Comparative genomic hybridization analysis of hepatoblastomas

Prior cytogenetic analyses of hepatoblastomas have shown the most common recurring abnormalities to be trisomy for chromosomes 2 and 20, and a recurrent translocation involving chromosomes 1 and 4 identified in a minority of cases. Four cases have shown double minute chromosomes, which provide cytogenetic evidence for gene amplification, although no particular genes or genetic regions have been shown to be amplified. To further investigate the cytogenetic changes involved in the pathogenesis and progression of hepatoblastoma, this study analyzes 10 tumors by comparative genomic hybridization. Regions of relative gain or loss were found in nine tumors. The most common recurrent abnormalities were gain of the long arm of chromosome 1 (six tumors), gain of chromosomes 2 (seven tumors), 17 (four tumors), and 20 (three tumors), and loss of chromosomes 4 and 1 (two tumors each). Four cases showed restricted regions of high-level gain at 1q32 or 2q24, regions that have previously been reported to be amplified in other tumors, but not in hepatoblastomas. A specific amplified gene has yet to be identified at these loci, although candidate genes have been proposed and may offer targets for future studies.