Fig. 3: SB-T-101141 induces a noncanonical ferroptosis via iron-dependent ROS.

A, B ROS detection of MCF-7 (A, left panel) and MDA-MB-453 (B, left panel) cells by a DCFH-DA probe. Cells were pretreated with DFOM (100 μM) or NAC (5 mM) for 1 h, followed by Paclitaxel (MCF-7, 3 μM; MDA-MB-453, 8 μM) or SB-T-101141 (MCF-7, 3 μM; MDA-MB-453, 8 μM) for 3 (MCF-7) or 12 (MDA-MB-453) h. Results were analyzed (MCF-7, A, right panel; MDA-MB-453, B, right panel) with the student t test (mean ± SD, n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. C Lipid ROS detection of MCF-7 cells with BODIPY 581/591 C11 probe (left panel). Cells were pretreated with DFOM (100 μM), Fer-1 (30 μM), or Lip-1 (5 μM) for 1 h, followed by SB-T-101141 (3 μM) for 16 h. Results were analyzed with the student t test (right panel) (mean ± SD, n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. D Lipid ROS detection of MCF-7 cells with BODIPY 581/591 C11 probe (left panel). Cells were pretreated with DFOM (100 μM), Fer-1 (30 μM), or Lip-1 (5 μM) for 1 h, followed by RSL3 (1 μM) for 16 h. Results were analyzed with the student t-test (right panel) (mean ± SD, n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. E, F LDH detection of MCF-7 (E) and MDA-MB-453 (F) cells. Cells were pretreated with DFOM (100 μM), NAC (5 mM) or Fer-1 (30 μM) for 1 h, followed by Paclitaxel (MCF-7: 3 μM; MDA-MB-453: 8 μM or 16 μM) or SB-T-101141 (MCF-7: 3 μM; MDA-MB-453: 8 μM or 16 μM) for 24 h. Results were analyzed with the student t test (mean ± SD, n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. G, H Cell viability analyses of MCF-7 (G) and MDA-MB-453 (H) cells. Cells were treated with Paclitaxel (MCF-7: 5 μM; MDA-MB-453: 8 μM) or SB-T-101141 (MCF-7: 5 μM; MDA-MB-453: 8 μM) for 36 h (MCF-7) or 24 h (MDA-MB-453) and analyzed using the student t test (mean ± SD, n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.