Abstract: Objective The aim was to study the role of apoptosis gene bcl-xl in the tumorigenesis of osteosarcoma.Methods The expression of bcl-xl was observed by immunohistochemical assay in twenty-seven classical osteosarcoma and twenty-two benign bone tumors.The extent of expression was evaluated by using half-quantitative method.Results The positive rate of bcl-xl expression was 100% in osteosarcoma, 4.5% in benign osteochondroma.There was a difference with statistical significance(P<0.01) between two positive rates.Conclusion No correlation exists between different differentiation and positive grade(P>0.05).The expression of bcl-xl is involved in the tumorigenesis of osteosarcoma, but not associated with the differentiation of osteosarcoma.

Key words: osteosarcoma, bcl-xl, immunohistochemistry