Nrf2-Keap1 pathway promotes cell proliferation and diminishes ferroptosis

Ferroptosis and cognitive impairment: Unraveling the link and potential therapeutic targets

Neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases, share key characteristics, notably cognitive impairment and significant cell death in specific brain regions. Cognition, a complex mental process allowing individuals to perceive time and place, is disrupted in these conditions. This consistent disruption suggests the possibility of a shared underlying mechanism across all neurodegenerative diseases. One potential common factor is the activation of pathways leading to cell death. Despite significant progress in understanding cell death pathways, no definitive treatments have emerged. This has shifted focus towards less-explored mechanisms like ferroptosis, which holds potential due to its involvement in oxidative stress and iron metabolism. Unlike apoptosis or necrosis, ferroptosis offers a novel therapeutic avenue due to its distinct biochemical and genetic underpinnings, making it a promising target in neurodegenerative disease treatment. Ferroptosis is distinguished from other cellular death mechanisms, by distinctive characteristics such as an imbalance of iron hemostasis, peroxidation of lipids in the plasma membrane, and dysregulated glutathione metabolism. In this review, we discuss the potential role of ferroptosis in cognitive impairment. We then summarize the evidence linking ferroptosis biomarkers to cognitive impairment brought on by neurodegeneration while highlighting recent advancements in our understanding of the molecular and genetic mechanisms behind the condition. Finally, we discuss the prospective therapeutic implications of targeting ferroptosis for the treatment of cognitive abnormalities associated with neurodegeneration, including natural and synthetic substances that suppress ferroptosis via a variety of mechanisms. Promising therapeutic candidates, including antioxidants and iron chelators, are being explored to inhibit ferroptosis and mitigate cognitive decline.

The Octadecanoids: Synthesis and Bioactivity of 18-Carbon Oxygenated Fatty Acids in Mammals, Bacteria, and Fungi

The octadecanoids are a broad class of lipids consisting of the oxygenated products of 18-carbon fatty acids. Originally referring to production of the phytohormone jasmonic acid, the octadecanoid pathway has been expanded to include products of all 18-carbon fatty acids. Octadecanoids are formed biosynthetically in mammals via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) activity, as well as nonenzymatically by photo- and autoxidation mechanisms. While octadecanoids are well-known mediators in plants, their role in the regulation of mammalian biological processes has been generally neglected. However, there have been significant advancements in recognizing the importance of these compounds in mammals and their involvement in the mediation of inflammation, nociception, and cell proliferation, as well as in immuno- and tissue modulation, coagulation processes, hormone regulation, and skin barrier formation. More recently, the gut microbiome has been shown to be a significant source of octadecanoid biosynthesis, providing additional biosynthetic routes including hydratase activity (e.g., CLA-HY, FA-HY1, FA-HY2). In this review, we summarize the current field of octadecanoids, propose standardized nomenclature, provide details of octadecanoid preparation and measurement, summarize the phase-I metabolic pathway of octadecanoid formation in mammals, bacteria, and fungi, and describe their biological activity in relation to mammalian pathophysiology as well as their potential use as biomarkers of health and disease.

Crosstalk between ferroptosis and autophagy: broaden horizons of cancer therapy

Ferroptosis and autophagy are two main forms of regulated cell death (RCD). Ferroptosis is a newly identified RCD driven by iron accumulation and lipid peroxidation. Autophagy is a self-degradation system through membrane rearrangement. Autophagy regulates the metabolic balance between synthesis, degradation and reutilization of cellular substances to maintain intracellular homeostasis. Numerous studies have demonstrated that both ferroptosis and autophagy play important roles in cancer pathogenesis and cancer therapy. We also found that there are intricate connections between ferroptosis and autophagy. In this article, we tried to clarify how different kinds of autophagy participate in the process of ferroptosis and sort out the common regulatory pathways between ferroptosis and autophagy in cancer. By exploring the complex crosstalk between ferroptosis and autophagy, we hope to broaden horizons of cancer therapy.

Electroacupuncture attenuates ferroptosis by promoting Nrf2 nuclear translocation and activating Nrf2/SLC7A11/GPX4 pathway in ischemic stroke

OBJECTIVE

Electroacupuncture has been shown to play a neuroprotective role following ischemic stroke, but the underlying mechanism remains poorly understood. Ferroptosis has been shown to play a key role in the injury process. In the present study, we wanted to explore whether electroacupuncture could inhibit ferroptosis by promoting nuclear factor erythroid-2-related factor 2 (Nrf2) nuclear translocation.

METHODS

The ischemic stroke model was established by middle cerebral artery occlusion/reperfusion (MCAO/R) in adult rats. These rats have been randomly divided into the EA + MCAO/R group, the MCAO/R group, the EA + MCAO/R + Brusatol group (the inhibitor of Nrf2), and the EA + MCAO/R + DMSO group, and the Sham group. The EA + MCAO/R group, EA + MCAO/R + Brusatol group, and the EA + MCAO/R + DMSO group received EA intervention 24 h after modeling for 7 consecutive days. The behavioral function was evaluated by Neurologic severity score (NSS), Garcia score, Foot-fault Test, and Rotarod Test. The infarct volume was detected by TTC staining, and the neuronal damage was observed by Nissl staining. The levels of Fe2+, reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) were measured by ELISA. The immunofluorescence and Western blotting were used to detect the expression of Total Nrf2, p-Nrf2, Nuclear Nrf2, and Cytoplasmic Nrf2, and the essential ferroptosis proteins, including glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11) and ferritin heavy chain 1 (FTH1). The mitochondria were observed by transmission electron microscopy (TEM).

RESULTS

Electroacupuncture improved neurological deficits in rats model of MCAO/R, decreased the brain infarct volume, alleviated neuronal damage, inhibited the Fe2+, ROS, and MDA accumulation, increased SOD levels, increased the expression of GPX4, SLC7A11 and FTH1, and rescued injured mitochondria. Especially, we found that the electroacupuncture up-regulated the expression of Nrf2, and promoted phosphorylation of Nrf2 and nuclear translocation, However, Nrf2 inhibitor Brusatol reversed the neuroprotective effect of electroacupuncture.

CONCLUSION

Electroacupuncture can alleviate cerebral I/R injury-induced ferroptosis by promoting Nrf2 nuclear translocation. It is expected that these data will provide novel insights into the mechanisms of electroacupuncture protecting against cerebral I/R injury and potential targets underlying ferroptosis in the stroke.

Magnolia kobus DC. suppresses neointimal hyperplasia by regulating ferroptosis and VSMC phenotypic switching in a carotid artery ligation mouse model

BACKGROUND

Magnolia kobus DC (MO), as a plant medicine, has been reported to have various physiological activities, including neuroprotective, anti-inflammatory, and anti-diabetic effects. However, vascular protective effects of MO remain incompletely understood. In this study, we evaluated the vascular protective effect of MO against ferroptosis in a carotid artery ligation (CAL)-induced neointimal hyperplasia mouse model and in aortic thoracic smooth muscle A7r5 cells.

METHODS

This study was conducted to estimate the vascular protective effects of MO by systematically measuring histopathological analysis and western blot analysis in CAL animal model. In vitro protective effects of MO were evaluated by estimating cell viability, reactive oxygen species (ROS) content, glutathione (GSH) levels, lipid peroxidation, mitochondrial morphological change, cell proliferation, migration, western blot analysis, and qRT-PCR against erastin (Era)-induced A7r5 cells.

RESULTS

MO intake significantly improved neointimal formation, inhibited ferroptosis and vascular smooth muscle cell (VSMC) phenotypes, and ameliorated the antioxidant system of carotid artery tissues. In addition, MO treatment effectively ameliorated Era-induced ferroptotic cytotoxicity, including cellular death, ROS production, and cell migration status. MO treatment also suppressed proliferation and migration in Era-induced A7r5 cells. MO considerably regulated Era-induced abnormal mechanisms related to ferroptotic changes, VSMC phenotype switching, and the ROS scavenging system in A7r5 cells.

CONCLUSION

MO has the potential for use as a functional food supplement, nutraceutical, or medicinal food, with protective effects on vascular health by regulating ferroptosis and VSMC phenotypic switching.

LRRC45 accelerates bladder cancer development and ferroptosis inhibition via stabilizing NRF2 by competitively KEAP1 interaction

Centrosomal dysregulation is closely linked to the genesis and progression of tumors. A comprehensive analysis of single-cell RNA sequencing (scRNA-seq) data has revealed that leucine-rich repeat-containing protein 45 (LRRC45), a centrosome linker protein crucial for maintaining centrosome cohesion and a member of the leucine-rich repeat-containing proteins (LRRCs) family, is significantly upregulated in bladder cancer. Notably, the elevated expression levels of LRRC45 were strongly correlated with a poor prognosis in patients. Furthermore, the depletion of LRRC45 in bladder cancer cells markedly inhibited tumorigenic proliferation and increased intracellular iron and reactive oxygen species (ROS) levels. It ultimately triggered ferroptosis, an iron-dependent form of programmed cell death characterized by lipid peroxidation. Mechanistic studies revealed that LRRC45 exerts its oncogenic effects through competitive interaction with Kelch-like ECH-associated protein 1 (KEAP1), which inhibits the ubiquitin-proteasome-mediated degradation of nuclear factor erythroid 2-related factor 2 (NRF2). This interaction enhances the nuclear translocation of NRF2 and its subsequent anti-ferroptotic activity. In conclusion, our studies highlight the critical role of LRRC45 in enhancing the stability of NRF2, thereby promoting the tumorigenic potential of bladder cancer. These insights suggest that targeting LRRC45 could serve as a promising molecular target for developing novel therapeutic interventions for bladder cancer.

PRKAA2 Promotes Tumor Growth and Inhibits Ferroptosis through SLC7A11/GSH/GPX4 Pathway in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most pervasive sort of lung cancer with deadly outcome. According to recent studies, a number of neoplastic disorders and ferroptosis are intimately connected. This study aims to identify the role of key ferroptosis-related gene (protein kinase AMP-activated catalytic subunit alpha 2, PRKAA2) and explore new directions for the diagnosis and treatment of NSCLC. The PRKAA2 expression and its influence on survival were analyzed in multiple public databases (TCGA, TIMER2.0, and GEPIA). And PRKAA2 mRNA level in NSCLC cells were examined by qRT-PCR. Silencing of PRKAA2 (sh-PRKAA2) were used to cell transfection. CCK-8, EdU, and flow cytometry assays were used to measure cell proliferation and apoptosis. The protein levels of ferroptosis markers (SLC7A11, GPX4, and NRF2) were determined by western blotting. Meanwhile, the related ferroptosis analysis, such as malondialdehyde (MDA) and glutathione (GSH), reactive oxygen species (ROS), iron, and Fe2+ levels were also detected in the transfected cells. Moreover, the relationship between PRKAA2 expression and SLC7A11 was analyzed. NSCLC xenograft mouse models were used for in vivo verification of the PRKAA2 function. Here, our data revealed that PRKAA2 was upregulated in NSCLC cells. Additionally, PRKAA2 strengthened cell proliferation and attenuated apoptosis and ferroptosis of NSCLC cells. The depletion of PRKAA2 enhanced the erastin-induced inhibition effect on cell growth, and notably increased the levels of MDA, ROS, iron, and Fe2+, while decreased GSH level in NSCLC cells. In the mechanism exploration, we discovered that PRKAA2 could activate the SLC7A11/GSH/GPx4 antioxidant pathway. The rescue experiments showed that SLC7A11 abrogated the inhibitive impacts of PRKAA2 repression on cellular proliferation, cell apoptosis, and ferroptosis in NSCLC. Besides, animal experiments proved that PRKAA2 enhanced NSCLC tumor growth in vivo. The results discovered that PRKAA2 accelerated the malignant progression, diminished apoptosis and ferroptosis in NSCLC through SLC7A11/GSH/GPX4 pathway. This study provide a novel target in the application of PRKAA2 for NSCLC treatment.

Natural products as Nrf2 modulators for ferroptosis inhibition in renal disease therapy: Recent progress and future prospects

BACKGROUND

The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2, NFE2L2) is a pivotal regulator of redox balance, metabolism, protein homeostasis and inflammation. Nrf2 is critically involved in both ferroptosis and renal diseases, and may serve as a significant target for many natural products in the treatment of renal diseases. However, a comprehensive overview on this topic is still lacking.

PURPOSE

To review the protective or therapeutic effects of natural products regulating Nrf2-related ferroptosis against various renal diseases.

METHODS

We systematically searched the electronic databases involving PubMed, Web of Science, Google Scholar, China National Knowledge Internet (CNKI), Wanfang Database and VIP Database. To ensure a comprehensive exploration, keywords including Nrf2, ferroptosis, natural products, phytochemicals, renal disease, kidney disease, kidney injury and nephropathy were employed.

RESULTS

Ferroptosis is deeply implicated in various kinds of renal diseases, notably including cisplatin-induced acute kidney injury, sepsis-associated acute kidney injury, renal ischemia/reperfusion injury, diabetic nephropathy, kidney stones and renal fibrosis. Nrf2 plays a regulatory role on many important genes related to iron metabolism, antioxidant system and lipid metabolism, thereby modulating ferroptosis. More than twenty natural products exert renoprotective effects by inhibiting ferroptosis via the regulation of Nrf2. This review presents a comprehensive overview of recent advancements in elucidating the ferroptosis involvement in renal diseases, the role of Nrf2 in regulating ferroptosis, and summarizes the renoprotective natural products as Nrf2 modulators for ferroptosis inhibition.

CONCLUSION

Through the comprehensive insights, this review clarifies the protective or therapeutic effects of natural products as Nrf2 modulators for ferroptosis inhibition in renal disease therapy, in the pursuit of providing new research ideas and directions for the treatment of renal diseases. Further drug development aimed at discovering more natural products and optimizing their utilization for disease treatment is necessary.

Deciphering ferroptosis in critical care: mechanisms, consequences, and therapeutic opportunities

Ischemia-reperfusion injuries (IRI) across various organs and tissues, along with sepsis, significantly contribute to the progression of critical illnesses. These conditions disrupt the balance of inflammatory mediators and signaling pathways, resulting in impaired physiological functions in human tissues and organs. Ferroptosis, a distinct form of programmed cell death, plays a pivotal role in regulating tissue damage and modulating inflammatory responses, thereby influencing the onset and progression of severe illnesses. Recent studies highlight that pharmacological agents targeting ferroptosis-related proteins can effectively mitigate oxidative stress caused by IRI in multiple organs, alleviating associated symptoms. This manuscript delves into the mechanisms and signaling pathways underlying ferroptosis, its role in critical illnesses, and its therapeutic potential in mitigating disease progression. We aim to offer a novel perspective for advancing clinical treatments for critical illnesses.

Ferroptosis driven by nanoparticles for tackling glioblastoma

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

Liraglutide and GLP-1(9-37) alleviated hepatic ischemia-reperfusion injury by inhibiting ferroptosis via GSK3β/Nrf2 pathway and SMAD159/Hepcidin/FTH pathway

Ferroptosis plays a pivotal role in the pathogenesis of ischemia-reperfusion injury (IRI). Liraglutide, as a GLP-1 receptor (GLP-1R) agonist, has exhibited extensive biological effects beyond its hypoglycemic action. Recent studies have shed light on the regulatory influence of Liraglutide on ferroptosis, yet the precise underlying mechanism remains elusive. GLP-1(9-37), as a metabolite of GLP-1, has a low affinity to GLP-1R. Its effect on ferroptosis remains unknown. In this study, we investigated the effects of Liraglutide and GLP-1(9-37) on the ferroptosis during hepatic ischemia-repferfusion (I/R), as well as the underlying specific mechanisms. We found that the administration of Liraglutide alleviated I/R-induced liver injury with less iron accumulation and lower lipid peroxidation, which was not entirely dependent on the presence of GLP-1R. Similarly, GLP-1(9-37) also exhibited these effects. Besides, both of them increased GPX4 expression and decreased COX2 expression. These effects were reversed by a High-Iron Diet. In vitro study showed similar results. In mechanism study, we found that both Liraglutide and GLP-1(9-37) treatment promoted the nuclear translocation of Nrf2 by inhibiting GSK-3β, thereby reducing lipid peroxides. Furthermore, they increased FTH and FTL expression via the SMAD159/Hepcidin pathway, which contributed to the decreased iron accumulation. In conclusion, this study determined that both Liraglutide and GLP-1(9-37) alleviated hepatic ischemia-reperfusion injury (HIRI) by suppressing ferroptosis via the activation of the GSK3β/Nrf2 pathway and the SMAD159/Hepcidin/FTH pathway.

Nrf2 Signaling in Renal Cell Carcinoma: A Potential Candidate for the Development of Novel Therapeutic Strategies

Renal cell carcinoma (RCC) is the most common type of kidney cancer arising from renal tubular epithelial cells and is characterized by a high aggressive behavior and invasiveness that lead to poor prognosis and high mortality rate. Diagnosis of RCC is generally incidental and occurs when the stage is advanced and the disease is already metastatic. The management of RCC is further complicated by an intrinsic resistance of this malignancy to chemotherapy and radiotherapy, which aggravates the prognosis. For these reasons, there is intense research focused on identifying novel biomarkers which may be useful for a better prognostic assessment, as well as molecular markers which could be utilized for targeted therapy. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcriptional factor that has been identified as a key modulator of oxidative stress response, and its overexpression is considered a negative prognostic feature in several types of cancers including RCC, since it is involved in various key cancer-promoting functions such as proliferation, anabolic metabolism and resistance to chemotherapy. Given the key role of Nrf2 in promoting tumor progression, this enzyme could be a promising biomarker for a more accurate prediction of RCC course and it can also represent a valuable therapeutic target. In this review, we provide a comprehensive literature analysis of studies that have explored the role of Nrf2 in RCC, underlining the possible implications for targeted therapy.

Down-regulation of HSPB1 and MGST1 promote ferroptosis and impact immune infiltration in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a leading cause of death in diabetic patients. Current therapies do not adequately resolve this problem and focus only on the optimal level of blood glucose for patients. Ferroptosis plays an important role in diabetes mellitus and cardiovascular diseases. However, the role of ferroptosis in DCM remains unclear. Differentially expressed ferroptosis-related genes (DE-FRGs) were identified by intersecting GSE26887 dataset and the Ferroptosis Database (FerrDb). The associations between the DE-FRGs and immune cells in DCM, estimated by CIBERSORTx algorithm, were analyzed. Using ow cytometry (FCM) to evaluated the infiltration of immune cells of myocardial tissues. The expression of DE-FRGs, Glutathione peroxidase 4 (GPX4) and Solute carrier family 7 member 11 (SLC7A11) were examined by real-time quantitative PCR and western blotting. 3 DE-FRGs were identified, which are Heat shock protein family B (small) member 1 (HSPB1), Microsomal glutathione S-transferase 1 (MGST1) and solute carrier family 40 member 1 (SLC40A1) respectively, and they were closely linked to immune cells in DCM. In vivo, the levels of CD8 + T cells, B cells and Treg cells were significantly decreased in the DCM group, while the levels of CD4 + T cells, M1 cells, M2 cells and monocytes were increased. Diabetes significantly decreased HSPB1 and MGST1 levels and increased ferroptosis compared to normal group. Furthermore, ferroptosis inhibitor ferrostatin-1 (Fer-1) alleviated high-fat diet (HFD)-induced cadiomyocyte injury and rescued the ferroptosis. This study suggests that ferroptosis related gene HSPB1 and MGST1 are closely related to immune cell infiltration, which may become therapeutic targets for DCM.

Nrf2: A critical participant in regulation of apoptosis, ferroptosis, and autophagy in gastric cancer

Nuclear factor erythroid 2-related factor-2 (Nrf2) is a specific transcription factor that maintains redox homeostasis by regulating the expression of anti-oxidative stress-related genes. Hyperactivation of Nrf2 is involved in tumor progression and is associated with chemoresistance in a large number of solid tumors. Programmatic cell death (PCD), such as apoptosis, ferroptosis, and autophagy, plays a crucial role in tumor development and chemotherapy sensitivity. Accumulating evidence suggests that some anti-tumor compounds and genes can induce massive production of reactive oxygen species (ROS) via inhibiting Nrf2 expression, which exacerbates oxidative stress and promotes Gastric cancer (GC) cell death, thereby enhancing the sensitivity of GC cells to chemotherapy-induced PCD. In this review, we summarize the role of antitumor drugs in interfering in three different types of PCD (apoptosis, ferroptosis, and autophagy) in GC cells by modulating Nrf2 expression, as well as the molecular mechanisms through which targeting Nrf2 brings about PCD and chemosensitivity. It is reasonable to believe that Nrf2 serves as a potential therapeutic target, and targeting Nrf2 by drug or gene regulation could provide a new strategy for the treatment of GC.

Panorama of artery endothelial cell dysfunction in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a fatal lung disease characterized by progressive pulmonary vascular remodeling. The initial cause of pulmonary vascular remodeling is the dysfunction of pulmonary arterial endothelial cells (PAECs), manifested by changes in the categorization of cell subtypes, endothelial programmed cell death, such as apoptosis, necroptosis, pyroptosis, ferroptosis, et al., overproliferation, senescence, metabolic reprogramming, endothelial-to-mesenchymal transition, mechanosensitivity, and regulation ability of peripheral cells. Therefore, it is essential to explore the mechanism of endothelial dysfunction in the context of PAH. This review aims to provide a comprehensive understanding of the molecular mechanisms underlying endothelial dysfunction in PAH. We highlight the developmental process of PAECs and changes in PAH and summarise the latest classification of endothelial dysfunction. Our review could offer valuable insights into potential novel EC-specific targets for preventing and treating PAH.

Characterizing the evolutionary dynamics of cancer proliferation in single-cell clones with SPRINTER

Proliferation is a key hallmark of cancer, but whether it differs between evolutionarily distinct clones co-existing within a tumor is unknown. We introduce the Single-cell Proliferation Rate Inference in Non-homogeneous Tumors through Evolutionary Routes (SPRINTER) algorithm that uses single-cell whole-genome DNA sequencing data to enable accurate identification and clone assignment of S- and G2-phase cells, as assessed by generating accurate ground truth data. Applied to a newly generated longitudinal, primary-metastasis-matched dataset of 14,994 non-small cell lung cancer cells, SPRINTER revealed widespread clone proliferation heterogeneity, orthogonally supported by Ki-67 staining, nuclei imaging and clinical imaging. We further demonstrated that high-proliferation clones have increased metastatic seeding potential, increased circulating tumor DNA shedding and clone-specific altered replication timing in proliferation- or metastasis-related genes associated with expression changes. Applied to previously generated datasets of 61,914 breast and ovarian cancer cells, SPRINTER revealed increased single-cell rates of different genomic variants and enrichment of proliferation-related gene amplifications in high-proliferation clones.

Unveiling Smyd-2's Role in Cytoplasmic Nrf-2 Sequestration and Ferroptosis Induction in Hippocampal Neurons After Cerebral Ischemia/Reperfusion

SET and MYND Domain-Containing 2 (Smyd-2), a specific protein lysine methyltransferase (PKMT), influences both histones and non-histones. Its role in cerebral ischemia/reperfusion (CIR), particularly in ferroptosis-a regulated form of cell death driven by lipid peroxidation-remains poorly understood. This study identifies the expression of Smyd-2 in the brain and investigates its relationship with neuronal programmed cell death (PCD). We specifically investigated how Smyd-2 regulates ferroptosis in CIR through its interaction with the Nuclear Factor Erythroid-2-related Factor-2 (Nrf-2)/Kelch-like ECH-associated protein (Keap-1) pathway. Smyd-2 knockout protects HT-22 cells from Erastin-induced ferroptosis but not TNF-α + Smac-mimetic-induced apoptosis/necroptosis. This neuroprotective effect of Smyd-2 knockout in HT-22 cells after Oxygen-Glucose Deprivation/Reperfusion (OGD/R) was reversed by Erastin. Smyd-2 knockout in HT-22 cells shows neuroprotection primarily via the Nuclear Factor Erythroid-2-related Factor-2 (Nrf-2)/Kelch-like ECH-associated protein (Keap-1) pathway, despite the concurrent upregulation of Smyd-2 and Nrf-2 observed in both the middle cerebral artery occlusion (MCAO) and OGD/R models. Interestingly, vivo experiments demonstrated that Smyd-2 knockout significantly reduced ferroptosis and lipid peroxidation in hippocampal neurons following CIR. Moreover, the Nrf-2 inhibitor ML-385 abolished the neuroprotective effects of Smyd-2 knockout, confirming the pivotal role of Nrf-2 in ferroptosis regulation. Cycloheximide (CHX) fails to reduce Nrf-2 expression in Smyd-2 knockout HT-22 cells. Smyd-2 knockout suppresses Nrf-2 lysine methylation, thereby promoting the Nrf-2/Keap-1 pathway without affecting the PKC-δ/Nrf-2 pathway. Conversely, Smyd-2 overexpression disrupts Nrf-2 nuclear translocation, exacerbating ferroptosis and oxidative stress, highlighting its dual regulatory role. This study underscores Smyd-2's potential for ischemic stroke treatment by disrupting the Smyd-2/Nrf-2-driven antioxidant capacity, leading to hippocampal neuronal ferroptosis. By clarifying the intricate interplay between ferroptosis and oxidative stress via the Nrf-2/Keap-1 pathway, our findings provide new insights into the molecular mechanisms of CIR and identify Smyd-2 as a promising therapeutic target.

Melatonin Improves H2O2-Induced Oxidative Stress in Sertoli Cells Through Nrf2-Keap1 Signaling Pathway

Background: Oxidative stress in the testicles of male livestock can cause reduced fertility. Melatonin is a natural product with antioxidant effects, but its specific antioxidant mechanism is still unclear. This study used calf testicular Sertoli cells as materials to explore the mechanism by which melatonin alleviates the oxidative stress of Sertoli cells, laying a foundation for improving the fertility of bulls. Methods: The optimal treatment concentrations of H2O2 and melatonin (MLT) were screened out using a CCK8 kit and MDA kit. Then, the cells were divided into four groups for treatment: control group, H2O2 treatment group, MLT treatment group, and H2O2 and MLT co-treatment group, then the MDA, ROS, GSH, and SOD contents were detected. Real-time quantitative PCR analysis and Western blot analysis were used to detect genes and proteins related to the Nrf2-Keap1 pathway. Immunofluorescence staining was used to analyze changes in Nrf2. Results: Research results show that the MDA content of cells in the group treated with H2O2 and MLT combined was significantly lower than that in the group treated with H2O2 alone, but there was no difference from the control group. Compared with the control group, the ROS level of cells in the H2O2-treated group significantly increased, and the content of GSH and SOD significantly decreased. Compared with the H2O2-treated group, the ROS level of cells in the H2O2 and MLT co-treated group significantly decreased, and the content of GSH and SOD increased significantly, but no difference from the control group. Similarly, MTL can alleviate the changes in cellular Nrf2, Keap1, HO-1, and NQO1 expression caused by H2O2. Conclusions: Melatonin activates the Nrf2-Keap1 signaling pathway in Sertoli cells, elevating the expression of HO-1 and NQO1, and thereby exerting its antioxidant capabilities.

Ferroptosis and Its Potential Role in the Physiopathology of Skeletal Muscle Atrophy

Skeletal muscle atrophy is a major health concern, severely affecting the patient's mobility and life quality. In the pathological process of skeletal muscle atrophy, with the progressive decline in muscle quality, strength, and function, the incidence of falling, fracture, and death is greatly increased. Unfortunately, there are no effective treatments for this devastating disease. Thus, it is imperative to investigate the exact pathological molecular mechanisms underlying the development of skeletal muscle atrophy and to identify new therapeutic targets. Decreased muscle mass, strength, and muscle fiber cross-sectional area are typical pathological features and manifestations of skeletal muscle atrophy. Ferroptosis, an emerging type of programmed cell death, is characterized by iron-dependent oxidative damage, lipid peroxidation, and reactive oxygen species accumulation. Notably, the understanding of its role in skeletal muscle atrophy is emerging. Ferroptosis has been found to play an important role in the intricate interplay between the pathological mechanisms of skeletal muscle atrophy and its progression caused by multiple factors. This provides new opportunities and challenges in the treatment of skeletal muscle atrophy. Therefore, we systematically elucidated the ferroptosis mechanism and its progress in skeletal muscle atrophy, aiming to provide a comprehensive insight into the intricate relationship between ferroptosis and skeletal muscle atrophy from the perspectives of iron metabolism and lipid peroxidation and to provide new insights for targeting the pathways related to ferroptosis and the treatment of skeletal muscle atrophy.

The interplay between cell death and senescence in cancer

Cellular senescence is a state of permanent proliferative arrest that occurs in response to DNA damage-inducing endogenous and exogenous stresses, and is often accompanied by dynamic molecular changes such as a senescence-associated secretory phenotype (SASP). Accumulating evidence indicates that age-associated increases in the upstream and downstream signals of regulated cell death, including apoptosis, necroptosis, pyroptosis, and ferroptosis, are closely related to the induction of cellular senescence and its phenotype. Furthermore, elevated levels of pro-inflammatory SASP factors with aging can be both a cause and consequence of several cell death modes, suggesting the reciprocal effects of cellular senescence and cells undergoing regulated cell death. Here, we review the critical molecular pathways of the regulated cell death forms and describe the crosstalk between aging-related signals and cancer. In addition, we discuss how targeting regulated cell death could be harnessed in therapeutic interventions for cancer. ABBREVIATIONS: Abbreviations that are not standard in this field are defined at their first occurrence in the article and are used consistently throughout the article.

The synergistic protective effects of paeoniflorin and β-ecdysterone against cardiac hypertrophy through suppressing oxidative stress and ferroptosis

Exploring feasible drugs for the treatment of pathological cardiac hypertrophy has always been a focus of cardiovascular disease research. Paeoniflorin (PF) and β-Ecdysterone (β-Ecd) are the main active components of Paeonia lactiflora and Achyranthes bidentata, which can be used for the treatment of cardiovascular diseases, but their mechanism of action remains unclear. This study focused on oxidative stress and ferroptosis to investigate the protective effects of PF and β-Ecd on cardiac hypertrophy in primary cardiomyocytes and C57BL/6 mice, utilizing the integration of CCK8 assays, ROS detection, molecular docking, real-time quantitative PCR, western blot, immunofluorescence, etc. The result of combination indices demonstrated a significant synergistic protective effect of PF and β-Ecd on cardiac hypertrophy. Furthermore, in vitro and in vivo studies further showed that the combination of PF and β-Ecd could improve the abnormalities of cell surface area, ANP, β-MHC, MDA, SOD, calcium ion, mitochondrial membrane potential and so on induced by cardiac hypertrophy through the inhibition effects of oxidative stress and iron metabolism, which might be closely related to the impact on the Nrf2/HO-1 and SLC7A11/GPX4 pathways. Altogether, this work revealed the mechanism of the combination of PF and β-Ecd in the treatment of cardiac hypertrophy from the aspects of suppressing oxidative stress and ferroptosis, aiming to promote effective treatment of the disease and the clinical application of PF and β-Ecd.

Dihydroartemisinin enhances the radiosensitivity of breast cancer by targeting ferroptosis signaling pathway through hsa_circ_0001610

OBJECTIVE

This study aimed to elucidate how DHA enhances the radiosensitivity of BC and to explain its potential mechanisms of action.

METHODS

The circular structure of hsa_circ_0001610 was confirmed by Sanger sequencing, RNase R treatment, RT-PCR analysis using gDNA or cDNA. Cellular localization of hsa_circ_0001610 and microRNA-139-5p (miR-139-5p) was detected by fluorescence in situ hybridization. Cell counting kit-8 assay, wound healing and colony formation tests for assessing cell proliferation, while flow cytometry was utilized to estimate cell cycle progression and apoptosis. Reactive oxygen species and malondialdehyde experiments were conducted to validate ferroptosis of BC cells. The expression of ncRNAs and mRNAs was quantified via qRT-PCR, and protein expression was analyzed using Western blot. The effects of hsa_circ_0001610 and DHA on radiosensitivity of BC in vivo were studied by establishing BC mice model.

RESULTS

In vivo and in vitro experimental results indicate that DHA promotes ferroptosis of BC cells at least partly by inhibiting hsa_circ_0001610/miR-139-5p/SLC7A11 pathway, thereby enhancing the radiosensitivity of BC cells.

CONCLUSIONS

Our findings showed that DHA can induce ferroptosis of BC cells by down-regulation of hsa_circ_0001610, thus enhancing radiosensitivity, suggesting a promising therapeutic strategy for enhancing BC radiosensitivity that is worthy of further exploration.

Exploring the Updated Roles of Ferroptosis in Liver Diseases: Mechanisms, Regulators, and Therapeutic Implications

Ferroptosis, a newly discovered mode of cell death, is a type of iron-dependent regulated cell death characterized by intracellular excessive lipid peroxidation and imbalanced redox. As the liver is susceptible to oxidative damage and the abnormal iron accumulation is a major feature of most liver diseases, studies on ferroptosis in the field of liver diseases are of great interest. Studies show that targeting the key regulators of ferroptosis can effectively alleviate or even reverse the deterioration process of liver diseases. System Xc- and glutathione peroxidase 4 are the main defense regulators of ferroptosis, while acyl-CoA synthetase long chain family member 4 is a key enzyme causing peroxidation in ferroptosis. Generally speaking, ferroptosis should be suppressed in alcoholic liver disease, non-alcoholic fatty liver disease, and drug-induced liver injury, while it should be induced in liver fibrosis and hepatocellular carcinoma. In this review, we summarize the main regulators involved in ferroptosis and then the mechanisms of ferroptosis in different liver diseases. Treatment options of drugs targeting ferroptosis are further concluded. Determining different triggers of ferroptosis can clarify the mechanism of ferroptosis occurs at both physiological and pathological levels.

ML385 promotes ferroptosis and radiotherapy sensitivity by inhibiting the NRF2-SLC7A11 pathway in esophageal squamous cell carcinoma

Radiotherapy is important in treating esophageal squamous cell carcinoma (ESCC) comprehensively. Resistance to radiotherapy is a prominent factor contributing to treatment failure in patients with ESCC. The objective of this study was to investigate the impact of ML385, an inhibitor of nuclear factor erythroid 2-related factor 2 (NRF2), on the radiosensitivity of ESCC and elucidate its underlying mechanism. We treated KYSE150 and KYSE510 cells with ML385 and ionising radiation separately or simultaneously, and observed the proliferation, apoptosis, cell cycle and ferroptosis of different conditions by colony formation assay and flow cytometry. Our findings reveal that NRF2 was activated by radiation and translocated from the cytoplasm to the nucleus after radiation. However, ML385 inhibited the expression and cytoplasm-to-nucleus translocation of NRF2. Compared with radiation, ML385 combined with radiation exhibited a significant inhibition on the clone formation ability of ESCC cells, induced apoptosis and promoted G2/M phase arrest. The treatment of ML385 combined with radiation markedly increased ROS and lipid peroxidation levels and decreased glutathione levels compared with the control, thus promoting the occurrence of ferroptosis. In addition, the expression trend of NRF2 was the same as that of proteins related ferroptosis, such as SLC7A11 and GPX4. After overexpression of SLC7A11, we found that significantly restored glutathione levels and alleviated ML385 combined with radiation-induced lipid peroxidation, indicating that ML385 plays a key role in radiotherapy sensitization by inhibiting the NRF2-SLC7A11 pathway. In vivo, ML385 also promoted the killing effect of radiation on xenografted tumours in nude mice. This study identifies NRF2 inhibitor ML385 as a radiosensitizer of ESCC, which highlights the therapeutic potential of the NRF2-SLC7A11 pathway and provides a deeper understanding of the mechanism of ferroptosis in esophageal squamous cell carcinoma.

Inhibition of GPX4 enhances CDK4/6 inhibitor and endocrine therapy activity in breast cancer

CDK4/6 inhibition in combination with endocrine therapy is the standard of care for estrogen receptor (ER+) breast cancer, and although cytostasis is frequently observed, new treatment strategies that enhance efficacy are required. Here, we perform two independent genome-wide CRISPR screens to identify genetic determinants of CDK4/6 and endocrine therapy sensitivity. Genes involved in oxidative stress and ferroptosis modulate sensitivity, with GPX4 as the top sensitiser in both screens. Depletion or inhibition of GPX4 increases sensitivity to palbociclib and giredestrant, and their combination, in ER+ breast cancer models, with GPX4 null xenografts being highly sensitive to palbociclib. GPX4 perturbation additionally sensitises triple negative breast cancer (TNBC) models to palbociclib. Palbociclib and giredestrant induced oxidative stress and disordered lipid metabolism, leading to a ferroptosis-sensitive state. Lipid peroxidation is promoted by a peroxisome AGPAT3-dependent pathway in ER+ breast cancer models, rather than the classical ACSL4 pathway. Our data demonstrate that CDK4/6 and ER inhibition creates vulnerability to ferroptosis induction, that could be exploited through combination with GPX4 inhibitors, to enhance sensitivity to the current therapies in breast cancer.

Targeting ALDH2 to augment platinum-based chemosensitivity through ferroptosis in lung adenocarcinoma

Ferroptosis is a regulated cell death driven by iron-dependent lipid peroxidation and associated with drug resistance in lung adenocarcinoma (LUAD). It's found that aldehyde dehydrogenase 2 (ALDH2), which is highly mutated in East Asian populations, is correlated with response to chemotherapy in LUAD patients. The rs671 variant knock-in, downregulation, and pharmacological inhibition of ALDH2 render LUAD cells more vulnerable to ferroptosis inducers and platinum-based chemotherapy. ALDH2 inhibits ferroptosis through the detoxification of 4-hydroxynonenal and malondialdehyde, the product of lipid peroxidation, as well as the production of NADH at the same time. Besides, ALDH2 deficiency leads to elevated intracellular pH (pHi), thus inhibiting the ERK/CREB1/GPX4 axis. Interestingly, ALDH2 is also regulated by CREB1, and the ALDH2 enzyme activity was decreased with elevated pHi. What's more, the elevated pHi caused by impaired ALDH2 activity promotes the biosynthesis of lipid droplets to counteract ferroptosis. At last, the effect of ALDH2 on ferroptosis and chemosensitivity is confirmed in patient-derived organoids and xenograft models. Collectively, this study demonstrates that ALDH2 deficiency confers sensitivity to platinum through ferroptosis in LUAD, and targeting ALDH2 is a promising new strategy to enhance the sensitivity of platinum-based chemotherapy for the treatment of LUAD patients.

Trimetazidine attenuates Ischemia/Reperfusion-Induced myocardial ferroptosis by modulating the Sirt3/Nrf2-GSH system and reducing Oxidative/Nitrative stress

Ferroptosis is a newly defined mode of cellular demise. The increasing investigation supports that ferroptosis is a crucial factor in the complex mechanisms of myocardial ischemia-reperfusion (I/R) injury. Hence, targeting ferroptosis is a novel strategy for treating myocardial injury. Although evidence suggests that trimetazidine (TMZ) is potentially efficacious against myocardial injury, the exact mechanism of this efficacy is yet to be fully elucidated. This study aimed to determine whether TMZ can act as a ferroptosis resistor and affect I/R-mediated myocardial injury. To this end, researchers have constructed in vitro and in vivo models of I/R using H9C2 cardiomyocytes, primary cardiomyocytes, and SD rats. Here, I/R mediated the onset of ferroptosis in vitro and in vivo, as reflected by excessive iron aggregation, GSH depletion, and the increase in lipid peroxidation. TMZ largely reversed this alteration and attenuated cardiomyocyte injury. Mechanistically, we found that TMZ upregulated the expression of Sirt3. Therefore, we used si-Sirt3 and 3-TYP to interfere with Sirt3 action in vitro and in vivo, respectively. Both si-Sirt3 and 3-TYP partly mitigated the inhibitory effect of TMZ on I/R-mediated ferroptosis and upregulated the expression of Nrf2 and its downstream target, GPX4-SLC7A11. These results indicate that TMZ attenuates I/R-mediated ferroptosis by activating the Sirt3-Nrf2/GPX4/SLC7A11 signaling pathway. Our study offers insights into the mechanism underlying the cardioprotective benefits of TMZ and establishes a groundwork for expanding its potential applications.

Mn(II)-Aloe-Emodin Nanoscale Coordination Polymer Enhances Ferroptosis by Synergistically Enhancing Reactive Oxygen Species Generation via the Nrf2-GPX4 Axis

Ferroptosis induction is particularly promising for cancer therapy when the apoptosis pathway is compromised. Current strategies in nanomedicine for inducing ferroptosis primarily focus on promoting the accumulation of reactive oxygen species (ROS). However, the presence of intracellular antioxidants, such as nuclear factor erythroid 2-related factor 2 (Nrf2), can limit the effectiveness of such therapy by activating detoxification systems and eliminating ROS. To overcome this challenge, we developed a synergistic ferroptosis-inducing agent by modifying manganese (Mn2+)-1,8-dihydroxy-3-hydroxymethyl-anthraquinone (aloe-emodin, AE) with polyvinyl pyrrolidone (PVP) to create nanoparticles (MAP NPs). In the tumor microenvironment, these NPs degraded and released AE and Mn(II), facilitating the generation of ROS and Mn(IV) through a Fenton-like reaction between hydrogen peroxide (H2O2) and Mn(II). Mn(IV) subsequently interacts with glutathione (GSH) to induce a cyclic catalytic effect, and the depletion of GSH diminished the activation of glutathione-dependent peroxidase 4 (GPX4). Furthermore, AE inhibits the activity of Nrf2 and depleted GSH, thereby synergistically enhancing antitumor efficacy. Here it is demonstrated that MAP NPs effectively generate a robust ROS storm within tumor cells, suggesting that high-performance ferroptosis therapy is effective. Additionally, the inclusion of Mn(II) in the MAP NPs enables real-time monitoring of therapeutic efficacy via magnetic resonance T1-weighted contrast imaging.

TCF4 trinucleotide repeat expansions and UV irradiation increase susceptibility to ferroptosis in Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD), the leading indication for corneal transplantation in the U.S., causes loss of corneal endothelial cells (CECs) and corneal edema leading to vision loss. FECD pathogenesis is linked to impaired response to oxidative stress and environmental ultraviolet A (UVA) exposure. Although UVA is known to cause nonapoptotic oxidative cell death resulting from iron-mediated lipid peroxidation, ferroptosis has not been characterized in FECD. We investigated the roles of genetic background and UVA exposure in causing CEC degeneration in FECD. Using ungenotyped FECD patient surgical samples, we found increased levels of cytosolic ferrous iron (Fe2+) and lipid peroxidation in end-stage diseased tissues compared with healthy controls. Using primary and immortalized cell cultures modeling the TCF4 intronic trinucleotide repeat expansion genotype, we found altered gene and protein expression involved in ferroptosis compared to controls including elevated levels of Fe2+, basal lipid peroxidation, and the ferroptosis-specific marker transferrin receptor 1. Increased cytosolic Fe2+ levels were detected after physiologically relevant doses of UVA exposure, indicating a role for ferroptosis in FECD disease progression. Cultured cells were more prone to ferroptosis induced by RSL3 and UVA than controls, indicating ferroptosis susceptibility is increased by both FECD genetic background and UVA. Finally, cell death was preventable after RSL3 induced ferroptosis using solubilized ubiquinol, indicating a role for anti-ferroptosis therapies in FECD. This investigation demonstrates that genetic background and UVA exposure contribute to iron-mediated lipid peroxidation and cell death in FECD, and provides the basis for future investigations of ferroptosis-mediated disease progression in FECD.

Associations of Vitamin D With GPX4 and Iron Parameters in Chronic Obstructive Pulmonary Disease Patients: A Case-Control Study

Background: Vitamin D deficiency elevates the risk of chronic obstructive pulmonary disease (COPD) patients. Iron parameters elevation and glutathione peroxidase 4 (GPX4) reduction are involved in the process of COPD. The goal is to explore the associations of vitamin D with GPX4 and iron parameters in COPD patients through a case-control study. Methods: COPD patients and control subjects were enrolled. Serum samples and lung tissues were collected. Serum vitamin D and iron levels and pulmonary ferritin and GPX4 expressions were determined. In addition, human pulmonary epithelial cells (BEAS-2B) were incubated with 1,25(OH)2D3 (100 nM), the active form of vitamin D3. Then, vitamin D receptor (VDR) and nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) signaling were detected. Results: In patients with COPD, serum 25-hydroxyvitamin D (25(OH)D) decreased, and iron and ferritin levels in serum and lung tissues increased. Furthermore, pulmonary expression of GPX4 was reduced. Correlative analyzes indicated that lung function was inversely correlated with iron parameters and positively correlated with GPX4. The results showed that serum 25(OH)D deficiency was associated with an elevation in serum iron parameters and a reduction in pulmonary GPX4. In addition, VDR- and Nrf-2-positive lung nuclei were decreased in COPD patients than in control subjects. In patients with COPD, the results indicated a positive relationship between VDR and Nrf-2. Further analysis revealed that Nrf-2-positive nuclei were negatively correlated with iron parameters. In vitro experiments found that 1,25(OH)2D3 treatment activated VDR signaling and elevated the expression of Nrf-2 and GPX4 in BEAS-2B cells. Conclusions: Vitamin D deficiency is positively associated with GPX4 reduction and iron parameters elevation in COPD patients. It is recommended to explore the role of vitamin D supplementation in the progression of COPD.

Transcription factor Nrf2 regulating the interaction of p16 facilitates hydroquinone-induced malignant transformation of TK6 cells by accelerating cell proliferation

The nuclear factor erythroid 2-related factor 2 (Nrf2) is overexpressed in multiple tumor cells. Nevertheless, the role of Nrf2 in malignant transformation induced by hydroquinone (HQ) is unknown. Here, we hypothesized that Nrf2 might participate in HQ-induced malignant transformation of TK6 cells, a line of normal human lymphoblastoid cells, by accelerating cell proliferation and regulating cell cycle progression. The data indicated that TK6 cells chronically exposed to HQ continuously activated Nrf2-Keap1 signaling pathway. Furthermore, we found that defects in Nrf2 inhibited cell proliferation and prevented cells from entering S phase from G1 phase. Mechanistically, Nrf2 is involved in cell cycle abnormalities induced by prolonged exposure to HQ by binding to p16, thereby activating the p16/Rb signaling pathway. Taken together, Nrf2 might be a potential driver of carcinogenesis that promotes malignant cell proliferation and affects cell cycle distribution.

Nrf2/Keap1/ARE regulation by plant secondary metabolites: a new horizon in brain tumor management

Brain cancer is regarded as one of the most life-threatening forms of cancer worldwide. Oxidative stress acts to derange normal brain homeostasis, thus is involved in carcinogenesis in brain. The Nrf2/Keap1/ARE pathway is an important signaling cascade responsible for the maintenance of redox homeostasis, and regulation of anti-inflammatory and anticancer activities by multiple downstream pathways. Interestingly, Nrf2 plays a somewhat, contradictory role in cancers, including brain cancer. Nrf2 has traditionally been regarded as a tumor suppressor since its cytoprotective functions are considered to be the principle cellular defense mechanism against exogenous and endogenous insults, such as xenobiotics and oxidative stress. However, hyperactivation of the Nrf2 pathway supports the survival of normal as well as malignant cells, protecting them against oxidative stress, and therapeutic agents. Plants possess a pool of secondary metabolites with potential chemotherapeutic/chemopreventive actions. Modulation of Nrf2/ARE and downstream activities in a Keap1-dependant manner, with the aid of plant-derived secondary metabolites exhibits promise in the management of brain tumors. Current article highlights the effects of Nrf2/Keap1/ARE cascade on brain tumors, and the potential role of secondary metabolites regarding the management of the same.

NRF2 and Thioredoxin Reductase 1 as Modulators of Interactions between Zinc and Selenium

BACKGROUND

Selenium and zinc are essential trace elements known to regulate cellular processes including redox homeostasis. During inflammation, circulating selenium and zinc concentrations are reduced in parallel, but underlying mechanisms are unknown. Accordingly, we modulated the zinc and selenium supply of HepG2 cells to study their relationship.

METHODS

HepG2 cells were supplied with selenite in combination with a short- or long-term zinc treatment to investigate intracellular concentrations of selenium and zinc together with biomarkers describing their status. In addition, the activation of the redox-sensitive transcription factor NRF2 was analyzed.

RESULTS

Zinc not only increased the nuclear translocation of NRF2 after 2 to 6 h but also enhanced the intracellular selenium content after 72 h, when the cells were exposed to both trace elements. In parallel, the activity and expression of the selenoprotein thioredoxin reductase 1 (TXNRD1) increased, while the gene expression of other selenoproteins remained unaffected or was even downregulated. The zinc effects on the selenium concentration and TXNRD activity were reduced in cells with stable NRF2 knockdown in comparison to control cells.

CONCLUSIONS

This indicates a functional role of NRF2 in mediating the zinc/selenium crosstalk and provides an explanation for the observed unidirectional behavior of selenium and zinc.

Synergistic induction of ferroptosis by targeting HERC1-NCOA4 axis to enhance the photodynamic sensitivity of osteosarcoma

Over the past 30 years, the survival rate for osteosarcoma (OS) has remained stagnant, indicating persistent challenges in diagnosis and treatment. Photodynamic therapy (PDT) has emerged as a novel and promising treatment modality for OS. Despite apoptosis being the primary mechanism attributed to PDT, it fails to overcome issues such as low efficacy and resistance. Ferroptosis, a Fe2+-dependent cell death process, has the potential to enhance PDT's efficacy by increasing reactive oxygen species (ROS) through the Fenton reaction. In this study, we investigated the anti-tumor mechanism of PDT and introduced an innovative therapeutic strategy that synergistically induces apoptosis and ferroptosis. Furthermore, we have identified HERC1 as a pivotal protein involved in the ubiquitination and degradation of NCOA4, while also uncovering a potential regulatory factor involving NRF2. Ultimately, by targeting the HERC1-NCOA4 axis during PDT, we successfully achieved full activation of ferroptosis, which significantly enhanced the anti-tumor efficacy of PDT. In conclusion, these findings provide new theoretical evidence for further characterizing mechanism of PDT and offer new molecular targets for the treatment of OS.

Advances in the Effects of Heat Stress on Ovarian Granulosa Cells: Unveiling Novel Ferroptosis Pathways

Heat stress has been one of the key research areas for researchers due to the wide-ranging effects and complex mechanisms of action of its stress product reactive oxygen species (ROS). The aim of this paper is to comprehensively review and summarize the effects of heat stress on ovarian granulosa cells and their mechanism of action. We systematically reviewed the effects of heat stress on ovarian granulosa cells, including intracellular steroid hormone changes, oxidative stress, apoptosis, and mitochondrial function. Meanwhile, this paper discusses in detail several major mechanisms by which heat stress induces apoptosis in ovarian granulosa cells, such as through the activation of apoptosis-related genes, induction of endoplasmic reticulum stress, and the mitochondrial pathway. In addition, we analyzed the mechanism of ferroptosis in ovarian granulosa cells under heat stress conditions, summarized the potential association between heat stress and ferroptosis in light of the existing literature, and explored the key factors in the mechanism of action of heat stress, such as the signaling pathways of Nrf2/Keap1, HSPs, and JNK, and analyzed their possible roles in the process of ferroptosis. Finally, this paper provides an outlook on the future research direction, describing the possible interaction between heat stress and ferroptosis, with a view to providing a theoretical basis for further understanding and revealing the complex mechanism of ferroptosis occurrence in ovarian granulosa cells under heat stress.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

Ferroptosis in glioma therapy: advancements in sensitizing strategies and the complex tumor-promoting roles

Ferroptosis, an iron-dependent form of non-apoptotic regulated cell death, is induced by the accumulation of lipid peroxides on cellular membranes. Over the past decade, ferroptosis has emerged as a crucial process implicated in various physiological and pathological systems. Positioned as an alternative modality of cell death, ferroptosis holds promise for eliminating cancer cells that have developed resistance to apoptosis induced by conventional therapeutics. This has led to a growing interest in leveraging ferroptosis for cancer therapy across diverse malignancies. Gliomas are tumors arising from glial or precursor cells, with glioblastoma (GBM) being the most common malignant primary brain tumor that is associated with a dismal prognosis. This review provides a summary of recent advancements in the exploration of ferroptosis-sensitizing methods, with a specific focus on their potential application in enhancing the treatment of gliomas. In addition to summarizing the therapeutic potential, this review also discusses the intricate interplay of ferroptosis and its potential tumor-promoting roles within gliomas. Recognizing these dual roles is essential, as they could potentially complicate the therapeutic benefits of ferroptosis. Exploring strategies aimed at circumventing these tumor-promoting roles could enhance the overall therapeutic efficacy of ferroptosis in the context of glioma treatment.

RNA m6A modification in ferroptosis: implications for advancing tumor immunotherapy

The pursuit of innovative therapeutic strategies in oncology remains imperative, given the persistent global impact of cancer as a leading cause of mortality. Immunotherapy is regarded as one of the most promising techniques for systemic cancer therapies among the several therapeutic options available. Nevertheless, limited immune response rates and immune resistance urge us on an augmentation for therapeutic efficacy rather than sticking to conventional approaches. Ferroptosis, a novel reprogrammed cell death, is tightly correlated with the tumor immune environment and interferes with cancer progression. Highly mutant or metastasis-prone tumor cells are more susceptible to iron-dependent nonapoptotic cell death. Consequently, ferroptosis-induction therapies hold the promise of overcoming resistance to conventional treatments. The most prevalent post-transcriptional modification, RNA m6A modification, regulates the metabolic processes of targeted RNAs and is involved in numerous physiological and pathological processes. Aberrant m6A modification influences cell susceptibility to ferroptosis, as well as the expression of immune checkpoints. Clarifying the regulation of m6A modification on ferroptosis and its significance in tumor cell response will provide a distinct method for finding potential targets to enhance the effectiveness of immunotherapy. In this review, we comprehensively summarized regulatory characteristics of RNA m6A modification on ferroptosis and discussed the role of RNA m6A-mediated ferroptosis on immunotherapy, aiming to enhance the effectiveness of ferroptosis-sensitive immunotherapy as a treatment for immune-resistant malignancies.

Ferroptosis-targeting drugs in breast cancer

In 2020, breast cancer surpassed lung cancer as the most common cancer in the world for the first time. Due to the resistance of some breast cancer cell lines to apoptosis, the therapeutic effect of anti-breast cancer drugs is limited. According to recent report, the susceptibility of breast cancer cells to ferroptosis affects the progress, prognosis and drug resistance of breast cancer. For instance, roblitinib induces ferroptosis of trastuzumab-resistant human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells by diminishing fibroblast growth factor receptor 4 (FGFR4) expression, thereby augmenting the susceptibility of these cells to HER2-targeted therapies. In tamoxifen-resistant breast cancer cells, Fascin exacerbates their resistance by repressing solute carrier family 7 member 11 (SLC7A11) expression, which in turn heightens their responsiveness to tamoxifen. In recent years, Chinese herbs extracts and therapeutic drugs have been demonstrated to elicit ferroptosis in breast cancer cells by modulating a spectrum of regulatory factors pertinent to ferroptosis, including SLC7A11, glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long chain family member 4 (ACSL4), and haem oxygenase 1 (HO-1). Here, we review the roles and mechanisms of Chinese herbal extracts and therapeutic drugs in regulating ferroptosis in breast cancer, providing potential therapeutic options for anti-breast cancer.

Targeting ferroptosis opens new avenues in gliomas

Gliomas are one of the most challenging tumors to treat due to their malignant phenotype, brain parenchymal infiltration, intratumoral heterogeneity, and immunosuppressive microenvironment, resulting in a high recurrence rate and dismal five-year survival rate. The current standard therapies, including maximum tumor resection, chemotherapy with temozolomide, and radiotherapy, have exhibited limited efficacy, which is caused partially by the resistance of tumor cell death. Recent studies have revealed that ferroptosis, a newly defined programmed cell death (PCD), plays a crucial role in the occurrence and progression of gliomas and significantly affects the efficacy of various treatments, representing a promising therapeutic strategy. In this review, we provide a comprehensive overview of the latest progress in ferroptosis, its involvement and regulation in the pathophysiological process of gliomas, various treatment hotspots, the existing obstacles, and future directions worth investigating. Our review sheds light on providing novel insights into manipulating ferroptosis to provide potential targets and strategies of glioma treatment.

Dual role of Nrf2 signaling in hepatocellular carcinoma: promoting development, immune evasion, and therapeutic challenges

Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and ranks as the third leading cause of cancer-related mortality globally. The liver performs a wide range of tasks and is the primary organ responsible for metabolizing harmful substances and foreign compounds. Oxidative stress has a crucial role in growth and improvement of hepatocellular carcinoma (HCC). Nuclear factor erythroid 2 (1)-related factor 2 (Nrf2) is an element that regulates transcription located in the cytoplasm. It controls the balance of redox reactions by stimulating the expression of many genes that depend on antioxidant response elements. Nrf2 has contrasting functions in the normal, healthy liver and HCC. In the normal liver, Nrf2 provides advantageous benefits, while in HCC it promotes harmful effects that support the growth and survival of HCC. Continuous activation of Nrf2 has been detected in HCC and promotes its advancement and aggressiveness. In addition, Activation of Nrf2 may lead to immune evasion, weakening the immune cells' ability to attack tumors and thereby promoting tumor development. Furthermore, chemoresistance in HCC, which is considered a form of stress response to chemotherapy medications, significantly impedes the effectiveness of HCC treatment. Stress management is typically accomplished by activating specific signal pathways and chemical variables. One important element in the creation of chemoresistance in HCC is nuclear factor-E2-related factor 2 (Nrf2). Nrf2 is a transcription factor that regulates the activation and production of a group of genes that encode proteins responsible for protecting cells from damage. This occurs through the Nrf2/ARE pathway, which is a crucial mechanism for combating oxidative stress within cells.

Cold atmospheric plasma enhances SLC7A11-mediated ferroptosis in non-small cell lung cancer by regulating PCAF mediated HOXB9 acetylation

Lung cancer is a leading cause of cancer death worldwide, with high incidence and poor survival rates. Cold atmospheric plasma (CAP) technology has emerged as a promising therapeutic approach for cancer treatment, inducing oxidative stress in malignant tissues without causing thermal damage. However, the role of CAP in regulating lung cancer cell ferroptosis remains unclear. Here, we observed that CAP effectively suppressed the growth and migration abilities of lung cancer cells, with significantly increased ferroptotic cell death, lipid peroxidation, and decreased mitochondrial membrane potential. Mechanistically, CAP regulates SLC7A11-mediated cell ferroptosis by modulating HOXB9. SLC7A11, a potent ferroptosis suppressor, was markedly reduced by HOXB9 knockdown, while it was enhanced by overexpressing HOXB9. The luciferase and ChIP assays confirmed that HOXB9 can directly target SLC7A11 and regulate its gene transcription. Additionally, CAP enhanced the acetylation modification level of HOXB9 by promoting its interaction with acetyltransferase p300/CBP-associated factor (PCAF). Acetylated HOXB9 affects its protein ubiquitination modification level, which in turn affects its protein stability. Notably, the upregulation of SLC7A11 and HOXB9 mitigated the suppressive effects of CAP on ferroptosis status, cell proliferation, invasion, and migration in lung cancer cells. Furthermore, animal models have also confirmed that CAP can inhibit the progression of lung cancer in vivo. Overall, this study highlights the significance of the downregulation of the HOXB9/SLC7A11 axis by CAP treatment in inhibiting lung cancer, offering novel insights into the potential mechanisms and therapeutic strategies of CAP for lung cancer.

Multifaceted bioinformatic analysis of m6A-related ferroptosis and its link with gene signatures and tumour-infiltrating immune cells in gliomas

Whether N6-Methyladenosine (m6A)- and ferroptosis-related genes act on immune responses to regulate glioma progression remains unanswered. Data of glioma and corresponding normal brain tissues were fetched from the TCGA database and GTEx. Differentially expressed genes (DEGs) were identified for GO and KEGG enrichment analyses. The FerrDb database was based to yield ferroptosis-related DEGs. Hub genes were then screened out using the cytoHubba database and validated in clinical samples. Immune cells infiltrating into the glioma tissues were analysed using the CIBERSORT R script. The association of gene signature underlying the m6A-related ferroptosis with tumour-infiltrating immune cells and immune checkpoints in low-grade gliomas was analysed. Of 6298 DEGs enriched in mRNA modifications, 144 were ferroptosis-related; NFE2L2 and METTL16 showed the strongest positive correlation. METTL16 knockdown inhibited the migrative and invasive abilities of glioma cells and induced ferroptosis in vitro. NFE2L2 was enriched in the anti-m6A antibody. Moreover, METTL16 knockdown reduced the mRNA stability and level of NFE2L2 (both p < 0.05). Proportions of CD8+ T lymphocytes, activated mast cells and M2 macrophages differed between low-grade gliomas and normal tissues. METTL16 expression was negatively correlated with CD8+ T lymphocytes, while that of NFE2L2 was positively correlated with M2 macrophages and immune checkpoints in low-grade gliomas. Gene signatures involved in the m6A-related ferroptosis in gliomas were identified via bioinformatic analyses. NFE2L2 interacted with METTL16 to regulate the immune response in low-grade gliomas, and both molecules may be novel therapeutic targets for gliomas.

Bryophyllum pinnatum (Lam.) Oken: unravelling therapeutic potential and navigating toxicity

Bryophyllum pinnatum (Lam.) Oken, a multipurpose medicinal herb, has drawn much interest for its therapeutic qualities from both traditional and modern medicine systems. Many active secondary metabolites, such as bufadienolides, triterpenes, phenols, alkaloids, glycosides, lipids, flavonoids, and organic acids, are responsible for the plant's curative properties. B. pinnatum exhibits a noteworthy significance in oncological research by exhibiting its ability to modify numerous pathways, which may suggest a potential anticancer impact. The herb is recommended for treating lithiasis, a common cause of renal failure, due to its effectiveness in dissolving stones and avoiding crystal formation. The plant has a major impact on diabetes, especially type II diabetes. Moreover, the versatility of B. pinnatum extends to its examination in connection to COVID-19. However, caution is warranted, as B. pinnatum has been reported to possess toxicity attributed to the presence of bufadienolides in its metabolic profile. A comprehensive investigation is essential to thoroughly understand and confirm the synthesis of potentially hazardous compounds. This is crucial for minimizing their presence and ensuring the safe consumption of B. pinnatum among diverse populations of organisms. This review highlights the various medical uses of B. pinnatum, including its ability to effectively treat kidney and liver diseases, as well as its anti-leishmanial, neuropharmacological, antibacterial, immunosuppressive, anti-tumour, and cytotoxic effects. While extensively employed in both traditional and scientific domains, the plant's complete medicinal potential, molecular mechanisms, safety profile, and pharmacodynamics remain ambiguous, rendering it an ideal candidate for pioneering research endeavours.

Research status and potential applications of circRNAs affecting colorectal cancer by regulating ferroptosis

Ferroptosis is an emerging form of non-apoptotic programmed cell death (PCD), characterized by iron-mediated oxidative imbalance. This process plays a significant role in the development and progression of various tumors, including colorectal cancer, gastric cancer, and others. Circular RNA (circRNA) is a stable, non-coding RNA type with a single-stranded, covalently closed loop structure, which is intricately linked to the proliferation, invasion, and metastasis of tumor cells. Recent studies have shown that many circRNAs regulate various pathways leading to cellular ferroptosis. Colorectal cancer, known for its high incidence and mortality among cancers, is marked by a poor prognosis and pronounced chemoresistance. To enhance our understanding of how circRNA-mediated regulation of ferroptosis influences colorectal cancer development, this review systematically examines the mechanisms by which specific circRNAs regulate ferroptosis and their critical role in the progression of colorectal cancer. Furthermore, it explores the potential of circRNAs as biomarkers and therapeutic targets in colorectal cancer treatment, offering a novel approach to clinical management.

Metabolically activated proteostasis regulators that protect against erastin-induced ferroptosis

We previously showed that the proteostasis regulator compound AA147 (N-(2-hydroxy-5-methylphenyl)benzenepropanamide) potently protects against neurotoxic insults, such as glutamate-induced oxytosis. Though AA147 is a selective activator of the ATF6 arm of the unfolded protein response in non-neuronal cells, AA147-dependent protection against glutamate toxicity in cells of neuronal origin is primarily mediated through activation of the NRF2 oxidative stress response. AA147 activates NRF2 through a mechanism involving metabolic activation of AA147 by endoplasmic reticulum (ER) oxidases, affording an AA147-based quinone methide that covalently targets the NRF2 repressor protein KEAP1. Previous results show that the 2-amino-p-cresol A-ring of AA147 is required for NRF2 activation, while the phenyl B-ring of AA147 is amenable to modification. Here we explore whether the protease-sensitive amide linker between the A- and B-rings of this molecule can be modified to retain NRF2 activation. We show that replacement of the amide linker of AA147 with a carbamate linker retains NRF2 activation in neuronal cells and improves protection against neurotoxic insults, including glutamate-induced oxytosis and erastin-induced ferroptosis. Moreover, we demonstrate that inclusion of this carbamate linker facilitates identification of next-generation AA147 analogs with improved cellular tolerance and activity in disease-relevant assays.

Advances in understanding the role of lncRNA in ferroptosis

LncRNA is a type of transcript with a length exceeding 200 nucleotides, which was once considered junk transcript with no biological function during the transcription process. In recent years, lncRNA has been shown to act as an important regulatory factor at multiple levels of gene expression, affecting various programmed cell death modes including ferroptosis. Ferroptosis, as a new form of programmed cell death, is characterized by a deficiency of cysteine or inactivation of glutathione peroxidase, leading to depletion of glutathione, aggregation of iron ions, and lipid peroxidation. These processes are influenced by many physiological processes, such as the Nrf2 pathway, autophagy, p53 pathway and so on. An increasing number of studies have shown that lncRNA can block the expression of specific molecules through decoy effect, guide specific proteins to function, or promote interactions between molecules as scaffolds. These modes of action regulate the expression of key factors in iron metabolism, lipid metabolism, and antioxidant metabolism through epigenetic or genetic regulation, thereby regulating the process of ferroptosis. In this review, we snapshotted the regulatory mechanism of ferroptosis as an example, emphasizing the regulation of lncRNA on these pathways, thereby helping to fully understand the evolution of ferroptosis in cell fate.

Nrf2 in human cancers: biological significance and therapeutic potential

The nuclear factor-erythroid 2-related factor 2 (Nrf2) is able to control the redox balance in the cells responding to oxidative damage and other stress signals. The Nrf2 upregulation can elevate the levels of antioxidant enzymes to support against damage and death. In spite of protective function of Nrf2 in the physiological conditions, the stimulation of Nrf2 in the cancer has been in favour of tumorigenesis. Since the dysregulation of molecular pathways and mutations/deletions are common in tumors, Nrf2 can be a promising therapeutic target. The Nrf2 overexpression can prevent cell death in tumor and by increasing the survival rate of cancer cells, ensures the carcinogenesis. Moreover, the induction of Nrf2 can promote the invasion and metastasis of tumor cells. The Nrf2 upregulation stimulates EMT to increase cancer metastasis. Furthermore, regarding the protective function of Nrf2, its stimulation triggers chemoresistance. The natural products can regulate Nrf2 in the cancer therapy and reverse drug resistance. Moreover, nanostructures can specifically target Nrf2 signaling in cancer therapy. The current review discusses the potential function of Nrf2 in the proliferation, metastasis and drug resistance. Then, the capacity of natural products and nanostructures for suppressing Nrf2-mediated cancer progression is discussed.

Induction of Ferroptosis by an Amalgam of Extracellular Vesicles and Iron Oxide Nanoparticles Overcomes Cisplatin Resistance in Lung Cancer

Extracellular vesicles (EVs) hold potential as effective carriers for drug delivery, providing a promising approach to resolving challenges in lung cancer treatment. Traditional treatments, such as with the chemotherapy drug cisplatin, encounter resistance in standard cell death pathways like apoptosis, prompting the need to explore alternative approaches. This study investigates the potential of iron oxide nanoparticles (IONP) and EVs to induce ferroptosis-a regulated cell death mechanism-in lung cancer cells. We formulated a novel EV and IONP-based system, namely 'ExoFeR', and observed that ExoFeR demonstrated efficient ferroptosis induction, evidenced by downregulation of ferroptosis markers (xCT/SLC7A11 and GPX4), increased intracellular and mitochondrial ferrous iron levels, and morphological changes in mitochondria. To enhance efficacy, tumor-targeting transferrin (TF)-conjugated ExoFeR (ExoFeR TF ) was developed. ExoFeR TF outperformed ExoFeR, exhibiting higher uptake and cell death in lung cancer cells. Mechanistically, nuclear factor erythroid 2-related factor 2 (Nrf2)-a key regulator of genes involved in glutathione biosynthesis, antioxidant responses, lipid metabolism, and iron metabolism-was found downregulated in the ferroptotic cells. Inhibition of Nrf2 intracellular translocation in ExoFeR TF -treated cells was also observed, emphasizing the role of Nrf2 in modulating ferroptosis-dependent cell death. Furthermore, ExoFeR and ExoFeR TF demonstrated the ability to sensitize chemo-resistant cancer cells, including cisplatin-resistant lung cancer patient-derived tumoroid organoids. In summary, ExoFeR TF presents a promising and multifaceted therapeutic approach for combating lung cancer by intrinsically inducing ferroptosis and sensitizing chemo-resistant cells.

Epigenetic repression of de novo cysteine synthetases induces intra-cellular accumulation of cysteine in hepatocarcinoma by up-regulating the cystine uptake transporter xCT

BACKGROUND

The metabolic reprogramming of amino acids is critical for cancer cell growth and survival. Notably, intracellular accumulation of cysteine is often observed in various cancers, suggesting its potential role in alleviating the oxidative stress associated with rapid proliferation. The liver is the primary organ for cysteine biosynthesis, but much remains unknown about the metabolic alterations of cysteine and their mechanisms in hepatocellular carcinoma cells.

METHODS

RNA-seq data from patients with hepatocarcinoma were analyzed using the TNMplot database. The underlying mechanism of the oncogenic alteration of cysteine metabolism was studied in mice implanted with BNL 1ME A.7 R.1 hepatocarcinoma.

RESULTS

Database analysis of patients with hepatocellular carcinoma revealed that the expression of enzymes involved in de novo cysteine synthesis was down-regulated accompanying with increased expression of the cystine uptake transporter xCT. Similar alterations in gene expression have also been observed in a syngeneic mouse model of hepatocarcinoma. The enhanced expression of DNA methyltransferase in murine hepatocarcinoma cells caused methylation of the upstream regions of cysteine synthesis genes, thereby repressing their expression. Conversely, suppression of de novo cysteine synthesis in healthy liver cells induced xCT expression by up-regulating the oxidative-stress response factor NRF2, indicating that reduced de novo cysteine synthesis repulsively increases cystine uptake via enhanced xCT expression, leading to intracellular cysteine accumulation. Furthermore, the pharmacological inhibition of xCT activity decreased intracellular cysteine levels and suppressed hepatocarcinoma tumor growth in mice.

CONCLUSIONS

Our findings indicate an underlying mechanism of the oncogenic alteration of cysteine metabolism in hepatocarcinoma and highlight the efficacy of alteration of cysteine metabolism as a viable therapeutic target in cancer.