Characterization of human primary enamel organ epithelial cells in vitro

Tooth enamel is formed by ameloblasts, which are derived from the epithelia[ cells of the enamel organ. Objective: The purpose of this study was to grow human ameloblast-like epithelial cells in culture. Design: Human fetal tooth organs were isolated, and the cells were separated by digestion in collagenase/dispase. The cells were cultured in KGM-2 media with and without serum and at different calcium concentrations. The expression of enamel matrix proteins was analyzed by RT-PCR and cytokeratin 14 was detected by immunohistochemistry. The cells were further characterized by osteogenesis/odontogenesis-related DNA array. Results: Cells isolated from the tooth organs grown in KGM-2 media containing 2-10% serum, were mixture of cobblestone and spindle shaped cells. Culturing these cells in KGM-2 with 0.05 mM calcium was selective for cobblestone ameloblasts-like cells (CAB), which were immunopositive for cytokeratin 14. Amelogenin, amelobtastin, enamelin, MMP-20 and KLK-4 were detected in CAB cells by RT-PCR. Osteogenesis SuperArray analyses could not detect the presence of typical molecules related to mesenchymal odontobtast or osteoblast lineage cells in these cultures. Conclusions: These studies showed that cobblestone-shaped ameloblast-like cells are selected from the tooth organ cells, by culture in KGM-2 media with 0.05 mM calcium. (C) 2005 Elsevier Ltd. All rights reserved.