FIGURE 6.

Cell cycle arrest due to suppression of WDR3 does not occur in cells deficient in Rb and p53. A, U2OS and SAOS-2 cells were mock-transfected, transfected with control siRNA, or siRNA targeting WDR3 and then analyzed for expression of WDR3, p21, MDM2, and α-tubulin by Western blot. Results represent one of three independent experiments with similar results. B, SAOS-2 cells transfected as in A for 72 h were assessed for cell size using the mean FSC-H signal on a flow cytometer. Data represent an average of the mean FSC-H from six independent samples and graphed as change in percentage cell size relative to control siRNA-transfected cells (siNEG) (*, p < 0.05, Student's t test). C, cell cycle profiles of SAOS-2 cells mock-transfected, transfected with control siRNA, or siRNA targeting WDR3 were stained with propidium iodide, and DNA content was analyzed by flow cytometry at 48 h (left panel) and 72 h (right panel) post-transfection. Graphs indicate the percentages of cells in G₁ (black), S (gray), and G₂/M (white) phases of the cell cycle from triplicate samples of three independent experiments.