their cargo, microRNAs (miRNAs) have emerged as critical regulators of gene expression with significant implications in cancer biology. Tumor-derived extracellular vesicle-associated microRNAs (EV-miRNAs) can reprogram recipient cells, promoting oncogenesis, metastasis, angiogenesis, and therapeutic resistance. This review provides a comprehensive overview of EV-miRNAs in cancer, examining their biogenesis, mechanisms of intercellular transfer, and functional roles in tumor progression. We discuss the clinical potential of EV-miRNAs as non-invasive biomarkers for cancer diagnosis and prognosis, as well as their emerging applications in targeted therapeutic strategies. Furthermore, we address current challenges related to isolation techniques, quantification methods, and standardization protocols that hinder clinical translation. Finally, we outline future directions for integrating EV-miRNA analysis into precision oncology frameworks and liquid biopsy platforms, highlighting opportunities to advance personalized cancer care.