Poly(adenosine diphosphate-ribose) polymerase-1 expression in cutaneous malignant melanomas as a new molecular marker of aggressive tumor.

Poly(adenosine diphosphate-ribose) polymerases (PARPs) are a family of enzymes, which catalyses poly (ADP-ribosyl)ation of DNA-binding proteins and directly involved in genomic stability, DNA repair, and apoptosis. In this study, we evaluated the immunomorphology of PARP-1 in melanoma and its prognostic importance. We studied PARP-1 expression by immunohistochemistry in a selected series of 54 primary cutaneous malignant melanoma (CMM). The findings of the present study suggest that the neoplastic progression toward the invasive (both horizontal and vertical) growth phase of CMM cells is characterized by the loss of cleavage of PARP-1, probably signaling an imbalance of the apoptotic process in these cells and leading to further gain to aggression. Over-expression of full-length PARP-1 was correlated with recurrence and/or progression of the disease and so act as a promising new biological marker of CMM. Our study represents the evidence of a direct correlation between the PARP-1-mediated apoptotic process and the biologic behavior of CMM.