OBJECTIVETo detect differentially expressed proteins in serum of patient with osteosarcoma.

METHODS8 serum protein samples were recruited (4 cases of osteosarcoma and 4 cases of normal adults), cross-labeled with variant CyDye, followed by two-dimensional differential in-gel electrophoresis (2-D DIGE), image analysis, and identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS).

RESULTS24 protein spot-features were significantly increased, and 34 were significantly decreased in the serum from patients with osteosarcoma relative to the controls. The mass spectrometry analysis revealed 18 unique proteins that were increased, and 25 unique proteins decreased in the serum of patients with osteosarcoma. Gelsolin was down-regulated in osteosarcoma, and Western blotting also confirmed a decreased level of gelsolin in the serum of patients with osteosarcoma.

CONCLUSIONOur results indicate that gelsolin may have great potential as a biomarker of osteosarcoma and as a potential target for therapy. These preliminary data suggest that incorporation of more samples and new datasets will permit the identification of serum biomarkers for osteosarcoma.