Fig. 3.

EGF induces intracellular H₂O₂ production. A, SKOV3 and OVCAR3 cells were serum starved for 24 h and treated with or without 100 ng/ml EGF. At the indicated time points, cells were washed twice with PBS and fixed with 10% formaldehyde. Intracellular H₂O₂ levels were measured by staining with CM-H2DCFDA (5 μm), and images were captured using a fluorescence microscope (top panel). The corresponding phase-contrast micrographs are shown in the bottom panel. B, SKOV3 cells were pretreated with 10 μm AG1478 (AG) or the H₂O₂ scavenger PEG-catalase (Cat) (1000 U/ml) for 30 min, followed by treatment with 100 ng/ml EGF for 30 min. Intracellular H₂O₂ levels were measured as described above. Scale bar, 200 μm.