ANEUSOMY OF CHROMOSOME-7 AND CHROMOSOME-17 DETECTED BY FISH IN PROSTATE-CANCER AND THE EFFECTS OF SELECTION IN-VITRO

Twenty prostate rumor specimens, obtained from radical prostatectomies , and two lymph node metastases were examined by classical and molecul ar cytogenetic methods. A sample from each tumor was analyzed histolog ically and used for touch preparations. Adjacent samples were used for preparation of single-cell suspensions before cell culture (DirFISH) and for establishing cell cultures, which were subsequently harvested for classical G-banding analysis. Fluorescence in situ hybridization ( FISH) was performed on touch preparations, DirFISH, and cells obtained from tissue culture. Biotinylated pericentromeric probes for chromoso mes 7 and 17, in addition to a digoxigenin-labeled X-chromosome probe, were used in a dual-color FISH assay. The results indicated that, in uncultured tumor cells, chromosome 17 was lost in 55% of specimens, ch romosome 7 was gained in 16% of specimens, and 9% of specimens showed large tetraploid populations. After cell culture, 23% of specimens sho wed loss of chromosome 17, no specimens showed gain of chromosome 7, a nd no tetraploid populations were present. This study suggests that lo ss of chromosome 17 may play an important role in the development of p rostate cancer, and that genetic changes observed after selection in v itro may not represent those in the original tumor. (C) 1994 Wiley-Lis s, Inc.