The Chemokine Receptor CXCR6 and Its Ligand CXCL16 Are Expressed in Carcinomas and Inhibit Proliferation

摘要: The chemokine receptor CXCR6 and its ligand CXCL16 are involved in inflammation. Thus far, they were known to be expressed mainly by T cells macrophages, respectively. However, we detected both all of 170 human primary mammary carcinomas at similar levels 8 carcinoma cell lines tested microarray analysis. Expression was confirmed reverse transcription-PCR for the also fluorescence-activated sorting several mouse mammary, colon, pancreatic lines. is a transmembrane protein from which soluble can cleaved off. form present on surface cells. Surprisingly, suppression either or led greatly enhanced proliferation vitro as well vivo, indicating that their interaction inhibits proliferation. This notion verified using inhibitory antibodies introduction into rare CXCL16-negative line. effect mediated G protein-coupled because it blocked G(i) inhibitor pertussis toxin. In contrast, proliferation, this but not via protein. It remarkable lose acquire growth advantage should selected during tumor progression. suggests an unknown important role formation. Proteases, possibly macrophage derived, might convert stimulatory chemokine.