Characterization of complex chromosomal in uveal melanoma by fluorescence in situ hybridization, spectral karyotyping, and comparative genomic hybridization

Several nonrandom recurrent chromosomal changes are observed in uveal melan oma. Some of these abnormalities, e.g., loss of chromosome 3, gain of the 6 arm of chromosome 8, and chromosome b abnormalities, are of prognostic val ue. Cytogenetic analysis and/or fluorescence in situ hybridization (FISH) a re used to detect these changes. In some cases, however, detailed cytogenet ic analysis is not possible due to the presence of complex abnormalities. T o define more accurately these cytogenetic changes. we have applied compara tive genomic hybridization (CGH) and/or spectral karyotyping (SKY) to two u veal melanoma cell lines and five primary uveal melanomas, with partially d efined and/or complex abnormalities. SKY provided additional information on 34/39 partially defined aberrant chromosomes and revealed a new abnormalit y, a der(17)t(7;17)(?;q?), that had not been recognized by conventional cyt ogenetics. Additionally. using SKY. abnormalities involving chromosome 6 or 8 were found to be twice as common as observed with cytogenetic analysis. CGH was especially useful in assigning the abnormalities identified by SKY to specific chromosomal regions and, in addition, resulted in the detection of a small deletion of chromosome region 3q13-21. We conclude that SKY and CGH, as methods complementary to cytogenetic and FISH analysis, provide mo re complete information on the chromosomal abnormalities occurring in uveal melanoma. (C) 2001 Wiley-Liss, Inc.