Ferroptosis, radiotherapy, and combination therapeutic strategies

LncRNA HOTAIRM1 promotes radioresistance in nasopharyngeal carcinoma by modulating FTO acetylation-dependent alternative splicing of CD44

BACKGROUND

Radiotherapy is the primary treatment for patients with nasopharyngeal carcinoma (NPC); however, almost 20% of patients experience treatment failure due to radioresistance. Therefore, understanding the mechanisms of radioresistance is imperative. HOTAIRM1 is deregulated in various human cancers, yet its role in NPC radioresistance are largely unclear.

METHODS

This study investigated the association between HOTAIRM1 and radioresistance using CCK8, flow cytometry, and comet assays. Additionally, xenograft mice and patient-derived xenografts (PDX) models were employed to elucidate the biological functions of HOTAIRM1, and transcriptomic RNA sequencing was utilized to identify its target genes.

RESULTS

Our study revealed an upregulation of HOTAIRM1 levels in radioresistant NPC cell lines and tissues. Furthermore, a positive correlation was noted between high HOTAIRM1 expression and increased NPC cell proliferation, reduced apoptosis, G2/M cell cycle arrest, and diminished cellular DNA damage following radiotherapy. HOTAIRM1 modulates the acetylation and stability of the FTO protein, and inhibiting FTO elevates the m6A methylation level of CD44 precursor transcripts in NPC cells. Additionally, silencing the m6A reading protein YTHDC1 was found to increase the expression of CD44V. HOTAIRM1 enhances NPC cell resistance to ferroptosis and irradiation through the HOTAIRM1-FTO-YTHDC1-CD44 axis. Mechanistically, HOTAIRM1 interacts with the FTO protein and induces m6A demethylation of the CD44 transcript. The absence of m6A modification in the CD44 transcript prevents its recognition by YTHDC1, resulting in the transition from CD44S to CD44V. An abundance of CD44V suppresses ferroptosis induced by irradiation and contributes to NPC radioresistance.

CONCLUSIONS

In conclusion, the results in this study support the idea that HOTAIRM1 stimulates CD44 alternative splicing via FTO-mediated demethylation, thereby attenuating ferroptosis induced by irradiation and promoting NPC radioresistance.

Ferroptosis: A novel therapeutic target of natural products against doxorubicin-induced cardiotoxicity

Doxorubicin (DOX), a commonly used chemotherapy drug, is hindered due to its tendency to induce cardiotoxicity (DIC). Ferroptosis, a novel mode of programmed cell death, has received substantial attention for its involvement in DIC. Recently, natural product-derived ferroptosis regulator emerged as a potential strategy for treating DIC. In this review, a comprehensive search was conducted across PubMed, Web of Science, Google Scholar, and ScienceDirect databases to gather relevant articles on the use of natural products for treating DIC in relation to ferroptosis. The available papers were carefully reviewed to summarize the therapeutic effects and underlying mechanisms of natural products in modulating ferroptosis for DIC treatment. It was found that ferroptosis plays an important role in DIC pathogenesis, with dysregulated expression of ferroptosis-related proteins strongly implicated in the condition. Natural products, such as flavonoids, polyphenols, terpenoids, and quinones can act as GPX4 activators, Nrf2 agonists, and lipid peroxidation inhibitors, thereby enhancing cell viability, attenuating myocardial fibrosis, improving cardiac function, and suppressing ferroptosis in both in vitro and in vivo models of DIC. This review demonstrates a strong correlation between DOX-induced cardiac ferroptosis and key proteins, such as GPX4, Keap1, Nrf2, AMPK, and HMOX1. Natural products are likely to exert therapeutic effects against DIC by modulating the activity of these proteins.

Lamivudine protects mice from gastric ulcer by activating PGK1 to suppress ferroptosis

Gastric ulcer is a highly prevalent digestive tract disease across the world, which is recurrent and hard to cure, sometimes transforming into gastric cancer if left untreated, posing great threat to human health. To develop new medicines for gastric ulcer, we ran a series of screens with ethanol stress model in GES-1 cells, and we uncovered that lamivudine rescued cells from ethanol toxicity. Then, we confirmed this discovery using the well-established ethanol-induced gastric ulcer model in mice and our findings suggest that lamivudine can directly activate phosphoglycerate kinase 1 (PGK1, EC 2.7.2.3), which binds and stimulates superoxide dismutase 1 (SOD1, EC 1.15.1.1) to inhibit ferroptosis and ultimately improve gastric ulcer. Moreover, AAV-PGK1 exhibited comparable gastroprotective effects to lamivudine. The findings are expected to offer novel therapeutic strategies for gastric ulcer, encompassing both lamivudine and AAV-PGK1.

Targeting Nrf2/PHKG2 axis to enhance radiosensitivity in NSCLC

While ferroptosis shows promise in anti-cancer strategy, the molecular mechanisms behind this process remain poorly understood. Our research aims to highlight the regulation of radiotherapy-induced ferroptosis in non-small cell lung cancer (NSCLC) via the NRF2/PHKG2 axis-mediated mechanism. To identify ferroptosis-associated genes associated with radioresistance in NSCLC, this study employed high-throughput transcriptome sequencing and Lasso risk regression analysis. Clinical samples were analyzed to confirm PHKG2 expression changes before and after radiotherapy. The study further examined ferritinophagy-related factors, intracellular iron levels, mitochondrial function, and ferroptosis in NSCLC cells undergoing radiation exposure to explore the effect of PHKG2 on radiosensitivity or radioresistance. The research also demonstrated the transcriptional inhibition of PHKG2 by NRF2 and created in situ transplantation tumor models of NSCLC to examine the role of NRF2/PHKG2 axis in NSCLC radiosensitivity and resistance in vivo. The Lasso risk regression model that incorporated ferroptosis-associated genes effectively predicted the prognosis of patients with NSCLC. Radiotherapy-sensitive tissues exhibited an increased expression of PHKG2. Overexpression of PHKG2 led to elevated intracellular iron levels by promoting ferritinophagy and increased mitochondrial stress-dependent ferroptosis induced by radiotherapy. PHKG2 transcription repression was achieved through NRF2. The FAGs-Lasso risk regression model can accurately predict the prognosis of NSCLC patients. Targeting Nrf2 upregulates the expression of PHKG2 and reverses radiotherapy resistance in NSCLC by promoting iron autophagy and inducing mitochondrial dysfunction, thereby increasing radiotherapy sensitivity.

GA receptor targeted chitosan oligosaccharide polymer nanoparticles improve non-alcoholic fatty liver disease by inhibiting ferroptosis

Excessive iron in the liver may exacerbate Non-alcoholic fatty liver disease (NAFLD) by increasing the risk of liver cell expansion, inflammation and fibrosis. Ferroptosis in liver cells may lead the progression of simple fatty liver degeneration to steatohepatitis (NASH). More and more studies shew that ferroptosis played a crucial role in the pathological process of NAFLD. Based on the mechanism of ferroptosis, this study first synthesized a liver targeted 18-β-Glycyrrhetinic-acid-chitosan oligosaccharide -N-acetylcysteine polymer (GCNp), and further curcumin (Cur) was used as model drug to prepare Cur loaded nanodelivery system (GCNp-Cur NPs). The particle size of GCNp-Cur NPs was 132.5 ± 9.8 nm, PDI was 0.148 ± 0.026 and the potential was 23.8 mV. GCNp-Cur NPs can regulate the GPX4/GSH pathway, inhibit lipid peroxidation, restore cellular oxidative environment, reduce free Fe2+, improve cellular lipid metabolism and iron metabolism, thereby NPs inhibited liver cell ferroptosis through multiple pathways. Additionally, GCNp-Cur NPs could also alleviate liver tissue lipid accumulation and oxidative damage, delaying disease progression, and providing a new method and theoretical basis for the treatment of NAFLD.

Research progress on GPX4 targeted compounds

Blocking the System Xc-_ GSH_GPX4 pathway to induce ferroptosis in tumor cells is a novel strategy for cancer treatment. GPX4 serves as the core of the System Xc-/GSH/GPX4 pathway and is a predominant target for inducing ferroptosis in tumor cells. This article summarizes compounds identified in current research that directly target the GPX4 protein, including inhibitors, activators, small molecule degraders, chimeric degraders, and the application of combination therapies with other drugs, aiming to promote further research on the target and related diseases.

The evolving process of ferroptosis in thyroid cancer: Novel mechanisms and opportunities

Thyroid cancer (TC) is a prevalent endocrine malignancy, with a significant increase in incidence worldwide. Ferroptosis is a novel form of programmed cell death, primarily caused by iron overload and reactive oxygen species (ROS)-dependent accumulation of lipid peroxides. The main manifestations of cellular ferroptosis are rupture of the outer membrane, crumpling of the mitochondria and shrinkage or disappearance of the mitochondrial cristae, thus leading to cell death. Ferroptosis is an important phenomenon in tumour progression, with crosstalk with tumour-associated signalling pathways profoundly affecting tumour progression, immune effects and treatment outcomes. The functions and mechanisms of ferroptosis in TC have also attracted increasing attention, mainly in terms of influencing tumour proliferation, invasion, migration, immune response, therapeutic susceptibility and genetic susceptibility. However, at present, the tumour biology of the morphological, biological and mechanism pathways of ferroptosis is much less deep in TC than in other malignancies. Hence, in this review, we highlighted the emerging role of ferroptosis in TC progression, including the novel mechanisms and potential opportunities for diagnosis and treatment, as well as discussed the limitations and prospects. Ferroptosis-based diagnostic and therapeutic strategies can potentially provide complementary management of TCs.

Targeting the regulation of iron homeostasis as a potential therapeutic strategy for nonalcoholic fatty liver disease

With aging and the increasing incidence of obesity, nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. NAFLD mainly includes simple hepatic steatosis, nonalcoholic steatohepatitis (NASH), liver fibrosis and hepatocellular carcinoma (HCC). An imbalance in hepatic iron homeostasis is usually associated with the progression of NAFLD and induces iron overload, reactive oxygen species (ROS) production, and lipid peroxide accumulation, which leads to ferroptosis. Ferroptosis is a unique type of programmed cell death (PCD) that is characterized by iron dependence, ROS production and lipid peroxidation. The ferroptosis inhibition systems involved in NAFLD include the solute carrier family 7 member 11 (SLC7A11)/glutathione (GSH)/glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1)/coenzyme Q10 (CoQ10)/nicotinamide adenine dinucleotide phosphate (NADPH) regulatory axes. The main promotion system involved is the acyl-CoA synthetase long-chain family (ACSL4)/arachidonic lipoxygenase 15 (ALOX15) axis. In recent years, an increasing number of studies have focused on the multiple roles of iron homeostasis imbalance and ferroptosis in the progression of NAFLD. This review highlights the latest studies about iron homeostasis imbalance- and ferroptosis-associated NAFLD, mainly including the physiology and pathophysiology of hepatic iron metabolism, hepatic iron homeostasis imbalance during the development of NAFLD, and key regulatory molecules and roles of hepatic ferroptosis in NAFLD. This review aims to provide innovative therapeutic strategies for NAFLD.

FSP1-mediated ferroptosis in cancer: from mechanisms to therapeutic applications

Ferroptosis is a new discovered regulated cell death triggered by the ferrous ion (Fe2+)-dependent accumulation of lipid peroxides associated with cancer and many other diseases. The mechanism of ferroptosis includes oxidation systems (such as enzymatic oxidation and free radical oxidation) and antioxidant systems (such as GSH/GPX4, CoQ10/FSP1, BH4/GCH1 and VKORC1L1/VK). Among them, ferroptosis suppressor protein 1 (FSP1), as a crucial regulatory factor in the antioxidant system, has shown a crucial role in ferroptosis. FSP1 has been well validated to ferroptosis in three ways, and a variety of intracellular factors and drug molecules can alleviate ferroptosis via FSP1, which has been demonstrated to alter the sensitivity and effectiveness of cancer therapies, including chemotherapy, radiotherapy, targeted therapy and immunotherapy. This review aims to provide important frameworks that, bring the regulation of FSP1 mediated ferroptosis into cancer therapies on the basis of existing studies.

Ferroptosis in thyroid cancer: Potential mechanisms, effective therapeutic targets and predictive biomarker

Thyroid cancer is a prevalent endocrine malignancy whose global incidence has risen over the past several decades. Ferroptosis, a regulated form of cell death distinguished by the excessive buildup of iron-dependent lipid peroxidates, stands out from other programmed cell death pathways in terms of morphological and molecular characteristics. Increasing evidence suggests a close association between thyroid cancer and ferroptosis, that is, inducing ferroptosis effectively suppresses the proliferation of thyroid cancer cells and impede tumor advancement. Therefore, ferroptosis represents a promising therapeutic target for the clinical management of thyroid cancer in clinical settings. Alterations in ferroptosis-related genes hold potential for prognostic prediction in thyroid cancer. This review summarizes current studies on the role of ferroptosis in thyroid cancer, elucidating its mechanisms, therapeutic targets, and predictive biomarkers. The findings underscore the significance of ferroptosis in thyroid cancer and offer valuable insights into the development of innovative treatment strategies and accurate predictors for the thyroid cancer.

Lycium Barbarum Polysaccharide-Derived Nanoparticles Protect Visual Function by Inhibiting RGC Ferroptosis and Microglial Activation in Retinal Ischemia‒Reperfusion Mice

Retinal ischemia‒reperfusion (IR) is a major contributor to vision impairment and irreversible vision loss due to retinal ganglion cell (RGC) injury or loss. Contemporary therapeutic approaches predominantly focus on the amelioration of symptoms rather than addressing the fundamental etiological factors. Oxidative stress is a notable feature and an important mediator of IR damage. Lycium barbarum polysaccharide (LBP), the main active ingredient of Lycium barbarum, has various pharmacological effects, including antioxidation, immunoregulation, and neuroprotective effects. In this study, the ROS-consumable moiety phenylboronic acid pinacol ester (PBA) is introduced to LBP molecules, which can self-assemble into nanoparticles in aqueous solution. This nanoparticle (termed PLBP) can reduce the cellular ROS levels and enhance the antioxidant capability of RGCs by activating the NRF2 pathway, thus protecting RGCs from ferroptosis and preserving visual function in response to IR injury. PLBP also reduces neuroinflammation by inhibiting the ability of microglia to phagocytose, migrate, secrete inflammatory cytokines, and activate the NF-κB pathway. In conclusion, this approach can be used as an inspiration for the future development of neuroprotective drugs.

Role of ferroptosis in radiation-induced soft tissue injury

Ionizing radiation has been pivotal in cancer therapy since its discovery. Despite its therapeutic benefits, IR causes significant acute and chronic complications due to DNA damage and the generation of reactive oxygen species, which harm nucleic acids, lipids, and proteins. While cancer cells are more vulnerable to ionizing radiation due to their inefficiency in repairing damage, healthy cells in the irradiated area also suffer. Various types of cell death occur, including apoptosis, necrosis, pyroptosis, autophagy-dependent cell death, immunogenic cell death, and ferroptosis. Ferroptosis, driven by iron-dependent lipid peroxide accumulation, has been recognized as crucial in radiation therapy's therapeutic effects and complications, with extensive research across various tissues. This review aims to summarize the pathways involved in radiation-related ferroptosis, findings in different organs, and drugs targeting ferroptosis to mitigate its harmful effects.

Diselenide-Containing Polymer Based on New Antitumor Mechanism as Efficient GSH Depletion Agent for Ferroptosis Therapy

Glutathione (GSH) depletion-induced ferroptosis has emerged as a promising treatment for malignant cancer. It works by inactivating glutathione peroxidase 4 (GPX4) and facilitating lipid peroxidation. However, effectively delivering inducers and depleting intracellular GSH remains challenging due to the short half-lives and high hydrophobicity of small-molecule ferroptosis inducers. These inducers often require additional carriers. Herein, diselenide-containing polymers can consume GSH to induce ferroptosis for pancreatic cancer therapy. The diselenide bonds are controllably built into the backbone of the polycarbonate with a targeting peptide CRGD (Cys-Arg-Gly-Asp), which allows for self-assembly into stable nanoparticles (denoted CRNSe) for self-delivery. Significantly, at a concentration of 12 µg mL-1, CRNSe binds to the active site cysteine of GSH resulting in a thorough depletion of GSH. In contrast, the disulfide-containing analog only causes a slight decrease in GSH level. Moreover, the depletion of GSH inactivates GPX4, ultimately inducing ferroptosis due to the accumulation of lipid peroxide in BxPC-3 cells. Both in vitro and in vivo studies have demonstrated that CRNSe exhibits potent tumor suppressive ability with few side effects on normal tissue. This study validates the anti-tumor mechanism of diselenide-containing polymers in addition to apoptosis and also provides a new strategy for inherently inducing ferroptosis in cancer therapy.

Berberine synergises with ferroptosis inducer sensitizing NSCLC to ferroptosis in p53-dependent SLC7A11-GPX4 pathway

Berberine (BBR) is a compound derived from Chinese herbal medicine, known for its anticancer properties through multiple signaling pathways. However, whether BBR can inhibit tumor growth by participating in ferroptosis remains unconfirmed. In this study, we demonstrated that berberine synergistically inhibited NSCLC in combination with multiple ferroptosis inducers, and this combination synergistically down-regulated the mRNA and protein expression of SLC7A11, GPX4, and NRF2, resulting in ferroptosis accompanied by significant depletion of GSH, and aberrant accumulation of reactive oxygen species and malondialdehyde. In a lung cancer allograft model, the combination treatment exhibited enhanced anticancer effects compared to using either drug alone. Notably, p53 is critical in determining the ferroptosis sensitivity. We found that the combination treatment did not elicit a synergistic anticancer effect in cells with a p53 mutation or with exogenous expression of mutant p53. These findings provide insight into the mechanism by which combination induces ferroptosis and the regulatory role of p53 in this process. It may guide the development of new strategies for treating NSCLC, offering great medical potential for personal diagnosis and treatment.

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 in Cancer Therapy: Mechanisms, Small Molecule Inducers, and Novel Approaches

Ferroptosis, a unique form of programmed cell death, is initiated by an excess of iron accumulation and lipid peroxidation-induced damage. There is a growing body of evidence indicating that ferroptosis plays a critical role in the advancement of tumors. The increased metabolic activity and higher iron levels in tumor cells make them particularly vulnerable to ferroptosis. As a result, the targeted induction of ferroptosis is becoming an increasingly promising approach for cancer treatment. This review offers an overview of the regulatory mechanisms of ferroptosis, delves into the mechanism of action of traditional small molecule ferroptosis inducers and their effects on various tumors. In addition, the latest progress in inducing ferroptosis using new means such as proteolysis-targeting chimeras (PROTACs), photodynamic therapy (PDT), sonodynamic therapy (SDT) and nanomaterials is summarized. Finally, this review discusses the challenges and opportunities in the development of ferroptosis-inducing agents, focusing on discovering new targets, improving selectivity, and reducing toxic and side effects.

Ferroptosis as a promising targeted therapy for triple negative breast cancer

PURPOSE

Triple negative breast cancer (TNBC) is a challenging subtype characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression. Standard treatment options are limited, and approximately 45% of patients develop distant metastasis. Ferroptosis, a regulated form of cell death triggered by iron-dependent lipid peroxidation and oxidative stress, has emerged as a potential targeted therapy for TNBC.

METHODS

This study utilizes a multifaceted approach to investigate the induction of ferroptosis as a therapeutic strategy for TNBC. It explores metabolic alterations, redox imbalance, and oncogenic signaling pathways to understand their roles in inducing ferroptosis, characterized by lipid peroxidation, reactive oxygen species (ROS) generation, and altered cellular morphology. Critical pathways such as Xc-/GSH/GPX4, ACSL4/LPCAT3, and nuclear factor erythroid 2-related factor 2 (NRF2) are examined for their regulatory roles in ferroptosis and their potential dysregulation contributing to cancer cell survival and resistance.

RESULTS

Inducing ferroptosis has been shown to inhibit tumor growth, enhance the efficacy of conventional therapies, and overcome drug resistance in TNBC. Lipophilic antioxidants, GPX4 inhibitors, and inhibitors of the Xc- system have been demonstrated to be potential ferroptosis inducers. Additionally, targeting the NRF2 pathway and exploring other ferroptosis regulators, such as ferroptosis suppressor protein 1 (FSP1), and the PERK-eIF2α-ATF4-CHOP pathway, may offer novel therapeutic avenues.

CONCLUSION

Further research is needed to understand the mechanisms, optimize therapeutic strategies, and evaluate the safety and efficacy of ferroptosis-targeted therapies in TNBC treatment. Overall, targeting ferroptosis represents a promising approach to improving treatment outcomes and overcoming the challenges posed by TNBC.

Ferrous sulfate combined with ultrasound emulsified cinnamaldehyde nanoemulsion to cause ferroptosis in Escherichia coli O157:H7

The purpose of this study was to investigate ferroptosis in Escherichia coli O157:H7 caused by ferrous sulfate (FeSO4) and to examine the synergistic effectiveness of FeSO4 combined with ultrasound-emulsified cinnamaldehyde nanoemulsion (CALNO) on inactivation of E. coli O157:H7 in vitro and in vivo. The results showed that FeSO4 could cause ferroptosis in E. coli O157:H7 via generating reactive oxygen species (ROS) and exacerbating lipid peroxidation. In addition, the results indicated that FeSO4 combined with CALNO had synergistic bactericidal effect against E. coli O157:H7 and the combined treatment could lead considerable nucleic acids and protein to release by damaging the cell membrane of E. coli O157:H7. Besides, FeSO4 combined with CALNO had a strong antibiofilm ability to inhibit E. coli O157:H7 biofilm formation by reducing the expression of genes related on biofilm formation. Finally, FeSO4 combined with CALNO exhibited the significant antibacterial activity against E. coli O157:H7 in hami melon and cherry tomato.

Progress and Challenges in Tumor Ferroptosis Treatment Strategies: A Comprehensive Review of Metal Complexes and Nanomedicine

Ferroptosis is a new form of regulated cell death featuring iron-dependent lipid peroxides accumulation to kill tumor cells. A growing body of evidence has shown the potential of ferroptosis-based cancer therapy in eradicating refractory malignancies that are resistant to apoptosis-based conventional therapies. In recent years, studies have reported a number of ferroptosis inducers that can increase the vulnerability of tumor cells to ferroptosis by regulating ferroptosis-related signaling pathways. Encouraged by the rapid development of ferroptosis-driven cancer therapies, interdisciplinary fields that combine ferroptosis, pharmaceutical chemistry, and nanotechnology are focused. First, the prerequisites and metabolic pathways for ferroptosis are briefly introduced. Then, in detail emerging ferroptosis inducers designed to boost ferroptosis-induced tumor therapy, including metal complexes, metal-based nanoparticles, and metal-free nanoparticles are summarized. Subsequently, the application of synergistic strategies that combine ferroptosis with apoptosis and other regulated cell death for cancer therapy, with emphasis on the use of both cuproptosis and ferroptosis to induce redox dysregulation in tumor and intracellular bimetallic copper/iron metabolism disorders during tumor treatment is discussed. Finally, challenges associated with clinical translation and potential future directions for potentiating cancer ferroptosis therapies are highlighted.

Prognostic value of different radiation-related cell death genes in patients with lung adenocarcinoma

BACKGROUND AND AIMS

Radiotherapy is widely applied for lung adenocarcinoma (LUAD), while individualized differences led to different outcomes. This study aimed to establish a multi-gene risk scoring model to predict the benefits of LUAD patients from radiotherapy, based on different types of cell death respectively.

RESULTS

Other than autophagy, pyroptosis, ferroptosis and Immunogenic cell death (ICD), the LUAD prognostic model based on apoptosis had the best performance, and the area under curves (AUCs) of the receiver operating curve (ROC) for 1-, 3-, and 5-year OS were 0.700,0.736,0.723,respectively. Such genes were involved as SLC7A5, EXO1, ABAT, NLRP1 and GAR1. Then patients were divided into high and low risk groups by the median apoptosis-LUAD risk score. For patients in the high-risk group, i.e., the radiotherapy-tolerant group, we screened adjuvant chemotherapy and found that besides the conventional first-line chemotherapy regimen, drugs such as Fludarabine, Pevonedistat, and Podophyllotoxin Bromide may also have potential therapeutic value.

CONCLUSION

The multi-gene risk scoring model based on apoptosis might predict the radiotherapy benefits of LUAD patients and for those radioresistant patients classified by the model we also provided effective adjuvant chemicals, which would be used to guide clinical treatment.

The role of ferroptosis in radiotherapy and combination therapy for head and neck squamous cell carcinoma (Review)

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive, heterogeneous tumour usually caused by alcohol and tobacco consumption, making it one of the most common malignancies worldwide. Despite the fact that various therapeutic approaches such as surgery, radiation therapy (RT), chemotherapy (CT) and targeted therapy have been widely used for HNSCC in recent years, its recurrence rate and mortality rate remain high. RT is the standard treatment choice for HNSCC, which induces reactive oxygen species production and causes oxidative stress, ultimately leading to tumour cell death. CT is a widely recognized form of cancer treatment that treats a variety of cancers by eliminating cancer cells and preventing them from reproducing. Immune checkpoint inhibitor and epidermal growth factor receptor are important in the treatment of recurrent or metastatic HNSCC. Iron death, a type of cell death regulated by peroxidative damage to phospholipids containing polyunsaturated fatty acids in cell membranes, has been found to be a relevant death response triggered by tumour RT in recent years. In the present review, an overview of the current knowledge on RT and combination therapy and iron death in HNSCC was provided, the mechanisms by which RT induces iron death in tumour cells were summarized, and therapeutic strategies to target iron death in HNSCC were explored. The current review provided important information for future studies of iron death in the treatment of HNSCC.

Baicalein improves the symptoms of polycystic ovary syndrome by mitigating oxidative stress and ferroptosis in the ovary and gravid placenta

BACKGROUND

Polycystic ovary syndrome is a metabolic and hormonal disorder that is closely linked to oxidative stress. Within individuals diagnosed with PCOS, changes occur in the ovaries, resulting in an excessive buildup of iron and peroxidation of lipids, both of which may be associated with the occurrence of ferroptosis. Baicalein, a flavonoid found in the roots of Scutellaria baicalensis and widely known as Chinese skullcap, is known for its anti-inflammatory and anti-ferroptotic properties, which protect against various diseases. Nevertheless, there has been no investigation into the impact of baicalein on polycystic ovary syndrome.

PURPOSE

This study aimed to correlate ferroptosis with polycystic ovary syndrome and to assess the effects of baicalein on ovarian dysfunction and placental development in pregnant patients.

STUDY DESIGN AND METHODS

Polycystic ovary syndrome was induced in a rat model through the administration of dehydroepiandrosterone, and these rats were treated with baicalein. Oxidative stress and inflammation levels were assessed in serum and ovaries, and tissue samples were collected for histological and protein analyses. Furthermore, different groups of female rats were mated with male rats to observe pregnancy outcomes and tissue samples were obtained for histological, protein, and RNA sequencing. Then, RNA sequencing of the placenta was performed to determine the key genes involved in ferroptosis negative regulation (FNR) signatures.

RESULTS

Baicalein was shown to reduce ovarian oxidative stress and pathology. Baicalein also ameliorated polycystic ovary syndrome by decreasing lipid peroxidation and chronic inflammation and modulating mitochondrial functions and ferroptosis in the ovaries. Specifically, glutathione peroxidase and ferritin heavy chain 1 were considerably downregulated in polycystic ovary syndrome gravid rats compared to their expression in the control group, and most of these differences were reversed after baicalein intervention.

CONCLUSIONS

Our findings, initially, indicated that baicalein could potentially enhance the prognosis of individuals suffering from polycystic ovary syndrome by reducing oxidative stress and ferroptosis, thus potentially influencing the formulation of a therapeutic approach to address this condition.

Recent advancements in nanomaterial-mediated ferroptosis-induced cancer therapy: Importance of molecular dynamics and novel strategies

Ferroptosis is a novel type of controlled cell death resulting from an imbalance between oxidative harm and protective mechanisms, demonstrating significant potential in combating cancer. It differs from other forms of cell death, such as apoptosis and necrosis. Molecular therapeutics have hard time playing the long-acting role of ferroptosis induction due to their limited water solubility, low cell targeting capacity, and quick metabolism in vivo. To this end, small molecule inducers based on biological factors have long been used as strategy to induce cell death. Research into ferroptosis and advancements in nanotechnology have led to the discovery that nanomaterials are superior to biological medications in triggering ferroptosis. Nanomaterials derived from iron can enhance ferroptosis induction by directly releasing large quantities of iron and increasing cell ROS levels. Moreover, utilizing nanomaterials to promote programmed cell death minimizes the probability of unfavorable effects induced by mutations in cancer-associated genes such as RAS and TP53. Taken together, this review summarizes the molecular mechanisms involved in ferroptosis along with the classification of ferroptosis induction. It also emphasized the importance of cell organelles in the control of ferroptosis in cancer therapy. The nanomaterials that trigger ferroptosis are categorized and explained. Iron-based and noniron-based nanomaterials with their characterization at the molecular and cellular levels have been explored, which will be useful for inducing ferroptosis that leads to reduced tumor growth. Within this framework, we offer a synopsis, which traverses the well-established mechanism of ferroptosis and offers practical suggestions for the design and therapeutic use of nanomaterials.

BIBR1532 combined with radiotherapy induces ferroptosis in NSCLC cells and activates cGAS-STING pathway to promote anti-tumor immunity

BACKGROUND

Telomerase, by safeguarding damaged telomeres and bolstering DNA damage repair, has the capacity to heighten the radioresistance of tumour cells. Thus, in turn, can compromise the efficacy of radiotherapy (RT) and radioimmunotherapy. Our previous studies have revealed that the highly selective telomerase inhibitor, BIBR1532, possesses the potential to enhance the radiosensitivity of Non-small cell lung cancer (NSCLC). In this study, we delve further into the impact of BIBR1532 on the immune activation induced by RT and elucidate the underlying mechanisms.

METHODS

Biological information analyses, immunofluorescence assays, western blot assays, flow cytometry analysis were conducted to elucidate the functions of the combination of BIBR1532 with radiotherapy in NSCLC. Intracellular levels of lipid peroxides, glutathione, malondialdehyde, and Fe2+ were measured as indicators of ferroptosis status. Both in vitro and in vivo studies were conducted to examine the antitumor effects.

RESULTS

Our findings indicate that the confluence of BIBR1532 with RT significantly augments the activation of the cGAS-STING pathway in both in vivo and in vitro settings, thereby fostering an effective anti-tumoral immune response. The effects can be ascribed to two key processes. Firstly, ionizing radiation, in precipitating DNA double-strand breaks (DSBs), prompts the release of tumour-derived double-stranded DNA (dsDNA) into the cytoplasm. Subsequently, BIBR1532 amplifies the activation of antigen-presenting cells by dsDNA post-RT and instigates the cGAS-STING pathway. Secondly, BIBR1532 enhances the ferroptosis response in NSCLC following RT, thereby promoting unrestrained lipid peroxidation and elevated levels of reactive oxygen species (ROS) within tumour cells. This ultimately leads to mitochondrial stress and the release of endogenous mitochondrial DNA (mtDNA) into the cytoplasm, thus facilitating the activation of the STING pathway and the induction of a type I interferon (IFN)-linked adaptive immune response.

CONCLUSION

This study underscores the potential of BIBR1532 as an efficacious and safe radiosensitizer and radioimmunotherapy synergist, providing robust preclinical research evidence for the treatment of NSCLC.

Inducing ferroptosis by traditional medicines: a novel approach to reverse chemoresistance in lung cancer

Lung cancer is the leading cause of global cancer-related deaths. Platinum-based chemotherapy is the first-line treatment for the most common type of lung cancer, i.e., non-small-cell lung cancer (NSCLC), but its therapeutic efficiency is limited by chemotherapeutic resistance. Therefore, it is vital to develop effective therapeutic modalities that bypass the common molecular mechanisms associated with chemotherapeutic resistance. Ferroptosis is a form of non-apoptotic regulated cell death characterized by iron-dependent lipid peroxidation (LPO). Ferroptosis is crucial for the proper therapeutic efficacy of lung cancer-associated chemotherapies. If targeted as a novel therapeutic mechanism, ferroptosis modulators present new opportunities for increasing the therapeutic efficacy of lung cancer chemotherapy. Emerging studies have revealed that the pharmacological induction of ferroptosis using natural compounds boosts the efficacy of chemotherapy in lung cancer or drug-resistant cancer. In this review, we first discuss chemotherapeutic resistance (or chemoresistance) in lung cancer and introduce the core mechanisms behind ferroptosis. Then, we comprehensively summarize the small-molecule compounds sourced from traditional medicines that may boost the anti-tumor activity of current chemotherapeutic agents and overcome chemotherapeutic resistance in NSCLC. Cumulatively, we suggest that traditional medicines with ferroptosis-related anticancer activity could serve as a starting point to overcome chemotherapeutic resistance in NSCLC by inducing ferroptosis, highlighting new potential therapeutic regimens used to overcome chemoresistance in NSCLC.

Molecular and cellular consequences of mitochondrial DNA double-stranded breaks

Mitochondria are subcellular organelles essential for life. Beyond their role in producing energy, mitochondria govern various physiological mechanisms, encompassing energy generation, metabolic processes, apoptotic events, and immune responses. Mitochondria also contain genetic material that is susceptible to various forms of damage. Mitochondrial double-stranded breaks (DSB) are toxic lesions that the nucleus repairs promptly. Nevertheless, the significance of DSB repair in mammalian mitochondria is controversial. This review presents an updated view of the available research on the consequences of mitochondrial DNA DSB from the molecular to the cellular level. We discuss the crucial function of mitochondrial DNA damage in regulating processes such as senescence, integrated stress response, and innate immunity. Lastly, we discuss the potential role of mitochondrial DNA DSB in mediating the cellular consequences of ionizing radiations, the standard of care in treating solid tumors.

New-generation advanced PROTACs as potential therapeutic agents in cancer therapy

Proteolysis-targeting chimeras (PROTACs) technology has garnered significant attention over the last 10 years, representing a burgeoning therapeutic approach with the potential to address pathogenic proteins that have historically posed challenges for traditional small-molecule inhibitors. PROTACs exploit the endogenous E3 ubiquitin ligases to facilitate degradation of the proteins of interest (POIs) through the ubiquitin-proteasome system (UPS) in a cyclic catalytic manner. Despite recent endeavors to advance the utilization of PROTACs in clinical settings, the majority of PROTACs fail to progress beyond the preclinical phase of drug development. There are multiple factors impeding the market entry of PROTACs, with the insufficiently precise degradation of favorable POIs standing out as one of the most formidable obstacles. Recently, there has been exploration of new-generation advanced PROTACs, including small-molecule PROTAC prodrugs, biomacromolecule-PROTAC conjugates, and nano-PROTACs, to improve the in vivo efficacy of PROTACs. These improved PROTACs possess the capability to mitigate undesirable physicochemical characteristics inherent in traditional PROTACs, thereby enhancing their targetability and reducing off-target side effects. The new-generation of advanced PROTACs will mark a pivotal turning point in the realm of targeted protein degradation. In this comprehensive review, we have meticulously summarized the state-of-the-art advancements achieved by these cutting-edge PROTACs, elucidated their underlying design principles, deliberated upon the prevailing challenges encountered, and provided an insightful outlook on future prospects within this burgeoning field.

[High expression of fragile X mental retardation protein inhibits ferroptosis of colorectal tumor cells by activating the RAS/MAPK signaling pathway]

OBJECTIVE

To investigate the mechanism by which fragile X mental retardation protein (FMRP) regulates ferroptosis evasion in colorectal cancer (CRC) cells.

METHODS

We examined FMRP expression levels in CRC cell lines using RT-qPCR and Western blotting and analyzed the biological functions and signaling pathways involved in FMRP-mediated regulation of CRC progression using the TCGA database. A lentiviral FMRP overexpression vector (Lv-FMRP) and 3 knockdown vectors (siFMRP-1, siFMRP-2, and siFMRP-3) were constructed, and their effects on proliferation of HCT116 cells were examined using CCK8 assay and plate clone formation assay; the changes in cell ferroptosis level was determined using MDA/ROS/GSH/Fe2+ kits, mitochondrial membrane potential changes were detected using JC-1 fluorescence staining, and the expressions of proteins associated with ferroptosis and the RAS/MAPK signaling pathway were detected using Western blotting. The subcutaneous tumorigenic potential of the transfected cells was evaluated in nude mice.

RESULTS

Compared with normal colonic mucosal epithelial NCM460 cells, the CRC cell lines had significantly higher FMRP expression level. Bioinformatics analysis suggested the involvement of FMRP in regulation of reactive oxygen, oxidative stress-induced cell death, mitochondrial respiration, and glutathione metabolism pathways. In the cell experiments, FMRP knockdown significantly inhibited proliferation of HCT116 cells, lowered cellular GSH content, increased MDA and ROS levels, Fe2+ fluorescence intensity, and mitochondrial membrane potential, and decreased SLC7A11/GPX4 protein expressions and the phosphorylation levels of ERK, MEK, MAPK, and RAS proteins; FMRP overexpression resulted in the opposite changes in the cells. In the tumor-bearing nude mice, HCT116 cells with FMRP knockdown showed attenuated tumorigenic potential with lowered xenograft growth rate and reduced SLC7A11 expression in the xenograft.

CONCLUSION

The high expression of FMRP inhibits ferroptosis in CRC cells and promotes progression of CRC by activating the RAS/MAPK signaling pathway.

Radiotherapy-sensitized cancer immunotherapy via cGAS-STING immune pathway by activatable nanocascade reaction

Radiotherapy-induced immune activation holds great promise for optimizing cancer treatment efficacy. Here, we describe a clinically used radiosensitizer hafnium oxide (HfO2) that was core coated with a MnO2 shell followed by a glucose oxidase (GOx) doping nanoplatform (HfO2@MnO2@GOx, HMG) to trigger ferroptosis adjuvant effects by glutathione depletion and reactive oxygen species production. This ferroptosis cascade potentiation further sensitized radiotherapy by enhancing DNA damage in 4T1 breast cancer tumor cells. The combination of HMG nanoparticles and radiotherapy effectively activated the damaged DNA and Mn2+-mediated cGAS-STING immune pathway in vitro and in vivo. This process had significant inhibitory effects on cancer progression and initiating an anticancer systemic immune response to prevent distant tumor recurrence and achieve long-lasting tumor suppression of both primary and distant tumors. Furthermore, the as-prepared HMG nanoparticles "turned on" spectral computed tomography (CT)/magnetic resonance dual-modality imaging signals, and demonstrated favorable contrast enhancement capabilities activated by under the GSH tumor microenvironment. This result highlighted the potential of nanoparticles as a theranostic nanoplatform for achieving molecular imaging guided tumor radiotherapy sensitization induced by synergistic immunotherapy.

Irradiated microparticles suppress prostate cancer by tumor microenvironment reprogramming and ferroptosis

Immunogenic cell death (ICD) plays a crucial role in triggering the antitumor immune response in the tumor microenvironment (TME). Recently, considerable attention has been dedicated to ferroptosis, a type of ICD that is induced by intracellular iron and has been demonstrated to change the immune desert status of the TME. However, among cancers that are characterized by an immune desert, such as prostate cancer, strategies for inducing high levels of ferroptosis remain limited. Radiated tumor cell-derived microparticles (RMPs) are radiotherapy mimetics that have been shown to activate the cGAS-STING pathway, induce tumor cell ferroptosis, and inhibit M2 macrophage polarization. RMPs can also act as carriers of agents with biocompatibility. In the present study, we designed a therapeutic system wherein the ferroptosis inducer RSL-3 was loaded into RMPs, which were tested in in vitro and in vivo prostate carcinoma models established using RM-1 cells. The apoptosis inducer CT20 peptide (CT20p) was also added to the RMPs to aggravate ferroptosis. Our results showed that RSL-3- and CT20p-loaded RMPs (RC@RMPs) led to ferroptosis and apoptosis of RM-1 cells. Moreover, CT20p had a synergistic effect on ferroptosis by promoting reactive oxygen species (ROS) production, lipid hydroperoxide production, and mitochondrial instability. RC@RMPs elevated dendritic cell (DC) expression of MHCII, CD80, and CD86 and facilitated M1 macrophage polarization. In a subcutaneously transplanted RM-1 tumor model in mice, RC@RMPs inhibited tumor growth and prolonged survival time via DC activation, macrophage reprogramming, enhancement of CD8+ T cell infiltration, and proinflammatory cytokine production in the tumor. Moreover, combination treatment with anti-PD-1 improved RM-1 tumor inhibition. This study provides a strategy for the synergistic enhancement of ferroptosis for prostate cancer immunotherapies.

Ficolin 3 promotes ferroptosis in HCC by downregulating IR/SREBP axis-mediated MUFA synthesis

BACKGROUND

Targeting ferroptosis has been identified as a promising approach for the development of cancer therapies. Monounsaturated fatty acid (MUFA) is a type of lipid that plays a crucial role in inhibiting ferroptosis. Ficolin 3 (FCN3) is a component of the complement system, serving as a recognition molecule against pathogens in the lectin pathway. Recent studies have reported that FCN3 demonstrates inhibitory effects on the progression of certain tumors. However, whether FCN3 can modulate lipid metabolism and ferroptosis remains largely unknown.

METHODS

Cell viability, BODIPY-C11 staining, and MDA assay were carried out to detect ferroptosis. Primary hepatocellular carcinoma (HCC) and xenograft models were utilized to investigate the effect of FCN3 on the development of HCC in vivo. A metabonomic analysis was conducted to assess alterations in intracellular and HCC intrahepatic lipid levels.

RESULTS

Our study elucidates a substantial decrease in the expression of FCN3, a component of the complement system, leads to MUFA accumulation in human HCC specimens and thereby significantly promotes ferroptosis resistance. Overexpression of FCN3 efficiently sensitizes HCC cells to ferroptosis, resulting in the inhibition of the oncogenesis and progression of both primary HCC and subcutaneous HCC xenograft. Mechanistically, FCN3 directly binds to the insulin receptor β (IR-β) and its pro-form (pro-IR), inhibiting pro-IR cleavage and IR-β phosphorylation, ultimately resulting in IR-β inactivation. This inactivation of IR-β suppresses the expression of sterol regulatory element binding protein-1c (SREBP1c), which subsequently suppresses the transcription of genes related to de novo lipogenesis (DNL) and lipid desaturation, and consequently downregulates intracellular MUFA levels.

CONCLUSIONS

These findings uncover a novel regulatory mechanism by which FCN3 enhances the sensitivity of HCC cells to ferroptosis, indicating that targeting FCN3-induced ferroptosis is a promising strategy for HCC treatment.

Understanding the Novel Approach of Nanoferroptosis for Cancer Therapy

As a new form of regulated cell death, ferroptosis has unraveled the unsolicited theory of intrinsic apoptosis resistance by cancer cells. The molecular mechanism of ferroptosis depends on the induction of oxidative stress through excessive reactive oxygen species accumulation and glutathione depletion to damage the structural integrity of cells. Due to their high loading and structural tunability, nanocarriers can escort the delivery of ferro-therapeutics to the desired site through enhanced permeation or retention effect or by active targeting. This review shed light on the necessity of iron in cancer cell growth and the fascinating features of ferroptosis in regulating the cell cycle and metastasis. Additionally, we discussed the effect of ferroptosis-mediated therapy using nanoplatforms and their chemical basis in overcoming the barriers to cancer therapy.

Ferroptosis and Lipid Metabolism in Acute Myocardial Infarction

Acute myocardial infarction (AMI) is triggered by the blockage of coronary arteries, leading to restricted blood flow to the myocardium, which results in damage and cell death. While the traditional understanding of cell death primarily revolves around apoptosis, a new player in the game has emerged: ferroptosis. This novel form of cell death relies on iron and is propelled by reactive oxygen species (ROS). Lipid metabolism, an indispensable physiological process, plays a vital role in preserving cellular homeostasis. However, when this metabolic pathway is disrupted, the accumulation of excess waste increases, specifically lipid peroxides, which are strongly linked to the occurrence and progression of AMI. As a result, comprehending this complex interaction between ferroptosis and lipid metabolism could pave the way for new therapeutic approaches in tackling AMI.

Astaxanthin Synergizes with Ionizing Radiation (IR) in Oral Squamous Cell Carcinoma (OSCC)

Astaxanthin (ATX) is known for its antioxidant and anti-inflammation functions yet its role in cancers requires more research. This study is aimed to reveal the potential synergetic effect of ATX with ionizing radiation (IR) in OSCC. Cell survival was measured after human OSCC cells including CAL27 and SCC9, and normal human oral keratinocytes (NHOKs) were treated with different concentrations of ATX for 24 h. Colony formation assays were performed after OSCC cells were treated with IR, ATX (20 μ M), or combined and survival fraction was analyzed. Malondialdehyde (MDA), glutathione (GSH), and intercellular iron levels were measured. Western blot method was used to measure the ferroptosis-related proteins, GPX4, SLC7A11, and ACSL4. In xenograft mice model, we evaluated the tumor volumes, tumor growth, and examined the GPX4/ACSL4 proteins in tumor tissues using Immunohistochemistry (IHC). ATX inhibited viability of OSCC cells but not NHOK. In OSCC cells, ATX further enhanced the cell death induced by IR. In addition, ATX promoted the MDA content, Iron levels but inhibited the GSH regulated by IR in cells. ATX could synergize with IR, further inhibiting GPX4, SLC7A11 and promoting ACSL4 in OSCC cells. In vivo, ATX and IR treatment inhibited OSCC tumor growth and the group with combined treatment showed the most inhibitory effect. GPX4 was inhibited by IR and further inhibited in the combined group while ACSL4 was promoted by IR and enhanced more significantly in the combined group. ATX might synergize with IR treatment in OSCC partly via ferroptosis.

Cuproptosis: unveiling a new frontier in cancer biology and therapeutics

Copper plays vital roles in numerous cellular processes and its imbalance can lead to oxidative stress and dysfunction. Recent research has unveiled a unique form of copper-induced cell death, termed cuproptosis, which differs from known cell death mechanisms. This process involves the interaction of copper with lipoylated tricarboxylic acid cycle enzymes, causing protein aggregation and cell death. Recently, a growing number of studies have explored the link between cuproptosis and cancer development. This review comprehensively examines the systemic and cellular metabolism of copper, including tumor-related signaling pathways influenced by copper. It delves into the discovery and mechanisms of cuproptosis and its connection to various cancers. Additionally, the review suggests potential cancer treatments using copper ionophores that induce cuproptosis, in combination with small molecule drugs, for precision therapy in specific cancer types.

Mechanism of metal ion-induced cell death in gastrointestinal cancer

Gastrointestinal (GI) cancer is one of the most severe types of cancer, with a significant impact on human health worldwide. Due to the urgent demand for more effective therapeutic strategies against GI cancers, novel research on metal ions for treating GI cancers has attracted increasing attention. Currently, with accumulating research on the relationship between metal ions and cancer therapy, several metal ions have been discovered to induce cell death. In particular, the three novel modes of cell death, including ferroptosis, cuproptosis, and calcicoptosis, have become focal points of research in the field of cancer. Meanwhile, other metal ions have also been found to trigger cell death through various mechanisms. Accordingly, this review focuses on the mechanisms of metal ion-induced cell death in GI cancers, hoping to provide theoretical support for further GI cancer therapies.

TLR3 activation enhances abscopal effect of radiotherapy in HCC by promoting tumor ferroptosis

Radiotherapy (RT) has been reported to induce abscopal effect in advanced hepatocellular carcinoma (HCC), but such phenomenon was only observed in sporadic cases. Here, we demonstrated that subcutaneous administration of Toll-like receptor 3 (TLR3) agonist poly(I:C) could strengthen the abscopal effect during RT through activating tumor cell ferroptosis signals in bilateral HCC subcutaneous tumor mouse models, which could be significantly abolished by TLR3 knock-out or ferroptosis inhibitor ferrostatin-1. Moreover, poly(I:C) could promote the presentation of tumor neoantigens by dendritic cells to enhance the recruitment of activated CD8+ T cells into distant tumor tissues for inducing tumor cell ferroptosis during RT treatment. Finally, the safety and feasibility of combining poly(I:C) with RT for treating advanced HCC patients were further verified in a prospective clinical trial. Thus, enhancing TLR3 signaling activation during RT could provide a novel strategy for strengthening abscopal effect to improve the clinical benefits of advanced HCC patients.

ATF3-CBS signaling axis coordinates ferroptosis and tumorigenesis in colorectal cancer

The induction of ferroptosis is promising for cancer therapy. However, the mechanisms enabling cancer cells to evade ferroptosis, particularly in low-cystine environments, remain elusive. Our study delves into the intricate regulatory mechanisms of Activating transcription factor 3 (ATF3) on Cystathionine β-synthase (CBS) under cystine deprivation stress, conferring resistance to ferroptosis in colorectal cancer (CRC) cells. Additionally, our findings establish a positively correlation between this signaling axis and CRC progression, suggesting its potential as a therapeutic target. Mechanistically, ATF3 positively regulates CBS to resist ferroptosis under cystine deprivation stress. In contrast, the suppression of CBS sensitizes CRC cells to ferroptosis through targeting the mitochondrial tricarboxylic acid (TCA) cycle. Notably, our study highlights that the ATF3-CBS signaling axis enhances ferroptosis-based CRC cancer therapy. Collectively, the findings reveal that the ATF3-CBS signaling axis is the primary feedback pathway in ferroptosis, and blocking this axis could be a potential therapeutic approach for colorectal cancer.

GPX4, ferroptosis, and diseases

GPX4 (Glutathione peroxidase 4) serves as a crucial intracellular regulatory factor, participating in various physiological processes and playing a significant role in maintaining the redox homeostasis within the body. Ferroptosis, a form of iron-dependent non-apoptotic cell death, has gained considerable attention in recent years due to its involvement in multiple pathological processes. GPX4 is closely associated with ferroptosis and functions as the primary inhibitor of this process. Together, GPX4 and ferroptosis contribute to the pathophysiology of several diseases, including sepsis, nervous system diseases, ischemia reperfusion injury, cardiovascular diseases, and cancer. This review comprehensively explores the regulatory roles and impacts of GPX4 and ferroptosis in the development and progression of these diseases, with the aim of providing insights for identifying potential therapeutic strategies in the future.

Synergistic Effect of Ferroptosis-Inducing Nanoparticles and X-Ray Irradiation Combination Therapy

Ferroptosis, characterized by the induction of cell death via lipid peroxidation, has been actively studied over the last few years and has shown the potential to improve the efficacy of cancer nanomedicine in an iron-dependent manner. Radiation therapy, a common treatment method, has limitations as a stand-alone treatment due to radiation resistance and safety as it affects even normal tissues. Although ferroptosis-inducing drugs help alleviate radiation resistance, there are no safe ferroptosis-inducing drugs that can be considered for clinical application and are still in the research stage. Here, the effectiveness of combined treatment with radiotherapy with Fe and hyaluronic acid-based nanoparticles (FHA-NPs) to directly induce ferroptosis, considering the clinical applications is reported. Through the induction of ferroptosis by FHA-NPs and apoptosis by X-ray irradiation, the therapeutic efficiency of cancer is greatly improved both in vitro and in vivo. In addition, Monte Carlo simulations are performed to assess the physical interactions of the X-rays with the iron-oxide nanoparticle. The study provides a deeper understanding of the synergistic effect of ferroptosis and X-ray irradiation combination therapy. Furthermore, the study can serve as a valuable reference for elucidating the role and mechanisms of ferroptosis in radiation therapy.

Self-Assembled Fe-Phenolic Acid Network Synergizes with Ferroptosis to Enhance Tumor Nanotherapy

Natural polyphenolic compound rosmarinic acid (RA) has good antitumor activity. However, the distinctive tumor microenvironment, characterized by low pH and elevated levels of glutathione (GSH), enhances the tolerance of tumors to the singular anti-tumor treatment mode using RA, resulting in unsatisfactory therapeutic efficacy. Targeting nonapoptotic programmed cell death processes may provide another impetus to inhibit tumor growth. RA possesses the capability to coordinate with metal elements. To solve the effect restriction of the above single treatment mode, it is proposed to construct a self-assembled nanocomposite, Fe-RA. Under tumor microenvironment, Fe-RA nanocomposite exerts the characteristics of POD-like enzyme activity and depletion of GSH, producing a large amount of hydroxyl radical (·OH) while disrupting the antioxidant defense system of tumor cells. Moreover, due to the enhanced permeability and retention effect (EPR), Fe-RA can transport Fe2+ to a greater extent to tumor cells and increase intracellular iron content. Causing an imbalance in iron metabolism in tumor cells and promoting cell ferroptosis. The results of the synchrotron X-ray absorption spectroscopy (XAS) and high-resolution mass spectrometry (HRMS) prove the successful complexation of Fe-RA nanocomposite. Density functional theory (DFT) explains the efficient catalytic mechanism of its peroxide-like enzyme activity and the reaction principle with GSH.

Glutamine inhibition combined with CD47 blockade enhances radiotherapy-induced ferroptosis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a formidable cancer type that poses significant treatment challenges, including radiotherapy (RT) resistance. The metabolic characteristics of tumors present substantial obstacles to cancer therapy, and the relationship between RT and tumor metabolism in HNSCC remains elusive. Ferroptosis is a type of iron-dependent regulated cell death, representing an emerging disease-modulatory mechanism. Here, we report that after RT, glutamine levels rise in HNSCC, and the glutamine transporter protein SLC1A5 is upregulated. Notably, blocking glutamine significantly enhances the therapeutic efficacy of RT in HNSCC. Furthermore, inhibition of glutamine combined with RT triggers immunogenic tumor ferroptosis, a form of nonapoptotic regulated cell death. Mechanistically, RT increases interferon regulatory factor (IRF) 1 expression by activating the interferon signaling pathway, and glutamine blockade augments this efficacy. IRF1 drives transferrin receptor expression, elevating intracellular Fe2+ concentration, disrupting iron homeostasis, and inducing cancer cell ferroptosis. Importantly, the combination treatment-induced ferroptosis is dependent on IRF1 expression. Additionally, blocking glutamine combined with RT boosts CD47 expression and hinders macrophage phagocytosis, attenuating the treatment effect. Dual-blocking glutamine and CD47 promote tumor remission and enhance RT-induced ferroptosis, thereby ameliorating the tumor microenvironment. Our work provides valuable insights into the metabolic and immunological mechanisms underlying RT-induced ferroptosis, highlighting a promising strategy to augment RT efficacy in HNSCC.

Intravenous immunoglobulin protects the integrity of the intestinal epithelial barrier and inhibits ferroptosis induced by radiation exposure by activating the mTOR pathway

Radiation exposure often leads to serious health problems in humans. The intestinal epithelium is sensitive to radiation damage, and radiation causes destruction of the intestinal epithelial barrier, which leads to radiation enteritis (RE), the loss of fluids, and the translocation of intestinal bacteria and toxins; radiation can even threaten survival. In this study, we aimed to explore the influence of IVIg on the integrity of the intestinal epithelial barrier after RE. Using a RE mouse model, we investigated the protective effects of intravenous immunoglobulin (IVIg) on the epithelial junctions of RE mice and validated these findings with intestinal organoids cultured in vitro. In addition, transmission electron microscopy (TEM), western blotting (WB) and immunostaining were used to further investigate changes in intestinal epithelial ferroptosis and related signaling pathways. When RE occurs, the intestinal epithelial barrier is severely damaged. IVIg treatment significantly ameliorated this damage to epithelial tight junctions both in vivo and in vitro. Notably, IVIg alleviated RE by inhibiting intestinal epithelial ferroptosis in RE mice. Mechanistically, IVIg promoted activation of the mTOR pathway and inhibited ferroptosis in the intestinal epithelium of mice. Rapamycin, which is a potent inhibitor of the mTOR protein, significantly abolished the protective effect of IVIg against radiation-induced damage to intestinal epithelial tight junctions. Overall, IVIg can prevent RE-induced damage to the intestinal epithelial barrier and inhibit ferroptosis by activating the mTOR pathway; this study provides a new treatment strategy for patients with RE caused by radiotherapy or accidental nuclear exposure.

Unlocking ferroptosis in prostate cancer - the road to novel therapies and imaging markers

Ferroptosis is a distinct form of regulated cell death that is predominantly driven by the build-up of intracellular iron and lipid peroxides. Ferroptosis suppression is widely accepted to contribute to the pathogenesis of several tumours including prostate cancer. Results from some studies reported that prostate cancer cells can be highly susceptible to ferroptosis inducers, providing potential for an interesting new avenue of therapeutic intervention for advanced prostate cancer. In this Perspective, we describe novel molecular underpinnings and metabolic drivers of ferroptosis, analyse the functions and mechanisms of ferroptosis in tumours, and highlight prostate cancer-specific susceptibilities to ferroptosis by connecting ferroptosis pathways to the distinctive metabolic reprogramming of prostate cancer cells. Leveraging these novel mechanistic insights could provide innovative therapeutic opportunities in which ferroptosis induction augments the efficacy of currently available prostate cancer treatment regimens, pending the elimination of major bottlenecks for the clinical translation of these treatment combinations, such as the development of clinical-grade inhibitors of the anti-ferroptotic enzymes as well as non-invasive biomarkers of ferroptosis. These biomarkers could be exploited for diagnostic imaging and treatment decision-making.

Micro(nano)-plastics exposure induced programmed cell death and corresponding influence factors

Plastic products have played an indispensable role in our daily lives for several decades, primarily due to their cost-effectiveness and unmatched convenience. Nevertheless, recent developments in nanotechnology have propelled our attention toward a distinct category of plastic fine particulates known as micro(nano)-plastics (MPs/NPs). The investigation of the cytotoxic effects of MPs/NPs has emerged as a central and burgeoning area of research in environmental toxicology and cell biology. In the scope of this comprehensive review, we have meticulously synthesized recent scientific inquiries to delve into the intricate interplay between MPs/NPs and programmed cell death mechanisms, which encompass a range of highly regulated processes. First, the signaling pathways and molecular mechanisms of different programmed death modalities induced by MPs/NPs were elaborated, including apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. The causes of different programmed deaths induced by MPs/NPs, such as size, surface potential, functional group modification, aging, biological crown, and co-exposure of MPs/NPs are further analyzed. In contrast, the various cellular programmed death modes induced by MPs/NPs are not alone most of the time, and lastly, the connections between different cellular programmed death modes induced by MPs/NPs, such as interconversion, mutual promotion, and mutual inhibition, are explained. Our primary objective is to unveil the multifaceted toxicological implications of MPs/NPs on the intricate web of cellular fate and biological homeostasis. This endeavor not only broadens our understanding of the potential risks associated with MPs/NPs exposure but also underscores the urgent need for comprehensive risk assessments and regulatory measures in the context of environmental health.

Deciphering Ferroptosis: From Molecular Pathways to Machine Learning-Guided Therapeutic Innovation

Ferroptosis is a unique form of cell death reliant on iron and lipid peroxidation. It disrupts redox balance, causing cell death by damaging the plasma membrane, with inducers acting through enzymatic pathways or transport systems. In cancer treatment, suppressing ferroptosis or circumventing it holds significant promise. Beyond cancer, ferroptosis affects aging, organs, metabolism, and nervous system. Understanding ferroptosis mechanisms holds promise for uncovering novel therapeutic strategies across a spectrum of diseases. However, detection and regulation of this regulated cell death are still mired with challenges. The dearth of cell, tissue, or organ-specific biomarkers muted the pharmacological use of ferroptosis. This review covers recent studies on ferroptosis, detailing its properties, key genes, metabolic pathways, and regulatory networks, emphasizing the interaction between cellular signaling and ferroptotic cell death. It also summarizes recent findings on ferroptosis inducers, inhibitors, and regulators, highlighting their potential therapeutic applications across diseases. The review addresses challenges in utilizing ferroptosis therapeutically and explores the use of machine learning to uncover complex patterns in ferroptosis-related data, aiding in the discovery of biomarkers, predictive models, and therapeutic targets. Finally, it discusses emerging research areas and the importance of continued investigation to harness the full therapeutic potential of targeting ferroptosis.

The roles of ferroptosis in cancer: Tumor suppression, tumor microenvironment, and therapeutic interventions

In cancer treatment, the recurrent challenge of inducing apoptosis through conventional therapeutic modalities, often thwarted by therapy resistance, emphasizes the critical need to explore alternative cell death pathways. Ferroptosis, an iron-dependent form of regulated cell death triggered by the lethal accumulation of lipid peroxides on cellular membranes, has emerged as one such promising frontier in oncology. Induction of ferroptosis not only suppresses tumor growth but also holds potential for augmenting immunotherapy responses and surmounting resistance to existing cancer therapies. This review navigates the role of ferroptosis in tumor suppression. Furthermore, we delve into the complex role of ferroptosis within the tumor microenvironment and its interplay with antitumor immunity, offering insights into the prospect of targeting ferroptosis as a strategic approach in cancer therapy.

Danggui Buxue Tang improves therapeutic efficacy of doxorubicin in triple negative breast cancer via ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Buxue Tang (DBT) has been used for over 800 years to enhance Qi and nourish Blood, and it is particularly beneficial for cancer patients. Recent research has shown that combining DBT with chemotherapy agents leads to superior anti-cancer effects, thereby enhancing therapeutic efficacy.

AIM OF THE STUDY

The aim of this study was to evaluate the effectiveness of a combination therapy involving doxorubicin (DOX) and Danggui Buxue Tang (DBT) in the treatment of triple-negative breast cancer (TNBC) and to elucidate the underlying mechanisms of action.

MATERIALS AND METHODS

In vitro experiments were performed using MDA-MB-231 and 4T1 cells, while in vivo experiments were carried out using MDA-MB-231 xenograft mice. The therapeutic effects of the combination therapy were evaluated using various techniques, including MTT assay, colony formation assay, flow cytometry, transwell assay, immunofluorescence, transmission electron microscopy (TEM), histological analysis, western blotting, and bioluminescence assay.

RESULTS

DBT was found to enhance DOX's anti-TNBC activity in vitro by promoting ferroptosis, as evidenced by the observed mitochondrial morphological changes using TEM. The combination therapy was also found to reduce the expression of Nrf2, HO-1, and GPX4, which are all targets for ferroptosis induction, while simultaneously increasing ROS production. Additionally, the combination therapy reduced nuclear accumulation and constitutive activation of Nrf2, which is a significant cause of chemotherapy resistance and promotes cancer growth. In vivo experiments using an MDA-MB-231 xenograft animal model revealed that the combination therapy significantly reduced tumor cell proliferation and accelerated TNBC deaths by modulating the Nrf2/HO-1/GPX4 axis, with no evidence of tissue abnormalities. Moreover, the combination therapy exhibited a liver protective effect, and administration of Fer-1 was able to reduce the ROS formation produced by the DBT + DOX combination therapy.

CONCLUSION

This study provides evidence that the combination therapy of DOX and DBT has the potential to treat TNBC by promoting ferroptosis through the Nrf2/HO-1/GPX4 axis.

Clonogenic assay and computational modeling using real cell images to study physical enhancement and cellular sensitization induced by metal nanoparticles under MV and kV X-ray irradiation

This study was initiated due to the physically unexplainable tumor controls resulting from metal nanoparticle (MNP) experiments even under MV X-ray irradiation. A more accurate explanation of the mechanism of radiosensitization induced by MNP is warranted, considering both its physical dose enhancement and biological sensitization, as related research is lacking. Thus, we aimed to examine the intricate dynamics involved in MNP-induced radiosensitization. We conducted specifically designed clonogenic assays for the A549 lung cancer cell line with MNP irradiated by 6 MV and 300 kVp X-rays. Two types of MNP were employed: one based on iron oxide, promoting ferroptosis, and the other on gold nanoparticles known for inducing a significant dose enhancement, particularly at low-energy X-rays. We introduced the lethality enhancement factor (LEF) as the fraction in the cell killing attributed to biological sensitization. Subsequently, Monte Carlo simulations were conducted to evaluate the radial dose profiles for each MNP, corresponding to the physical enhancement. Finally, the local effect model was applied to the clonogenic assay results on real cell images. The LEF and the dose enhancement in the cytoplasm were incorporated to increase the accuracy in the average lethal events and, consequently, in the survival fraction. The results reveal an increased cell killing for both of the MNP under MV and kV X-ray irradiation. In both types of MNP, the LEF reveals a biological sensitization evident. The sensitizer enhancement ratio, derived from the calculations, exhibited only 3% and 1% relative differences compared to the conventional linear-quadratic model for gold and ferroptosis inducer nanoparticles, respectively. These findings indicate that MNPs sensitize cells via radiation through mechanisms akin to ferroptosis inducers, not exclusively relying on a physical dose enhancement. Their own contributions to survival fractions were successfully integrated into computational modeling.