Subtle genomic alterations and genomic instability revealed in diploid cancer cell lines

To investigate if genomic instability exists in tumors with cytogenetically normal karyotypes, we analyzed four diploid cancer cell lines A204, CAL51, CH1 and SK-UT-1B. We detected subtle genomic changes in all four cell lines. More of these alterations were found in A204 and CH1 than in the microsatellite unstable lines CAL51 and SK-UT-1B. The number of de novo, non-clonal chromosome rearrangements was also significantly higher in CH1 than CAL51 and SK-UT-1B (p = 0.001). This study reveals multiple genomic abnormalities in tumors with near normal karyotypes and suggests that genomic instability may be essential in cancer development.