Lewis y Expressed in Oral Squamous Cell Carcinoma Attenuates Malignant Properties via Down-regulation of EGF Signaling

Abstract

Background/Aim: Lewis y is expressed in oral squamous cell carcinoma (OSCC) cells and tumors. Previously, we reported that Lewis y was not expressed in invasion areas, and attenuation of proliferation and invasion in OSCC cells was caused by over-expression of Lewis y. However, the roles of Lewis y in the attenuation of malignant properties have not been clarified. In this study, we investigated the roles of Lewis y in OSCC. Materials and Methods: The levels of Lewis y on EGFR and the phosphorylation levels of EGFR in OSCC cells were analyzed by immunoprecipitation and western blot. EGFR cross-linking and binding kinetics of EGF were performed. Results: Upon EGF stimulation, phosphorylation and dimer formation of EGFR were more prominent in Lewis y– cells. EGF binding kinetics showed reduced binding sites in Lewis y+ cells. Conclusion: Lewis y reduced EGF binding to EGFR, leading to suppression of malignant properties through suppression of EGF signaling.