The Roles of CXCR4 and CXCR7 in Melanocyte and Melanoma Motility

Chemokines are signaling proteins released by cells in response to chemical stimuli in their environment. The chemokine stromal derived factor 1 (SDF1) has been regularly studied due to its role in the growth and metastasis of multiple cancers, including melanoma. SDF1 has two known receptors: CXCR4 and CXCR7. Previous research has mainly focused on CXCR4 receptor signaling, which influences many cell responses, among them the migration of neural crest cells and the amount of receptor expression is upregulated in melanoma. CXCR7 receptor signaling is not as well studied but has been shown to influence melanocyte migration and constrain melanoma tumor growth in vivo where as CXCR4 could not. It is not known, however, how relevant CXCR7 may be in the capability of melanocyte and melanoma migration. Here, I studied the potential roles of CXCR4 and CXCR7 in melanocyte and melanoma migration in vitro by genetically silencing both receptors. My data shows that the CXCR7 receptor is more important for migratory capabilities of melanocytes and melanoma cells than the CXCR4 receptor. These findings suggest that down regulating or blocking the CXCR7 receptor through targeted therapies may show a substantial effect in melanoma treatment.