Fig. 6

Hyperactive NRF2 promotes radioresistance by inhibiting ferroptosis in ESCC cells. a Western blot analysis showing NRF2 levels in KYSE 30 and KYSE 150 cell lines with overexpression of NRF2 (NF-OE), and negative control (NC). b Lipid peroxidation assessment of NC and NF-OE 24 h after 6 Gy RT in KYSE 30 and KYSE 150 cells, respectively. Bar graph showing RT-induced relative fold changes of lipid peroxidation levels per 10,000 cells by C11-BODIPY staining in the indicated cells. c Quantitative RT-PCR analysis of PTGS2 expression in NC and NF-OE KYSE 30 or KYSE 150 cells 24 h after 6 Gy RT, respectively. d TEM images of NC and NF-OE KYSE 150 cells 24 h after exposure to 6 Gy of RT. Nu: nucleus; red arrows: mitochondria; yellow arrows: autophagosome; Scale bars: 5 µm. e Representative images of clonogenic survival assays in NC and NF-OE KYSE 30 or KYSE 150 cells pre-treated with 5 μM ferrostatin-1 or DMSO for 24 h, followed by exposure to 2 Gy or 4 Gy of RT, respectively. f The quantified clonogenic survival assay in NC and NF-OE KYSE 30 or KYSE 150 cells that were pre-treated with 5 μM ferrostatin-1 or DMSO for 24 h followed by 2 Gy or 4 Gy of RT. g Quantified cell proliferation assay curves analyzed by CCK-8 in NC and NF-OE KYSE 30 or KYSE 150 cells pre-treated with 5 μM ferrostatin-1 or DMSO for 24 h, followed by exposure to 6 Gy RT. Each experiment was conducted independently triplicate. Student’s t-test (two-tailed) was used for statistical analysis, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Bar graphs: mean ± SEM, n = 3