Fig. 6: The acrolein scavenger Hydralazine enhances chemotherapeutic efficacy.

A Percentage of cell death in CT-26 cells at 48 h after stimulation with one or more of the following: 4-hydroperoxycyclophosphamide (4HC), Z-VAD-FMK (zVAD), hydralazine (HZ), and necrostatin-1 (Nec-1). B Mean tumor volume in wild-type (WT) Balb/c mice 10 days after CT-26 cancer cells engraftment, treated with a vehicle, hydralazine (HZ), cyclophosphamide (CP), or CP plus HZ. Mice were treated with CP and/or HZ every 2 days until sacrificed. C Representative images of hematoxylin and eosin staining in necrotic (top row) and viable (middle row) tumor regions, immunohistochemical staining of phosphorylated mixed lineage kinase domain-like pseudokinase (pMLKL, bottom row), and quantification of necrotic areas or pMLKL-positive cells per high-power field (HPF). Each dot represents mean necrotic area or pMLKL-positive cells per mouse. D Mean tumor volume in WT Balb/c nude mice 12 days after HT-29 cancer cells engraftment, treated with vehicle, HZ, CP, or CP plus HZ. Mice were treated with CP and/or HZ every 2 days until sacrificed. E Schematics depicting the mechanisms by which metabolically-derived or exogenously sourced acrolein inhibits necroptosis and promotes chemoresistance. Data are shown as mean ± SEM (A–D). ****P < 0.0001 and ***P = 0.0005 (one-way ANOVA; n = 4 from 4 biologically independent samples) (A). ****P < 0.0001 and **P = 0.0024 (two-way ANOVA; n = 10 per group) (B). ****P < 0.0001, ***P = 0.0009, **P = 0.0097 and ns = 0.4714 (one-way ANOVA; n = 8) (C). ****P < 0.0001, **P = 0.0032 for vehicle versus CP and **P = 0.0029 for CP versus CP plus HZ (two-way ANOVA; for vehicle, n = 7 and others, n = 8 per group) (D). Scale bars, 100 μm for hematoxylin and eosin staining and 50 μm for immunohistochemical staining. Source data are provided as a Source Data file.