Expressions of chemokine receptors 4 and 7 in cutaneous malignant melanoma and pigmented nevus tissues and their significance

Objective To measure expressions of chemokine receptor 4 (CXCR4) and CXCR7 in cutaneous malignant melanoma (CMM) and pigmented nevus tissues, and to explore their correlations with pathological features. Methods Skin specimens were obtained from the lesions of 40 patients with CMM (CMM group) and 40 patients with pigmented nevus (pigmented nevus group). An immunohistochemical study was performed to measure expressions of CXCR4 and CXCR7 in these specimens. Results In the CMM group, 8 (20.0%) and 6 (15.0%) specimens were negative (-), 5 (12.5%) and 4 (10.0%) mildly positive (+), 13 (32.5%) and 9 (22.5%) moderately positive (++), 14 (35.0%) and 21 (52.2%) strongly positive (+++), for CXCR4 and CXCR7 respectively. Of the pigmented nevus specimens, 20 (50.0%) and 14 (35.0%) were negative (-), 17 (42.5%) and 25 (62.5%) mildly positive (+), 3 (7.5%) and 1 (2.5%) moderately positive (++), for CXCR4 and CXCR7 respectively, but none was strongly positive (+++) for either of them. There were significant differences in the expressions of CXCR4 and CXCR7 between the CMM group and pigmented nevus group (U = 317, 256.5, respectively, both P 0.05). No significant difference was observed in the expression of CXCR7 among patients of different age, gender, or among melanomas with different degrees of ulceration or lymphocytic infiltration, or between melanoma tissues from patients with lymphatic metastasis and those without (all P > 0.05), but it was significantly higher in non-acral than in acral melanomas (U = 64, P 1.00 mm than in those ≤ 1.00 mm (U = 81.5, P < 0.05), and higher in Clark’s level Ⅲ-Ⅴ than in Ⅰ-Ⅱmelanomas (U = 60.5, P < 0.05). Conclusion Both CXCR4 and CXCR7 are expressed to different extents in CMM and pigmented nevus tissues, suggesting that they may participate in the occurrence and development of CMM. Key words: Melanoma; Nevus; Immunohistochemistry; Receptors, CXCR4; Receptors, CXCR7