c-Myc Knockdown in Endothelial Cells Leads to Senescence.

<p><b>A.</b> Representative images showing morphological changes associated with senescence in c-Myc deficient endothelial cells compared to NS-control. <b>B.</b> Quantitative analysis of senescence-associated-β-galactosidase activity in control and knockdown endothelial cells (n = 8). <b>C.</b> Determination of population doubling along passage (n = 8). <b>D.</b> Time-course cell cycle analysis of control and knockdown endothelial cells showing accumulation in G1-phase (n = 3–7). <b>E.</b> Representative western blot image of control and knockdown cells showing upregulation of the cell cycle inhibitor p21, 3–4 days after knockdown. Actin was used as loading control (n = 3). *p<0.05, **p<0.005. NS, control; KD, knockdown. Magnification = 20X.