Figure 4.

PdPT induces GPX4 protein degradation. (A,B) A549 and NCI-H1299 cells were treated with PdPT for indicated does or time and then PARP and GPX4 protein levels were assayed using western blot. (C) A549 and NCI-H1299 cells were treated with PdPT (5 μM) in the absence or presence of z-VAD-FMK (50 μM), ferrostatin-1 (2.5 μM), deferoxamine (100 μM) for 24 h. The protein levels of PARP and GPX4 were assayed using western blot. (D) A549 and NCI-H1299 cells were treated with PdPT (5 μM) in the absence or presence of bortezomib (BTZ, 100 nM) for 24 h. The protein level of GPX4 was assayed using western blot. (E) A549 and NCI-H1299 cells were treated with PdPT (5 μM), CDDP (10 μM), BTZ (100 nM), and b-AP15 (1 μM) for 24 h, and then indicated proteins were assayed using western blot. (F,G) Immunoprecipitation analysis of GPX4-Ub complex formation in A549 and NCI-H1299 cells following PdPT treatment for 24 h.