The effect of cancer cell-derived exosomal proteins on macrophage polarization: An in-depth review

Cancer is characterized by unregulated cell proliferation, enabling it to invade and spread to different organs and tissues in the body. Cancer progression is intricately influenced by the complex dynamics within the tumor microenvironment (TME). The TME is a composite and dynamic network comprising cancer cells and various immune cells, including tumor-associated macrophages. Exosomes facilitate the communication between different cancer cells as well as other types of cells. This review particularly focuses on exosomal proteins derived from different cancer cells in mounting the complex crosstalk between cells of cancer and macrophages within the TME. Most cancer-derived exosomal proteins polarize macrophages towards M2 phenotype, promoting cancer aggressiveness, while a few have role switching towards the M1 phenotype, inhibiting cancer proliferation, respectively. In this review, we summarize, for the first time, the dual impact of cancer cell-derived exosomal proteins on macrophage polarization and the associated signaling pathways, offering valuable insights for developing innovative therapeutic strategies against diverse cancer types.