Research Article

DNA Ligase IV Prevents Replication Fork Stalling and Promotes Cellular Proliferation in Triple Negative Breast Cancer

Figure 7

Lig4 depletion causes increases in levels of pDNA-PKcs S2056. (a) Lig4 depleted BT549 or scrambled control (NT) treated cells were treated with HU or PBS and protein isolated as outlined in the methods section. Phosphorylation of DNA-PKcs at Ser 2056 and total DNA-PKcs levels were assessed using immunoblot. (b) Densitometry analysis of three biological replicates. Loading control (vinculin) normalized mean intensity values of pDNA-PKcs S2056 per treatment were first normalized to total DNA-PKcs followed by normalizing to control cells treated with vehicle (1 h) values (p<0.01, n=3). Untransfected BT549 cell lysate served as the negative control and lysate from 10 Gy irradiated BT549 cells served as the positive control.