Mild Oxidative Stress Reduces NRF2 SUMOylation to Promote Kras/Lkb1/Keap1 Mutant Lung Adenocarcinoma Cell Migration and Invasion

Figure 3

SUMOylation of NRF2 is critical for its antioxidant ability in KLK LUAD via transcriptional activation of Cat. (a) The intracellular ROS and H₂O₂ levels and GSH/GSSG ratio in four stable cell lines constructed from A549 cells (3 replicates per group). (b) Heat map and trend graph comparing the patterns of antioxidant gene expression in four stable cell lines constructed from A549 cells. (c) Validation of gene expression involved in antioxidant pathways by quantitative real-time PCR in four stable cell lines constructed from A549 cells (3 replicates per group). Cat: catalase; Sirt3: Sirtuin 3; Nqo1: NAD(P)H quinone dehydrogenase 1; Hmox1: heme oxygenase 1; Gclc: glutamate-cysteine ligase catalytic subunit; Gclm: glutamate-cysteine ligase modifier subunit; Gpx2: glutathione peroxidase 2; Gpx4: glutathione peroxidase 4. (d) Catalase protein expression analyzed by Western blotting in four stable cell lines constructed from A549 cells. Blots were quantified and normalized to β-actin expression. (e) ChIP assay of NRF2 occupancy in the locus of Cat promoter in A549-shNRF2+WT and A549-shNRF2+K110R cells. (f) A549-shNRF2+WT and A549-shNRF2+K110R cells were treated with 100 μΜ TBHP or 200 μΜ H₂O₂ for 12 h. The intracellular ROS level was then measured by flow cytometry. TBHP: tert-butyl hydroperoxide; H₂O₂: hydrogen peroxide. , , and .

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