Fig. 1.

Demonstration of chromosomal instability screen using a kinase cDNA library. (A) Mitotic escape in NL-20 cells results in viable tetraploids. NL-20 cells were treated overnight with colcemid or DMSO. Cells were fixed and stained for flow cytometry. (B) Kinase overexpression screen identifies kinases that regulate chromosomal stability. NL-20 cells were transduced with kinase cDNA constructs and grown with or without puromycin selection for 4 d. Cells were fixed and stained for flow cytometry. The percentage of cells with increased ploidy was calculated. The table represents those kinases that showed a reproducible increased ploidy phenotype in both NL-20 and HBE135 cells. (C) FISH analysis verifies increased ploidy. NL-20 cells were infected with the indicated kinase cDNAs and fixed for FISH analysis after 4 d. Fixed nuclei were stained with a chromosome 8-specific probe and counterstained with propidium iodide. The table shows the percentage of cells with greater than two copies of chromosome 8 for the indicated kinases.