Figure S4.

Aurora B or Haspin inhibition bypasses the metaphase checkpoint induced by Topo II catalytic inhibitors. (A) Live single-cell analysis of mitotic progression. Quantitation of time to anaphase and decondensation during drug treatments. Hesperadin (1 µM), an Aurora B inhibitor (Hauf et al., 2003), and 5-ITu (10 µM), a Haspin inhibitor (De Antoni et al., 2012), were added to metaphase cells 10 min after ICRF-193 was added. Each vertical bar represents one cell, with each cell being scored for time to anaphase and decondensation from the start of the time course. Cells that remained arrested in metaphase for the duration of the experiment are indicated by a red bar. (B) Representative immunofluorescent-stained images of pseudometaphase HeLa cells (nocodazole arrested) treated with ICRF-193 ± 5-ITu for 45 min. CREST, red; Aurora B, green. After ICRF-193 treatment, Aurora B localizes to the KPCs and chromosome core (right). After ICRF-193 + 5-ITu treatment (left), Aurora B typically localizes diffusely on chromatin and is present on some KPCs. The histogram plot shows classification of Aurora B staining pattern. Error bars, standard deviation. Bars, 10 µm. Data were collected from at least three independent experiments.