DNA amplification and chromosomal translocations are accompanied by chromosomal instability: analysis of seven human colon cancer cell lines by comparative genomic hybridization and spectral karyotyping

Genetic instability in human cancers is classified as chromosomal instability (CIN) or microsatellite instability (MIN). DNA amplification and translocations are observed frequently in various cancers. We used comparative genomic hybridization (CGH) and spectral karyotyping (SKY) to study seven human colon cancer cell lines and investigate the relations among genetic instability, DNA amplification, and chromosomal translocations. DNA amplification was found in five cell lines (COLO320DM, COLO201, WiDr, CoCM-1, and CACO-2), and all were aneuploid. In these five cell lines, segments of chromosomes were translocated to other chromosomes. In contrast, cell lines with MIN, DLD-1, and LoVo did not show DNA amplification. The LoVo cells with MIN were considered near diploid and contained translocations. These findings suggest that DNA amplification and chromosomal translocations are accompanied by CIN.