Overexpression of gankyrin reduces pRB levels and makes <i>Lmna</i><sup>+/+</sup> cells refractory to p16<sup>ink4a</sup>-induced arrest.

<p>(A) Western analysis of <i>Lmna</i><sup>+/+</sup> infected with a control plasmid, <i>Lmna</i><sup>+/+</sup>-Cont, or gankyrin, <i>Lmna</i><sup>+/+</sup>-Gank, and uninfected <i>Lmna</i><sup>−/−</sup> fibroblasts. <i>Rb</i><sup>−/−</sup> fibroblasts were included as a control for pRB levels. (B) Cells were transfected with GFP-p16<sup>ink4a</sup> or GFP-p21<sup>cip1</sup> and GFP-positive cells were scored; S-phase cells were identified by BrdU incorporation. The percentage of cells positive for GFP and BrdU incorporation were quantified. Results are shown with standard deviations from triplicate samples; 150 cells were counted per sample. (C) Flow cytometry was conducted on <i>Lmna</i><sup>+/+</sup>-Cont and <i>Lmna</i><sup>+/+</sup>-Gank cells transfected with GFP or GFP-p16<sup>ink4a</sup>.</p>