Ferroptosis as a potential target for cancer therapy

Targeted sonodynamic therapy induces tumor cell quasi-immunogenic ferroptosis and macrophage immunostimulatory autophagy in glioblastoma

In this study, we demonstrated the mechanism of a glioblastoma (GBM)-targeted sonodynamic therapy (SDT) strategy employing platelets loaded with a sonosensitizer based on functionalized boron nitride nanoparticles carrying chlorin e6 (BNPD-Ce6). In the in vitro study, we first found that the BNPD-Ce6-mediated sonodynamic action (SDA) induced remarkable viability loss, DNA damage, and cell death in the GBM cells (GBCs) but not macrophages. Surprisingly, the SDA-exposed GBCs displayed a ferroptotic phenotype while the SDA-exposed macrophages underwent immuno-stimulatory autophagy and potently potentiated the SDA's toxicity to the GBCs. The ferroptotic GBCs induced by the SDA were found to be quasi-immunogenic, characterized by the emission of some alarmins such as ATP, HSP90, and CRT, but absent HMGB1, a potent endogenous adjuvant. As such, the SDA-stressed GBCs were unable to stimulate the BMDMs. This defect, interestingly, could be rescued by platelets as a donor of HMGB1 which markedly enhanced the BNPD-Ce6's sonotoxicity to the GBCs. In the in vivo study, we first employed BNPD-Ce6-loaded platelets to achieve ultrasound-triggered, targeted delivery of BNPD-Ce6 in grafted intra-cranial GBMs and subsequent sonodynamic tumor damage. An SDT regimen designed based on these results slowed the growth of grafted intra-cranial GBMs and significantly increased the survival of the host animals. Pathological examination of the SDT-treated GBMs revealed tissue necrosis and destruction and validated the in vitro observations. Finally, the depletion of macrophages was found to abrogate the efficacy of the SDT in subcutaneous GBC grafts. In conclusion, the BNPD-Ce6@Plt-mediated SDT is a practicable and efficacious anti-GBM therapy. Its therapeutic mechanism critically involves a synergy of tumor cell ferroptosis, macrophage stimulation, and platelet activation induced by the SDA.

Mechanisms and Therapeutic Potential of GPX4 in Pain Modulation

Pain, a complex symptom encompassing both sensory and emotional dimensions, constitutes a significant global public health issue. Oxidative stress is a pivotal factor in the complex pathophysiology of pain, with glutathione peroxidase 4 (GPX4) recognized as a crucial antioxidant enzyme involved in both antioxidant defense mechanisms and ferroptosis pathways. This review systematically explores GPX4's functions across various pain models, including neuropathic, inflammatory, low back, and cancer-related pain. Specifically, the focus includes GPX4's physiological roles, antioxidant defense mechanisms, regulation of ferroptosis, involvement in signal transduction pathways, and metabolic regulation. By summarizing current research, we highlight the potential of GPX4-targeted therapies in pain management.

Computational discovery of novel GPX4 inhibitors from herbal sources as potential ferroptosis inducers in cancer therapy

Ferroptosis, a cell death regulation process dependent on iron levels, represents a promising therapeutic target in cancer treatment. However, the scarcity of potent ferroptosis inducers hinders advancement in this area. This study addresses this gap by screening the PubChem database for compounds with favorable ADMET properties to identify potential GPX4 inhibitors. A structure-based virtual screening was conducted to compare binding affinities of selected compounds to that of RSL3. The candidates-isochondrodendrine, hinokiflavone, irinotecan, and ginkgetin-were further analyzed through molecular dynamics (MD) simulations to assess their stability within the GPX4-ligand complexes. The computed binding free energies for RSL3, isochondrodendrine, hinokiflavone, irinotecan and ginkgetin were -80.12, -107.31, -132.03, and -137.52 and -91.11 kJ/mol, respectively, indicating their significantly higher inhibitory effects compared to RSL3. These findings highlight the potential for developing novel GPX4 inhibitors to promote ferroptosis, warranting further experimental validation.

Circ_0082374 Promotes the Tumorigenesis and Suppresses Ferroptosis in Non-small Cell Lung Cancer by Up-Regulating GPX4 Through Sequestering miR-491-5p

Circular RNAs (circRNAs) have been identified to be dysregulated in non-small cell lung cancer (NSCLC) and implicated in the progression of this cancer. Here, this work aimed to investigate the role and mechanism of circ_0082374 on NSCLC progression. Levels of circ_0082374, miR-491-5p, GPX4 (glutathione peroxidase 4) and epithelial-mesenchymal transition (EMT)-related proteins were examined by quantitative real-time PCR or western blotting, respectively. Cell proliferation and metastasis were detected using cell counting kit-8, colony formation, EdU, transwell, and Scratch assays. Cell ferroptosis was evaluated by measuring cell survival after the treatment of different ferroptosis inducers or inhibitors, as well as the accumulation of intracellular reactive oxygen species (ROS), ferrous iron (Fe2+) and malondialdehyde (MDA). The binding between miR-491-5p and circ_0082374 or GPX4 was confirmed using dual-luciferase reporter and RNA pull-down assays. In vivo experiments were conducted using murine xenograft assay and immunohistochemistry. Circ_0082374 was a stable circRNA with high expression in NSCLC tissues and cells. Functionally, circ_0082374 silencing suppressed NSCLC cell proliferation and metastasis. Moreover, its down-regulation enhanced ferroptosis by decreasing iron and lipid peroxidation accumulation. Mechanistically, circ_0082374 could indirectly up-regulate GPX4 expression via miR-491-5p, indicating the circ_0082374/miR-491-5p/GPX4 competitive endogenous RNAs (ceRNA) network. Rescue experiments demonstrated that the miR-491-5p/GPX4 axis mediated the regulatory effects of circ_0082374 exerted on NSCLC cells. Moreover, knockdown of circ_0082374 impeded NSCLC growth and EMT via regulating miR-491-5p and GPX4. Circ_0082374 silencing could suppress NSCLC cell proliferation, metastasis and induce ferroptosis through miR-491-5p/GPX4 axis, suggesting a novel therapeutic approach for NSCLC patients.

FDA-approved disulfiram induces ferroptosis via alteration of redox balance and lipid peroxidation and overcomes carfilzomib resistance in multiple myeloma

Multiple myeloma (MM), a malignant plasma cell disorder, remains incurable due to inevitable chemo-resistance development, including carfilzomib (CFZ) leading to relapse and poor patient outcomes. Therefore, new treatment strategies, including using FDA-approved alcohol deterrent disulfiram (DSF) are under investigation. The present study investigated the effect of DSF on ferroptosis and CFZ resistance in MM cells. Our findings indicate that DSF increases the production of cytosolic and mitochondrial reactive oxygen species, and causes a loss of mitochondrial Δψ and an elevation in lipid peroxidation in MM cells. DSF treatment in MM cell lines led to the significant downregulation of ferroptotic genes, including glutathione peroxidase 4. Moreover, ferroptosis inhibitor liproxstatin-1rescued DSF-induced ferroptosis by promoting glutathione peroxidase 4 upregulation. DSF alone overcomes CFZ resistance through lipid peroxidation elevation and acts synergistically with CFZ in CFZ-resistant MM cell lines. Our results suggest that DSF is a promising anti-myeloma agent for overcoming CFZ resistance in MM through ferroptosisinduction.

Exploring ferroptosis and miRNAs: implications for cancer modulation and therapy

Ferroptosis is a novel, iron-dependent form of non-apoptotic cell death characterized by the accumulation of lipid reactive oxygen species (ROS) and mitochondrial shrinkage. It is closely associated with the onset and progression of various diseases, especially cancer, at all stages, making it a key focus of research for developing therapeutic strategies. Numerous studies have explored the role of microRNAs (miRNAs) in regulating ferroptosis by modulating the expression of critical genes involved in iron metabolism and lipid peroxidation. Due to their diversity, unique properties, and dynamic expression patterns in diseases, exosomal miRNAs are emerging as promising biomarkers. Exosomes act as biological messengers, delivering miRNAs to target cells through specific internalization, thus influencing the ferroptosis response in recipient cells. This review summarizes the roles of miRNAs, with particular focus on exosomal miRNAs, in ferroptosis and their implications for cancer pathology. By examining the molecular mechanisms of miRNAs, we aim to provide valuable insights into potential therapeutic approaches.

Circular RNA circBNC2 inhibits tumorigenesis by modulating ferroptosis and acts as a nanotherapeutic target in prostate cancer

BACKGROUND

Metastasis is a leading cause of cancer-related death in castration-resistant prostate cancer (CRPC) patients. Circular RNAs (circRNAs) have emerged as key regulators of the metastasis of various cancers. However, the functional effects and regulatory mechanisms of circRNAs in metastatic CRPC (mCRPC) remain largely unknown.

METHODS

The expression of circBNC2 in prostate cancer (PCa), CRPC and neuroendocrine prostate cancer (NEPC) tissues was analyzed through bioinformatics analysis. Functional assays, including cell proliferation, migration, invasion and ferroptosis, were conducted in vitro and in vivo. The interactions between circBNC2, miR-4298, and ACSL6 were explored via luciferase reporter assays, RNA immunoprecipitation, and western blotting analysis. In addition, for the first time in PCa, we developed novel nanobowls (NBs) loaded with docetaxel (DTX) and circBNC2 (Dc-NBs) and evaluated the antitumor efficacy of Dc-NBs in a photothermal therapy (PTT) strategy.

RESULTS

We identified a novel tumor-suppressive circRNA, circBNC2, in human PCa, CRPC and NEPC samples via bioinformatic analysis. CircBNC2 expression was significantly downregulated in PCa tissues and PCa cell lines. Functional assays demonstrated that circBNC2 inhibited PCa cell proliferation and migration both in vitro and in vivo. Mechanistically, circBNC2 acted as a sponge for miR-4298, and ACSL6 was identified as a direct target of the circBNC2/miR-4298 axis. Moreover, we demonstrated that ACSL6 is essential for mediating circBNC2-regulated ferroptosis in PCa cells. More importantly, we demonstrated the nanodelivery of Dc-NBs, which exhibited significant antitumor effects in both subcutaneous and metastatic PCa models.

CONCLUSION

This study revealed the tumor-suppressive role of circBNC2 in mCRPC by driving ferroptosis via the circBNC2/miR-4298/ACSL6 axis. Additionally, we developed an efficient and safe PTT strategy based on a nanodelivery system that codelivers circBNC2 and DTX, highlighting its potential as a novel therapeutic approach for mCRPC.

Targeting ferroptosis in gastrointestinal tumors: Interplay of iron-dependent cell death and autophagy

Ferroptosis is a regulated cell death mechanism distinct from apoptosis, autophagy, and necroptosis, marked by iron accumulation and lipid peroxidation. Since its identification in 2012, it has developed into a potential therapeutic target, especially concerning GI disorders like PC, HCC, GC, and CRC. This interest arises from the distinctive role of ferroptosis in the progression of diseases, presenting a new avenue for treatment where existing therapies fall short. Recent studies emphasize the promise of focusing on ferroptosis to fight GI cancers, showcasing its unique pathophysiological mechanisms compared to other types of cell death. By comprehending how ferroptosis aids in the onset and advancement of GI diseases, scientists aim to discover novel drug targets and treatment approaches. Investigating ferroptosis in gastrointestinal disorders reveals exciting possibilities for novel therapies, potentially revolutionizing cancer treatment and providing renewed hope for individuals affected by these tumors.

Apigenin facilitates apoptosis of acute lymphoblastic leukemia cells via AMP-activated protein kinase-mediated ferroptosis

Background

The outcomes of pediatric patients with acute lymphoblastic leukemia (ALL) remain far less than favorable. While apigenin is an anti-cancer agent, studies on the mechanism by which it regulates ALL cell cycle progression are inadequate. Ferroptosis and AMP-activated protein kinase (AMPK) signaling are important processes for ALL patients. However, it remains unclear whether apigenin works by affecting AMPK and apoptosis.

Materials and Methods

SUP-B15 and T-cell Jurkat ALL cells were treated with apigenin, and cell viability and apoptosis were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays, respectively. The thiobarbituric acid-reactive substances (TBARS) assay was used to evaluate lipid peroxidation. Intracellular Fe2+ levels were measured using a commercial kit. Corresponding proteins were detected by western blotting.

Results

Results showed that apigenin reduced cell viability and the levels of Ki67 and proliferating cell nuclear antigen (PCNA) expression in a concentration-dependent manner in both types of ALL cells. Apigenin also exerted anti-apoptotic effects on SUP-B15 and Jurkat cells. Apigenin activated AMP-activated protein kinase (AMPK) signaling and induced ferroptosis, and those effects were attenuated by inhibition of AMPK. Eventually, the reduced cell proliferation and increased cell apoptosis caused by apigenin in ALL cells were partly abolished by AMPK inhibition.

Conclusion

In summary, apigenin exerted anti-leukemia activity in ALL cells, and that effect was partially achieved by activation of AMPK signaling. Our findings suggest apigenin as a potential drug for treatment of ALL.

Targeting the initiator to activate both ferroptosis and cuproptosis for breast cancer treatment: progress and possibility for clinical application

Breast cancer is the most commonly diagnosed cancer worldwide. Metal metabolism is pivotal for regulating cell fate and drug sensitivity in breast cancer. Iron and copper are essential metal ions critical for maintaining cellular function. The accumulation of iron and copper ions triggers distinct cell death pathways, known as ferroptosis and cuproptosis, respectively. Ferroptosis is characterized by iron-dependent lipid peroxidation, while cuproptosis involves copper-induced oxidative stress. They are increasingly recognized as promising targets for the development of anticancer drugs. Recently, compelling evidence demonstrated that the interplay between ferroptosis and cuproptosis plays a crucial role in regulating breast cancer progression. This review elucidates the converging pathways of ferroptosis and cuproptosis in breast cancer. Moreover, we examined the value of genes associated with ferroptosis and cuproptosis in the clinical diagnosis and treatment of breast cancer, mainly outlining the potential for a co-targeting approach. Lastly, we delve into the current challenges and limitations of this strategy. In general, this review offers an overview of the interaction between ferroptosis and cuproptosis in breast cancer, offering valuable perspectives for further research and clinical treatment.

Regulation and therapy: the role of ferroptosis in DLBCL

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of B-cell non-Hodgkin's lymphoma (NHL), up to 30%-40% of patients will relapse and 10%-15% of patients have primary refractory disease, so exploring new treatment options is necessary. Ferroptosis is a non-apoptotic cell death mode discovered in recent years. Its occurrence pathway plays an essential impact on the therapeutic effect of tumors. Numerous studies have shown that modulating critical factors in the ferroptosis pathway can influence the growth of tumor cells in hematological malignancies including DLBCL. This review highlights recent advances in ferroptosis-related genes (FRGs), including STAT3, Nrf2, and ZEB1, and focuses on the clinical potential of ferroptosis inducers such as IKE, α-KG, DMF, and APR-246, which are currently being explored in clinical studies for their therapeutic effects in DLBCL. Correlational studies provide a novel idea for the research and treatment of ferroptosis in DLBCL and other hematological malignancies and lay a solid foundation for future studies.

In defence of ferroptosis

Rampant phospholipid peroxidation initiated by iron causes ferroptosis unless this is restrained by cellular defences. Ferroptosis is increasingly implicated in a host of diseases, and unlike other cell death programs the physiological initiation of ferroptosis is conceived to occur not by an endogenous executioner, but by the withdrawal of cellular guardians that otherwise constantly oppose ferroptosis induction. Here, we profile key ferroptotic defence strategies including iron regulation, phospholipid modulation and enzymes and metabolite systems: glutathione reductase (GR), Ferroptosis suppressor protein 1 (FSP1), NAD(P)H Quinone Dehydrogenase 1 (NQO1), Dihydrofolate reductase (DHFR), retinal reductases and retinal dehydrogenases (RDH) and thioredoxin reductases (TR). A common thread uniting all key enzymes and metabolites that combat lipid peroxidation during ferroptosis is a dependence on a key cellular reductant, nicotinamide adenine dinucleotide phosphate (NADPH). We will outline how cells control central carbon metabolism to produce NADPH and necessary precursors to defend against ferroptosis. Subsequently we will discuss evidence for ferroptosis and NADPH dysregulation in different disease contexts including glucose-6-phosphate dehydrogenase deficiency, cancer and neurodegeneration. Finally, we discuss several anti-ferroptosis therapeutic strategies spanning the use of radical trapping agents, iron modulation and glutathione dependent redox support and highlight the current landscape of clinical trials focusing on ferroptosis.

Targeting Non-Apoptotic Pathways with the Cell Permeable TAT-Conjugated NOTCH1 RAM Fragment for Leukemia and Lymphoma Cells

Targeting nonapoptotic cell death offers a promising strategy for overcoming apoptosis resistance in cancer. In this study, we developed Tat-Ram13, a 25-mer peptide that fuses the NOTCH1 intracellular domain fragment RAM13 with a cell-penetrating HIV-1 TAT, for the treatment of T-cell acute lymphoblastic leukemia with aberrant NOTCH1 mutation. Tat-Ram13 significantly downregulated NOTCH1-target genes in T-ALL cell lines. Furthermore, the peptide had potent cytotoxic effects on various human leukemia and lymphoma cell lines. However, it did not affect normal lymphocytes and monocytes, some subsets of leukemia cells, or adherent tumor cells. This cell-selective cytotoxic activity was closely correlated with the peptide uptake via macropinocytosis in leukemia cells. In leukemia cells, Tat-Ram13 triggered rapid cell death. This cell death involved mitochondrial membrane depolarization and extracellular release of lactate dehydrogenase and high-mobility group box-1 protein without activation of caspase-3 or cleavage of PARP-1. These results suggest that Tat-Ram13 cell death is nonapoptotic and mediated by rapid plasma membrane rupture. Moreover, alanine scanning analysis identified four critical hydrophobic amino acids in the RAM13 domain essential for its cytotoxicity. Consequently, these results suggest that Tat-Ram13 is a tumor-selective, nonapoptotic cell death-inducing agent for treating refractory leukemia and lymphomas with apoptosis resistance.

Ferroptosis driven by nanoparticles for tackling glioblastoma

Glioblastoma (GBM) is the most aggressive, malignant, and drug-resistant brain tumor. There are no effective treatment options for GBM, which usually leads to relapses that cause patients to die a few months later. Ferroptosis, a newly discovered mechanism of regulated cell death, has been identified as a tumor suppressor in solid tumors and represents an alternative to apoptosis resistance. This mechanism of cell death is characterized by iron overload, which is responsible for generating reactive oxygen species (ROS) in the cell. Understanding the ferroptosis pathway and its key regulators can be used to develop rational delivery systems that specifically target these regulators in GBM cells and promote cell death. This review conducted a systematic literature search to better understand the potential of ferroptosis as a target for developing nanoparticles to tackle GBM. The mechanisms of action, design parameters, efficacy, and safety concerns of 16 nanoparticles were evaluated, demonstrating the potential of combining ferroptosis inducers with nanocarriers to promote a selective delivery to the tumor microenvironment.

Thyroid-associated ophthalmopathy and ferroptosis: a review of pathological mechanisms and therapeutic strategies

Thyroid-associated ophthalmopathy (TAO) is an inflammatory orbital disease associated with autoimmune thyroid disorders. Owing to the ambiguous nature of the pathogenesis, contemporary pharmacological treatment strategies predominantly involve the use of glucocorticoids and immunosuppressants. However, the adverse effects associated with these agents in clinical practice necessitate further investigation into the disease's pathogenesis and the identification of novel therapeutic targets and pharmacological interventions. Recent studies suggest that ferroptosis, a novel form of regulated cell death, may play a role in TAO pathogenesis. This review aims to explore the involvement of ferroptosis in TAO and evaluate its potential as a therapeutic target. Key topics include the epidemiology, clinical manifestations, and pathophysiology of TAO, along with the molecular mechanisms of ferroptosis. Evidence supporting ferroptosis in TAO and the therapeutic implications of targeting this pathway are also discussed, alongside challenges and future directions in this emerging research area.

TR-107, an Agonist of Caseinolytic Peptidase Proteolytic Subunit, Disrupts Mitochondrial Metabolism and Inhibits the Growth of Human Colorectal Cancer Cells

Oxidative phosphorylation is an essential metabolic process for cancer proliferation and therapy resistance. The ClpXP complex maintains mitochondrial proteostasis by degrading misfolded proteins. Madera Therapeutics has developed a class of highly potent and selective small-molecule activators (TR compounds) of the ClpXP component caseinolytic peptidase proteolytic subunit (ClpP). This approach to cancer therapy eliminates substrate recognition and activates nonspecific protease function within mitochondria, which has shown encouraging preclinical efficacy in multiple malignancies. The class-leading compound TR-107 has demonstrated significantly improved potency in ClpP affinity and activation and enhanced pharmacokinetic properties over the multitargeting clinical agent ONC201. In this study, we investigate the in vitro efficacy of TR-107 against human colorectal cancer cells. TR-107 inhibited colorectal cancer cell proliferation in a dose- and time-dependent manner and induced cell cycle arrest at low nanomolar concentrations. Mechanistically, TR-107 downregulated the expression of proteins involved in the mitochondrial unfolded protein response and mitochondrial DNA transcription and translation. TR-107 attenuated oxygen consumption rate and glycolytic compensation, confirming inactivation of oxidative phosphorylation and a reduction in total cellular respiration. Multiomics analysis of treated cells indicated a downregulation of respiratory chain complex subunits and an upregulation of mitophagy and ferroptosis pathways. Further evaluation of ferroptosis revealed a depletion of antioxidant and iron toxicity defenses that could potentiate sensitivity to combinatory chemotherapeutics. Together, this study provides evidence and insight into the subcellular mechanisms employed by colorectal cancer cells in response to potent ClpP agonism. Our findings demonstrate a productive approach to disrupting mitochondrial metabolism, supporting the translational potential of TR-107.

Reactivation of MAPK-SOX2 pathway confers ferroptosis sensitivity in KRASG12C inhibitor resistant tumors

The clinical success of KRASG12C inhibitors (G12Ci) including AMG510 and MRTX849 is limited by the eventual development of acquired resistance. A novel and effective treatment to revert or target this resistance is urgent. To this end, we established G12Ci (AMG510 and MRTX849) resistant KRASG12C mutant cancer cell lines and screened with an FDA-approved drug library. We found the ferroptosis inducers including sorafenib and lapatinib stood out with an obvious growth inhibition in the G12Ci resistant cells. Mechanistically, the G12Ci resistant cells exhibited reactivation of MAPK signaling, which repressed SOX2-mediated expression of cystine transporter SLC7A11 and iron exporter SLC40A1. Consequently, the low intracellular GSH level but high iron content engendered hypersensitivity of these resistant tumors to ferroptosis inducers. Ectopic overexpression of SOX2 or SLC7A11 and SLC40A1 conferred resistance to ferroptosis in the G12Ci resistant cells. Ferroptosis induced by sulfasalazine (SAS) achieved obvious inhibition on the tumor growth of xenografts derived from AMG510-resistant KRASG12C-mutant cells. Collectively, our results suggest a novel therapeutic strategy to treat patients bearing G12Ci resistant cancers with ferroptosis inducers.

Ferroptosis contributes to the progression of female-specific neoplasms, from breast cancer to gynecological malignancies in a manner regulated by non-coding RNAs: Mechanistic implications

Ferroptosis, a recently identified type of non-apoptotic cell death, triggers the elimination of cells in the presence of lipid peroxidation and in an iron-dependent manner. Indeed, ferroptosis-stimulating factors have the ability of suppressing antioxidant capacity, leading to the accumulation of reactive oxygen species (ROS) and the subsequent oxidative death of the cells. Ferroptosis is involved in the pathophysiological basis of different maladies, such as multiple cancers, among which female-oriented malignancies have attracted much attention in recent years. In this context, it has also been unveiled that non-coding RNA transcripts, including microRNAs, long non-coding RNAs, and circular RNAs have regulatory interconnections with the ferroptotic flux, which controls the pathogenic development of diseases. Furthermore, the potential of employing these RNA transcripts as therapeutic targets during the onset of female-specific neoplasms to modulate ferroptosis has become a research hotspot; however, the molecular mechanisms and functional alterations of ferroptosis still require further investigation. The current review comprehensively highlights ferroptosis and its association with non-coding RNAs with a focus on how this crosstalk affects the pathogenesis of female-oriented malignancies, from breast cancer to ovarian, cervical, and endometrial neoplasms, suggesting novel therapeutic targets to decelerate and even block the expansion and development of these tumors.

Ferroptosis and the tumor microenvironment

Ferroptosis is a type of regulated cell death characterized by its non-apoptotic, iron-dependent and oxidative nature. Since its discovery in 2012, extensive research has demonstrated its pivotal roles in tumorigenesis, metastasis and cancer therapy. The tumor microenvironment (TME) is a complex ecosystem comprising cancer cells, non-cancer cells, extracellular matrix, metabolites and cytokines. Recent studies have underscored a new paradigm in which non-cancer cells in the TME, such as immune and stromal cells, also play significant roles in regulating tumor progression and therapeutic resistance typically through complicated crosstalk with cancer cells. Notably, this crosstalk in the TME were partially mediated through ferrotopsis-related mechanisms. This review provides a comprehensive and systematic summary of the current findings concerning the roles of ferroptosis in the TME and how ferroptosis-mediated TME reprogramming impacts cancer therapeutic resistance and progression. Additionally, this review outlines various ferroptosis-related therapeutic strategies aimed at targeting the TME.

Global Proteomics Indicates Subcellular-Specific Anti-Ferroptotic Responses to Ionizing Radiation

Cells have many protective mechanisms against background levels of ionizing radiation orchestrated by molecular changes in expression, post-translational modifications, and subcellular localization. Radiotherapeutic treatment in oncology attempts to overwhelm such mechanisms, but radioresistance is an ongoing challenge. Here, global subcellular proteomics combined with Bayesian modeling identified 544 differentially localized proteins in A549 cells upon 6 Gy X-ray exposure, revealing subcellular-specific changes of proteins involved in ferroptosis, an iron-dependent cell death, suggestive of potential radioresistance mechanisms. These observations were independent of expression changes, emphasizing the utility of global subcellular proteomics and the promising prospect of ferroptosis-inducing therapies for combating radioresistance.

Sialic Acid-Targeted Ru(II)/Ir(III)/Re(I) Complexes for Ferroptosis Induction in Triple-Negative Breast Cancer

Ferroptosis has been recognized as an iron-based nonapoptotic-regulated cell death process. In the quest of resisting the unyielding vehemence of triple-negative breast cancer (TNBC), herein we have showcased the ferroptosis-inducing heteroleptic [LIrcRu], [LIrcIrh], and [LIrcRe] complexes, enabling them to selectively target "sialic acid", an overexpressed cancer cell-surface marker. The open-circuit potential (OCP) measurements in live cancer cells revealed the specific interaction between TNBC and the complexes, whereas control experiments with normal cells did not exhibit such interactions. GSH depletion, GPx4 inhibition, NADH/NADPH oxidation, lipid peroxidation, COX-2 activation, and Nrf2 inactivation were meticulously investigated upon treatment with these complexes to establish a strong basis for ferroptosis. Among all complexes, the complex [LIrcIrh] (IC50 = 25 ± 2.17 μM) has been well-documented as a potent ferroptosis inducer, which unveils the sturdy interaction with sialic acid possessing the highest binding constant (Kb = 0.71 × 105 M-1, ΔG = -279345.8026 kcal/mol) along with the highest serum albumin binding affinity (KHSA = 0.67 × 106 M-1) and significant DNA intercalation (Kb = 0.56 × 105 M-1, Kapp = 1.06 × 106 M-1, and C50 of intercalation is 76.56 μM), displaying the decreased current intensity in differential pulse voltammetry (DPV). Moreover, the complex [LIrcIrh] exhibited mitochondrial dysfunction and membrane damage (diminished MMP, ΔΨm) through the production of copious reactive oxygen species (ROS) in MDA-MB-231 cells upon considerable accumulation in mitochondria (Pearson's coefficient = 0.842). The analysis of the field emission scanning electron microscopy (FE-SEM) image has marked the vivid membrane damage induced by the complex [LIrcIrh], exhibiting ablaze evidence for the destruction of TNBC cells through ferroptosis.

NEDD4L contributes to ferroptosis and cell growth inhibition in esophageal squamous cell carcinoma by facilitating xCT ubiquitination

The oncogene xCT plays an indispensable role in tumor growth by protecting cancer cells from oxidative stress and ferroptosis. Emerging evidence indicated xCT function is tightly controlled by posttranslational modifications, especially ubiquitination. However, it still remains unclear what specific regulatory mechanism of xCT by ubiquitin ligases in human cancers. Here, we reported that NEDD4L, an E3 ubiquitin ligases, inhibited esophageal squamous cell carcinoma (ESCC) tumor growth and facilitated ferroptosis by ubiquitination of xCT. NEDD4L expression was declined in ESCC and was associated with tumor invasion, lymph node metastasis and distant metastasis. Silencing NEDD4L triggered ESCC tumor growth. Meanwhile, knock down of NEDD4L prevented the accumulation of ROS, elevated the level of GSH, reduced the content of MDA in ESCC cells, thereby inhibiting ferroptosis. Mechanistically, NEDD4L directly bound to the ∆CT domain of xCT through its WW and HECT domain. More importantly, NEDD4L promoted xCT degradation by facilitating its polyubiquitination in ESCC cells. Collectively, these findings suggest that NEDD4L is crucial in governing the stability of xCT and mediating ferroptosis in ESCC.

Improving understanding of ferroptosis: Molecular mechanisms, connection with cellular senescence and implications for aging

In the face of cell damage, cells can initiate a response ranging from survival to death, the balance being crucial for tissue homeostasis and overall health. Cell death, in both accidental and regulated forms, plays a fundamental role in maintaining tissue homeostasis. Among the regulated mechanisms of cell death, ferroptosis has garnered attention for its iron-dependent phospholipid (PL) peroxidation and its implications in aging and age-related disorders, as well as for its therapeutic relevance. In this review, we provide an overview of the mechanisms, regulation, and physiological and pathological roles of ferroptosis. We present new insights into the relationship between ferroptosis, cellular senescence and aging, emphasizing how alterations in ferroptosis pathways contribute to aging-related tissue dysfunction. In addition, we examine the therapeutic potential of ferroptosis in aging-related diseases, offering innovative insights into future interventions aimed at mitigating the effects of aging and promoting longevity.

FXR deficiency induced ferroptosis via modulation of the CBP-dependent p53 acetylation to suppress breast cancer growth and metastasis

Farnesoid X receptor (NR1H4/FXR) functions as a scavenger of lipid peroxide products and drives the proliferation and metastasis of various cancers. However, the underlying molecular mechanisms remain poorly understood. In our study, we found that the expression levels of FXR, vimentin and SLC7A11 were significantly higher in breast cancer tissues, particularly in metastatic cancer tissues compared to non-metastatic ones. Furthermore, the increased FXR expression was positively correlated with vimentin and SLC7A11 in clinical tumor specimens. In addition, a high level of FXR correlated with poor prognosis in patients with breast cancer. Both Z-Guggulsterone (Z-GS), as a pharmacological inhibitor of FXR, and silencing FXR curbed proliferation and migration of breast cancer cells by promoting ferroptosis. Notably, our results showed that FXR competitively bound to CREB-binding protein (CBP) to suppress the interaction between p53 and CBP in the nucleus, and thus prevented p53 acetylation at lys382, which was essential for upregulating the expression of SLC7A11. Conversely, FXR knockdown increased the interaction between p53 and CBP and promoted p53 acetylation, which ultimately led to facilitating ferroptosis in breast cancer cells. More importantly, we also found that Z-GS inhibited TGF-β1-induced tumor growth and metastasis of breast cancer primarily through ferroptosis via regulating CBP-dependent p53 acetylation in nude mice. In conclusion, the FXR was first reported as a tumor promoter that enhanced the proliferation and metastasis of breast cancer cells through regulating CBP-dependent p53 K382 acetylation. It proposes that FXR may serve as a potential therapeutic target for the treatment of breast cancer.

Ferroptosis in Cancer: Epigenetic Control and Therapeutic Opportunities

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a critical pathway in cancer biology. This review delves into the epigenetic mechanisms that modulate ferroptosis in cancer cells, focusing on how DNA methylation, histone modifications, and non-coding RNAs influence the expression and function of essential genes involved in this process. By unraveling the complex interplay between these epigenetic mechanisms and ferroptosis, the article sheds light on novel gene targets and functional insights that could pave the way for innovative cancer treatments to enhance therapeutic efficacy and overcome resistance in cancer therapy.

Inhibition of VDAC1 oligomerization blocks cysteine deprivation-induced ferroptosis via mitochondrial ROS suppression

Ferroptosis, a regulated form of cell death dependent on reactive oxygen species (ROS), is characterized by iron accumulation and lethal lipid peroxidation. Mitochondria serve as the primary source of ROS and thus play a crucial role in ferroptosis initiation and execution. This study highlights the role of mitochondrial ROS and the significance of voltage-dependent anion channel 1 (VDAC1) oligomerization in ferroptosis induced by cysteine deprivation or ferroptosis-inducer RSL3. Our results demonstrate that the mitochondria-targeted antioxidants MitoQ and MitoT effectively block ferroptosis induction and that dysfunction of complex III of the mitochondrial electron transport chain contributes to ferroptosis induction. Pharmacological inhibitors that target VDAC1 oligomerization have emerged as potent suppressors of ferroptosis that reduce mitochondrial ROS production. These findings underscore the critical involvement of mitochondrial ROS production via complex III of the electron transport chain and the essential role of VDAC1 oligomerization in ferroptosis induced by cysteine deprivation or RSL3. This study deepens our understanding of the intricate molecular networks governing ferroptosis and provides insights into the development of novel therapeutic strategies targeting dysregulated cell death pathways.

Ferroptosis as a hero against oral cancer

Cancer is an abnormal condition altering the cells to proliferate out of control simultaneously being susceptible to evolution. The lining which is made up of tissues in the lips, upper throat and mouth can undergo mutations, is recognised as mouth cancer or oral cancer. Substantial number of mouth lesions are identified at a point where it is typically not possible to get effective remedial care. Ferroptosis is a cutting-edge instance of cellular destruction which stands out in distinction to other sorts of cell death. It appears to have distinctive cellular, molecular and gene-level attributes and scavenges on deposits of reactive oxygen species triggered via iron-induced lipid peroxidation. It is said to be involved dichotomously in cancer development. Because the ferroptotic tumour cells put out numerous chemicals that alternatively signal for cancer attenuation or growth. There is increasing proof that researchers are now keenly investigating to stimulate ferroptosis through various inducers and pathways in the intent for oral cancer therapeutics, specifically to kill malignant tumours that refuse to respond well to conventional treatments. Also, it has the ability to reverse chemotherapy and radiotherapy resistance in victims maximising the success rate of the treatments. This review centres on the stimulation of ferroptosis as a stand-alone therapy for oral cancer, or in combination with other medicines, agents and pathways.

Synthesis, anticancer activity and mechanism of action of Fe(III) complexes

To inhibit the growth and metastasis of triple-negative breast cancer (TNBC), two Fe(III) thiosemicarbazone complexes (Fe1 and Fe2) were designed and synthesized. The structures of the Fe(III) complexes were characterized by single crystal X-ray diffraction. The antiproliferative activity of Fe1 and Fe2 against four cancer lines (MDA-MB-231, T98G, HepG2, 143B) and human renal proximal tubular epithelial cell line (HK-2) was evaluated by MTT assay. Among all cells, Fe2 showed significant cytotoxicity to TNBC cells (MDA-MB-231), with an IC50 value of 12.38 μM. Furthermore, Fe2 showed less toxicity to HK-2 cells. The two Fe(III) complexes can produce excess of reactive oxygen species, decrease of mitochondrial membrane potential, and induce DNA damage, then lead to apoptosis of MDA-MB-231 cells. In addition, Fe1 and Fe2 can also inhibit migration and invasion of MDA-MB-231 cells. This study provides guidance for the development of metal complexes that inhibit the growth and metastasis of TNBC.

Paraptosis-A Distinct Pathway to Cell Death

Cell death is a critical biological process necessary for development, tissue maintenance, and defense against diseases. To date, more than 20 forms of cell death have been identified, each defined by unique molecular pathways. Understanding these different forms of cell death is essential for investigating the pathogenesis of diseases such as cancer, neurodegenerative disorders, and autoimmune conditions and developing appropriate therapies. Paraptosis is a distinct form of regulated cell death characterized by cytoplasmic vacuolation and dilatation of cellular organelles like the mitochondria and endoplasmic reticulum (ER). It is regulated by several signaling pathways, for instance, those associated with ER stress, calcium overload, oxidative stress, and specific cascades such as insulin-like growth factor I receptor (IGF-IR) and its downstream signaling pathways comprising mitogen-activated protein kinases (MAPKs) and Jun N-terminal kinase (JNK). Paraptosis has been observed in diverse biological contexts, including development and cellular stress responses in neuronal, retinal, endothelial, and muscle cells. The induction of paraptosis is increasingly important in anticancer therapy, as it targets non-apoptotic stress responses in tumor cells, which can be utilized to induce cell death. This approach enhances treatment efficacy and addresses drug resistance, particularly in cases where cancer cells are resistant to apoptosis. Combining paraptosis-inducing agents with traditional therapies holds promise for enhancing treatment efficacy and overcoming drug resistance, suggesting a valuable strategy in anticancer therapy.

Transforming cancer detection and treatment with nanoflowers

Nanoflowers, an innovative class of nanoparticles with a distinctive flower-like structure, have garnered significant interest for their straightforward synthesis, remarkable stability, and heightened efficiency. Nanoflowers demonstrate versatile applications, serving as highly sensitive biosensors for rapidly and accurately detecting conditions such as diabetes, Parkinson's, Alzheimer's, and foodborne infections. Nanoflowers, with their intricate structure, show significant potential for targeted drug delivery and site-specific action, while also exhibiting versatility in applications such as enzyme purification, water purification from dyes and heavy metals, and gas sensing through materials like nickel oxide. This review also addresses the structural characteristics, surface modification, and operational mechanisms of nanoflowers. The nanoflowers play a crucial role in preventing premature drug leakage from nanocarriers. Additionally, the nanoflowers contribute to averting systemic toxicity and suboptimal therapy efficiency caused by hypoxia in the tumor microenvironment during chemotherapy and photodynamic therapy. This review entails the role of nanoflowers in cancer diagnosis and treatment. In the imminent future, the nanoflowers system is poised to revolutionize as a smart material, leveraging its exceptional surface-to-volume ratio to significantly augment adsorption efficiency across its intricate petals. This review delves into the merits and drawbacks of nanoflowers, exploring synthesis techniques, types, and their evolving applications in cancer.

Vitamin C in the Management of Thyroid Cancer: A Highway to New Treatment?

Thyroid cancer (TC) is the most common endocrine malignancy, with an increased global incidence in recent decades, despite a substantially unchanged survival. While TC has an excellent overall prognosis, some types of TC are associated with worse patient outcomes, depending on the genetic setting. Furthermore, oxidative stress is related to more aggressive features of TC. Vitamin C, an essential nutrient provided with food or as a dietary supplement, is a well-known antioxidant and a scavenger of reactive oxygen species; however, at high doses, it can induce pro-oxidant effects, acting through multiple biological mechanisms that play a crucial role in killing cancer cells. Although experimental data and, less consistently, clinical studies, suggest the possibility of antineoplastic effects of vitamin C at pharmacological doses, the antitumor efficacy of this nutrient in TC remains at least partly unexplored. Therefore, this review discusses the current state of knowledge on the role of vitamin C, alone or in combination with other conventional therapies, in the management of TC, the mechanisms underlying this association, and the perspectives that may emerge in TC treatment strategies, and, also, in light of the development of novel functional foods useful to this extent, by implementing novel sensory analysis strategies.

Synergistic ferroptosis in triple-negative breast cancer cells: Paclitaxel in combination with Erastin induced oxidative stress and Ferroportin-1 modulation in MDA-MB-231 cells

Ferroptosis is an important regulated cell death mechanism characterized by iron-dependent lipid peroxidation and oxidative stress. In this study, we examined the ferroptosis-inducing effect of the combined use of Paclitaxel, a microtubule-stabilizing agent, and Erastin, a ferroptosis inducer, in breast cancer cells. In this context, the combination of the compounds in question was applied to the cells and the presence of a synergistic effect was determined by calculating the combination index. Glutathione (GSH) levels and glutathione peroxidase (GPX) activity were determined by commercial assay kits, and the effect of the compounds on lipid peroxidation was determined by measurement of malondialdehyde (MDA) levels. Additionally, the effect of combination treatment on ferroptotic protein expression was determined by western blot. Our findings revealed that the combination treatment caused a significant change in mitochondrial function by causing an increase in the depolarized/viable cell population. Additionally, there was a significant increase in intracellular reactive oxygen species (ROS) levels compared to single applications of the compounds. The significant increase observed in malondialdehyde (MDA) levels revealed that the combination treatment increased lipid peroxidation. Moreover, intracellular GSH levels and glutathione peroxidase (GPX) activity significantly decreased by Paclitaxel-Erastin combination. The expression of ferroptosis-regulating proteins was significantly downregulated. The findings showed that the Paclitaxel-Erastin combination synergistically contributed to the accumulation of lipid reactive oxygen species and induced the ferroptotic cell death pathway in breast cancer cells.

Targeting Ferroptosis as an Advance Strategy in Cancer Therapy

Significance: This study innovates by systematically integrating the molecular mechanisms of iron death and its application in cancer therapy. By deeply analyzing the interaction between iron death and the tumor microenvironment, the study provides a new theoretical basis for cancer treatment and directions for developing more effective treatment strategies. In addition, the study points to critical issues and barriers that need to be addressed in future research, providing valuable insights into the use of iron death in clinical translation. Recent Advances: These findings are expected to drive further advances in cancer treatment, bringing patients more treatment options and hope. Through this paper, we see the great potential of iron death in cancer treatment and look forward to more research results being translated into clinical applications in the future to contribute to the fight against cancer. Critical Issues: In today's society, cancer is still one of the major diseases threatening human health. Despite advances in existing treatments, cancer recurrence and drug resistance remain a severe problem. These problems increase the difficulty of treatment and bring a substantial physical and mental burden to patients. Therefore, finding new treatment strategies to overcome these challenges has become significant. Future Directions: The study delved into the molecular basis of iron death in tumor biology. It proposed a conceptual framework to account for the interaction of iron death with the tumor immune microenvironment, guide treatment selection, predict efficacy, explore combination therapies, and identify new therapeutic targets to overcome cancer resistance to standard treatments, peeving a path for future research and clinical translation of ferroptosis as a potential strategy in cancer therapy. Antioxid. Redox Signal. 41, 616-636. [Figure: see text].

Assessment of ferroptosis as a promising candidate for metastatic uveal melanoma treatment and prognostication

Uveal melanoma (UM) is the most common primary intraocular tumour in adults. Local resection, radiation therapy, and enucleation are the current first-line, primary UM treatments. However, regardless of the treatment received, around 50% of UM patients will develop metastatic disease within five to 7 years. In the largest published series of unselected patients with metastatic UM (mUM), the median survival time after diagnosis of metastasis was 3.6 months, with less than 1% of patients surviving beyond 5 years. Approved drugs for treatment of mUM include systemic treatment with tebentafusp-tebn or isolated hepatic perfusion (IHP) with melphalan. However, these drugs are only available to a subset of patients and improve survival by only a few months, highlighting the urgent need for new mUM treatments. Accurately predicting which patients are at high risk for metastases is also crucial. Researchers are developing gene expression signatures in primary UM to create reliable prognostic models aimed at improving patient follow-up and treatment strategies. In this review we discuss the evidence supporting ferroptosis, a non-apoptotic form of cell death, as a potential novel treatment target and prognosticator for UM.

Inorganic Nanomedicine-Mediated Ferroptosis: A Synergistic Approach to Combined Cancer Therapies and Immunotherapy

Ferroptosis, a form of regulated cell death characterized by iron-dependent lipid peroxidation, has generated substantial interest in cancer therapy. Various methods have been developed to induce ferroptosis in tumor cells, including approved drugs, experimental compounds, and nanomedicine formulations. Unlike apoptosis, ferroptosis presents unique molecular and cellular features, representing a promising approach for cancers resistant to conventional treatments. Recent research indicates a strong link between ferroptosis and the tumor immune microenvironment, suggesting the potential of ferroptosis to trigger robust antitumor immune responses. Multiple cellular metabolic pathways control ferroptosis, including iron, lipid, and redox metabolism. Thus, understanding the interaction between tumor metabolism and ferroptosis is crucial for developing effective anticancer therapies. This review provides an in-depth discussion on combining inorganic nanoparticles with cancer therapies such as phototherapy, chemotherapy, radiotherapy, and immunotherapy, and the role of ferroptosis in these combination treatments. Furthermore, this paper explores the future of tumor treatment using nanomedicine, focusing on how inorganic nanoparticles can enhance ferroptosis in tumor cells and boost antitumor immunity. The goal is to advance ferroptosis-based nanomedicine from the laboratory to clinical applications.

Circ_0005397 inhibits ferroptosis of pancreatic cancer cells by up-regulating PCBP2 through KAT6A/H3K9Ac

Pancreatic cancer is a highly aggressive and lethal carcinoma. Circular RNAs (circRNAs) serve key regulatory functions in pancreatic cancer. Ferroptosis was induced by erastin treatment and analyzed by examining malondialdehyde (MDA), iron, Fe2+ and glutathione (GSH). C11-BODIPY 581/591 was used to stain cells for analyzing lipid peroxidation. RNA immunoprecipitation, pull-down and chromatin immunoprecipitation assays were applied to evaluate intermolecular interaction. Mice received subcutaneous injection of pancreatic cancer cells as a model of subcutaneous tumor for in vivo tests. Circ_0005397 was abundantly expressed in pancreatic cancer, and its upregulation was associated with low survival of patients with pancreatic cancer. Circ_0005397 expression was induced by EIF4A3. PCBP2 was highly expressed in pancreatic cancer, and circ_0005397 and PCBP2 were positively correlated in patients with pancreatic cancer. Circ_0005397 knockdown sensitized pancreatic carcinoma cells to ferroptosis via downregulating PCBP2. Circ_0005397 promoted PCBP2 transcription via facilitating the binding of KAT6A and H3K9ac to PCBP2 promoter. Silencing of circ_0005397 reduced tumor growth by enhancing erastin-induced ferroptosis in vivo. EIF4A3-induced circ_0005397 inhibited erastin-induced ferroptosis in pancreatic cancer by promoting PCBP2 expression through KAT6A and H3K9ac.

Genistein and daidzein induce ferroptosis in MDA-MB-231 cells

OBJECTIVES

In recent years, there has been a growing interest in targeting ferroptosis for the treatment and prevention of multiple cancers. This study aimed to assess the contribution of ferroptosis to the antiproliferative effects of genistein (GN) and daidzein (DZ) in breast cancer cell lines.

METHODS

MDA-MB-231 and MCF-7 cells were employed as an in vitro model. The antiproliferative effects of GN and DZ were determined by WST-1 assay in the presence of specific inhibitors of different cell death pathways. The mRNA expressions of Gpx4 and Fsp-1, the levels of lipid peroxidation, glutathione (GSH)/glutathione disulfide (GSSG) ratio, and intracellular iron ion content were assessed in GN- or DZ-treated cells.

RESULTS

GN and DZ were found to cause ferroptotic cell death in MDA-MB-231, as confirmed by the reversal of viability when cells were pretreated with ferrostatin-1. Furthermore, both phytochemicals induced biochemical markers of ferroptosis, including lipid peroxidation and iron ions levels, and decreased GSH/GSSG levels. The mRNA expression levels of the main anti-ferroptotic genes, Gpx4 and Fsp-1, were diminished by the treatment of both phytochemicals. Surprisingly, ferroptosis did not play a role in GN- or DZ-induced cell death in MCF-7 cells.

CONCLUSION

Our findings highlight the potential of GN and DZ as ferroptosis inducers in triple-negative breast cancer cells.

Exploring the anti-cancer potential of SGLT2 inhibitors in breast cancer treatment in pre-clinical and clinical studies

The link between type 2 diabetes mellitus (T2DM) and an increased risk of breast cancer (BC) has prompted the exploration of novel therapeutic strategies targeting shared metabolic pathways. This review focuses on the emerging evidence surrounding the potential anti-cancer effects of sodium-glucose cotransporter-2 (SGLT2) inhibitors in the context of BC. Preclinical studies have demonstrated that various SGLT2 inhibitors, such as canagliflozin, dapagliflozin, ipragliflozin, and empagliflozin, can inhibit the proliferation of BC cells, induce apoptosis, and modulate key cellular signaling pathways. These mechanisms include the activation of AMP-activated protein kinase (AMPK), suppression of mammalian target of rapamycin (mTOR) signaling, and regulation of lipid metabolism and inflammatory mediators. The combination of SGLT2 inhibitors with conventional treatments, including chemotherapy and radiotherapy, as well as targeted therapies like phosphoinositide 3-kinases (PI3K) inhibitors, has shown promising results in enhancing the anti-cancer efficacy and potentially reducing treatment-related toxicities. The identification of specific biomarkers or genetic signatures that predict responsiveness to SGLT2 inhibitor therapy could enable more personalized treatment selection and optimization, particularly for challenging BC subtypes [e, g., triple negative BC (TNBC)]. Ongoing and future clinical trials investigating the use of SGLT2 inhibitors, both as monotherapy and in combination with other agents, will be crucial in elucidating their translational potential and guiding their integration into comprehensive BC care. Overall, SGLT2 inhibitors represent a novel and promising therapeutic approach with the potential to improve clinical outcomes for patients with various subtypes of BC, including the aggressive and chemo-resistant TNBC.

A novel AIE-based mitochondria-targeting fluorescent probe for monitoring of the fluctuation of endogenous hypochlorous acid in ferroptosis models

Ferroptosis is a way of cell death mainly due to the imbalance between the production and degradation of lipid reactive oxygen species, which is closely associated with various diseases. Endogenous hypochlorous acid (HOCl) mainly produced in mitochondria is regarded as an important signal molecule of ferroptosis. Therefore, monitoring the fluctuation of endogenous HOCl is beneficial to better understand and treat ferroptosis-related diseases. Inspired by the promising aggregation-induced emission (AIE) properties of tetraphenylethene (TPE), herein, we rationally constructed a novel AIE-based fluorescent probe, namely QTrPEP, for HOCl with nice mitochondria-targeting ability and high sensitivity and selectivity. Probe QTrPEP consisted of phenylborate ester and the AIE fluorophore of quinoline-conjugated triphenylethylene (QTrPE). HOCl can brighten the strong fluorescence through a specific HOCl-triggered cleavage of the phenylborate ester bond and release of QTrPE, which has been demonstrated by MS, HPLC, and DLS experiments. In addition, combining QTrPE-doped test strips with a smartphone-based measurement demonstrated the excellent performance of the probe to sense HOCl. The obtained favorable optical properties and negligible cytotoxicity allowed the use of this probe for tracking of HOCl in three different cells. In particular, this work represents the first AIE-based mitochondria-targeting fluorescent probe for monitoring the fluctuation of HOCl in ferroptosis.

Iron(III)-salophene catalyzes redox cycles that induce phospholipid peroxidation and deplete cancer cells of ferroptosis-protecting cofactors

Ferroptosis, a lipid peroxidation-driven cell death program kept in check by glutathione peroxidase 4 and endogenous redox cycles, promises access to novel strategies for treating therapy-resistant cancers. Chlorido [N,N'-disalicylidene-1,2-phenylenediamine]iron (III) complexes (SCs) have potent anti-cancer properties by inducing ferroptosis, apoptosis, or necroptosis through still poorly understood molecular mechanisms. Here, we show that SCs preferentially induce ferroptosis over other cell death programs in triple-negative breast cancer cells (LC50 ≥ 0.07 μM) and are particularly effective against cell lines with acquired invasiveness, chemo- or radioresistance. Redox lipidomics reveals that initiation of cell death is associated with extensive (hydroper)oxidation of arachidonic acid and adrenic acid in membrane phospholipids, specifically phosphatidylethanolamines and phosphatidylinositols, with SCs outperforming established ferroptosis inducers. Mechanistically, SCs effectively catalyze one-electron transfer reactions, likely via a redox cycle involving the reduction of Fe(III) to Fe(II) species and reversible formation of oxo-bridged dimeric complexes, as supported by cyclic voltammetry. As a result, SCs can use hydrogen peroxide to generate organic radicals but not hydroxyl radicals and oxidize membrane phospholipids and (membrane-)protective factors such as NADPH, which is depleted from cells. We conclude that SCs catalyze specific redox reactions that drive membrane peroxidation while interfering with the ability of cells, including therapy-resistant cancer cells, to detoxify phospholipid hydroperoxides.

Iron and cancer: overview of the evidence from population-based studies

Iron is an essential nutrient required for various physiological processes in the body. However, iron imbalance can potentially contribute to initiating and promoting cancer development. Epidemiological studies have investigated the relationship between dietary iron intake and the risk of different types of cancer, yet, not all studies have consistently shown a significant association between dietary iron and cancer risk. Also, studies have shown different effects of dietary heme and non-heme iron intake on cancer risk. While some epidemiological studies suggest a possible link between high dietary iron (mainly heme-iron) intake and increased cancer risk, the evidence remains inconsistent. Moreover, multiple iron biomarkers, which can mirror physiological iron status, have demonstrated varied correlations with the risk of cancer, contingent upon the specific biomarker analyzed and the type of cancer being investigated. Here, we have investigated the current evidence on the potential relationship between dietary iron intake on one hand, and iron biomarkers on the other hand, with the risk of developing different types of cancer, including breast, prostate, lung, pancreatic, colon, colorectal, and liver cancers. Further research is warranted to better understand the complex relationship between dietary iron, physiological iron and cancer development. Future research should account for factors that affect and interact with dietary iron and physiological iron levels, such as genetic susceptibility, overall diet quality, and lifestyle habits.

Immunometabolism of ferroptosis in the tumor microenvironment

Ferroptosis is an iron-dependent form of cell death that results from excess lipid peroxidation in cellular membranes. Within the last decade, physiological and pathological roles for ferroptosis have been uncovered in autoimmune diseases, inflammatory conditions, infection, and cancer biology. Excitingly, cancer cell metabolism may be targeted to induce death by ferroptosis in cancers that are resistant to other forms of cell death. Ferroptosis sensitivity is regulated by oxidative stress, lipid metabolism, and iron metabolism, which are all influenced by the tumor microenvironment (TME). Whereas some cancer cell types have been shown to adapt to these stressors, it is not clear how immune cells regulate their sensitivities to ferroptosis. In this review, we discuss the mechanisms of ferroptosis sensitivity in different immune cell subsets, how ferroptosis influences which immune cells infiltrate the TME, and how these interactions can determine epithelial-to-mesenchymal transition (EMT) and metastasis. While much focus has been placed on inducing ferroptosis in cancer cells, these are important considerations for how ferroptosis-modulating strategies impact anti-tumor immunity. From this perspective, we also discuss some promising immunotherapies in the field of ferroptosis and the challenges associated with targeting ferroptosis in specific immune cell populations.

External RF-EMF alters cell number and ROS balance possibly via the regulation of NADPH metabolism and apoptosis

The influence of weak radio-frequency electromagnetic field (RF-EMF) on living organisms raises new concern because of the Industrial, Scientific, and Medical (ISM) frequency band at 6.78 MHz being promoted by the AirFuel Alliance for mid-range wireless power transfer (WPT) applications and product development. Human exposure to the RF-EMF radiation is unavoidable. In this study, we employed in vitro cell culture and molecular biology approach coupled with integrated transcriptomic and proteomic analyses to uncover the effects of RF-EMF on cells at molecular and cellular levels. Our study has demonstrated that weak RF-EMF is sufficient to exert non-thermal effects on human umbilical vein endothelial cells (HUVEC). Exposure of weak RF-EMF promotes cell proliferation, inhibits apoptosis and deregulates ROS balance. Alteration of several signaling pathways and key enzymes involved in NADPH metabolism, cell proliferation and ferroptosis were identified. Our current study provide solid evidence for the first time that the present safety standards that solely considered the thermal effect of RF-EMF on cell tissue are inadequate, prompt response and modification of existing Guidelines, Standards and Regulation are warranted.

Abnormal Histopathological Expression of Klotho, Ferroptosis, and Circadian Clock Regulators in Pancreatic Ductal Adenocarcinoma: Prognostic Implications and Correlation Analyses

Pancreatic ductal adenocarcinoma (PDAC) is an extremely lethal tumor with increasing incidence, presenting numerous clinical challenges. The histopathological examination of novel, unexplored biomarkers offers a promising avenue for research, with significant translational potential for improving patient outcomes. In this study, we evaluated the prognostic significance of ferroptosis markers (TFRC, ALOX-5, ACSL-4, and GPX-4), circadian clock regulators (CLOCK, BMAL1, PER1, PER2), and KLOTHO in a retrospective cohort of 41 patients deceased by PDAC. Immunohistochemical techniques (IHC) and multiple statistical analyses (Kaplan-Meier curves, correlograms, and multinomial linear regression models) were performed. Our findings reveal that ferroptosis markers are directly associated with PDAC mortality, while circadian regulators and KLOTHO are inversely associated. Notably, TFRC emerged as the strongest risk marker associated with mortality (HR = 35.905), whereas CLOCK was identified as the most significant protective marker (HR = 0.01832). Correlation analyses indicate that ferroptosis markers are positively correlated with each other, as are circadian regulators, which also positively correlate with KLOTHO expression. In contrast, KLOTHO and circadian regulators exhibit inverse correlations with ferroptosis markers. Among the clinical variables examined, only the presence of chronic pathologies showed an association with the expression patterns of several proteins studied. These findings underscore the complexity of PDAC pathogenesis and highlight the need for further research into the specific molecular mechanisms driving disease progression.

Inhibition of FSP1: A new strategy for the treatment of tumors (Review)

Ferroptosis, a regulated form of cell death, is intricately linked to iron‑dependent lipid peroxidation. Recent evidence strongly supports the induction of ferroptosis as a promising strategy for treating cancers resistant to conventional therapies. A key player in ferroptosis regulation is ferroptosis suppressor protein 1 (FSP1), which promotes cancer cell resistance by promoting the production of the antioxidant form of coenzyme Q10. Of note, FSP1 confers resistance to ferroptosis independently of the glutathione (GSH) and glutathione peroxidase‑4 pathway. Therefore, targeting FSP1 to weaken its inhibition of ferroptosis may be a viable strategy for treating refractory cancer. This review aims to clarify the molecular mechanisms underlying ferroptosis, the specific pathway by which FSP1 suppresses ferroptosis and the effect of FSP1 inhibitors on cancer cells.

GOLPH3 inhibits erastin-induced ferroptosis in colorectal cancer cells

Ferroptosis is a novel form of programmed cell death and is considered to be a druggable target for colorectal cancer (CRC) therapy. However, the role of ferroptosis in CRC and its underlying mechanism are not fully understood. In the present study we found that a protein enriched in the Golgi apparatus, Golgi phosphoprotein 3 (GOLPH3), was overexpressed in human CRC tissue and in several CRC cell lines. The expression of GOLPH3 was significantly correlated with the expression of ferroptosis-related genes in CRC. The overexpression of GOLPH3 in Erastin-induced Caco-2 CRC cells reduced ferroptotic phenotypes, whereas the knockdown of GOLPH3 potentiated ferroptosis in HT-29 CRC cells. GOLPH3 induced the expression of prohibitin-1 (PHB1) and prohibitin-2 (PHB2), which also inhibited ferroptosis in Erastin-treated CRC cells. Moreover, GOLPH3 interacted with PHB2 and nuclear factor erythroid 2-related factor 2 (NRF2) in Caco-2 cells. These observations indicate that GOLPH3 is a negative regulator of ferroptosis in CRC cells. GOLPH3 protects these cells from ferroptosis by inducing the expression of PHB1 and PHB2, and by interacting with PHB2 and NRF2.

SNHG1: Redefining the Landscape of Hepatocellular Carcinoma through Long Noncoding RNAs

Hepatocellular carcinoma (HCC) represents a global health concern, ranking as the sixth most common malignancy worldwide and the third leading cause of cancer-related mortality. Despite advances in research, the diagnosis and prognosis of such malignancy remain challenging. Alpha-fetoprotein, the current serum biomarker used in the management of HCC, has limited sensitivity and specificity, making early detection and effective management more difficult. Thus, new management approaches in diagnosis and prognosis are needed to improve the outcome and survival of HCC patients. SNHG1 is a long noncoding RNA mainly expressed in the cell and cytoplasm of cells and is consistently upregulated in tissues and cell lines of HCC, where it acts as an important regulator of various processes: modulation of p53 activity, sponging of microRNAs with consequent upregulation of their target mRNAs, regulation of fatty acid, iron and glucose metabolism, and interaction with immune cells. The deregulation of these processes results in abnormal cell division, angiogenesis, and apoptosis, thus promoting various aspects of tumorigenesis, including proliferation, invasion, and migration of cells. Clinically, a higher expression of SNHG1 predicts poorer clinical outcomes by significantly correlating with bigger, less differentiated, and more aggressive tumors, more advanced disease stages, and lower overall survival in HCC patients. This article comprehensively summarizes the current understanding of the multifaceted roles of SNHG1 in the pathogenesis of HCC, while also highlighting its clinicopathological correlations, therefore concluding that it has potential as a biomarker in HCC diagnosis and prognosis.

Tumoral Malignancy Decreases Coupled with Higher ROS and Lipid Peroxidation in HCT116 Colon Cancer Cells upon Loss of PRDX6

Peroxiredoxin 6 (PRDX6) is an atypical member of the peroxiredoxin family that presents not only peroxidase but also phospholipase A2 and lysophosphatidylcholine acyl transferase activities able to act on lipid hydroperoxides of cell membranes. It has been associated with the proliferation and invasive capacity of different tumoral cells including colorectal cancer cells, although the effect of its removal in these cells has not been yet studied. Here, using CRISPR/Cas9 technology, we constructed an HCT116 colorectal cancer cell line knockout for PRDX6 to study whether the mechanisms described for other cancer cells in terms of proliferation, migration, and invasiveness also apply in this tumoral cell line. HCT116 cells lacking PRDX6 showed increased ROS and lipid peroxidation, a decrease in the antioxidant response regulator NRF2, mitochondrial dysfunction, and increased sensitivity to ferroptosis. All these alterations lead to a decrease in proliferation, migration, and invasiveness in these cells. Furthermore, the reduced migratory and invasive capacity of HCT116 cancer cells is consistent with the observed cadherin switch and decrease in pro-invasive proteins such as MMPs. Therefore, the mechanism behind the effects of loss of PRDX6 in HCT116 cells could differ from that in HepG2 cells which is coherent with the fact that the correlation of PRDX6 expression with patient survival is different in hepatocellular carcinomas. Nonetheless, our results point to this protein as a good therapeutic target also for colorectal cancer.

Targeting ferroptosis in ovarian cancer: Novel strategies to overcome chemotherapy resistance

AIMS

This review investigates the role of ferroptosis in combating chemotherapy resistance in ovarian cancer, with a focus on its underlying mechanisms and therapeutic implications.

MAIN METHODS

A database search was conducted up to December 2023 using PubMed, Scopus, Google Scholar, Web of Science, and the Cochrane Library. The keywords "ovarian cancer," "ferroptosis," "cisplatin," and "cisplatin resistance" were employed. We included studies that offered original data on the application of ferroptosis in platinum-based chemotherapy, focusing on both in-vitro and in-vivo research models.

KEY FINDINGS

Our review reveals that ferroptosis significantly influences drug resistance in ovarian cancer. It investigates the existing studies to understand the role of ferroptosis in platinum resistance and explores its underlying mechanisms and assesses potential therapeutic strategies that uses ferroptosis to improve outcomes. The findings underscore the importance of ferroptosis in enhancing the effectiveness of platinum-based treatments and improving patient prognosis.

SIGNIFICANCE

The potential of ferroptosis induction to develop novel therapeutic strategies against ovarian cancer, especially in cisplatin-resistant cases, is promising. The preliminary nature of these findings highlights the necessity for further research to bring these insights into clinical practice. This would not only improve treatment outcomes and prognosis but also encourage ongoing studies into ferroptosis as a viable therapeutic approach.

Iron Regulates Cellular Proliferation by Enhancing the Expression of Glucose Transporter GLUT3 in the Liver

Iron is often accumulated in the liver during pathological conditions such as cirrhosis and cancer. Elevated expression of glucose transporters GLUT1 and GLUT3 is associated with reduced overall survival in patients with hepatocellular carcinoma. However, it is not known whether iron can regulate glucose transporters and contribute to tumor proliferation. In the present study, we found that treatment of human liver cell line HepG2 with ferric ammonium citrate (FAC) resulted in a significant upregulation of GLUT3 mRNA and protein in a dose-dependent manner. Similarly, iron accumulation in mice fed with high dietary iron as well as in mice injected intraperitoneally with iron dextran enhanced the GLUT3 expression drastically in the liver. We demonstrated that iron-induced hepatic GLUT3 upregulation is mediated by the LKB1/AMPK/CREB1 pathway, and this activation was reversed when treated with iron chelator deferiprone. In addition, inhibition of GLUT3 using siRNA prevented iron-mediated increase in the expression of cell cycle markers and cellular hyperproliferation. Furthermore, exogenous sodium beta-hydroxybutyrate treatment prevented iron-mediated hepatic GLUT3 activation both in vitro and in vivo. Together, these results underscore the importance of iron, AMPK, CREB1 and GLUT3 pathways in cell proliferation and highlight the therapeutic potential of sodium beta-hydroxybutyrate in hepatocellular carcinoma with high GLUT3 expression.