Identification of EWS/FLI-1 transcripts in giant-cell tumor of bone

The EWS/FLI-I fusion gene, resulting from a t(11;22) translocation, plays a key role in the pathogenesis of Ewing's sarcoma. We demonstrate the presen ce of EWS/FLI-I hybrid transcripts also in giant-cell tumor, a bone neoplas m featuring intermediate characteristics between benign and malignant lesio ns. Chimeric products were detected by semi-nested PCR after 2 cycles of am plification in 13/15 cases of giant-cell tumor, and their presence was conf irmed by Southern and Western blots and fluorescence in situ hybridization. Moreover, 3/8 primary cultures of giant-cell tumor showed the same type of hybrid transcript observed in the original tumor sample. Sequencing of PCR products confirmed the presence of EWS and FLI-I sequences in these produc ts. Detection of EWS/FLI-I fusion transcripts in giant-cell tumor of bone p rovides a model for the study of the transforming mechanisms of the EWS/FLI -I fusion gene in mesenchymal tumors. Int. J. Cancer 87:328-335, 2000. (C) 2000 Wiley-Liss, Inc.