Exosomes are small extracellular vesicles containing proteins, nucleic acids and lipids, which can transmit information between cells, and can interfere with the epigenetic characteristics and functions of recipient cells. Tumor‑derived exosomes play a crucial role as communicators in the tumor microenvironment, and are involved in the occurrence and development of various tumors. The present review article summarizes the biogenesis of exosomes and their communication with local and remote cells, focusing on the function of tumor‑derived exosomes in the tumor microenvironment, including the promotion of angiogenesis, the induction of epithelial mesenchymal transformation, and the activation and inhibition of immune cells, as well as the effects of exosomes on the tumor microenvironment during microbial infections. Additionally, the effects of exosomes on tumor immunotherapy and the potential applications of exosomes as biomarkers, delivery vehicles and cancer vaccines in cancer diagnostics and therapeutics are discussed.
Keywords: clinical applications; exosome; immunotherapy; tumor immunomodulation.