Figure 4.

The effects of ATF4 on Sev-induced ferroptosis in glioma cells. U87 and U251 cells were transfected with ATF4 siRNA or negative control sequences, followed by treatment with 5.1% Sev for 2 h. Cell viability was detected using CCK-8 assay in U87 (A) and U251 cells (B). Fe2+ concentrations were determined by colorimetric assay in U87 and U251 cells (C). ROS assay combined with flow cytometry was used to observe the content of ROS generation in U87 and U251 cells (D); the ratio of ROS generation was calculated (E). The expression of ferroptosis-associated protein CHAC1, GPX4, ferritin, and transferrin in U87 and U251 cells was detected using Western blotting; GAPDH was used as the internal control (F, G). Data were expressed as mean ± standard deviation. *p < 0.05, **p < 0.01, ***P<0.0001, compared with control.