Prognostic Significance of NOGO-A/B and NOGO-B Receptor Expression in Malignant Melanoma - A Preliminary Study.

Background: Neurite outgrowth inhibitor type B (NOGO-B) and its receptor (NGBR) were shown to regulate various crucial cellular processes and may be therefore potential factors influencing carcinogenesis. Materials and Methods: Expression of NOGO-A, NOGO-A/B and NGBR was studied in benign melanocytic lesions and primary tumors and metastases of malignant melanoma (MM). Results: Cytoplasmic expression of the studied antigens was detected in melanocytes and MM cells. NOGO-A/B expression was significantly lower in metastatatic MM cases compared to primary MM tumors (p<0.01) and bening melanocytic lesions (p<0.001). In primary MM tumors, NOGO-A expression intensity positively correlated with NOGO-A/B (r=0.32, p<0.05) and NGBR expression (r=0.53, p<0.0001). NOGO-B and NGBR immunoreactivity correlated negatively with depth of primary MM infiltration (both p<0.01). Moreover, low NOGO-A/B expression was a factor of poor prognosis of primary MM. Conclusion: NOGO-A/B may be a negative prognostic factor of MM.