Multifaceted roles of CCL20 (C-C motif chemokine ligand 20): mechanisms and communication networks in breast cancer progression

Emerging studies have demonstrated notable roles of CCL20 in breast cancer progression. Based on these findings, CCL20 has become a potential therapeutic target for cancer immunotherapy. Accordingly, studies utilizing monoclonal antibodies to target CCL20 are currently being experimented. However, the existence of cytokine network in the tumor microenvironment collectively regulates tumor progression. Hence, a deeper understanding of the role of CCL20 and the underlying signaling pathways regulating the functions of CCL20 may provide a novel strategy for therapeutic interventions. This review provides the current knowledge on how CCL20 interacts with breast cancer cells to influence tumor progression via immunosuppression, angiogenesis, epithelial to mesenchymal transition, migration/invasion and chemoresistance. As a possible candidate biomarker, we also reviewed signal pathways and other factors in the tumor microenvironment regulating the tumor-promoting functions of CCL20. These new insights may be useful to design new potent and selective CCL20 inhibitors against breast cancer in the future.