Fig. 5.

EGF induces Snail expression at the transcriptional level through H₂O₂ production. A, SKOV3 cells were treated with 100 ng/ml EGF for various times, and the mRNA levels of Snail (left panel) and Slug (right panel) were analyzed by RT-qPCR. B, SKOV3 cells were treated with AG1478 (AG) (10 μm) in the presence or absence of 100 ng/ml EGF for 3 h (Snail) or 6 h (Slug), and mRNA levels were analyzed by RT-qPCR. C, SKOV3 cells were treated with PEG-catalase (Cat) (1000 U/ml) in the presence or absence of 100 ng/ml EGF for 3 h (Snail) or 6 h (Slug), and mRNA levels were analyzed by RT-qPCR. Note that PEG-catalase inhibits only EGF-induced Snail mRNA levels. D, SKOV3 cells were treated with H₂O₂ for different durations, and mRNA levels of Snail and Slug were examined by RT-qPCR. Results are expressed as mean ± sem of at least three independent experiments. *, P < 0.05 compared with control (Ctrl). #, P < 0.05 compared with EGF.