Research progress of drugs for cancer immunotherapy based on CCL2/CCR2 signaling axis

C-C motif chemokine ligand 2 (CCL2) and its receptor CCR2 are closely related to tumorigenesis and tumor progression. The CCL2/CCR2 signaling axis promotes tumor progression through multiple mechanisms: CCL2 binds to CCR2 on the surface of tumor cells, and thus promotes tumor growth/survival and metastasis; more importantly, CCL2 recruits a variety of immunosuppressive cells to aggregate in the tumor microenvironment, and inhibits the function and activity of immune cells, promoting tumor progression. The article reviews the CCL2/CCR2 signaling axis and its role in tumors and tumor microenvironment, with particular focus on the advances in clinical research on drugs targeting CCL2/CCR2 signaling axis, in order to gain an in-depth and overall understanding of the mechanism of action of CCL2/CCR2 axis in tumor progression and develop more effective anti-tumor immunotherapeutic agents.