Expressions of CXCR7/ligands may be involved in oral carcinogenesis

Oral carcinogenesis is a multistep process and requires accumulation and interplay of a series of molecular events. Chemokines and their receptors have been suggested to play important roles in the initiation or progression of cancers. Until now, no report focuses on their alterations in premalignant stage of oral squamous cell carcinoma (OSCC). Compared with normal tissues, mRNA levels of 9 chemokines and 3 chemokine receptors including CXCR7 in oral leukoplakia (OLK) were increased more than two folds by microarray analysis. Then, CXCR7 was selected for further confirmation and immunohistochemistry examination during multistage oral carcinogenesis. CXCR7 was expressed in 85% of OLK and 86% of OSCC. However, only 8% (1 of 13 cases) of normal tissue displayed CXCR7 immunostaining. The positive ratios of CXCR7, CXCL12 and CXCL11 in OLK and OSCC tissues respectively, were significantly higher than that in normal epithelia (P < 0.05), although no significant difference was found between OLK and OSCC. Meanwhile, CXCR7 always concomitantly expressed with it ligands in OLK and OSCC tissues. Our results indicated that CXCR7-CXCL12/CXCL11 axis might play important roles in oral carcinogenesis.