Figure 1.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance correlates with Akt activation in ovarian cancer cells. Cell viability was assessed in four ovarian cancer cell lines by a short-term assay where cells were incubated with TRAIL (100 ng/ml) for 48 h and viability was assessed by XTT assay (a), and by a long-term assay where cells were treated with TRAIL (100 ng/ml) or left untreated (control) for 2 h and colonies were counted after 14 days (b). Apoptosis was measured by determining oligosomal DNA fragementation (c) and the percentage of apoptosis (d) was measured as percentage of hypoploid cells assessed by flow cytometry analysis during exposure to TRAIL (100 ng/ml) for 24 h. Data shown are means±s.e.m. derived from three independent experiments. (e) Expression/phosphorylation of Akt, FLIP_L and FLIP_S were analyzed by western blotting with appropriate antibodies. Representative immunoblot from three independent experiements. *P<0.001.