Expression of Bone Morphogenetic Proteins in Giant Cell Tumor of Bone

Background: A giant cell tumor (GCT) of bone is a locally aggressive tumor with a propensity for local recurrence. A characteristic pattern of peripheral bone formation has been described in GCT recurrence in soft tissue, and in some pulmonary metastases from benign GCT. Although the bone formation in GCT in supposedly due to bone morphogenetic proteins (BMPs), the expression pattern of BMPs in GCT has not been well investigated. Materials and Methods: The expression of BMPs in GCT tissues, cultured stromal cells from GCT, and osteoclast-like giant cells harvested by laser microdissection (LM), as well as from control osteosarcoma (NOS-1) cells was analyzed using reverse transcriptional-semiquantitative PCR. Results: BMP 2, 3, 4, 5 and 6 were expressed in the GCT tissue. The cultured GCT cells expressed BMP 2, 4, 5 and 6. The osteoclast-like giant cells expressed BMP 2, 3, 5 and 6 and BMP 5 was expressed at the highest level. Conclusion: Both stromal cells and osteoclast-like cells in GCT expressed several kinds of BMPs.