Figure 1.

Knockdown of Ku proteins in WI38 human fibroblast cells leads to growth arrest. WI38 fibroblast cells were infected with a shRNA vector directed against the Ku80 protein. 24 hours following infection, cultures were placed into puromycin-containing selection medium for 72 hours. (A) Total protein was collected and a representative western blot for Ku80 and Ku70 is shown. Tubulin levels are shown as a loading control. Similar reductions in Ku levels were obtained over multiple trials. (B) WI38 cells were seeded and counted at Days 1, 2, 3 and 6 on a Guava EasyCyte Mini flow cytometer to determine growth kinetics compared to non-infected cells. Each cell type and timepoint was measured in triplicate and standard deviation was measured and is shown.