Comparative proteomic analysis of human osteosarcoma cell and primary cultured osteoblastic cell

Background and purpose:At present,osteosarcoma is one of the most common malignant bone tumors in adolescents.Most patients are diagnosed at the advanced stage,making its 5-year survival rate very low.Therefore,finding the special target protein may improve prognosis for patients with osteosarcoma.In recent years,with the development of proteomics,finding tumor markers has become easier.This study applied the comparative proteomic theory and its techniques in order to find differently expressed proteins between the osteosarcoma cells and human primary cultured osteoblastic cells.These proteins can be biomarkers for early diagnosis and treatment of osteosarcoma.Methods:Both osteosarcoma cells SaOS-2 and human primary cultured osteoblastic cells were collected and split to extract the protein.Then 2-DE electrophoresis was conducted.The 2-DE maps were visualized after silver staining and analyzed by the ImageMaster 2D software.The differently expressed proteins were then identified using MALDI-TOF-mass spectrometry.Western blot was used to verify the results from the proteomic analyses of 8 patients with osteosarcoma.Results:Thirteen protein spots were significantly different between osteosarcoma and osteoblastic cells in the 2-DE maps.After mass spectroscopic identification and data base searches,we found that in osteosarcoma cells,the level of heat shock protein 70(HSP70),actin capping protein,ATP synthase,mitochondrial heat shock protein 75(Mthsp75),ubiquinol-cytochrome-c reductase complex core protein Ⅰ(UQCRC1),Ras-related nuclear protein,UCH-L1 and PRDX4 were all elevated.However,the level of pyruvate dehydrogenase E1(PDH E1),KIAA0088,prohibitin(PHB),and Annexin V all decreased.Subsequent Western blot analyses of UQCRC1,UCH-L1 and PRDX4 in osteosarcoma tissues confirmed the results obtained by the proteomic analyses.Conclusion:Proteomic analysis can identify protein variances in osteosarcoma as well as provide probable new biomarkers that are correlated with the biological behavior of osteosarcoma.