Abstract: Objective To investigate the role of vascular endothelial cell growth factor (VEGF), nm23 and microvessel density (MVD) in the pathogenesis of malignant melanoma(MM). Methods The specimens from forty-seven cases of malignant melanoma and 10 cases of melanocytic nevus were examined for VEGF, nm23 and CD34 by immunohistochemistry. The density of microvessels was calculated. Results Positive VEGF expression rate and MVD in malignant melanoma were significantly higher than those in melanocytic nevus(both P<0.01). Positive VEGF expression rate and MVD in the patients with lymph node metastasis were remarkably higher than those without lymph node metastasis, respectively(P<0.05, P<0.01). Along with the increase of the depth of invasion, VEGF positive expression rate and MVD were increased, the values in gradeⅠMM were lower than those in grade Ⅳ MM(P<0.05) and grade ⅤMM(P<0.01). The nm23 positive expression rate in malignant melanoma was lower than that in melanocytic nevus(P<0.01). In the patients with lymph node metastasis, the positive nm23 expression rate was markedly lower than that without lymph node metastasis(P<0.01). No significant correlation was found between the nm23 expression rate and the clinical pattern of the tumor and the depth of invasion. Conclusion The expression of VEGF and nm23 might play an important role in the development and metastasis of malignant melanoma.

Key words: Endothelial growth factors, Melanoma, Oncogene proteins