Evaluation of MMP-9, MMP-13, MMP-21, and TIMP-1 expressions in malign melanom, dysplastic nevi, and banal nevi.

Objective: Although the role of MMPs in the pathogenesis of melanoma is known, few studies have investigated their role in the development of nevi and dysplastic nevi. This study aims to search the expression differences of MMP-9, MMP-13, MMP-21, and TIMP-1 between malignant melanoma (MM), intradermal nevi (IDN), and dysplastic nevi (DN).

Methods: MMP-9, MMP-13, MMP-21, and TIMP-1 antibodies were studied immunohistochemically for 60 cases in our pathology clinic archive between 2013 and 2014.

Results: The MM group had the highest expression percentage and intensity for MMP-9 (p<0.001). There was no statistical significance between MMP-13 expression intensities of lesion cells and stromal cells and stromal expression intensities (p>0.05). MMP-21 lesion staining intensities in DN and MM compared to IDN were statistically significant (p=0.001, p=0.011, respectively). For TIMP-1, there was a significant difference between the IDN and the MM group regarding the staining proportion of lesion cells (p<0.01). There was a statistically significant difference in all groups according to lesion cells' expression intensity. (IDN-DN p<0.001, IDN-MM p=0.044, DN-MM p<0.001).

Conclusion: The following markers can be helpful when lesions cannot be differentiated; increased staining proportions and intensity of MMP-9 in both lesion and stromal cells favor MM in cases where MM and IDN cannot be differentiated. The increased MMP-13 staining proportion of lesion cells can favor DN in cases where the pathologist cannot differentiate DN and MM. Intense expression of MMP-21 by lesion cells can be a potential marker for evaluating the lesion in favor of DN in cases where DN and IDN cannot be differentiated. The high expression intensity of TIMP-1 in lesion cells can favor DN in cases where there is ambiguity between DN and MM. High expression proportion and intensity of stromal cells of TIMP-1 can be useable in favor of MM in cases where MM and DN cannot be differentiated.