Pigment epithelium-derived factor as a new diagnostic marker for melanocytic tumors

Pigment epithelium-derived factor (PEDF), a potent antiangiogenetic factor, has been lately known to correlate well with angiogenic and metastatic potentials of tumor cells. We investigated the expression of PEDF protein in various types of human tumor cells by an immunohistochemical technique using a monoclonal antibody. Consequently, we found the significantly frequent and intense expression of PEDF in human melanocytic tumor cells including malignant melanoma as compared to non-melanocytic ones. We evaluated the diagnostic usefulness of anti-PEDF antibody in melanocytic tumors by comparing its immunoreactive sensitivity with that of other conventional melanocytic markers such as S-100 protein, HMB-45 and Melan-A, and found that PEDF possess the equal ability to others on its sensitivity. We finally concluded that PEDF is a useful diagnostic marker for melanocytic tumors, especially malignant melanomas, by its use in combination with other markers.