Exosomes and microRNAs: Powerful mediators of cancer and their clinical applications

Exosomes are nanoscale extracellular vesicles secreted by nearly all cell types, playing a crucial role in intercellular communication. These vesicles transport biomolecules, including proteins, lipids, and nucleic acids, particularly microRNAs (miRNAs), which regulate post-transcriptional gene expression. In cancer, exosomes influence critical processes such as cell proliferation, angiogenesis, metastasis, and therapeutic resistance by transferring oncogenic or tumor-suppressor miRNAs to recipient cells. Their stability in biological fluids and their ability to protect molecular cargo make them promising candidates for non-invasive diagnostics and targeted therapeutics. This review explores the mechanisms of exosome biogenesis, their molecular composition, and their roles in cancer progression, alongside emerging clinical applications and challenges.