Actinic cheilitis: Epithelial expression of COX-2 and its association with mast cell tryptase and PAR-2

Abstract

Cyclooxygenase-2 (COX-2) is overexpressed in various types of human malignancies, including oral cancers. Recent studies have shown that mast cell-derived protease tryptase can induce COX-2 expression by the cleavage of proteinase-activated receptor-2 (PAR-2). Actinic cheilitis (AC) is a premalignant form of lip cancer characterized by an increased density of tryptase-positive mast cells. To investigate the possible contribution of tryptase to COX-2 overexpression during early lip carcinogenesis, normal lip (n = 24) and AC (n = 45) biopsies were processed for COX-2, PAR-2 and tryptase detection, using RT-PCR and immunohistochemistry. Expression scores were obtained for each marker and tested..