Expression of Urokinase-type Plasminogen Activator and Its Receptor in Keloids

Background:The urokinase-mediated plasminogen activation (uPA) system plays a central role in a number of cellular processes including tissue remodeling, cell migration, and angiogenesis.Elevated uPA activity has also been seen with tumor invasion and metastasis in a variety of malignancies.Keloids represent an aberrant form of wound healing characterized by uncontrolled growth with invasion beyond the margins of the original wound.The regulation of this cellular process remains poorly understood.We hypothesize that keloids will have increased staining percentage for uPA and its receptor (uPAR) compared with normal scars.To our knowledge, no previous studies have examined the relationship of uPAR in keloid formation.Design: Analysis of uPAR expression by immunohistochemistry in paraffin sections from 20 keloids and 18 normal scars.Expression was graded by a dermatopathologist according to percentage of cells staining for uPAR.