Genome-wide analysis of sixteen chordomas by comparative genomic hybridization and cytogenetics of the first human chordoma cell line, U-CHI

Cytogenetic information on chordomas is rudimentary and restricted to GTG-b anding analysis of 26 cases worldwide. In this study, we present the chromo somal imbalances detected in a series of 16 chordomas (10 sacrococcyeal, fi ve sphenooccipital, and one spinal) from 13 patients using comparative geno mic hybridization (CGH) and fluorescence in situ hybridization (FISH). On a verage, 3.2 losses and 4.2 gains were detected per tumor. The most common D NA copy number alterations were losses on chromosomal arms 3p (50%) and 1p (44%). Losses of 3p were detected in five of seven primary chordomas. There fore, the loss of 3p might be an early event in chordoma genesis. The most common gains involved 7q (69%), 20 (50%), 5q (38%), and 12q (38%). Addition ally, we raised the first human chordoma cell line, U-CH I, from a recurren ce of a sacral chordoma. U-CH I and its parent tumor had almost the same CG H profile. According to GTG-banding and multicolor FISH, U-CH I has the fol lowing clonal chromosomal abnormalities: der(1)t(1;22), del(4), +del(5), +d el(6), +7, del(9), del(10), +der(20)t(10;20), +21. Thus, the novel permanen t human chordoma cell line U-CH I has chordoma-typical cytogenetic aberrati ons. Our data suggest that tumor suppressor genes or mismatch repair genes (located at 1p31 and 3p14) and oncogenes (located in 7q36) might be involve d in chordoma genesis. (C) 2001 Wiley-Liss, Inc.