Inhibition of ERRγ by DN200434 sensitizes sorafenib-resistant HCC cells to ferroptosis. (A) Representative western blot analysis of ERRγ protein levels in sorafenib-resistant (SR) Huh7 (left panel) and SK-Hep1 cells (right panel) in the presence/absence of DN200434. (B, C) Representative images of C11-BODIPY and quantification of C11-BODIPY fluorescence in sorafenib-resistant (SR) Huh7 (B) and SK-Hep1 (C) cells treated with sorafenib or DN200434. Quantification of C11-BODIPY fluorescence in cells. (D, E) Representative immunofluorescence staining with anti-4-HNE, and quantification of 4-HNE fluorescence in sorafenib-resistant (SR) Huh7 (D) and SK-Hep1 (E) cells treated with sorafenib or DN200434. (F) Relative cell death of sorafenib-resistant (SR) Huh7 (left panel) and SK-Hep1 cells (right panel). Cell death was assessed by LDH release after treatment for 24 h with sorafenib or DN200434 in the presence/absence of ferrostatin-1 or GSH. Scale bar, 20 μm. Data are expressed as the mean ± SEM of three independent experiments. N.S., not significant; *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. Sora, Sorafenib; DN, DN200434.
