Fig. 3

Breast primary epithelial cells (BPECs) show chromosome instability. a Binucleated BPECs stained with 4',6-diamidino-2-phenylindole (DAPI) showing: I a normal binucleated cell; II a binucleated cell with two micronuclei, III with a nuclear bud, and IV with a nucleoplasmic bridge. b Frequency of abnormal nuclear morphologies per binucleated cell in 12BPECs at initial, medium and late population doubling (PD). Bar 10 μm. c Frequencies of the different types of structural chromosome aberrations observed in metaphase plates of 12BPEC at an early, a mid and a late PD.  d Representative examples of structural chromosome aberrations as detected by centromere + telomere peptide nucleic acid (PNA)- fluorescence in situ hybridization (FISH) (left) and M-FISH (right) probes. e Frequencies of aneuploidy (showing results for 12BPECs at an early, a mid and a late PD). Each column represents accumulated aneuploidy frequencies from the six analyzed chromosomes (1, 4, 6, 12, 17, 18). f Representative image of single nucleus hybridized with centromeric probes specific for chromosome 1, 14 and 18. Arrows three copies of chromosome 18. g Frequencies of tetraploidy. Each bar represents the frequency of cells with a tetraploid set of chromosomes as ascertained after hybridization with probes for chromosomes 1, 4, 6, 12, 17 and 18 (shown results for 12BPECs at an early, a mid and a late PD). h Representative image of a tetraploid nucleus