Figure 1

Triptolide inhibited the proliferation of SKOV-3 cells and induced the accumulation of HIF-1α protein. A. SKOV-3 cells were exposed to triptolide of gradient concentrations for 72 h. The proliferation inhibition was determined by SRB assays. B. SKOV-3 cells at normoxia (upper panel), 1% O₂ hypoxia (middle panel) or CoCl₂ (150 μM) mimic hypoxia (lower panel) were treated with tiptolide for 12 h and then subjected to standard Western blotting analyses for the levels of HIF-1α and HIF-1β proteins. C and D. A549 (C) and DU145 (D) cells at 1% O₂ hypoxia were treated with tiptolide for 12 h and Western blotting analyses were done as in B. E. SKOV-3 cells at CoCl₂ (150 μM) mimic hypoxia were treated with tiptolide at 1000 nM for 12 h. Then the cells were subjected to Western blotting for the levels of HIF-1α, HIF-1β proteins (left panel); or the cells were used to do co-immunoprecipitation assays for the binding between HIF-1α and HIF-1β (middle and right panels). F. SKOV-3 cells at 1% O₂ hypoxia were treated with tiptolide at gradient concentrations for 12 h. Then the cells were subjected to Western blotting for the levels of HIF-2α proteins. All the experiments were performed three times and the representative results were presented.