Multipolar mitotic cells in the human cell line NHIK 3025 following treatment with the mitotic inhibitor NY 4137.

Treatment of human NHIK 3025 cells during interphase with the mitotic inhibitor 2-(2-thenyl) sulfonyl-5-bromopyrimidine (NY 4137) induced the formation of multipolar mitotic cells. A 4 h pulse treatment with 0.010 mM NY 4137 induced the formation of such cells regardless of whether treatment occurred in G1 or S phase. Approximately 35% of the cells originating from such multipolar mitotic divisions had less-than-normal G1 DNA content. Recordings of the DNA content of these small cells by means of flow cytometry showed that the amount of DNA per cell varied randomly. Subpopulations were separated by centrifugal elutriation on the basis of differences in cellular volume. Simultaneous two-parametric recordings of DNA versus total cellular protein showed that even though cells contained an amount of DNA less than G1 cells, there was a proportionality between DNA content and protein content despite variations in cell size.