Comparative genomic hybridization reveals previously undescribed amplifications and deletions in the chronic myeloid...

We used comparative genomic hybridization (CGH) to identify a number of previously undescribed chromosomal imbalances in K-562, a spontaneously transformed cell line originally derived from leukemic cells of a chronic myeloid leukemia (CML) patient in blast crisis. Noteworthy were a discrete amplification in band 13q31, increased copy number of chromosome arms 1q, 5p, 6p, and 16q, and loss of material from 8p, 9p, 10q, and 17p. Amplification within bands 9q34 and 22q11.2 was consistent with previous descriptions of increased copy number of the CML-specific 5'BCR-3'ABL fusion gene in K-562. However, amplification of a large distal segment, 9q31-->9q34, mostly proximal to the ABL locus, was unexpected and is unlikely to be related to BCR-ABL recombination. Previous karyotype studies are reviewed in detail and compared with the CGH findings.