TY - EJOU
AU - Aldeghaither, Sara Y.
AU - Alsughayyir, Jawaher
AU - Fatima, Sabiha
AU - Alfhili, Mohammad A.
TI - Death Ligand Signaling Involving the COX/PKC/MLKL Axis Mediates Erythrocyte Death by HDAC/DNMT Inhibitor, Parthenolide, through ROS Generation and Calcium Mobilization
T2 - BIOCELL
PY - 2025
VL - 49
IS - 11
SN - 1667-5746
AB - Objectives: Targeting epigenetic modifications in anticancer therapy is a promising approach to overcoming cancer cell chemoresistance. The histone deacetylase/DNA methyltransferase inhibitor, parthenolide (PTL), has antitumor activity, but contrasting findings exist on its effect in normal cells. This study aims to examine the non-genomic toxic mechanisms of PTL in human erythrocytes. Methods: Cell death as stimulated by 20–200 μM of PTL for 24 h at 37°C was assessed using fluorescence-assorted cell sorting and spectrophotometric assays. Canonical markers of cell death, including membrane scrambling, oxidative stress, and Ca2+ mobilization, were captured by annexin V-fluorescein isothiocyanate, 2′,7′-dichlorodihydrofluorescein diacetate, and Fluo4/AM labeling, respectively. Rescue experiments using a wide array of inhibitors were also conducted. Results: PTL stimulated significant membrane scrambling and blebbing, and showed potent hemolytic activity coupled with significant elevations in dichlorofluorescein and Fluo4 fluorescence. While hemolysis was ameliorated by glutathione, caffeine, acetylsalicylic acid, staurosporin, necrosulfonamide, guanosine, and Ca2+ deprivation, it was rather exacerbated by necrostatin-2, tumor necrosis factor α (TNFα) or Fas ligand (FasL) neutralization, and concurrent Ca2+ deprivation and membrane depolarization. In contrast, eryptosis was attenuated by N-acetyl-cysteine, TNFα, or FasL blockade, and simultaneous Ca2+ elimination and KCl enrichment; and augmented by necrostatin-2, necrosulfonamide, and adenosine triphosphate. Interestingly, loss of volume was only prevented by melatonin, acetylsalicylic acid, and N(gamma)-nitro-L-arginine methyl ester. Conclusion: PTL stimulates oxidative hemolysis and eryptosis through Ca2+ mobilization and death ligand signaling involving the cyclooxygenase/protein kinase C/mixed lineage kinase domain-like pseudokinase axis. This research highlights the non-genomic toxic mechanisms of PTL and presents potential pharmacological targets for mitigating its adverse off-target effects.
KW - Parthenolide; hemolysis; eryptosis; oxidative stress; death ligand
DO - 10.32604/biocell.2025.071827