Up-regulation of EGF receptor and its ligands, AREG, EREG, and HB-EGF in oral lichen planus

ObjectiveThis study aimed to investigate the roles of the epidermal growth factor receptor (EGFR) family members and their ligands in oral lichen planus (OLP).Study designThe expressions of 4 EGFR-like receptors and 6 EGF-like ligands were measured in OLP tissues from 10 patients and compared with the levels in normal oral mucosa (NOM) from 10 healthy donors.ResultsOf the receptors, only EGFR mRNA and protein were more highly expressed in OLP compared with NOM tissues. Regarding the ligands, the mRNAs of amphiregulin (AREG), epiregulin (EREG), and heparin-binding EGF-like growth factor (HB-EGF) were more highly expressed in OLP compared with NOM tissues. These ligands were strongly expressed by infiltrating lamina propria lymphocytes as well as epithelial keratinocytes in OLP lesions, as shown by immunohistochemistry.ConclusionsThe enhanced EGFR expression on the keratinocytes in OLP lesions and the up-regulation of EGF-like ligands in keratinocytes and infiltrating mononuclear cells could contribute to the carcinogenesis and pathogenesis of OLP.