Chromosomal alterations in 15 breast cancer cell lines by comparative genomic hybridization and spectral karyotyping

Breast cancer cell lines have been widely used as models in functional and therapeutical studies, but their chromosomal alterations are not well known . We characterized the chromosomal aberrations in 15 commonly used human br east carcinoma cell lines (BT-474, BT-549, CAMA-1, DU4475, MCF7, MDA-MB-134 , MDA-MB- 157, MDA-MB-361, MDA-MB-436, MPE600, SK-BR-3, T-47D, UACC-8 12, U ACC-893, and ZR-75-1) by comparative genomic hybridization (CGH) and spectr al karyotyping (SKY). By CGH the most frequent gains were detected at 1q, 8 q, 20q, 7, 11 q 13, 17q, 9q, and 16p, whereas losses were most common at 8p , 11q14-qter, 18q, and Xq. SKY revealed a multitude of structural and numer ical chromosomal aberrations. Simple translocations, typically consisting o f entire translocated chromosome arms, were the most common structural aber rations. Complex marker chromosomes included material from up to seven diff erent chromosomes, Evidence for a cytogenetic aberration not previously des cribed in breast cancer, the isoderivative chromosome, was found in two cel l lines. Translocations t(8; 11), t(12; 16), t(1;16), and t(15;17) were fre quently found, although the resulting derivative chromosomes and their brea kpoints were strikingly dissimilar. The chromosomes most frequently involve d in translocations were 8, 1, 17, 16, and 20. An excellent correlation was found between the number of translocation events found by SKY in the indiv idual cell lines, and the copy number gains and losses detected by CGH, ind icating thar the majority of translocations are unbalanced. (C) 2000 Wiley- Liss, Inc.