CDK-1 inhibition in G2 increases K-MT stability.

<p>A) Quantification of the percentage of mitotic cells with monopolar spindles following drug treatment as in 1A with or without the addition of 0.5 nM Taxol during MG-132 and MG-132 + STLC. Bars represent the mean and error bars represent the s.e.m. of at least 827 cells from 5 experiments. A statistically significant difference exists between DMSO- and RO-3306-treated cells (p < 0.001), and a statistically significant difference exists between cells treated or not treated with Taxol (p < 0.001). B) Representative images of RPE-1 cells treated with a double thymidine block, washout, 5 h recovery, 3 h RO-3306 or DMSO, washout, 90 min MG-132 +/- taxol, and 6 min nocodazole +/- taxol. In images presented as a heat map, black indicates low intensity and yellow-white indicates high intensity. In overlay, tubulin is shown in green, kinetochores (CREST staining) in magenta, centrin in yellow, and DNA in blue; scale bar, 5 μm. C) Quantification of the sum fluorescence intensity of MT polymer remaining in cells after the treatments described in B, normalized to DMSO without taxol. Box-and-whisker plots indicate the 10^th, 25^th, 50^th, 75^th, and 90^th percentile as well as outliers from at least 60 cells from at least 4 experiments. A statistically significant difference exists between DMSO- and RO-3306-treated cells (p = 0.003), and a statistically significant difference exists between cells treated or not treated with Taxol (p < 0.001).