H-C Wang1, T-J Li. 1. Department of Oral Pathology, Peking University School and Hospital of Stomatology, Haidian District, Beijing, China.
Abstract
OBJECTIVES: To investigate the growth characteristics and effects on osteoclastogenesis in fibroblasts isolated from keratocystic odontogenic tumor (KCOT) fibrous capsule. MATERIALS AND METHODS: Fibroblasts isolated from KCOT fibrous capsule and normal gingival mucosa were cultured in vitro. Their colony-forming units and proliferative activity were investigated, and the osteoclastogenic effects were also observed by a co-culture system with osteoclast precursor cell line Raw264.7. The mRNA of several genes related to bone resorption (IL-6, VEGF, COX-2, and M-CSF) was analyzed by real-time PCR. RESULTS: Keratocystic odontogenic tumor fibroblasts developed fewer CFU and had longer population doubling time than gingival fibroblasts (P < 0.05). In contrast to gingival fibroblasts, KCOT fibroblasts expressed less IL-6, COX-2, and M-CSF (P < 0.05); however, the Raw264.7 co-cultured with KCOT fibroblasts developed more osteoclast-like cells and expressed higher level of nfatc1 than that co-cultured with gingival fibroblasts. Increased COX-2 expression and VEGF expression were detected in KCOT fibroblasts and Raw264.7 co-culture system (P < 0.05). CONCLUSION: Although KCOT fibroblasts showed lower level of cell proliferation than gingival fibroblasts, higher osteoclastogenic ability was detected when co-cultured with Raw264.7. These results suggest that the cell-cell interaction in the co-culture system, possibly by increasing COX-2 and VEGF expression, may be responsible for the increased osteoclastogenic effects of KCOT fibroblasts.
OBJECTIVES: To investigate the growth characteristics and effects on osteoclastogenesis in fibroblasts isolated from keratocystic odontogenic tumor (KCOT) fibrous capsule. MATERIALS AND METHODS: Fibroblasts isolated from KCOT fibrous capsule and normal gingival mucosa were cultured in vitro. Their colony-forming units and proliferative activity were investigated, and the osteoclastogenic effects were also observed by a co-culture system with osteoclast precursor cell line Raw264.7. The mRNA of several genes related to bone resorption (IL-6, VEGF, COX-2, and M-CSF) was analyzed by real-time PCR. RESULTS:Keratocystic odontogenic tumor fibroblasts developed fewer CFU and had longer population doubling time than gingival fibroblasts (P < 0.05). In contrast to gingival fibroblasts, KCOT fibroblasts expressed less IL-6, COX-2, and M-CSF (P < 0.05); however, the Raw264.7 co-cultured with KCOT fibroblasts developed more osteoclast-like cells and expressed higher level of nfatc1 than that co-cultured with gingival fibroblasts. Increased COX-2 expression and VEGF expression were detected in KCOT fibroblasts and Raw264.7 co-culture system (P < 0.05). CONCLUSION: Although KCOT fibroblasts showed lower level of cell proliferation than gingival fibroblasts, higher osteoclastogenic ability was detected when co-cultured with Raw264.7. These results suggest that the cell-cell interaction in the co-culture system, possibly by increasing COX-2 and VEGF expression, may be responsible for the increased osteoclastogenic effects of KCOT fibroblasts.