Figure 3.

The effects of HIF-1α on cisplatin-induced apoptotic cell death. (A) After HIF-1α knockdown, sensitization of A549 cells to cisplatin was measured following a 12-h exposure to normoxia or hypoxia. (B) After HIF-1α knockdown, the apoptotic cell death rate caused by 10 µg/ml cisplatin was measured by Annexin V/propidium iodide double staining followed by cytometric analysis following a 12-h exposure to normoxia or hypoxia. (C) Chemosensitivity was evaluated by measuring cell viability after 0, 12, 24, 48 and 72-h exposure to hypoxia or normoxia with the addition of cisplatin. *P<0.05 vs. normoxia. HIF-1α, hypoxia inducible facor-1α; NC, negative control.