Fig. 5.

The FF-ROS mutagenic activity of Late exposure is mediated by NF-κB, and that of Early exposure is mediated by ERK. (a) The AID mRNA expression in FE25 cells treated with 10 % FF, H₂O₂ (100 μM) for 6 h, 100 % FF, and H₂O₂ (250 μM) for 2 min with and without SN50 (NF-κB inhibitor) or ulixertinib (ERK1/2 inhibitor) at a concentration of 100 nM with 2 h pretreatment. (b) Immunofluorescence staining of NF-κB in FE25 cells with or without 10 % FF treatment for 5 h. (c) Western blot analysis of phosphorylated NF-κB with or without 10 % FF treatment. (d) Western blot analysis of phosphorylated ERK with or without 100 % FF for 1 min in FE25 cells. * p < 0.05, ** p < 0.01, *** p < 0.001 compared to control; ^# p < 0.05, ^{# #} p < 0.01, ^{# # #} p < 0.001 comparisons of FF and H₂O₂ with or without inhibitors by two-tailed paired Student's t-test.