CXCR7 in tumorigenesis and progression

Chemokines, a family of small cytokines, were initially characterized as proinflammatory chemoattractant cytokines that regulated cell trafficking and adhesion. Today, attention focuses on chemokines because evidence shows that they play a critical role in tumor initiation, promotion, and progression. CXCR7, a seven-transmembrane G-protein-coupled CXC chemokine receptor, has recently been identified as binding with high affinity to chemokines CXCL11 (I-TAC) and CXCL12 (SDF-1). In this review, we highlight the current knowledge about the role of CXCR7 in the biologic processes of cancer, including cancer growth, survival, adhesion, invasion, metastasis, angiogenesis, and progression. The use of peptides, small molecules, antibodies, or small interfering RNA to target CXCR7 shows promise as new potential avenues for the treatment of cancer.