Figure 6.
ATM inhibitor KU-55933 inhibits ERK phosphorylation in response to BrdU photolysis. (A) U87 cells labeled with BrdU, either left untreated lane (lane1–4) or treated with KU-55933 at 10 µM (lane 5–8) for 30 min before treatment with Hoechst dye and UV-A irradiation (Lanes 1 and 5, no UV-A; 2 and 6, 15 J/m2; 3 and 7, 50 J/m2; and 4 and 8, 150 J/m2). Cells from each set were collected 3 h after irradiation and processed for western blotting. ERK denotes equal loading. The figure shows representative western blots of triplicate repeats. (B) Densitometic analysis of (A) presented in graph form. Data points, ERK phosphorylation levels plotted against UV-A dose, error bars. SEM; n = 3. Fold (x) denotes changes in p-ERK levels compared to control (no UV-A) normalized to total ERK levels. *p < 0.05.