Treatment with BI2536, a Polo-kinase inhibitor, interferes with centriole reduplication.

<p><b>A</b> U2OS GFP-Centrin1 cells were treated with 1.9 µg/ml aphidicolin to induce centriole reduplication for 75 h. In parallel, treatment with 100 nM BI2536 or DMSO as control was performed. Cell extracts were resolved by SDS-PAGE and analyzed on Western blot level with anti-NPM/B23 and anti-pS4 NPM/B23 antibodies. α-Tubulin, loading control. <b>B</b> Indirect immunofluorescence analysis from the experiment described in (A) was carried out specific for γ-Tubulin after methanol fixation. Insets show enlargement of centrioles. GFP-Centrin1, green; γ-Tubulin, red; DNA, blue. Scale bar, 10 µm. <b>C</b> For statistics, the experiment in (B) was also scored for centriole reduplication (>4 GFP-Centrin1 dots/centrioles or >2 γ-Tubulin dots/centrosomes) by microscopy. For quantification, more than 200 cells were analyzed for centriole reduplication in three independent experiments. Black bars, GFP-Centrin1 signal; grey bars, γ-Tubulin staining; unt, untreated; aph, aphidicolin.