Immunoexpression of CXCL12 and CXCR4 in Radicular Cysts, Dentigerous Cysts, and Odontogenic Keratocysts

Abstract

The aim of this study was to evaluate the immunoexpression of chemokine CXCL12 and its receptor CXCR4 in radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs), and to correlate the findings with morphologic parameters of RCs (inflammatory infiltrate and cystic epithelium). Twenty RCs, 20 DCs, and 20 OKCs were submitted to immunohistochemistry. The percentages of cytoplasmic (CXCL12 and CXCR4) and nuclear (CXCR4) staining in epithelial and fibrous capsule cells were determined. RCs and DCs exhibited higher epithelial expression of CXCL12 than OKCs (P<0.05). The expression of CXCL12 in the fibrous capsule was higher in DCs than in RCs and OKCs (P<0.05). Higher cytoplasmic expression of CXCR4 was observed in the epithelial lining and fibrous capsule of RCs and DCs compared with OKCs (P<0.05). In the fibrous capsule, DCs exhibited higher nuclear expression of CXCR4 than OKCs (P<0.05). No significant differences in the immunoexpression of CXCL12 or CXCR4 were observed according to the morphologic parameters of RCs (P>0.05). Strong positive correlations were found between cytoplasmic and nuclear expression of CXCR4 in the epithelial lining of RCs and DCs and in the fibrous capsule of all groups (P<0.05). The results suggest the participation of CXCL12 and CXCR4 in the pathogenesis of RCs, DCs, and OKCs. These proteins may be particularly relevant for the development of odontogenic cysts with less aggressive biological behavior, irrespective of their nature (inflammatory or developmental). In RCs, the expression of CXCL12 and CXCR4 may not be related to the intensity of the inflammatory infiltrate or the status of cystic epithelium.