Genomic organization of the 8p11-p12 amplicon in three breast cancer cell lines.

Amplification of chromosomal regions leads to an increase of DNA copy number and expression of oncogenes in human breast cancer (HBC). Amplification of the 8p11-p12 region occurs in 10-15% of primary, uncultured HBCs. In our panel of 11 breast cancer cells, three cell lines, SUM-44, SUM-52, and SUM-225, have overlapping amplicons in the 8p11-p12 region. To characterize genome structure of the amplified regions, we performed fluorescence in situ hybridization using 8p11-p12 BAC clones in the 3 cell lines. The results revealed that the 8p11-p12 amplicon has a highly complex structure and that FGFR1 is not in the common core-amplified domain in 3 breast cancer cell lines with the amplicon. These 3 cell lines provide good models for genetic and functional studies of candidate oncogenes of the 8p11-p12 region.