New insights on the role of CXCR4 in cancer metastasis.

The evolutionarily conserved chemokine superfamily encodes small peptide molecules that bind G-protein-coupled receptors. In humans, this superfamily includes at least 46 ligands and 18 receptors. In general, chemokines and their receptors form a chemotactic network that regulates the migration of cells to specific micro-anatomical destinations within an organism in an organized and non-random manner. Recent studies place chemokine-chemokine receptor pairs at the centre of not only physiological cell migration, but also pathological processes such as metastasis. This mini review considers some recent data on how chemokines regulate tumour cells during metastasis. These observations suggest novel ways for pharmacological intervention.