Detection Of Chromosome Aneuploidy In Interphase Cells From Primary Human Melanoma Using Fluorescence In Situ Hybridization.
M. Balázs, Á. Bégány*, J. Hunyadi*, Zs. Ádám and R. Ádány, University School of Medicine, Departments of Hygiene and Epidemiology, and Dermatology, Debrecen, Hungary.
The development of fluorescence in situ hybridization (FISH) with chromosome specific nucleic acid probes has greatly improved our ability to investigate the in situ cytogenetics of solid tumors. In this study we have used FISH with chromosome specific repetitive DNA probes to evaluate numerical chromosome aberrations in case of male patient with melanoma. The number of distinct hybridization domains specific for repetitive pericentromeric sequences on chrs. 1, 7, 11, 15, 17, 20, X and Y were used as indicators for copy number changes in interphase melanoma cells. The tumor showed a heterogeneous copy number distribution for each chromosome. The largest population of cells had two copies for chrs. 1, 7, 11, 15, 17 and 20, but significant number of nuclei were labeled for one and three copies. Simultaneous hybridization for chrs. 1, 15, 17 and 20 in combination with chr. 9 showed independent assortment, i.e. cells with one copy for chr. 9 had either one, two or three copies for chromosome 1, 15, 17, and 20 suggesting that a multiple independent events are responsible for the final copy number distribution in case of different chromosomes. Copy number alterations were also found for the sex chromosomes. The majority of cells surprisingly had two X chrs., while the chr. Y was found to be deleted in almost 90% of the cell population.