Matrix metalloproteinase-12 expression is increased in cutaneous melanoma and associated with tumor aggressiveness

Cutaneous melanoma is the most malignant form of skin cancer characterized by aggressive invasion. Matrix metalloproteinases play essential roles in tumor invasion due to their ECM degrading capacity. However, the clinical significance of matrix metalloproteinasis (MMP)-12 in human cutaneous melanoma has not been addressed yet. In the present study, we investigated MMP-12 expression level in 298 patients with cutaneous melanoma and 60 normal skin tissue specimens by immunohistochemistry assay. Appropriate statistical analysis was utilized to determine the association of MMP-12 with clinical features and prognosis of melanoma. Results showed that MMP-12 expression was increased in cutaneous melanoma compared with that in normal skin. It was also found that MMP-12 expression in melanoma was significantly associated with tumor invasion and metastasis. Univariate survival analysis indicated that patients with melanoma of high MMP-12 expression had unfavorable overall survival compared with those of low MMP-12 expression. Cox's proportional hazards analysis showed that MMP-12 expression was an independent prognostic marker of overall survival for patients with cutaneous melanoma. These results proved that MMP-12 expression was increased in cutaneous melanoma and associated with tumor progression. It also provided the first evidence that MMP-12 level could be an independent prognostic marker for patients with cutaneous melanoma.