Establishment of mesenchymal cell line derived from human developing odontoma.

ABSTRACT

OBJECTIVES: An odontoma, which shows proliferating odontogenic epithelium and mesenchymal tissue, is one of the most common odontogenic tumors encountered. These are commonly found in tooth-bearing regions, although the etiology remains unknown. There are no previous reports of an established line of immortalized human odontoma cells. METHODS: Using odontoma fragments obtained from a girl treated at our department, we established an immortalized human odontoma cell line and investigated cell morphology, dynamic proliferation, the presence of contamination, and karyotype. Moreover, cell characterization was examined using osteogenic and odontogenic markers. RESULTS: We successfully established a mesenchymal odontoma cell (mOd cells). The cells were found to be fibroblastic and had a high level of telomerase activity. Cell growth was confirmed after more than 200 population doublings without significant growth retardation. mOd cells expressed mRNA for differentiation markers, including collagen type I (COLI), alkaline phosphatase, bone sialoprotein, osteopontin, osteocalcin, cementum-derived protein (CP-23), dentin sialophosphoprotein (DSPP), and distal-less homeobox 3 (DLX3), as well as bone morphogenetic proteins (BMPs). In addition, they showed a high level of calcified nodule formation activity in vitro. CONCLUSIONS: We successfully established a cell line that may be useful for investigating the mechanisms of normal odontogenesis as well as characteristics of odontoma tumors.