Figure 1.

Suppression of FOXM1 by RNAi sensitizes human cancer cells to H₂O₂-induced oxidative stress. A: Treatment strategy. FOXM1 reduces intracellular ROS levels by inducing the expression of ROS scavengers. Co-treatment with ROS inducers and FOXM1 inhibitors elevates the levels of ROS, leading to cell death. B: Breast cancer cells MDA-MB-231 were transfected with control and FOXM1 siRNA for 72 hours, then treated with 300 μmol/L H₂O₂ and 10 μmol/L H₂DCF-DA dye for 30 minutes. Intracellular ROS production was determined by flow cytometry. Graph shows quantification as fold of ROS induction compared with control cells, means ± SD of a representative triplicate experiment. C: MIA PaCa-2 vector control and FOXM1 knockdown pancreatic cancer cells were treated with the indicated concentrations of H₂O₂. Twenty-four hours after treatment, cells were harvested and immunoblotting was performed with antibodies against cleaved caspase-3. β-Actin was used as the loading control. D: MDA-MB-231 vector control and FOXM1 knockdown breast cancer cells were treated with H₂O₂ as indicated. Twenty-four hours after treatment, cells were harvested and immunoblotting was performed for cleaved caspase-3 and β-actin as the loading control.