[Expression of ADAM12 (Meltrin-alpha) gene in giant cell tumor of bone].

OBJECTIVE

To detect expression and location of ADAM12 (meltrin-alpha) gene in giant cell tumor of bone and to study its effect on the formation of multinucleated giant cells in the tumor.

METHODS

ADAM12 mRNA was detected by RT-PCR and RNA in situ hybridization in 18 cases of giant cell tumors, 6 cases of cultured tumor cells, 2 specimens of embryonic muscle tissue and 5 specimens of adult muscle tissue.

RESULTS

RT-PCR showed that 12/18 (67%) cases of giant cell tumor of bone expressed ADAM12 mRNA. RNA in situ hybridization demonstrated positive ADAM12 mRNA in 12 cases of the detected tumors. The ADAM 12 mRNA positive signal was localized in the cytoplasm of almost all multinucleated giant cells and mononuclear stromal cells. However, the expression of ADAM12 mRNA decreased gradually, and eventually lost with increased passages of tumor cells and the disappearance of multinucleated giant cells in the culture.

CONCLUSION

Multinucleated giant cells probably originated from the fusion of mononuclear stromal cells and ADAM12 may participate in the fusion process.