Effect of FBXW 7 knockdown in glioma cells. Normal mitosis figures in control siRNA transfected cells (A) and examples of abnormal mitosis in U87 cells transfected with siRNA against FBXW 7 (B). Chromosomes are stained with DAPI (blue) and spindle poles with anti-Aurora-A antibody (red), bar = 10 μm. Quantification of abnormal mitosis detected as in B, 48 h after transfection with siRNA against FBXW 7. More than 3400 cells were analyzed for each condition. Aurora-A positive cells as in A and B were classified as mitotic and accounted for around 4% of total cells in controls. FBXW 7 siRNA-transfected cells showed significantly less mitotic figures (72.2% of controls, P = 0.0094), fewer normal metaphases (27.5% of controls, P = 0.022), but much more abnormal mitoses (7.3 fold compared to controls, P = 0.0042; unpaired t-test, two-tailed).