Figure 2.

TOPK depletion alters cell cycle progression following IR.Bromodeoxyuridine (BrdU) was added to cells 30 min before fixation and cell cycle stage was assessed by flow cytometry analysis using anti-BrdU and PI staining. The impact of TOPK depletion by siRNA on cell cycle progression was assessed in asynchronous HCT116 cells (A) and in HCT116 cells released from double thymidine block (B) following 4 Gy irradiation at T=0. Numbers indicate the percentage G₁ population (PI−/BrdU−, lower left quadrant) or G₂/M population (PI+/BrdU−, lower right quadrant). Early S (BrdU+/PI−, top left quadrant). Late S (BrdU+/PI+, top right quadrant). (C) Immunoblotting was used to assess the effect of TOPK knockdown on the expression of cell cycle proteins in samples from the experiment described in (B). Vinculin was used as a loading control. Data displayed are representative of three independent repeats.