Fig. 3

A schematic illustration of the CRC-derived exosome mechanisms for CRC metastasis. CRC-derived exosomes represent extracellular vesicles produced by CRC cells that transport various substances such as nucleic acids, proteins, lipids, and metabolites throughout the tumor microenvironment. These exosomes play a pivotal role in the formation of PMNs. Primary tumor cells release exosomes that can disseminate to distant metastatic sites and modulate local cells within the pre-metastatic microenvironment through diverse signaling pathways, such as upregulation of pro-inflammatory gene expression and immunosuppressive cytokine secretion. Moreover, these exosomes also participate in regulating the immune response, promoting increased angiogenesis, and facilitating cellular epithelial-mesenchymal transition (EMT). Their involvement is particularly prominent in liver, lung, and peritoneal metastases. In these metastatic sites, exosomes act as crucial mediators between cancer cells and the surrounding microenvironment, thereby facilitating the reorganization of the secondary site to enable successful tumor colonization