Figure 5

HIF-1α silencing partially prevented the proliferation inhibition and apoptosis induction by triptolide. A. siRNAs targeting three different sequences of the HIF-1α gene were used to effectively silence this gene in SKOV-3 cells (Western blotting). GFP siRNA was used as scrambled control. B. The SKOV-3 cells transfected with HIF-1α or GFP siRNA were treated with triptolide for 48 h and then subjected to SRB assays for the proliferation inhibition. C. The SKOV-3 cells transfected with HIF-1α or GFP siRNA were treated with triptolide for 36 h and then assayed for apoptotic induction by flow cytometry as described in the Materials and Methods section. The representative histograms were from three independent experiments with similar results. D. The apoptosis rate from C. Data shown in B and D were expressed as mean ± SD, n = 3. The significant difference between triptolide-treated groups and hypoxia-control groups was analyzed by Student t test. * P < 0.05.