Chemokines in tumor angiogenesis and metastasis.

Chemokines are a large group of low molecular weight cytokines that are known to selectively attract and activate different cell types. Although the primary function of chemokines is well recognized as leukocyte attractants, recent evidences indicate that they also play a role in number of tumor-related processes, such as growth, angiogenesis and metastasis. Chemokines activate cells through cell surface seven trans-membranes, G-protein-coupled receptors (GPCR). The role played by chemokines and their receptors in tumor pathophysiology is complex as some chemokines favor tumor growth and metastasis, while others may enhance anti-tumor immunity. These diverse functions of chemokines establish them as key mediators between the tumor cells and their microenvironment and play critical role in tumor progression and metastasis. In this review, we present some of the recent advances in chemokine research with special emphasis on its role in tumor angiogenesis and metastasis.