Detailed marker chromosome analysis in cell line U-BLC1, established from transitional-cell carcinoma of the bladder

A permanent cell line, U-BLCI, was established from a primary transitional- cell carcinoma, TCC, of the urinary bladder. Karyotype analysis showed the line to be highly aberrant, with a near-triploid chromosome number of 68 to 73. Comparative genomic hybridization revealed some distinct differences b etween the primary tumor and the established cell line. Karyotype analysis showed 3 marker chromosomes with homogeneously staining regions, HSRs, in t he cell line. The HSRs were isolated by microdissection and the microdissec tion probes were hybridized to normal metaphase chromosomes. The HSRs conta in sequences known to be frequently involved in amplification in transition al-cell carcinoma of the bladder, 6p22, 7p11-p12, 9p23-pter, and one region not yet reported to be amplified in primary TCC of the bladder, Ip31-p32. A candidate-gene approach showed that in the region 7p11-p12 the EGFR locus is amplified and highly expressed. Int. J. Cancer 80:903-910, 1999. (C) 19 99 Wiley-Liss Inc.