Iron Load Toxicity in Medicine: From Molecular and Cellular Aspects to Clinical Implications

The interplay between the myeloperoxidase-hypochlorous acid system, heme oxygenase, and free iron in inflammatory diseases

Accumulated unbound free iron (Fe(II or III)) is a redox engine generating reactive oxygen species (ROS) that promote oxidative stress and inflammation. Iron is implicated in diseases with free radical pathology including cardiovascular, neurodegenerative, reproductive disorders, and some types of cancer. While many studies focus on iron overload disorders, few explore the potential link between the myeloperoxidase-hypochlorous acid (MPO-HOCl) system and localized iron accumulation through heme and iron‑sulfur (FeS) cluster protein destruction. Although inducible heme oxygenase (HO-1), the rate-limiting enzyme in heme catabolism, is frequently associated with these diseases, we hypothesize that HOCl also contributes to the generation of free iron and heme degradation products. Furthermore, HO-1 and HOCl may play a dual role in free iron accumulation by regulating the activity of key iron metabolism proteins. Enzymatic and non-enzymatic modulators, as well as scavengers of HOCl, can help prevent heme destruction and reduce the accumulation of free iron. Given iron's role in disease progression and severity, identifying the primary sources, mechanisms, and mediators involved in free iron generation is crucial for developing effective pharmacological treatments. Further investigation focusing on the specific contributions of the MPO-HOCl system and free iron is necessary to explore novel strategies to mitigate its harmful effects in biological systems.

Artesunate induces ferroptosis in osteosarcoma through NCOA4-mediated ferritinophagy

Osteosarcoma (OS) is a prevalent primary malignant bone tumor that lacks effective therapeutic interventions. Artesunate (ART) has been proved to have remarkable treatment effects on severe malaria and anti-tumor properties. This study aimed to investigate the anti-OS effects and underlying mechanisms of ART. The potential mechanisms of ART-mediated anti-OS activity were analyzed by using RNA sequencing, iron accumulation, lipid peroxidation, western blotting, and small interfering RNA (siRNA) transfection. In vivo, a xenograft mice model was adopted to explore the anticancer effect of ART. The present study revealed that ART significantly suppressed OS cell proliferation. Subsequent results suggested that ART exerted anti-OS activity mainly through the ferroptosis pathway. ART decreased the GSH/GSSG ratio, xCT and GPX4 expression, while increasing MDA and lipid peroxidation, which were reversed by Fer-1, DFO, 3-MA, and NCOA4 silencing. Mechanistically, ART upregulated the expression of TFR and DMT1, and triggered ferritinophagy by upregulating the expression of NCOA4, which increased Fe2+ accumulation and triggered ferroptosis. In addition, cytoplasmic iron further activated Mfrn2-mediated transportation of cytoplasmic free iron into the mitochondria, resulting in mitochondrial iron overload, eventually leading to lipid peroxidation and ferroptosis. Furthermore, in an OS xenograft mouse model, administration of ART inhibited tumor growth by ferroptosis. Collectively, our findings indicated that ART has the potential anti-OS capacity through NCOA4-mediated ferritinophagy, which might shed light on the future of OS therapy.

Convolutional neural networks for automatic MR classification of myocardial iron overload in thalassemia major patients

OBJECTIVES

To develop a deep-learning model for supervised classification of myocardial iron overload (MIO) from magnitude T2* multi-echo MR images.

MATERIALS AND METHODS

Eight hundred twenty-three cardiac magnitude T2* multi-slice, multi-echo MR images from 496 thalassemia major patients (285 females, 57%), labeled for MIO level (normal: T2* > 20 ms, moderate: 10 ≤ T2* ≤ 20 ms, severe: T2* < 10 ms), were retrospectively studied. Two 2D convolutional neural networks (CNN) developed for multi-slice (MS-HippoNet) and single-slice (SS-HippoNet) analysis were trained using 5-fold cross-validation. Performance was assessed using micro-average, multi-class accuracy, and single-class accuracy, sensitivity, and specificity. CNN performance was compared with inter-observer agreement between radiologists on 20% of the patients. The agreement between patients' classifications was assessed by the inter-agreement Kappa test.

RESULTS

Among the 165 images in the test set, a multi-class accuracy of 0.885 and 0.836 was obtained for MS- and SS-Hippo-Net, respectively. Network performances were confirmed on external test set analysis (0.827 and 0.793 multi-class accuracy, 29 patients from the CHMMOTv1 database). The agreement between automatic and ground truth classification was good (MS: κ = 0.771; SS: κ = 0.614), comparable with the inter-observer agreement (MS: κ = 0.872, SS: κ = 0.907) evaluated on the test set.

CONCLUSION

The developed networks performed classification of MIO level from multiecho, bright-blood, and T2* images with good performances.

KEY POINTS

Question MRI T2* represents the established clinical tool for MIO assessment. Quality control of the image analysis is a problem in small centers. Findings Deep learning models can perform MIO staging with good accuracy, comparable to inter-observer variability of the standard procedure. Clinical relevance CNN can perform automated staging of cardiac iron overload from multiecho MR sequences facilitating non-invasive evaluation of patients with various hematologic disorders.

Hepatic Iron Overload and Hepatocellular Carcinoma: New Insights into Pathophysiological Mechanisms and Therapeutic Approaches

Hepatocellular carcinoma (HCC), the most common form of primary liver cancer, is rising in global incidence and mortality. Metabolic dysfunction-associated steatotic liver disease (MASLD), one of the leading causes of chronic liver disease, is strongly linked to metabolic conditions that can progress to liver cirrhosis and HCC. Iron overload (IO), whether inherited or acquired, results in abnormal iron hepatic deposition, significantly impacting MASLD development and progression to HCC. While the pathophysiological connections between hepatic IO, MASLD, and HCC are not fully understood, dysregulation of glucose and lipid metabolism and IO-induced oxidative stress are being investigated as the primary drivers. Genomic analyses of inherited IO conditions reveal inconsistencies in the association of certain mutations with liver malignancies. Moreover, hepatic IO is also associated with hepcidin dysregulation and activation of ferroptosis, representing promising targets for HCC risk assessment and therapeutic intervention. Understanding the relationship between hepatic IO, MASLD, and HCC is essential for advancing clinical strategies against liver disease progression, particularly with recent IO-targeted therapies showing potential at improving liver biochemistry and insulin sensitivity. In this review, we summarize the current evidence on the pathophysiological association between hepatic IO and the progression of MASLD to HCC, underscoring the importance of early diagnosis, risk stratification, and targeted treatment for these interconnected conditions.

New Insights into Aspirin's Anticancer Activity: The Predominant Role of Its Iron-Chelating Antioxidant Metabolites

Epidemiological studies have suggested that following long-term, low-dose daily aspirin (LTLDA) administration for more than 5 years at 75-100 mg/day, 20-30% of patients (50-80 years old) had a lower risk of developing colorectal cancer (CRC) and about the same proportion in developing iron deficiency anemia (IDA). In cases of IDA, an increase in iron excretion is suspected, which is caused by aspirin chelating metabolites (ACMs): salicylic acid, salicyluric acid, 2,5-dihydroxybenzoic acid, and 2,3-dihydroxybenzoic acid. The ACMs constitute 70% of the administered aspirin dose and have much longer half-lives than aspirin in blood and tissues. The mechanisms of cancer risk reduction in LTLDA users is likely due to the ACM's targeting of iron involved in free radical damage, iron-containing toxins, iron proteins, and associated metabolic pathways such as ferroptosis. The ACMs from non-absorbed aspirin (about 30%) may also mitigate the toxicity of heme and nitroso-heme and other iron toxins from food, which are responsible for the cause of colorectal cancer. The mode of action of aspirin as a chelating antioxidant pro-drug of the ACMs, with continuous presence in LTLDA users, increases the prospect for prophylaxis in cancer and other diseases. It is suggested that the anticancer effects of aspirin depend primarily on the iron-chelating antioxidant activity of the ACMs. The role of aspirin in cancer and other diseases is incomplete without considering its rapid biotransformation and the longer half-life of the ACMs.

Testosterone and Erythrocyte Lifespan

CONTEXT

Endogenous and exogenous androgens increase circulating erythrocytes and hemoglobin but their effects on erythrocyte lifespan is not known.

OBJECTIVE

To investigate androgen effects on immature and mature erythrocyte lifespan in humans and mice using novel nonradioactive minimally invasive methods.

DESIGN

Human erythrocyte lifespan was estimated using alveolar carbon monoxide concentration and blood hemoglobin in Levitt's formula in hypogonadal or transgender men before and up to 18 weeks after commencing testosterone (T) treatment. Erythrocyte lifespan was estimated in androgen receptor knockout and wild-type mice after T or DHT treatment of intact females or orchidectomized males using in vivo biotin labelling of erythrocyte surface epitopes for reticulocytes (Ter119+CD71+) and 2 markers of erythrocytes (CD45-, Ter119+CD71-) monitoring their blood disappearance rate by flow cytometry.

RESULTS

Before treatment, hypogonadal and transgender men had marked reduction in erythrocyte lifespan compared with controls. T treatment increased erythrocyte lifespan at 6 weeks but returned to pretreatment levels at 18 weeks, whereas serum T and blood hemoglobin were increased by T treatment remaining elevated at 18 weeks. In mice, T and DHT treatment had higher erythrocyte (but not reticulocyte) lifespan but neither orchidectomy nor androgen receptor inactivation significantly influenced erythrocyte or reticulocyte lifespan.

CONCLUSION

We conclude that hypogonadal men have reduced erythrocyte lifespan and acute androgen-induced increase in circulating erythrocyte lifespan may contribute to the well-known erythropoietic effects of androgens, but longer term effects require further investigation to determine how much they contribute to androgen-induced increases in circulating hemoglobin.

Shikonin suppresses proliferation of osteosarcoma cells by inducing ferroptosis through promoting Nrf2 ubiquitination and inhibiting the xCT/GPX4 regulatory axis

Osteosarcoma (OS) is a prevalent primary malignant bone tumor which lacks effective therapeutic interventions. Ferroptosis is a new form of programmed cell death characterized by iron-dependent accumulation of lethal lipid oxidation, which provides a potential alternative intervene for the OS treatment. Shikonin is the major bioactive component extracted from the roots of lithospermum erythrorhizon which is also known as "Zicao" in traditional Chinese medicine, has been proved to have exhibits remarkable anti-tumor properties in several cancers. However, whether ferroptosis participated in the shikonin mediated anti-OS activity still remains to be clarified. Herein, we provide evidence that shikonin possesses the capability to induce the ferroptosis, and elucidate the underlying mechanisms in the treatment of OS. In the present study, it was found that shikonin significantly suppressed OS cells proliferation and blocked the cell cycle progression in vitro. Subsequent results revealed that shikonin could trigger ferroptosis in OS cells by promoting the Fe2+ accumulation, reactive oxygen species and lipid peroxidation formation, malondialdehyde production and mitochondrial damage. Further study showed that the effects of OS cell proliferation and death caused by shikonin could be successfully reversed by ferroptosis inhibitor ferrostatin-1, indicating that ferroptosis participated in the shikonin mediated anti-OS activity. Mechanistically, shikonin physically interacted with Nrf2, a critical regulator of ferroptosis, and influenced Nrf2 stability via inducing ubiquitin degradation, which suppressed the expression of Nrf2 downstream targets xCT and GPX4, and led to stimulating ferroptosis. Collectively, our findings indicated that shikonin induced OS cells ferroptosis through Nrf2/xCT/GPX4 regulatory axis, which might shed light on exploiting shikonin as a promising candidate for the future OS therapy.

Targeting nucleus pulposus cell death in the treatment of intervertebral disc degeneration

Background

Intervertebral disc degeneration (IDD) is a progressive age-related disorder characterized by the reduction in the number of nucleus pulposus cells (NPCs) and degradation of extracellular matrix (ECM), thereby leading to chronic pain and disability. The pathogenesis of IDD is multifaceted, and current therapeutic strategies remain limited. The nucleus pulposus (NP), primarily composed of NPCs, proteoglycans, and type II collagen, constitutes essential components for maintaining intervertebral disc (IVD) function and spinal motion. The disturbed homeostasis of NPCs is closely associated with IDD. Accumulating evidence increasingly suggests the crucial role of programmed cell death (PCD) in regulating the homeostasis of NPCs.

Aims

This review aimed to elucidate various forms of PCD and their respective roles in IDD, and investigate diverse strategies targeting the cell death of NPCs for IDD treatment.

Materials & Methods

We collected the relevant literature regarding PCD and their roles in the development of IDD. Subsequently, we comprehensively summarized the intricate association between PCD and IDD, and also explored the potential and application of cell therapy and traditional Chinese medicine (TCM) in the prevention and treatment of IDD.

Results

Current literature indicated that the PCD of NPCs was closely associated with the pathogenesis of IDD. Additionally, the development of targeted pharmaceuticals based on the mechanisms of PCD could effectively impede the loss of NPCs.

Conclusion

This review demonstrated that targeting the PCD of NPCs may be a promising strategy for the treatment of IDD.

An encounter between metal ions and natural products: natural products-coordinated metal ions for the diagnosis and treatment of tumors

Natural products-coordinated metal ions to form the nanomedicines are in the spotlight for cancer therapy. Some natural products could be coordinated with metal ions forming nanomedicines via simple and green environmental self-assembly, which not only improved the bioavailability of natural products, but also conferred multiple therapeutic modalities and multimodal imaging. On the one hand, in the weak acidity, glutathione (GSH) and hydrogen peroxide (H2O2) overexpression of tumor microenvironment (TME), such carrier-free nanomedicines could be further enhanced the therapeutic effect via optimizing the species of metal ions. On the other hand, nanomedicines could exert the precise treatment of tumor under the guidance of multiple imaging. Hence, this review summarized the research progress in recent years on the application of natural product-coordinated metal ions in cancer therapy. In addition, the prospects and challenges for the application of natural product-coordinated metal ions were discussed, especially how to improve targeting ability and stability and assess the safety of metal ions, so as to facilitate the clinical translation and application of natural product-coordinated metal ions nanomedicines.

Cardiovascular Effects of Splenomegaly and Splenectomy in Beta-Thalassemia Major

Background Beta-thalassemia major is a genetic blood disease complicated by splenomegaly, and splenectomy is a standard therapy for this medical condition. Although splenectomy results not only in the improvement of the hematological status, the long-term consequences to the cardiovascular system are still questionable. Objective The aim of the study was to assess and compare the cardiovascular impact of splenomegaly and splenectomy in patients with beta-thalassemia major. Methodology This is a cross-sectional survey conducted at Hayatabad Medical Complex, Peshawar, from January 2024 to June 2024. A total of 88 beta-thalassemia major patients were divided into two groups: 44 patients with splenomegaly were recruited and compared with 44 post-splenectomy patients. Outcomes that were assessed in this study from the medical records were cardiac function test, ejection fraction, left ventricular hypertrophy, thromboembolic incidences, pulmonary embolism, deep vein thrombosis, blood pressure level, and the biochemical markers, B-type natriuretic peptide (BNP) and troponin. The data were analyzed using the Statistical Package for the Social Sciences (SPSS) version 26 (IBM Corp., Armonk, USA). Results Patients with splenectomy exhibited slightly lower hemoglobin levels and higher transfusion requirements but had better ejection fractions compared to those with splenomegaly. In contrast, the splenomegaly group demonstrated worse cardiovascular outcomes, including higher rates of left ventricular hypertrophy, pulmonary hypertension, arrhythmias, thromboembolic events, and elevated BNP levels, indicating increased cardiovascular morbidity and hemodynamic strain. Logistic regression analysis further suggested that splenectomy reduces the risk of cardiomyopathy, particularly in younger patients, while the splenomegaly group experiences a greater burden of acute cardiovascular complications. Conclusion Splenectomy in beta-thalassemia major patients offers improved cardiac function and hemoglobin levels while reducing transfusion needs, but it does not eliminate the risks of long-term cardiovascular and thromboembolic complications, such as deep vein thrombosis and pulmonary embolism. On the other hand, patients with splenomegaly face more severe and immediate cardiovascular risks, including hypertension, arrhythmias, and thromboembolic events. These findings underscore the importance of tailored management strategies to optimize outcomes for both groups.

Comprehensive review of perioperative factors influencing ferroptosis

The perioperative period encompasses all phases of patient care from the decision to perform surgery until full recovery. Ferroptosis, a newly identified type of regulated cell death, influences a wide array of diseases, including those affecting the prognosis and regression of surgical patients, such as ischemia-reperfusion injury and perioperative cognitive dysfunction. This review systematically examines perioperative factors impacting ferroptosis such as surgical trauma-induced stress, tissue hypoxia, anesthetics, hypothermia, and blood transfusion. By analyzing their intrinsic relationships, we aim to improve intraoperative management, enhance perioperative safety, prevent complications, and support high-quality postoperative recovery, ultimately improving patient outcomes.

l-cysteine capped MoS2 QDs for dual-channel imaging and superior Fe3+ ion sensing in biological systems

MoS2 quantum dots (MQDs) with an average size of 1.9 ± 0.7 nm were synthesized using a microwave-assisted method. Absorbance studies confirmed characteristic transitions of MoS2, with absorption humps at 260-280 nm and 300-330 nm, and a band gap of 3.6 ± 0.1 eV. Fluorescence emission studies showed dominant blue and some green emissions under 315 nm excitation, with an absolute quantum yield of ∼9%. The MQDs exhibited fluorescence stability over time after repeated quenching cycles across various pH and media systems. In vitro toxicity tests indicated cytocompatibility, with around 80% cell survival at 1000 mg L-1. Confocal imaging demonstrated significant uptake and vibrant fluorescence in cancerous and non-cancerous cell lines. The MQDs showed strong selectivity towards Fe3+ ions, with a detection limit of 27.61 ± 0.25 nM. Recovery rates for Fe3+ in phosphate buffer saline (PBS) and simulated body fluid (SBF) systems were >97% and >98%, respectively, with a relative standard deviation (RSD) within 3%, indicating precision. These findings suggest that MQDs have high potential for diagnostic applications involving Fe3+ detection due to their fluorescence stability, robustness, enhanced cell viability, and dual-channel imaging properties.

Ferroptosis and cuproptosis: Metal-dependent cell death pathways activated in response to classical chemotherapy - Significance for cancer treatment?

Apoptosis has traditionally been regarded as the desired cell death pathway activated by chemotherapeutic drugs due to its controlled and non-inflammatory nature. However, recent discoveries of alternative cell death pathways have paved the way for immune-stimulatory treatment approaches in cancer. Ferroptosis (dependent on iron) and cuproptosis (dependent on copper) hold promise for selective cancer cell targeting and overcoming drug resistance. Copper ionophores and iron-bearing nano-drugs show potential for clinical therapy as single agents and as adjuvant treatments. Here we review up-to-date evidence for the involvement of metal ion-dependent cell death pathways in the cytotoxicity of classical chemotherapeutic agents (alkylating agents, topoisomerase inhibitors, antimetabolites, and mitotic spindle inhibitors) and their combinations with cuproptosis and ferroptosis inducers, indicating the prospects, advantages, and obstacles of their use.

Ferroptosis as an emerging target in sickle cell disease

Sickle cell disease (SCD) is an inherited hemoglobin disorder marked by red blood cell sickling, resulting in severe anemia, painful episodes, extensive organ damage, and shortened life expectancy. In SCD, increased iron levels can trigger ferroptosis, a specific type of cell death characterized by reactive oxygen species (ROS) and lipid peroxide accumulation, leading to damage and organ impairments. The intricate interplay between iron, ferroptosis, inflammation, and oxidative stress in SCD underscores the necessity of thoroughly understanding these processes for the development of innovative therapeutic strategies. This review highlights the importance of balancing the complex interactions among various factors and exploitation of the knowledge in developing novel therapeutics for this devastating disease.

The Importance and Essentiality of Natural and Synthetic Chelators in Medicine: Increased Prospects for the Effective Treatment of Iron Overload and Iron Deficiency

The supply and control of iron is essential for all cells and vital for many physiological processes. All functions and activities of iron are expressed in conjunction with iron-binding molecules. For example, natural chelators such as transferrin and chelator-iron complexes such as haem play major roles in iron metabolism and human physiology. Similarly, the mainstay treatments of the most common diseases of iron metabolism, namely iron deficiency anaemia and iron overload, involve many iron-chelator complexes and the iron-chelating drugs deferiprone (L1), deferoxamine (DF) and deferasirox. Endogenous chelators such as citric acid and glutathione and exogenous chelators such as ascorbic acid also play important roles in iron metabolism and iron homeostasis. Recent advances in the treatment of iron deficiency anaemia with effective iron complexes such as the ferric iron tri-maltol complex (feraccru or accrufer) and the effective treatment of transfusional iron overload using L1 and L1/DF combinations have decreased associated mortality and morbidity and also improved the quality of life of millions of patients. Many other chelating drugs such as ciclopirox, dexrazoxane and EDTA are used daily by millions of patients in other diseases. Similarly, many other drugs or their metabolites with iron-chelation capacity such as hydroxyurea, tetracyclines, anthracyclines and aspirin, as well as dietary molecules such as gallic acid, caffeic acid, quercetin, ellagic acid, maltol and many other phytochelators, are known to interact with iron and affect iron metabolism and related diseases. Different interactions are also observed in the presence of essential, xenobiotic, diagnostic and theranostic metal ions competing with iron. Clinical trials using L1 in Parkinson's, Alzheimer's and other neurodegenerative diseases, as well as HIV and other infections, cancer, diabetic nephropathy and anaemia of inflammation, highlight the importance of chelation therapy in many other clinical conditions. The proposed use of iron chelators for modulating ferroptosis signifies a new era in the design of new therapeutic chelation strategies in many other diseases. The introduction of artificial intelligence guidance for optimal chelation therapeutic outcomes in personalised medicine is expected to increase further the impact of chelation in medicine, as well as the survival and quality of life of millions of patients with iron metabolic disorders and also other diseases.

Silver nanoparticles induce iron accumulation-associated cognitive impairment via modulating neuronal ferroptosis

Silver nanoparticles (AgNPs) are widely used in daily life and medical fields owing to their unique physicochemical properties. Daily exposure to AgNPs has become a great concern regarding their potential toxicity to human beings, especially to the central nervous system. Ferroptosis, a newly recognized programmed cell death, was recently reported to be associated with the neurodegenerative process. However, whether and how ferroptosis contributes to AgNPs-induced neurotoxicity remain unclear. In this study, we investigated the role of ferroptosis in neurotoxic effects induced by AgNPs using in vitro and in vivo models. Our results showed that AgNPs induced a notable dose-dependent cytotoxic effect on HT-22 cells and cognitive impairment in mice as indicated by a decline in learning and memory and brain tissue injuries. These findings were accompanied by iron overload caused by the disruption of the iron transport system and activation of NCOA4-mediated autophagic degradation of ferritin. The excessive free iron subsequently induced GSH depletion, loss of GPX and SOD activities, differential expression of Nrf2 signaling pathway elements, down-regulation of GPX4 protein and production of lipid peroxides, initiating ferroptosis cascades. The mitigating effects of ferrostatin-1 and deferoxamine on iron overload, redox imbalance, neuronal cell death, impairment of mice learning and memory, Aβ deposition and synaptic plasticity reduction suggested ferroptosis as a potential molecular mechanism in AgNPs-induced neurotoxicity. Taken together, these results demonstrated that AgNPs induced neuronal cell death and cognitive impairment with Aβ deposition and reduction of synaptic plasticity, which were mediated by ferroptosis caused by iron-mediated lipid peroxidation. Our study provides new insights into the underlying mechanisms of AgNPs-induced neurotoxicity and predicts potential preventive strategies.

Iron toxicity, ferroptosis and microbiota in Parkinson's disease: Implications for novel targets

Parkinson's Disease (PD) is a progressive neurodegenerative disease characterized by loss of dopaminergic neurons in substantia nigra pars compacta (SNpc). Iron (Fe)-dependent programmed cell death known as ferroptosis, plays a crucial role in the etiology and progression of PD. Since SNpc is particularly vulnerable to Fe toxicity, a central role for ferroptosis in the etiology and progression of PD is envisioned. Ferroptosis, characterized by reactive oxygen species (ROS)-dependent accumulation of lipid peroxides, is tightly regulated by a variety of intracellular metabolic processes. Moreover, the recently characterized bi-directional interactions between ferroptosis and the gut microbiota, not only provides another window into the mechanistic underpinnings of PD but could also suggest novel interventions in this devastating disease. Here, following a brief discussion of PD, we focus on how our expanding knowledge of Fe-induced ferroptosis and its interaction with the gut microbiota may contribute to the pathophysiology of PD and how this knowledge may be exploited to provide novel interventions in PD.

Interplay of Ferroptosis and Cuproptosis in Cancer: Dissecting Metal-Driven Mechanisms for Therapeutic Potentials

Iron (Fe) and copper (Cu), essential transition metals, play pivotal roles in various cellular processes critical to cancer biology, including cell proliferation, mitochondrial respiration, distant metastases, and oxidative stress. The emergence of ferroptosis and cuproptosis as distinct forms of non-apoptotic cell death has heightened their significance, particularly in connection with these metal ions. While initially studied separately, recent evidence underscores the interdependence of ferroptosis and cuproptosis. Studies reveal a link between mitochondrial copper accumulation and ferroptosis induction. This interconnected relationship presents a promising strategy, especially for addressing refractory cancers marked by drug tolerance. Harnessing the toxicity of iron and copper in clinical settings becomes crucial. Simultaneous targeting of ferroptosis and cuproptosis, exemplified by the combination of sorafenib and elesclomol-Cu, represents an intriguing approach. Strategies targeting mitochondria further enhance the precision of these approaches, providing hope for improving treatment outcomes of drug-resistant cancers. Moreover, the combination of iron chelators and copper-lowering agents with established therapeutic modalities exhibits a synergy that holds promise for the augmentation of anti-tumor efficacy in various malignancies. This review elaborates on the complex interplay between ferroptosis and cuproptosis, including their underlying mechanisms, and explores their potential as druggable targets in both cancer research and clinical settings.

Drug Selection and Posology, Optimal Therapies and Risk/Benefit Assessment in Medicine: The Paradigm of Iron-Chelating Drugs

The design of clinical protocols and the selection of drugs with appropriate posology are critical parameters for therapeutic outcomes. Optimal therapeutic protocols could ideally be designed in all diseases including for millions of patients affected by excess iron deposition (EID) toxicity based on personalised medicine parameters, as well as many variations and limitations. EID is an adverse prognostic factor for all diseases and especially for millions of chronically red-blood-cell-transfused patients. Differences in iron chelation therapy posology cause disappointing results in neurodegenerative diseases at low doses, but lifesaving outcomes in thalassemia major (TM) when using higher doses. In particular, the transformation of TM from a fatal to a chronic disease has been achieved using effective doses of oral deferiprone (L1), which improved compliance and cleared excess toxic iron from the heart associated with increased mortality in TM. Furthermore, effective L1 and L1/deferoxamine combination posology resulted in the complete elimination of EID and the maintenance of normal iron store levels in TM. The selection of effective chelation protocols has been monitored by MRI T2* diagnosis for EID levels in different organs. Millions of other iron-loaded patients with sickle cell anemia, myelodysplasia and haemopoietic stem cell transplantation, or non-iron-loaded categories with EID in different organs could also benefit from such chelation therapy advances. Drawbacks of chelation therapy include drug toxicity in some patients and also the wide use of suboptimal chelation protocols, resulting in ineffective therapies. Drug metabolic effects, and interactions with other metals, drugs and dietary molecules also affected iron chelation therapy. Drug selection and the identification of effective or optimal dose protocols are essential for positive therapeutic outcomes in the use of chelating drugs in TM and other iron-loaded and non-iron-loaded conditions, as well as general iron toxicity.