A New CXCR4 Receptor Antagonist - Effects on Cell Growth and Tumor Microenvironment in a Glioma Model

The chemokine receptor CXCR4 is a widely expressed G protein-coupled receptor. Although initially linked with leukocyte trafficking, CXCR4 is expressed in various tumors, where it is strictly related to cell motility, proliferation and survival. In gliomas, CXCR4 activation by the agonist CXCL12 has been demonstrated to regulate the recruitment of the surrounding microglia/macrophages. Therefore, the CXCL12/CXCR4 signaling pathway is emerging as a potential therapeutic target. In this study we evaluated the effects mediated by a new CXCR4 receptor antagonist, the cyclic peptide Phe-7, compared with AMD3100, a well-known CXCR4 inhibitor, on a human glioma cell line (U87MG), and the influence of these drugs on microglial reactivity, by using intracranial xenografts.