Figure 7.

Forced declustering of centrosomes kills cancer cells with extra-centrosomes. (A) Multipolar anaphases induced by HSET depletion in N1E-115 cells. Representative still images from DIC movies of N1E-115 cells after HSET (n = 435) or control (n = 265) siRNA. Colored arrowheads indicate mitotic cells immediately before and after the onset of anaphase. Bar, 10 μm. (B) Loss of cell viability and inhibition of colony formation by N1E-115 cells after 6 d of HSET siRNA. (Left panel) Relative cell number in control and HSET-depleted (−HSET) cells from three independent experiments after 6 d post-transfection. Bright-field images of control and HSET-depleted N1E-115 cells. (Inset) A surviving N1E-115 cell after HSET depletion stained for senescence-associated β-galactosidase activity (blue). (Right panel) Graph represents the average colony number from two independent experiments in four different areas (area, 10 mm²). The corresponding images are shown below. (C) HSET RNAi-induced cell death in various cancer cell lines in proportion to the fraction of cells with extra centrosomes. Relative cell number in control (CTR) and HSET-depleted (−HSET) cells after 6 d post-transfection. HSET can be efficiently depleted from the different cell lines as shown in Supplemental Figure S9. Percentage of cells with more than two centrosomes (>2c) is indicated below the graph. Graph shows the average of three independent experiments. All graphics represent mean ± SD. (**) P < 0.005; (***) P < 0.001, Student’s t-test.