Emerging Therapeutic Strategies Targeting GPX4-Mediated Ferroptosis in Head and Neck Cancer

Abstract

Ferroptosis, a regulated form of iron-dependent lipid peroxidation-induced cell death, has emerged as a compelling therapeutic strategy to overcome treatment resistance in head and neck cancer (HNC). Glutathione peroxidase 4 (GPX4), a selenoenzyme responsible for detoxifying phospholipid hydroperoxides, plays a central role in blocking ferroptosis and is frequently upregulated in therapy-resistant HNC subtypes. In this review, we examine the multifaceted regulation of GPX4 expression and function, including transcriptional, post-transcriptional, epigenetic, and proteostatic mechanisms. We explore how GPX4 suppression through pharmacologic inhibitors (e.g., RSL3, withaferin A, statins), metabolic stress, or combined therapies (e.g., radiotherapy, EGFR inhibitors, immunotherapy) induces ferroptosis and resensitizes resistant tumors. We also summarize emerging biomarkers, including GPX4, ACSL4, SLC7A11, and NCOA4, that predict ferroptosis sensitivity and may guide patient selection for ferroptosis-targeted therapies. Single-cell and spatial transcriptomics reveal significant intratumoral heterogeneity in ferroptosis susceptibility, underscoring the need for precision approaches. Despite promising preclinical data, challenges such as drug delivery, toxicity, and resistance mechanisms remain. Nevertheless, the ferroptosis-GPX4 axis represents a unique vulnerability in HNC that can be therapeutically exploited. Integrating ferroptosis modulation into personalized oncology may transform outcomes for patients with refractory disease.

Keywords: GPX4; ferroptosis; head and neck cancer; lipid peroxidation; therapy resistance.

Figure 1

Mechanistic role of GPX4 in ferroptosis. This diagram illustrates the central role of GPX4 in suppressing ferroptosis by reducing phospholipid hydroperoxides (e.g., PE-AA-OOH) to non-toxic lipid alcohols. GPX4 activity depends on intracellular GSH, which is synthesized from cysteine provided by the cystine/glutamate antiporter system Xc⁻ (SLC7A11/SLC3A2). The GSH regeneration cycle involving GR and the incorporation of selenium into GPX4 via the mevalonate pathway are also depicted. The availability of GSH is further modulated by glutaminolysis and selenium incorporation into GPX4 via the mevalonate pathway. Lipid peroxidation is driven by iron-mediated Fenton reactions and facilitated by ACSL4 and lipoxygenases. The roles of enzymes such as LPCAT3, ALOX15, and antioxidant defense systems, including FSP1, DHODH, and GCH1/BH₄, are included to show compensatory pathways under GPX4 inhibition. When GPX4 is impaired, lipid peroxides accumulate, triggering ferroptosis. Additional ferroptosis suppressors such as FSP1, DHODH, and GCH1/BH₄ provide auxiliary antioxidant defense, especially under GPX4-deficient conditions. This figure integrates metabolic, redox, and lipid regulatory elements central to ferroptosis execution. AA, arachidonic acid; AdA, adrenic acid; ALOX, lipoxygenase; BH₄, tetrahydrobiopterin; CoQ₁₀, coenzyme Q₁₀; DHODH dihydroorotate dehydrogenase; FSP1, ferroptosis suppressor protein 1; GCH1, GTP cyclohydrolase 1; γ-GCS, glutamate-cysteine ligase; GPX4, glutathione peroxidase 4; GR, glutathione reductase; GS, glutamine synthetase; GSH, glutathione; GSSG, glutatione disulfide; HO•, hydroxyl radical; IPP, isopentenyl pyrophosphate; LPCAT3, lysophosphatidylcholine acyltransferase 3; PE, phosphatidylethanolamine; PLOOH, phospholipid hydroperoxides; PUFA, polyunsaturated fatty acid; Se, selenium; SLC7A11, solute carrier family 7 member 11; system Xc⁻, cystine/glutamate exchange transporter.

Figure 2

Regulation of GPX4 expression and function in head and neck cancer. This diagram summarizes the multilayered regulatory mechanisms governing GPX4 expression in head and neck cancer (HNC). Transcriptionally, GPX4 is induced by Nrf2 binding to antioxidant response elements (AREs) and repressed through KEAP1 or STAT3 inhibition. Post-transcriptionally, non-coding RNAs such as miR-15a-3p, miR-324-3p, and miR-1287-5p downregulate GPX4 mRNA, while lncRNAs (e.g., PVT1, OIP5-AS1) act as molecular sponges that sequester these miRNAs. m⁶A RNA demethylation by FTO and histone modifications by PRMT4 also regulate GPX4 expression. Post-translational control involves PPT1-mediated lysosomal degradation and SUMOylation pathways, with SENP1 indirectly modulating ACSL4 activity and ferroptosis sensitivity. These layers collectively determine ferroptosis resistance in therapy-refractory HNC. ACSL4, acyl-CoA synthetase long-chain family member 4; ceRNA, competing endogenous RNA; FTO, fat mass and obesity-associated protein; Keap1, Kelch-like ECH-associated protein 1; lncRNA, long noncoding RNAs; m⁶A, N⁶-methyladenosine; miRNA, microRNA; Nrf2, nuclear erythroid 2-related factor; PPT1, palmitoyl-protein thioesterase 1; PRMT4, protein arginine methyltransferase 4; SENP1, SUMO-specific protease 1; STAT3, signal transducer and activator of transcription 3; SUMO, small ubiquitin-like modifier.

Figure 3

Translational and therapeutic implications of GPX4 inhibition in head and neck cancer. This diagram illustrates diverse therapeutic strategies targeting GPX4 and its associated pathways to induce ferroptosis in HNC. GPX4-targeting agents include direct inhibitors such as RSL3, ML162, withaferin A, and trifluoperazine, and indirect modulators like allicin and fucoxanthin that suppress GPX4 expression via the Nrf2/HO-1 axis. Statins inhibit the mevalonate pathway, reducing selenocysteine-tRNA biosynthesis and impairing GPX4 synthesis. Additional mechanisms include glutaminolysis inhibition (e.g., CB-839), photodynamic therapy, and hyperbaric oxygen to promote oxidative stress and radiosensitization. Immunotherapy strategies amplify ferroptosis through IFN-γ-mediated SLC7A11 suppression. Additional combinatorial approaches involving EGFR or PI3K-AKT inhibitors further potentiate ferroptotic responses. Nanoparticle-based delivery platforms enhance tumor selectivity and minimize systemic toxicity. These combined interventions highlight ferroptosis as a promising therapeutic vulnerability in resistant HNC. AKT, protein kinase B; EGFR, epidermal growth factor receptor; GLS1, glutaminase; IFN-γ, interferon gamma; ML162, molecular libraries 162; PI3K, phosphoinositide 3-kinase; ROS, reactive oxygen species; RSL3, RAS-selective lethal 3.