Expression of membrane-associated mucins in cultivated human oral mucosal epithelial cells

Purpose: Membrane-associated mucins present in the cells of the ocular surface epithelium (MUC1, -4, and -16) are believed to contribute to the maintenance of the health and wet surface of epithelial cells. Recent studies have reported the use of cultivated oral mucosal epithelial sheet transplantation for reconstruction of the ocular surface. We studied the expression of membrane-associated mucins in cultivated human oral mucosal epithelial sheets and compared it with that in human ocular surface epithelial cells. Methods: Specimens (3 X 3 mm) of oral mucosal tissue were harvested from healthy volunteers. The oral mucosal epithelial cells obtained from the specimens, the corneal epithelial cells, or an oral mucosal cell line (KB cells) were cultured together with mitomycin C-treated 3T3 feeder cells on temperature-responsive culture surfaces for 2 weeks to produce stratified cell sheets. Reverse transcriptase-polymerase chain reaction was used to determine the expression of membrane-associated mucins (MUC 1, -3, -4, -12, -13, -15, -16, and -17) in these cells. Results: MUC 1, -4, and -16 but not -3, -12, -13, -15, or -17 mRNA was detected in the oral mucosal epithelial sheet and in the corneal epithelial sheet. KB cells, although unable to produce a stratified cell sheet, showed expression of MUC1, -12, -13, and -16 mRNA. Conclusions: The membrane-associated mucins of the ocular surface, MUC1, -4, and -16, are expressed in human oral mucosal epithelial sheets and corneal epithelium. These membrane-associated mucins may therefore contribute to ocular surface reconstruction after oral mucosal epithelial sheet transplantation for patients with severe ocular surface disorders.