Progress of exosomes in regulating tumor metastasis by remodeling the pre-metastatic immune microenvironment

Exosomes play an important role in the metastatic microenvironment, acting as a transmission belt that facilitates intercellular communication. By delivering proteins, nucleic acids, and other substances in the exosomes, they can change the function of the receptor target cells, change the microenvironment of the metastatic site, and promote the colonization of the tumor cells, thus promoting cancer metastasis. The interaction between tumor cells and the surrounding microenvironment is complex, with exosomes serving as key facilitators of crosstalk between the primary tumor microenvironment and the pre-metastasis microenvironment. Despite many current studies to explore exosomes, we still do not have a detailed understanding of the role and mechanism of exosomes in the pre-metastatic immune microenvironment, and there are many challenges in the clinical application of exosomes. In this paper, we summarize the role of exosomes in regulating the pre-metastatic immune microenvironment and its mechanism, focusing on how exosomes regulate the function of immune cells in the pre-metastatic microenvironment to promote tumor metastasis. In addition, the potential application of exosomes in tumor immunotherapy and strategies for targeting exosomes are discussed. This will contribute to the immunotherapy of cancer metastasis and promote the clinical application of exosomes.