Vol. 9, Special Issue 7, Part B (2025)

Extracellular vesicles (EVs) are crucial mediators which intercellular communication, transporting a diverse cargo of biologically active molecules, including proteins, lipids, and various RNA species. These vesicles are integral to maintaining tissue homeostasis and significantly contribute to the pathogenesis of numerous diseases, particularly in the context of cancer initiation and progression. EVs and their molecular contents reflect the pathological state of their donor cells, rendering them valuable as potential biomarkers detectable in various body fluids. This review discusses the physiological roles of EVs in processes such as reproduction, immune modulation and nervous system function, emphasizing their broader biological importance. The EVs also have a role in neoplasia, from early cancer initiation and shaping the tumor microenvironment to promoting tumor growth, progression, and the formation of pre-metastatic niches and subsequent metastasis. EVs have promising utility as non-invasive biomarkers for disease detection, prognosis, and therapeutic monitoring. Clinically, tumor-derived EVs are promising non-invasive cancer biomarkers for early detection, diagnosis, prognosis, and therapy monitoring, with EV-derived DNA, RNA, and proteins showing significant potential. EV-based therapies, leveraging their cargo for drug delivery or inhibiting their function, are emerging. While methods like electron microscopy, flow cytometry, nanoparticle tracking, and biochemical assays (immunoblotting, immunosorbent assays, mass spectrometry) are used for EV analysis, standardization and heterogeneity remain challenges. Despite these hurdles, EVs represent a profound area of research with immense significance for future diagnostic and therapeutic advancements in both human and veterinary medicine.