ABSTRACT
The patient was a man in his 60s with the gradually increasing mass in his mouth. A well-defined, elastic soft mass with a major diameter of 60 mm was found on the right floor of mouth. The magnetic resonance imaging findings showed a well-defined mass with high signal on both T1 and T2-weighted image in the right sublingual space. The mass was slightly heterogeneous inside and had a septum-like appearance. The tumor was resected with care not to damage the capsule. Histopathological findings showed mature adipocytes, spindle-shaped cells, and collagenous components. Spindle cells were CD34-positive. The tumor was diagnosed as spindle cell lipoma. The patient was followed up for 6 months with no recurrence. Spindle cell lipoma is a rare entity and this is the largest case in the oral cavity. Because there are wide variety of adipocytic tumors, the careful examination of their imaging and histopathological findings is essential.
ABSTRACT
Bone morphogenetic protein-2 (BMP-2) promotes the differentiation of non-osteogenic mesenchymal cells to osteogenic cells. In this study, we isolated human adipose-derived stem cells (hASCs) and investigated the effects of recombinant human BMP-2 (rhBMP-2) and extracellular Ca2+ concentration ([Ca2+]out) on the osteogenic differentiation of hASCs. rhBMP-2 promoted calcium deposition in hASCs and stimulated the mRNA expressions of six proteins known to be involved in the osteogenic differentiation of hASCs: Runx2, osterix, alkaline phosphatase, osteonectin, bone sialoprotein and osteocalcin. Elevation of [Ca2+]out enhanced the level of alkaline phosphatase enzyme, increased the mRNA expressions of Runx2 and osteocalcin and induced the expressions of BMP-2 mRNA and protein in hASCs. Elevation of [Ca2+]out transiently increased the intracellular Ca2+ concentration ([Ca2+]in) due to activation of the calcium-sensing receptor (CaSR). The Ca2+-induced expressions of BMP-2 mRNA and protein were inhibited by the calmodulin antagonist, W-7. Furthermore, elevation of [Ca2+]out decreased the cytoplasmic level of phosphorylated nuclear factor of activated T-cell-2 (NFAT-2) and increased the nuclear level of dephosphorylated NFAT2. Taken together, these results suggest that rhBMP-2 promotes the osteogenic differentiation of hASCs. Furthermore, an increase in [Ca2+]out enhances the expression of BMP-2 via activation of the CaSR, elevation of [Ca2+]in and stimulation of Ca2+/calmodulin-dependent NFAT-signaling pathways.
