Figure 5.

T₃/TR-induced cisplatin, doxorubicin and TRAIL resistance is mediated via Bim downregulation. (a) J7-TR cells were treated with the indicated reagents for 24 h after T₃ (0 or 10 nM) stimulation for 48 h, and cell viability was measured using the MTT assay. Data are presented as relative absorbance values (%) of vehicle-treated cells. The extent of caspase-3 activation and proportion of apoptotic cells were determined via (b) western blotting and (c) flow cytometry, respectively. (d) Bim-_S was ectopically overexpressed in J7-TR cells via adenovirus infection in the presence or absence of T₃ for 48 h, and Bim proteins were determined via western blotting. Cells were subsequently stimulated with the indicated agents for 24 h. (e) Cell viabilities were determined with the MTT assay. (f and g) Caspase-3 activation was determined via western blotting and the percentage of apoptotic cells was assessed with PI-stained flow cytometry. (h) J7-Neo and J7-TR cells were subcutaneously injected into the flanks of nude mice. At 24 days after tumor inoculation, mice were treated with vehicle, cisplatin or doxorubicin. Tumor volumes were measured once every 3 days, and tumor growth curves are shown. Differences between data were evaluated using Student's t-test (**P<0.01; *P<0.05)