Can genetic instability be studied at the single chromosome level in cancer cells? Evidence from human melanoma cells

We evaluated whether genetic instability, which is the hallmark of cancer c ells, can be investigated at the single chromosomal level. We established i n culture and examined a human malignant melanoma cell line and its 11 dist inct clones as well as peripheral blood cultures from the original patient by G-banding, C-banding, and silver-staining (AgNOR) techniques. There were six marker chromosomes common to most of the II clones and eight or nine a dditional marker chromosomes found in only one or in very few clones. Chrom osome 1 had a pericentric inversion in the C-banded region in both the tumo r and the lymphocyte metaphase spreads. This same homologue was also involv ed in the formation of one of the shared marker chromosomes; this marker, i n turn, was rearranged to form two unique markers in one clone. Our finding s suggest that genetic instability can be studied at the single chromosome level. Moreover, this study further supports our earlier contention that pe ripheral blood lymphocyte cultures can show chromosomal lesions that are st able markers in cancer cells. (C) Elsevier Science inc., 1999. All rights r eserved.