Isolation of osteosarcoma-associated amplified DNA sequences using representational difference analysis.

Comparative genomic hybridization analysis of a primary osteosarcoma and its metastasis revealed two regions of DNA amplification, one at 17p11.2-12 and one at 19q12-13. Subsequent representational difference analysis of the primary tumor resulted in the isolation of two distinct tumor-amplified DNA fragments originating from chromosome 19. A YAC clone corresponding to one of the two isolated DNA fragments was used for fluorescence in situ hybridization on normal human lymphocyte metaphases and tumor-derived nuclei. This resulted in the localization of this YAC to 19q12-13.1 and confirmed the amplification status of the isolated fragment in the tumors. The availability of such RDA-isolated sequences may be instrumental in the search for genes relevant for tumor development.