Figure 5

Akt inhibitors increase the radiosensitivity of U87MG cells. A. U87MG cells were treated with vehicle or 10 μM SH-5 for 16 hrs, and then irradiated with 6 Gy. Total cell lysate was harvested 1 hr after IR and subjected to Western blot analysis with the indicated antibody. Cells without IR treatment were used as a control. The relative ratio of P-Akt-Ser473 to total Akt pooled from two different experiments are shown in the right panel. Results represent mean ± SEM, ***:p < 0.001 compared to vehicle (one-way ANOVA) B. Cells were treated with vehicle (control) or 10 μM SH-5 for 16 hrs, then irradiated with indicated dosage. 4 hr after IR, cells were fed with drug-free medium, and incubated for another 20 hr at 37°C, after which they were trypsinized and seeded for clonogenic survival assay. Colony-forming efficiency was determined 14 d later. C. U87MG cells were treated with vehicle or 1 μM MK-2206 for 1 hr, and then irradiated with 6 Gy. Total cell lysate was harvested 1 hr after IR and subjected to Western blot analysis with the indicated antibody. Cells without IR treatment were used as a control. D. Cells were treated with vehicle (control) or 1 μM MK-2206 for 1 hr, then irradiated with indicated dosage. 4 hr after IR, cells were fed with drug-free medium, and incubated for another 20 hr at 37°C, after which they were trypsinized and seeded for clonogenic survival assay. Colony-forming efficiency was determined 14 d later.