The Role of Cystine/Glutamate Antiporter SLC7A11/xCT in the Pathophysiology of Cancer

The critical role of ferroptosis in virus-associated hematologic malignancies and its potential value in antiviral-antitumor therapy

Epstein-Barr Virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV), and human T-cell leukemia virus type 1 (HTLV-1) are key infectious agents linked to the development of various hematological malignancies, including Hodgkin's lymphoma, non-Hodgkin's lymphoma, and adult T-cell leukemia/lymphoma. This review highlights the critical knowledge gaps in understanding the role of ferroptosis, a novel form of cell death, in virus-related tumors. We focus on how ferroptosis influences the host cell response to these viral infections, revealing groundbreaking mechanisms by which the three viruses differentially regulate core pathways of ferroptosis, such as iron homeostasis, lipid peroxidation, and antioxidant systems, thereby promoting malignant transformation of host cells. Additionally, we explore the potential of antiviral drugs and ferroptosis modulators in the treatment of virus-associated hematological malignancies.

Assembly fluorescent probe-based detection of gamma-glutamyl transferase activity in tumor

Detection of γ-glutamyltransferase (GGT) activity in cancer cells is crucial for understanding tumor progression and metabolic dysregulation. However, the accurate detection of GGT remains challenging due to its complex intracellular distribution and interactions with other enzymes. This study introduces a novel hemicyanine-based sensor, named GP, designed for the sensitive and real-time detection of GGT in tumor cells. By leveraging the unique optical properties of hemicyanines in the near-infrared spectrum, the GP sensor enables deeper tissue penetration and minimizes background interference, which is essential for tumor imaging. The sensor incorporates a GGT-specific recognition sequence that selectively binds to GGT, facilitating precise monitoring of its enzymatic activity through fluorescence signals generated by intramolecular charge transfer (ICT). Our results show that the GP probe exhibits high selectivity for GGT, distinguishing it from other biological molecules. Evaluation under tumor-relevant conditions confirms the probe's robustness for both research and clinical applications. In cancer cell models, GP successfully detects increased GGT activity, suggesting its potential for non-invasive monitoring of tumor dynamics. Overall, this study demonstrates GP as a promising tool for the accurate detection of GGT activity, with significant implications for understanding cancer-related metabolic changes and tumor biology.

A novel FTO-targeting nanodrug induces disulfidptosis and ameliorates the suppressive tumor immune environment to treat uveal melanoma

Uveal melanoma (UM) is the most prevalent primary ocular malignancy in adults, with high lethality and limited effective treatment options. Despite identified driver mutations in GNAQ, GNA11, and BAP1, therapeutic advancements have been minimal. This study highlights the pivotal role of N6-methyladenosine (m6A) modifications in UM pathogenesis and progression, focusing on the demethylase FTO as a therapeutic target. Elevated FTO expression in UM tissues correlates with decreased m6A levels, increased aggressiveness, and poor prognosis. The FTO inhibitor meclofenamic acid (MA) restored m6A levels, upregulated SLC7A11, and induced disulfidptosis, a unique form of cell death triggered by GSH depletion and NADPH consumption. To address MA's limitations in bioavailability and tumor targeting, we developed an MA-loaded nucleic acid nanodrug (SNAMA). SNAMA demonstrated effective tumor growth inhibition in orthotopic and metastatic UM models through GSH-responsive release and m6A-mediated disulfidptosis activation. Incorporating a PD-L1 aptamer into SNAMA further improved tumor targeting and immune modulation, enhancing therapeutic efficacy. This study identifies FTO as a critical target for UM therapy and introduces SNAMA-apt as a promising nanodrug. The findings offer a foundation for m6A-targeted approaches in UM and other malignancies, addressing bioavailability, targeting, and immune evasion challenges.

Toxicological evaluation and metabolic profiling of earthworms (Eisenia fetida) after exposure to microplastics and acetochlor

In recent years, microplastic (MPs) and pesticide pollution have become prominent issues in the field of soil pollution. This research endeavored to assess the impact of ultraviolet radiation (UV) on the characteristics of microplastics, as well as investigating the toxicological effect on earthworms (Eisenia fetida) when subjected to the dual stressors of microplastics and acetochlor (ACT). This research found that microplastics aged under UV were more prone to wear and tear in the environment, and produced more oxygen-containing functional groups. Chronic exposure experiments were conducted on ACT and aged-MPs. The results revealed that aged-MPs and ACT inhibited earthworm growth, induced oxidative stress, and caused damage to both the body cavity muscles and the intestinal lumen. Compared with individual exposure, combined exposure increased the oxidative products (superoxide dismutase (SOD) and catalase (CAT)) and altered the expression levels of related genes (TCTP and Hsp70) significantly. PE inflicted more significant harm to the earthworm intestinal tissue compared to PBAT. By 1H-NMR metabolomics, the investigation delved into the repercussions of PE and ACT on the metabolic pathways of earthworms. Exposure to ACT and PE can disrupt the stability of intestinal membranes stability, amino acid metabolism, neuronal function, oxidative stress and energy metabolism. Overall, the research revealed that combined exposure of MPs and ACT exacerbated the negative effects on earthworms significantly, and contributed valuable insights to environmental risk assessment of the combined toxicity of microplastics and pesticides.

lncRNA CASC9 stabilizes MUC1 by binding to U2AF2 to inhibit cellular ferroptosis and alleviate LPS-induced cell injury

BACKGROUND

Sepsis-induced acute lung injury (ALI) is a critical condition with a limited number of treatment options. The regulatory role of long noncoding RNA cancer susceptibility candidate 9 (lncRNA CASC9) in ferroptosis, a specific type of cell death, has been linked to this condition.

METHODS

In this study, HPAEpiCs were treated with lipopolysaccharide (LPS) to model sepsis-induced acute lung injury. Various assays were employed, including RNA immunoprecipitation (RIP) and RNA pull-down to investigate lncRNA CASC9 interactions with U2 small nuclear RNA auxiliary factor 2 (U2AF2) and Mucin 1 (MUC1), Cell Counting Kit-8 (CCK-8) for cell viability, ELISA for inflammatory cytokines, Calcein-AM/PI staining for live/dead cell visualization, Reagent kit detection of lipid reactive oxygen species (ROS) and Malondialdehyde (MDA) assays for oxidative stress markers, iron and Glutathione (GSH) assays for redox status, qPCR for gene expression, and western blot for protein levels.

RESULTS

The expression of lncRNA CASC9 was significantly decreased in LPS-induced cell models. Overexpression of lncRNA CASC9 reduced ferroptosis, as indicated by improved cell viability, decreased inflammatory cytokines, and restored redox homeostasis (reduced MDA and ROS, and iron levels, and increased GSH level). The lncRNA CASC9 interacts with U2AF2 to stabilize MUC1 mRNA, enhance MUC1 expression and reduce ferroptosis. Knockdown of U2AF2 reversed these effects, highlighting lncRNA CASC9's regulatory role in ferroptosis via MUC1 stabilization. MUC1 overexpression similarly reduced LPS-induced ferroptosis, supporting the protective role of the lncRNA CASC9/U2AF2/MUC1 pathway.

CONCLUSION

This study demonstrated that lncRNA CASC9 regulates sepsis-induced ALI by stabilizing MUC1 mRNA through U2AF2 interaction, thereby inhibiting ferroptosis.

Activation, interaction and intimation of Nrf2 pathway and their mutational studies causing Nrf2 associated cancer

Responses against infection trigger several signaling pathways that lead to the production of cytokines, these cytokines release ROS and RNS, damaging DNA and proteins turn into various diseases including cancer. To combat these harmful cytokines, the Nrf2 pathway is activated. The gene NFE2L2 encodes Nrf2, which is divided into seven conserved domains (Neh1-7). The DLG and ETGE motifs, conserved sequences of amino acid in the Neh2 domain of Nrf2, bind to the BTB domain of Keap1. BTB domain promotes Keap1's homodimerization resulting in Cul3 recruitment providing scaffold formation to E2 ubiquitin ligase to form ubiquitin complex. Under normal conditions, this complex regularly degrades Nrf2. However, once the cell is exposed to oxidative stress by ROS interaction with Keap1 resulting in conformational changes that stabilize the Nrf2. Nrf2 further concentrates on the nucleus where it binds with the transcriptional factor to perform the desired genes transcription for synthesizing SOD, GSH, CAT, and various other proteins which reduce the ROS levels preventing certain diseases. To prevent cells from oxidative stress, molecular hydrogen activates the Nrf2 pathway. To activate the Nrf2 pathway, molecular hydrogen oxidizes the iron porphyrin which acts as an electrophile and interacts with Keap1's cysteine residue.

Epigenetic and post-translational modifications in ferroptosis regulation and hepatocellular carcinoma: New frontiers in therapeutic targeting

Hepatocellular carcinoma (HCC), the predominant kind of liver cancer, continues to be a significant contributor to cancer-related deaths globally, influenced by intricate molecular processes and strong resistance to existing chemotherapy. Iron-dependent lipid peroxidation induces ferroptosis, a controlled form of cell death that plays a crucial role in inhibiting tumor growth and treatment resistance in HCC. Recent research has shown that epigenetic modifications, such as DNA methylation, histone modifications, regulation by non-coding RNAs (ncRNAs), and post-translational modification (PTM) like ubiquitination, phosphorylation, acetylation, and methylation, play a crucial role in fine-tuning ferroptosis. These alterations alter the structure of chromatin, gene expression, and protein function, thereby affecting cancer cells' fate. This review emphasizes the complex functions of epigenetic and post-translational alterations in controlling ferroptosis, providing valuable insights into their potential as therapeutic targets in HCC. The unraveling of these pathways offers a significant opportunity for novel therapies targeted at surmounting drug resistance and enhancing patient outcomes in liver cancer.

ca-circSCN8A Promotes HPASMCs Ferroptosis via LLPS Initiated R-Loop

BACKGROUND

Ferroptosis has been implicated in pulmonary hypertension (PH), and chromatin-associated RNAs are increasingly recognized as key regulators of this process. However, the detailed mechanism remains unexplored.

METHODS

Bioinformatics, Sanger sequencing, and RNase R digestion were used to identify the upregulation of ca-circSCN8A. Functional gain and loss assays were used to unveil the role of ca-circSCN8A in hypoxic redox-dependent ferroptosis in human pulmonary arterial smooth muscle cells and a PH mice model. Interaction between ca-circSCN8A and FUS was detected via RNA immunoprecipitation and pull-down assays. Fluorescence recovery after photobleaching, ChIRP-qPCR, malondialdehyde, reduced glutathione, and glutathione were conducted to explore the potential molecular mechanism.

RESULTS

ca-circSCN8A was identified and confirmed to be upregulated in PH. Its overexpression promoted hypoxia-induced ferroptosis in human pulmonary arterial smooth muscle cells. Under hypoxic conditions, ca-circSCN8A recruited EP300 to facilitate the lactylation of FUS, triggering the formation of a ca-circSCN8A/FUS/EP300 complex via liquid-liquid phase separation. Liquid-liquid phase separation maintained the stability of the R-loop formed by ca-circSCN8A and ferroptosis-related gene SLC7A11 (solute carrier family 7 member 11) promoter that inhibits its transcription, further result in the disruption of the redox homeostasis and causing ferroptosis in human pulmonary arterial smooth muscle cells.

CONCLUSIONS

ca-circSCN8A recruits EP300 to promote the lactylation of FUS, thereby driving liquid-liquid phase separation-mediated complex formation with FUS and EP300. This process enables ca-circSCN8A to form an R-loop with the nonhost SLC7A11 promoter, contributing to the regulation of hypoxia-induced ferroptosis in human pulmonary arterial smooth muscle cells. This study provides the first evidence that circRNAs can form R-loops with nonhost genes in a liquid-liquid phase separation-dependent manner. Our findings highlight ca-circSCN8A as a crucial regulator of ferroptosis in hypoxic PH and a potential therapeutic target for PH.

Advancing glioblastoma therapy: Learning from the past and innovations for the future

Marred by a median survival of only around 12-15 months coupled with poor prognosis and effective therapeutic deprived drug armory, treatment/management of glioblastoma has proved to be a daunting task. Surgical resection, flanked by radiotherapy and chemotherapy with temozolomide, stands as the standard of care; however, this trimodal therapy often manifests limited efficacy due to the heterogeneous and highly infiltrative nature of GBM cells. In addition, the existence of the blood-brain barrier, tumor microenvironment, and the immunosuppressive nature of GBM, along with the encountered resistance of GBM cells towards conventional therapy, also hinders the therapeutic applications of chemotherapeutics in GBM. This review presents key insights into the molecular pathology of GBM, including genetic mutations, signaling pathways, and tumor microenvironment characteristics. Recent innovations such as immunotherapy, oncolytic viral therapies, vaccines, nanotechnology, electric field, and cancer neuroscience, as well as their clinical progress, have been covered. In addition, this compilation also encompasses a discussion on the role of personalized medicine in tailoring treatments based on individual tumor profiles, an approach that is gradually shifting the paradigm in GBM management. Endowed with the learnings imbibed from past failures coupled with the zeal to embrace novel/multidisciplinary approaches, researchers appear to be on the right track to pinpoint more effective and durable solutions in the context of GBM treatment.

Electroacupuncture improves cognitive function in high-fat diet/streptozocin-induced type 2 diabetic mice by inhibiting autophagy-related ferroptosis

At present, there lacks a definitive pharmaceutical intervention or therapeutic approach for diabetes-associated cognitive impairment. Herein, we delved into the impact of electroacupuncture on cognitive function in high-fat diet/streptozocin (HFD/STZ)-induced type 2 diabetes mellitus (T2DM) mice and underlying mechanisms. Hippocampal insulin resistance was determined by western blot analysis. Cognitive function was evaluated by Morris water maze test. The morphology of the hippocampal neurons was observed through hematoxylin & eosin staining and Nissl staining. Synaptic plasticity was assessed by western blot analysis. Immunofluorescence, immunohistochemistry, western blot and real-time PCR were employed to detect the levels of ferroptosis markers, autophagy markers, and netrin-1. Electroacupuncture treatment exhibited ameliorative outcomes on hippocampal insulin resistance, spatial learning, memory function, neuronal damage, and synaptic plasticity in T2DM mice. Furthermore, it effectively suppressed neuronal ferroptosis in the hippocampus by upregulating GPX4 and SLC7A11 expression, and reducing 4-HNE expression. Meanwhile, electroacupuncture intervention increased the levels of Beclin1 and LC3II/LC3I, as well as decreased the levels of p62 and phosphorylated-mTOR in the hippocampus of T2DM mice, suggesting that electroacupuncture facilitated autophagy activation by inhibiting mTOR activity. 3-MA-mediated autophagy inhibition undermined the beneficial effects of electroacupuncture on neuronal ferroptosis and cognitive deficits in T2DM mice. Additionally, the beneficial effects of electroacupuncture on autophagy and ferroptosis was achieved by upregulation of netrin-1 in the hippocampus. Our study revealed that electroacupuncture therapy inhibited neuronal ferroptosis via the activation of autophagy, thereby ameliorating cognitive deficits in T2DM mice.

Identification of shared important genes associated with ferroptosis across different etiologies of acute lung injury

Acute lung injury (ALI) of different etiologies has shared pathophysiologic process, from which we speculated that ALI of different etiologies may share common molecular features. While the shared genetic characteristics of ALI remain unclear. In this paper, we aimed to identify shared ferroptosis-associated and bottleneck genes from acute lung injury of different etiologies. Firstly, we extracted five groups of gene sets related to three distinct models of ALI from the Gene Expression Omnibus (GEO) database. Then, through the utilization of weighted gene co-expression network analysis (WGCNA), we identified 3 significant gene modules and ascertained 7 shared co-expressed genes affected by these models. Subsequently, through the utilization of differential gene expression analysis and protein-protein interaction network analysis for the 3 gene modules, the shared bottleneck gene Slc7a11 was identified. Moreover, the 7 shared co-expressed genes subjected to these three ALI models were used to identify shared ferroptosis-associated genes via the FerrDb database. Finally, the key gene Slc7a11 was confirmed and validated. In addition, we observed that Slc7a11 is both a driver and a suppressor gene in the FerrDb database. Interestingly, we found the expression level of Slc7a11 was significantly upregulated in the three ALI models. Experimentally, we confirmed the expression of Slc7a11 in rat ALI tissues by using immunofluorescence staining and real-time polymerase chain reaction (qRT-PCR) assays. Collectively, our findings complement the exploration of the shared pathogenesis of ALI. There are genetic features shared by ALI of different etiology and the increased expression of Slc7a11 was identified in the three different etiologies of ALI, which can improve our understanding of the shared molecular mechanisms underlying ALI.

The intersection of ferroptosis and non-coding RNAs: a novel approach to ovarian cancer

Understanding the core principles of ovarian cancer has been significantly improved through the exploration of Ferroptosis, a type of cell death triggered by iron that leads to an increase in lipid peroxides. Current research has shed light on the critical functions of non-coding RNAs, such as circRNAs, lncRNAs, and miRNAs, in regulating ferroptosis in ovarian cancer. The aim of this paper is to comprehensively analyze how ncRNAs influence the development of ferroptosis in ovarian cancer cells. In-depth exploration is undertaken to understand the intricate ways in which ncRNAs regulate essential elements of ferroptosis, including iron management and lipid peroxidation levels. We also investigate their significant involvement in the progression of this type of cellular demise. It should be emphasized that ncRNAs can impact the synthesis of crucial proteins, such as GPX4, a key contributor to the cellular defense against oxidation, and ACSL4, involved in lipid formation. In addition, we examine the correlation between ncRNAs and well-known pathways associated with oxidative stress and cell death. The consequences of these discoveries are noteworthy, since focusing on particular ncRNAs could potentially render ovarian cancer cells more vulnerable to ferroptosis, effectively combating drug resistance problems. This discussion highlights the growing significance of ncRNAs in governing ferroptosis and their potential as useful biomarkers and treatment targets for ovarian cancer. We intend to promote additional research into the involvement of ncRNAs in controlling ferroptosis, based on current findings, with the ultimate goal of informing targeted therapeutic strategies and improving long-term treatment outcomes for individuals suffering from OC.

Synergistic Strategies for Lung Cancer Immunotherapy: Combining Phytochemicals and Immune-Checkpoint Inhibitors

Lung cancer remains one of the most widespread and deadliest malignant tumors globally, with a particularly high mortality rate among all cancers. Recently, immunotherapy, particularly immune checkpoint inhibitors (ICIs), has emerged as a crucial treatment strategy for lung cancer patients, following surgical intervention, radiotherapy, chemotherapy, and targeted drug therapies. However, the therapeutic limitations are caused owing to their low response rate and undesirable side effects such as immune-related pneumonitis. Therefore, developing new strategies to improve the efficacy of ICIs while minimizing immune-related adverse events will be crucial for cancer immunotherapy. The tumor immune microenvironment plays a significant role in the success of lung cancer immunotherapy, and the immunosuppressive characteristics of the immune microenvironment are one of the major obstacles to the poor immunotherapeutic effect. Phytochemicals, naturally occurring compounds in plants, have shown promise in enhancing cancer immunotherapy by remodeling the immunosuppressive microenvironment, offering the potential to increase the efficacy of ICIs. Therefore, this review summarizes the associated mechanisms of phytochemicals remodeling the immunosuppressive microenvironment in lung cancer. Additionally, the review will focus on the synergistic effects of combining phytochemicals with ICIs, aiming to improve anticancer efficacy and reduce side effects, which may hopefully offer novel strategies to overcome current limitations in immunotherapy.

Unlocking the potential of organopalladium complexes for high-grade serous ovarian cancer therapy

High-Grade Serous Ovarian Cancer (HGSOC) is the most common and lethal subtype of ovarian cancer, known for its high aggressiveness and extensive genomic alterations. Typically diagnosed at an advanced stage, HGSOC presents formidable challenges in drug therapy. The limited efficacy of standard treatments, development of chemoresistance, scarcity of targeted therapies, and significant tumor heterogeneity render this disease incurable with current treatment options, highlighting the urgent need for novel therapeutic approaches to improve patient outcomes. In this study we report a straightforward and stereoselective synthetic route to novel Pd(II)-vinyl and -butadienyl complexes bearing a wide range of monodentate and bidentate ligands. Most of the synthesized complexes exhibited good to excellent in vitro anticancer activity against ovarian cancer cells. Particularly promising is the water-soluble complex bearing two PTA (1,3,5-triaza-7-phosphaadamantane) ligands and the Pd(II)-butadienyl fragment. This compound combines excellent cytotoxicity towards cancer cells with substantial inactivity towards non-cancerous ones. This derivative was selected for further studies on ex vivo tumor organoids and in vivo mouse models, which demonstrate its remarkable efficacy with surprisingly low collateral toxicity even at high dosages. Moreover, this class of compounds appears to operate through a ferroptotic mechanism, thus representing the first such example for an organopalladium compound.

NINJ1 in Cell Death and Ferroptosis: Implications for Tumor Invasion and Metastasis

NINJ1 was initially recognized for its role in nerve regeneration and cellular adhesion. Subsequent studies have uncovered its participation in cancer progression, where NINJ1 regulates critical steps in tumor metastasis, such as cell migration and invasion. More recently, NINJ1 has emerged as a multifunctional protein mediating plasma membrane rupture (PMR) in several lytic cell death processes, including apoptosis, necroptosis, and pyroptosis. However, its role in ferroptosis-an iron-dependent form of lytic cell death characterized by lipid peroxidation-remained unclear until 2024. Ferroptosis is a tumor suppression mechanism that may be particularly relevant to detached and metastatic cancer cells. This review explores the role of NINJ1 in tumor invasion and metastasis, focusing on its regulation of ferroptosis via a non-canonical mechanism distinct from other cell deaths. We discuss the process of ferroptosis and its implications for cancer invasion and metastasis. Furthermore, we review recent studies highlighting the diverse roles of NINJ1 in ferroptosis regulation, including its canonical function in PMR and its non-canonical function of modulating intracellular levels of glutathione (GSH) and coenzyme A (CoA) via interaction with xCT anti-porter. Given that ferroptosis has been associated with tumor suppression, metastasis, the elimination of treatment-resistant cancer cells, and tumor dormancy, NINJ1's modulation of ferroptosis presents a promising therapeutic target for inhibiting metastasis. Understanding the dual role of NINJ1 in promoting or restraining ferroptosis depending on cellular context could open avenues for novel anti-cancer strategies to enhance ferroptotic vulnerability in metastatic tumors.

Insights on the crosstalk among different cell death mechanisms

The phenomenon of cell death has garnered significant scientific attention in recent years, emerging as a pivotal area of research. Recently, novel modalities of cellular death and the intricate interplay between them have been unveiled, offering insights into the pathogenesis of various diseases. This comprehensive review delves into the intricate molecular mechanisms, inducers, and inhibitors of the underlying prevalent forms of cell death, including apoptosis, autophagy, ferroptosis, necroptosis, mitophagy, and pyroptosis. Moreover, it elucidates the crosstalk and interconnection among the key pathways or molecular entities associated with these pathways, thereby paving the way for the identification of novel therapeutic targets, disease management strategies, and drug repurposing.

Microbes, macrophages, and melanin: a unifying theory of disease as exemplified by cancer

It is widely accepted that cancer mostly arises from random spontaneous mutations triggered by environmental factors. Our theory challenges the idea of the random somatic mutation theory (SMT). The SMT does not fit well with Charles Darwin's theory of evolution in that the same relatively few mutations would occur so frequently and that these mutations would lead to death rather than survival of the fittest. However, it would fit well under the theory of evolution, if we were to look at it from the vantage point of pathogens and their supporting microbial communities colonizing humans and mutating host cells for their own benefit, as it does give them an evolutionary advantage and they are capable of selecting genes to mutate and of inserting their own DNA or RNA into hosts. In this article, we provide evidence that tumors are actually complex microbial communities composed of various microorganisms living within biofilms encapsulated by a hard matrix; that these microorganisms are what cause the genetic mutations seen in cancer and control angiogenesis; that these pathogens spread by hiding in tumor cells and M2 or M2-like macrophages and other phagocytic immune cells and traveling inside them to distant sites camouflaged by platelets, which they also reprogram, and prepare the distant site for metastasis; that risk factors for cancer are sources of energy that pathogens are able to utilize; and that, in accordance with our previous unifying theory of disease, pathogens utilize melanin for energy for building and sustaining tumors and metastasis. We propose a paradigm shift in our understanding of what cancer is, and, thereby, a different trajectory for avenues of treatment and prevention.

Research progress of cysteine transporter SLC7A11 in endocrine and metabolic diseases

SLC7A11, often called xCT, belongs to the SLC family of transporters, which mediates the cellular influx of cystine and the efflux of glutamate. These transport processes are crucial for synthesizing GSH, enhancing the cell's ability to mitigate oxidative stress (OS). Emerging studies highlight the pivotal role of OS in triggering and exacerbating various metabolic and endocrine disorders, underlining the critical importance of regulating SLC7A11 expression levels. This study reviews the diverse roles of SLC7A11 in endocrine and metabolic diseases, examining its relationship with the metabolism of three key nutrients: proteins and amino acids, carbohydrates, and lipids. Additionally, the involvement of SLC7A11 in the onset and development of various common endocrine and metabolic disorders is analyzed. Additionally, it provides an overview of the current clinical and experimental use of SLC7A11 inhibitors and agonists. This review aims to offer insightful perspectives into the involvement of SLC7A11 in endocrine and metabolic pathologies and to foster the development of innovative therapeutic strategies that target SLC7A11.

Role of solute carrier transporters in ovarian cancer (Review)

Solute carrier (SLC) transporters are involved in various biological processes associated with metabolic reprogramming and cancer, supporting the increased requirement of nutrients and energy. Over the past decade, there have been significant advancements in understanding the expression and function of SLCs in ovarian cancer (OC). This gynecological condition has a high mortality rate and limited treatment options; thus, early diagnosis remains a target clinically. OC exhibits complexity and heterogeneity, resulting in different clinical characteristics, resistance to chemotherapy drugs and poor prognosis. Additionally, SLCs have a different expression pattern between healthy and tumor tissue, and consequently, their inhibition or activation could modify signaling pathways involved in the tumor growth process, such as cell proliferation, apoptosis and drug accumulation. The present review aims to consolidate current data to provide a comprehensive understanding of the potential importance of SLCs in OC. Additionally, it seeks to offer guidance for further research on utilizing SLCs as prognostic biomarkers and therapeutic targets.

The LKB1-AMPK Signaling Axis Modulates Ferroptosis in Fibroblast-Like Synoviocytes Derived from Rheumatoid Arthritis

BACKGROUND/OBJECTIVES

Ferroptosis is a type of regulated cell death that involves iron-dependent accumulation of lipid peroxides. Because fibroblast-like synoviocytes (FLSs) in patients with rheumatoid arthritis (RA) have a hyperplastic and inflammatory phenotype, selective induction of FLS cell death is considered a potential treatment strategy for RA. Liver kinase B1 (LKB1)-activated AMP-activated protein kinase (AMPK) signaling regulates the inflammation and migration of RA FLSs, contributing to RA pathogenesis. Here, we aimed to determine the effect of LKB1 knockdown on the ferroptosis pathway in RA FLSs.

METHODS

Synovial tissues from patients with RA (n = 5) were transfected with siRNA targeting LKB1. Cell viability was evaluated via 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and Annexin V/7-aminoactinomycin D (7-AAD) staining. Ferroptosis was assessed using boron-dipyrromethene (BODIPY) lipid probes, a ferrous ion detection kit, and a glutathione detection assay. Expression of hallmarks of various cell death pathways was analyzed using western blot.

RESULTS

RA FLS cell death significantly increased after transfection with LKB1 siRNA (p < 0.01). Lipid peroxidation was upregulated and the expression levels of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) were suppressed in LKB1-deficient cells. Additionally, LKB1 inhibition made RA FLSs highly sensitive to ferroptosis. When RA FLSs were incubated with an activator of AMPK, LKB1 knockdown-mediated inhibition was restored through upregulated expression of GPX4 and SLC7A11.

CONCLUSIONS

these findings suggest that LKB1-AMPK signaling is essential to protect RA FLSs against ferroptosis.

In defence of ferroptosis

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

Exploring the Diagnostic and Prognostic Predictive Values of Ferroptosis-related Markers in Lung Adenocarcinoma

BACKGROUND

Lung Adenocarcinoma (LUAD), a common and aggressive form of lung cancer, poses significant treatment challenges due to its low survival rates.

AIM

To better understand the role of ferroptosis driver genes in LUAD, this study aimed to explore their diagnostic and prognostic significance, as well as their impact on treatment approaches and tumor immune function in LUAD.

METHODS

To accomplish the defined goals, a comprehensive methodology incorporating both in silico and wet lab experiments was employed. A comprehensive analysis was conducted on a total of 233 ferroptosis driver genes obtained from the FerrDB database. Utilizing various TCGA databases and the RT-qPCR technique, the expression profiles of 233 genes were examined. Among them, TP53, KRAS, PTEN, and HRAS were identified as hub genes with significant differential expression. Notably, TP53, KRAS, and HRAS exhibited substantial up-regulation, while PTEN demonstrated significant down-regulation at both the mRNA and protein levels in LUAD samples. The dysregulation of hub genes was further associated with poor overall survival in LUAD patients. Additionally, targeted bisulfite-sequencing (bisulfite-seq) analysis revealed aberrant promoter methylation patterns linked to the dysregulation of hub genes.

RESULTS & DISCUSSION

Furthermore, hub genes were found to participate in diverse oncogenic pathways, highlighting their involvement in LUAD tumorigenesis. By leveraging the diagnostic and prognostic potential of ferroptosis driver hub genes (TP53, KRAS, PTEN, and HRAS), significant advancements can be made in the understanding and management of LUAD pathogenesis.

CONCLUSION

Therapeutic targeting of these genes using specific drugs holds great promise for revolutionizing drug discovery and improving the overall survival of LUAD patients.

SLC7A11 Inhibitors Represent a Promising Therapeutic Target by Facilitating the Induction of Ferroptosis in Breast Cancer

It is predicted with near certainty that an estimated 310,720 women will be diagnosed with invasive breast carcinoma in 2024, while the number of men will be significantly lower at around 2,800, highlighting the alarming prevalence of this cancer across the sexes. The Solute Carrier Family 7 Member 11(SLC7A11) gene is vital for the exchange of extracellular cystine for glutamate at a 1:1 ratio and its expression is significantly increased in various tumors. Numerous research studies have shown that SLC7A11 expression is fine-tuned at several levels, contributing to its pharmacological functions in tumors, such as maintaining cellular redox balance, promoting cell proliferation, and influencing ferroptosis. Many studies suggest that reducing SLC7A11 expression and activity may be beneficial for cancer treatment, making it a promising target for therapy. However, recent findings also suggest that inhibiting SLC7A11 in certain scenarios may increase the survival of cancer cells and promote drug resistance. This review begins with a brief overview of the properties of SLC7A11, including its structural features and physiological functions, followed by a summary of its potential regulators. We then delve deeper into its role in cancer, particularly breast cancer, and explore the relationships between SLC7A11 and ferroptosis, proliferation, metastasis, and therapeutic resistance. Consequently, more customized therapeutic approaches should be considered when targeting SLC7A11 in the context of breast cancer. Thus, high expression of SLC7A11 is associated with poor prognosis in breast cancer, and various inhibitors have been identified that can effectively target this transporter. Innovative therapeutic strategies, including immunotherapies targeting SLC7A11, can potentially reduce tumor growth and metastasis in breast cancer models.

SLC7A11 Expression Is Up-Regulated in HPV- and Tobacco-Associated Lung Cancer

High-risk human papillomaviruses (HR-HPVs) are the etiological agents of cervical, anogenital, and a subset of oropharyngeal cancers. In addition, HR-HPVs have been detected in lung carcinomas worldwide, even though the role of these viruses in this type of cancer is not fully understood. This study evaluated the presence of HPV in a cohort of 204 lung cancer cases by multiplex polymerase chain reaction (PCR)-Luminex. In addition, we used transcriptomic approaches to characterize the HPV-associated gene expression profile in the context of tobacco-smoke-associated lung cancer. HPV16 was detected in 8/204 lung carcinomas (4.0%). Through a significance analysis of microarrays (SAM) analysis, we found that the solute carrier family 7-member 11 (SLC7A11/xCT) gene (an antiporter that mediates the uptake of extracellular cystine) is up-regulated in tobacco-smoke- and HPV-associated lung cancers. In addition, SLC7A11 up-regulation correlates with both HR-HPV16 E6/E7 expression and tobacco smoke exposure in lung epithelial cells. Furthermore, we found decreased survival in HPV/SLC7A11-positive patients with lung cancer when compared to HPV/SLC7A11-negative cases. Thus, this study suggests that SLC7A11 up-regulation is associated with both HPV-positive and tobacco-smoke-associated lung carcinomas, with a potential association with clinical prognosis.

Ferroptosis: insight into the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignances in the world, with high morbidity and mortality. Due to the hidden onset of symptoms, there are huge obstacles in early diagnosis, recurrence, metastasis and drug resistance. Although great strides have been made in the treatment of HCC, effective treatment options are still limited and achieving longer survival for patients remains urgent. Ferroptosis is a novel type of programmed cell death that is mainly caused by iron-dependent oxidative damage. With further investigations, ferroptosis has been proved to be associated with the occurrence and development of various tumors. This article reviews the regulatory mechanism and signal transduction pathways of ferroptosis, investigates the complex relationship between autophagy, sorafenib resistance and immunotherapy with ferroptosis involved in HCC, providing new ideas and directions for the treatment of HCC.

New Emerging Therapeutic Strategies Based on Manipulation of the Redox Regulation Against Therapy Resistance in Cancer

Background: Resistance to standard therapeutic methods, including chemotherapy, immunotherapy, and targeted therapy, remains a critical challenge in effective cancer treatment. Redox homeostasis modification has emerged as a promising approach to address medication resistance. Objective: This review aims to explore the mechanisms of redox alterations and signaling pathways contributing to treatment resistance in cancer. Methods: In this study, a comprehensive review of the molecular mechanisms underlying drug resistance governed by redox signaling was conducted. Emphasis was placed on understanding how tumor cells manage increased reactive oxygen species (ROS) levels through upregulated antioxidant systems, enabling resistance across multiple therapeutic pathways. Results: Key mechanisms identified include alterations in drug efflux, target modifications, metabolic changes, enhanced DNA damage repair, stemness preservation, and tumor microenvironment remodeling. These pathways collectively facilitate tumor cells' adaptive response and resistance to various cancer treatments. Conclusion: Developing a detailed understanding of the interrelationships between these redox-regulated mechanisms and therapeutic resistance holds potential to improve treatment effectiveness, offering valuable insights for both fundamental and clinical cancer research. Antioxid. Redox Signal. 00, 000-000.

Exploiting acquired vulnerability to develop novel treatments for cholangiocarcinoma

Cholangiocarcinoma (CCA) presents a formidable therapeutic challenge due to its extensive heterogeneity and plasticity, which inevitably lead to acquired resistance to current treatments. However, recent evidence suggests that acquired drug resistance is associated with a fitness cost resulting from the myriad of acquired alterations under the selective pressure of the primary treatment. Consequently, CCA patients with acquired resistance are more susceptible to alternative therapies that are ineffective as monotherapies. This phenomenon, termed "acquired vulnerability," has garnered significant interest in drug development, as the acquired alterations could potentially be exploited therapeutically. This review elucidates the modes of acquired vulnerability, methods for identifying and exploiting acquired vulnerabilities in cancer (particularly in CCA), and strategies to enhance the clinical efficacy of drug combinations by leveraging the principle of acquired vulnerability. Identifying acquired vulnerabilities may pave the way for novel drug combinations to effectively treat highly heterogeneous and adaptable malignancies such as CCA.

Integrated stress response-upregulated mitochondrial SLC1A5var enhances glucose dependency in human breast cancer cells in vitro

Breast cancer is the most commonly diagnosed cancer among women. The growth of triple-negative breast cancer (TNBC) cells is glucose-dependent. The integrated stress response (ISR) is a cellular stress response to glucose depletion. The ISR-solute carrier family 7 member 11 pathway is activated during glucose depletion and contributes to glucose dependence by decreasing intracellular glutamate levels. Solute carrier family 1 member 5 (SLC1A5) and the mitochondrial solute carrier family 1 member 5 variant (SLC1A5var) are glutamine transporters that play essential roles in the reprogramming of cancer metabolism. However, whether ISR can regulate mitochondrial SLC1A5var expression and further affect glucose dependence remains unclear. Glucose depletion-, oligomycin-, and salubrinal-activated activating transcription factor-4 (ATF4) induced SLC1A5var expression. ATF4 is critical for SLC1A5var regulation, as it binds to specific regulatory elements in its promoter. SLC1A5var knockdown decreases glucose depletion-induced cell death, whereas SLC1A5var overexpression increases glucose depletion-induced cell death in TNBC cells. SLC1A5var knockdown reduced cancer cell proliferation, colony formation, and migration, whereas SLC1A5var overexpression increased cell proliferation and migration. Moreover, the knockdown of SLC1A5var reduces the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) while increasing the maximal OCR and ECAR under glucose depletion. These results suggest that activated ISR-induced increased expression of SLC1A5var may regulate mitochondrial oxidative phosphorylation and glycolytic metabolic characteristics to enhance glucose depletion-induced cell death. In conclusion, SLC1A5var plays a vital role in metabolic reprogramming and may be a potential target for breast cancer treatment.

Ferroptosis-related LINC02535/has-miR-30c-5p/EIF2S1 axis as a novel prognostic biomarker involved in immune infiltration and progression of PDAC

BACKGROUND

PDAC, also known as pancreatic ductal adenocarcinoma, is often diagnosed at a late stage due to nonspecific symptoms and a distinct lack of reliable biomarkers for timely diagnosis. Ferroptosis, a novel non-apoptotic cell death mode discovered in recent years, is strongly linked to the progression of PDAC and the evasion of the immune system. The objective of this study is to discover a novel ceRNA biomarker associated with ferroptosis and investigate its possible molecular mechanisms and therapeutic potential in PDAC.

METHODS

Based on the FerrDb and TCGA databases, the R survival package was used to screen for ferroptosis-related mRNAs associated with PDAC prognosis. The ferroptosis-related ceRNA network was identified by miRTarBase, miRNet, and starBase and visualized using Cytoscape. The LASSO regression analysis was used to build a risk model associated with ceRNA. Additionally, we investigated the correlation between the ceRNA axis and the infiltration of immune cells in PDAC by employing the ssGSEA algorithm. Spearman correlation analysis was used to investigate the association between the ceRNA network and the expression levels of immune checkpoint genes in PDAC. The prediction of potential medications for PAAD patients with high risk scores was conducted using the R package oncoPredict and the Genomics of Drug Sensitivity in Cancer (GDSC) repository. Expression levels of LINC02535 in clinical specimens and PDAC cell lines were determined using qRT-PCR. CCK-8, colony formation, EdU, wound healing, and transwell assays were performed to assess the impact of reducing LINC02535 on the growth, migration, and invasion of PDAC cell lines BxPC3 and PANC1.

RESULTS

We first discovered a new LINC02535/miR-30c-5p/EIF2S1 axis associated with ferroptosis and created a prognostic nomogram for predicting overall survival. Meanwhile, the risk scores of the LINC02535/miR-30c-5p/EIF2S1 axis associated with ferroptosis were linked to immune subtypes in PDAC. The high immune infiltration subtype exhibited elevated ceRNA risk scores and EIF2S1 expression. The correlation analysis revealed a positive correlation between ceRNA risk scores and four immune cells, namely Activated CD4 T cell, Memory B cell, Neutrophil, and Type 2 T helper cell, as well as four immune checkpoint genes, namely CD274, HAVCR2, PDCD1LG2, and TIGIT. The analysis of drug sensitivity indicated that individuals with a high-risk score may exhibit greater sensitivity to inhibitors targeting MEK1/2 compared to those with a low-risk score. In our validation experiments, it was observed that the expression of LINC02535 was increased in both PDAC tissues and cell lines. Additionally, the inhibition of LINC02535 resulted in decreased proliferation, migration, and invasion of PDAC cells. Rescue experiments demonstrated that LINC02535 promoted PDAC cell growth and metastasis by upregulating EIF2S1 expression.

CONCLUSION

To summarize, a novel ferroptosis-associated LINC02535/miR-30c-5p/EIF2S1 ceRNA network for PDAC patients was established. The analysis of this network's functionality offers potential insights for clinical decision-making and the advancement of precision medicine.

P62-autophagic pathway degrades SLC7A11 to regulate ferroptosis in doxorubicin-induced cardiotoxicity

Doxorubicin-induced cardiotoxicity (DIC) poses a significant challenge, impeding its widespread application. Emerging evidence suggests the involvement of ferroptosis in the DIC. While the downregulation of SLC7A11 expression has been linked to the promotion of ferroptosis, the precise regulatory mechanism remains unclear. Recent studies, including our own, have highlighted abnormal levels of autophagy adapter protein P62 and autophagy in DIC development. Thus, our study aimed to further investigate the role of autophagy and ferroptosis in DIC, elucidating underlying molecular mechanisms across molecular, cellular, and whole-organ levels utilizing gene knockdown, immunoprecipitation, and mass spectrometry techniques. The results of our findings unveiled cardiomyocyte damage, heightened autophagy levels, and ferroptosis in DOX-treated mouse hearts. Notably, inhibition of autophagy levels attenuated DOX-induced ferroptosis. Mechanistically, we discovered that the autophagy adaptor protein P62 mediates the entry of SLC7A11 into the autophagic pathway for degradation. Furthermore, the addition of autophagy inhibitors (CQ or BAF) could elevate SLC7A11 and GPX4 protein expression, reduce the accumulation of Fe2+ and ROS in cardiomyocytes, and thus mitigate DOX-induced ferroptosis. In summary, our findings underscore the pivotal role of the P62-autophagy pathway in SLC7A11 degradation, modulating ferroptosis to exacerbate DIC. This finding offers significant insights into the underlying molecular mechanisms of DOX-induced ferroptosis and identifies new targets for reversing DIC.

Amino Acid Deprivation in Glioblastoma: The Role in Survival and the Tumour Microenvironment-A Narrative Review

BACKGROUND

Glioblastoma is the most common and aggressive primary brain tumour, characterised by its invasive nature and complex metabolic profile. Emerging research highlights the role of amino acids (AAs) in glioblastoma metabolism, influencing tumour growth and the surrounding microenvironment.

METHODS

This narrative review synthesises recent pre-clinical studies focusing on the metabolic functions of AAs in glioblastoma. Key areas include the effects of AA deprivation on tumour growth, adaptive mechanisms, and the tumour microenvironment.

RESULTS

The effects related to arginine, glutamine, methionine, and cysteine deprivation have been more extensively reported. Arginine deprivation in arginine-auxotrophic glioblastomas induces apoptosis and affects cell adhesion, while glutamine deprivation disrupts metabolic pathways and enhances autophagy. Methionine and cysteine deprivation impact lipid metabolism and ferroptosis. Tumour adaptive mechanisms present challenges, and potential compensatory responses have been identified. The response of the microenvironment to AA deprivation, including immune modulation, is critical to determining therapeutic outcomes.

CONCLUSIONS

Targeting AA metabolism offers a promising approach for glioblastoma treatment, with potential targeted drugs showing clinical promise. However, the complexity of tumour adaptive mechanisms and their impact on the microenvironment necessitates further research to optimise combination therapies and improve therapeutic efficacy.

Identification of metabolic biomarkers in idiopathic pulmonary arterial hypertension using targeted metabolomics and bioinformatics analysis

Pulmonary arterial hypertension (PAH) is a life-threatening disease with a poor prognosis, and metabolic abnormalities play a critical role in its development. This study used metabolomics, machine learning algorithms and bioinformatics to screen for potential metabolic biomarkers associated with the diagnosis of PAH. In this study, plasma samples were collected from 17 patients diagnosed with idiopathic pulmonary arterial hypertension (IPAH) and 20 healthy controls. Plasma metabolomic profiling was performed by high-performance liquid chromatography-mass spectrometry. Gene profiles of PAH patients were obtained from the GEO database. Key differentially expressed metabolites (DEMs) and metabolism-related genes were subsequently identified using machine learning algorithms. Twenty differential plasma metabolites associated with IPAH were identified (VIP score > 1 and p < 0 0.05), and enrichment analysis revealed the arginine biosynthesis pathway as the most altered pathway. Using machine learning models, including least absolute shrinkage and selection operator (LASSO), random forest (RF) and support vector machine (SVM), we extracted key metabolites that correlated with clinical phenotypes. Our results suggested that five metabolites, kynurenine, homoserine, tryptophan, AMP, and spermine, are potential biomarkers for IPAH. Bioinformatics analysis also identified 3 metabolism-related genes, MAPK6, SLC7A11 and CDC42BPA, that are strongly correlated with pulmonary hypertension, demonstrating strong predictive power and clinical relevance. Our findings revealed some key genes associated with metabolism in PH, and provided crucial information about complex metabolic reprogramming signals and may lead to the identification of useful metabolic biomarkers for the diagnosis of PAH.

The reverse transsulfuration pathway affects the colonic microbiota and contributes to colitis in mice

Cystathionine γ-lyase (CTH) is a critical enzyme in the reverse transsulfuration pathway, the major route for the metabolism of sulfur-containing amino acids, notably converting cystathionine to cysteine. We reported that CTH supports gastritis induced by the pathogen Helicobacter pylori. Herein our aim was to investigate the role of CTH in colonic inflammation. First, we found that CTH is induced in the colon mucosa in mice with dextran sulfate sodium-induced colitis. Expression of CTH was completely absent in the colon of Cth-/- mice. We observed that clinical and histological parameters are ameliorated in Cth-deficient mice compared to wild-type animals. However, Cth deletion had no effect on tumorigenesis and the level of dysplasia in mice treated with azoxymethane-DSS, as a reliable model of colitis-associated carcinogenesis. Mechanistically, we determined that the deletion of the gene Slc7a11 encoding for solute carrier family 7 member 11, the transporter of the anionic form of cysteine, does not affect DSS colitis. Lastly, we found that the richness and diversity of the fecal microbiota were significantly increased in Cth-/- mice compared to both WT and Slc7a11-/- mice. In conclusion, our data suggest that the enzyme CTH represents a target for clinical intervention in patients with inflammatory bowel disease, potentially by beneficially reshaping the composition of the gut microbiota.

Disulfidptosis: a novel cell death modality induced by actin cytoskeleton collapse and a promising target for cancer therapeutics

Disulfidptosis is a novel discovered form of programmed cell death (PCD) that diverges from apoptosis, necroptosis, ferroptosis, and cuproptosis, stemming from disulfide stress-induced cytoskeletal collapse. In cancer cells exhibiting heightened expression of the solute carrier family 7 member 11 (SLC7A11), excessive cystine importation and reduction will deplete nicotinamide adenine dinucleotide phosphate (NADPH) under glucose deprivation, followed by an increase in intracellular disulfide stress and aberrant disulfide bond formation within actin networks, ultimately culminating in cytoskeletal collapse and disulfidptosis. Disulfidptosis involves crucial physiological processes in eukaryotic cells, such as cystine and glucose uptake, NADPH metabolism, and actin dynamics. The Rac1-WRC pathway-mediated actin polymerization is also implicated in this cell death due to its contribution to disulfide bond formation. However, the precise mechanisms underlying disulfidptosis and its role in tumors are not well understood. This is probably due to the multifaceted functionalities of SLC7A11 within cells and the complexities of the downstream pathways driving disulfidptosis. This review describes the critical roles of SLC7A11 in cells and summarizes recent research advancements in the potential pathways of disulfidptosis. Moreover, the less-studied aspects of this newly discovered cell death process are highlighted to stimulate further investigations in this field.

NEK10 kinase ablation affects mitochondrial morphology, function and protein phosphorylation status

BACKGROUND

NEK10, a serine/threonine/tyrosine kinase belonging to the NEK (NIMA-related kinases) family, has been associated with diverse cellular processes. However, no specific target pathways have been identified. Our previous work knocking down NEK10 in HeLa cells suggested a functional association with mitochondria, as we observed altered mitochondrial morphology, mitochondrial oxygen consumption, mtDNA integrity, and reactive oxygen species levels.

METHODS

To better understand this association, we studied human HAP1 cells fully knockout for NEK10 and confirmed that NEK10 has an important role in mitochondrial homeostasis. We performed the study of mitochondrial respiration, mitochondrial morphology, mitochondrial mass, and mtDNA analysis. Additionally, we showed proteome and phosphoproteome data of crude mitochondrial fraction of Parental and NEK10 KO cells using liquid chromatography-mass spectrometry (LC-MS/MS).

RESULTS

In the absence of NEK10 several mitochondrial functions were disturbed. Moreover, proteome and phosphoproteome analyses of mitochondrial fractions showed that NEK10 alters the threonine phosphorylation status of several mitochondrial/endoplasmic reticulum components, including HSP60, NDUFB4, and TOM20. These changes impacted the steady-state levels of a larger group of proteins, preferentially involving respiratory complexes and autophagy pathways.

CONCLUSION

We concluded that NEK10 plays a key role in mitochondrial function, possibly by modulating the phosphorylation status of mitochondrial proteins.

Targeting Ferroptosis as an Advance Strategy in Cancer Therapy

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

UBR5 mediates colorectal cancer chemoresistance by attenuating ferroptosis via Lys 11 ubiquitin-dependent stabilization of Smad3-SLC7A11 signaling

Chemoresistance remains a principal culprit for the treatment failure in colorectal cancer (CRC), especially for patients with recurrent or metastatic disease. Deciphering the molecular basis of chemoresistance may lead to novel therapeutic strategies for this fatal disease. Here, UBR5, an E3 ubiquitin ligase frequently overexpressed in human CRC, is demonstrated to mediate chemoresistance principally by inhibiting ferroptosis. Paradoxically, UBR5 shields oxaliplatin-activated Smad3 from proteasome-dependent degradation via Lys 11-linked polyubiquitination. This novel chemical modification of Smad3 facilitates the transcriptional repression of ATF3, induction of SLC7A11 and inhibition of ferroptosis, contributing to chemoresistance. Consequently, targeting UBR5 in combination with a ferroptosis inducer synergistically sensitizes CRC to oxaliplatin-induced cell death and control of tumor growth. This study reveals, for the first time, a major clinically relevant chemoresistance mechanism in CRC mediated by UBR5 in sustaining TGFβ-Smad3 signaling and tuning ferroptosis, unveiling its potential as a viable therapeutic target for chemosensitization.

Glutamine transporters as effective targets in digestive system malignant tumor treatment

Glutamine is one of the most abundant non-essential amino acids in human plasma and plays a crucial role in many biological processes of the human body. Tumor cells take up a large amount of glutamine to meet their rapid proliferation requirements, which is supported by the upregulation of glutamine transporters. Targeted inhibition of glutamine transporters effectively inhibits cell growth and proliferation in tumors. Among all cancers, digestive system malignant tumors (DSMTs) have the highest incidence and mortality rates, and the current therapeutic strategies for DSMTs are mainly surgical resection and chemotherapy. Due to the relatively low survival rate and severe side effects associated with DSMTs treatment, new treatment strategies are urgently required. This article summarizes the glutamine transporters involved in DSMTs and describes their role in DSMTs. Additionally, glutamine transporter-target drugs are discussed, providing theoretical guidance for the further development of drugs DSMTs treatment.

Cerebroprotein hydrolysate-I ameliorates cognitive dysfunction in APP/PS1 mice by inhibiting ferroptosis via the p53/SAT1/ALOX15 signalling pathway

Ferroptosis, an iron-dependent lipid peroxidation-driven cell death pathway, has been linked to the development of Alzheimer's disease (AD). However, the role of ferroptosis in the pathogenesis of AD remains unclear. Cerebroprotein hydrolysate-I (CH-I) is a mixture of peptides with neurotrophic effects that improves cognitive deficits and reduces amyloid burden. The present study investigated the ferroptosis-induced signalling pathways and the neuroprotective effects of CH-I in the brains of AD transgenic mice. Seven-month-old male APPswe/PS1dE9 (APP/PS1) transgenic mice were treated with intraperitoneal injections of CH-I and saline for 28 days. The Morris water maze test was used to assess cognitive function. CH-I significantly improved cognitive deficits and attenuated beta-amyloid (Aβ) aggregation and tau phosphorylation in the hippocampus of APP/PS1 mice. RNA sequencing revealed that multiple genes and pathways, including ferroptosis-related pathways, were involved in the neuroprotective effects of CH-I. The increased levels of lipid peroxidation, ferrous ions, reactive oxygen species (ROS), and altered expression of ferroptosis-related genes (recombinant solute carrier family 7, member 11 (SLC7A11), spermidine/spermine N1-acetyltransferase 1 (SAT1) and glutathione peroxidase 4 (GPX4)) were significantly alleviated after CH-I treatment. Quantitative real-time PCR and western blotting were performed to investigate the expression of key ferroptosis-related genes and the p53/SAT1/arachidonic acid 15-lipoxygenase (ALOX15) signalling pathway. The p53/SAT1/ALOX15 signalling pathway was found to be involved in mediating ferroptosis, and the activation of this pathway was significantly suppressed in AD by CH-I. CH-I demonstrated neuroprotective effects against AD by attenuating ferroptosis and the p53/SAT1/ALOX15 signalling pathway, thus providing new targets for AD treatment.

Digitonin-Loaded Nanoscale Metal-Organic Framework for Mitochondria-Targeted Radiotherapy-Radiodynamic Therapy and Disulfidptosis

The efficacy of radiotherapy (RT) is limited by inefficient X-ray absorption and reactive oxygen species generation, upregulation of immunosuppressive factors, and a reducing tumor microenvironment (TME). Here, the design of a mitochondria-targeted and digitonin (Dig)-loaded nanoscale metal-organic framework, Th-Ir-DBB/Dig, is reported to overcome these limitations and elicit strong antitumor effects upon low-dose X-ray irradiation. Built from Th6O4(OH)4 secondary building units (SBUs) and photosensitizing Ir(DBB)(ppy)2 2+ (Ir-DBB, DBB = 4,4'-di(4-benzoato)-2,2'-bipyridine; ppy = 2-phenylpyridine) ligands, Th-Ir-DBB exhibits strong RT-radiodynamic therapy (RDT) effects via potent radiosensitization with high-Z SBUs for hydroxyl radical generation and efficient excitation of Ir-DBB ligands for singlet oxygen production. Th-Ir-DBB/Dig releases digitonin in acidic TMEs to trigger disulfidptosis of cancer cells and sensitize cancer cells to RT-RDT through glucose and glutathione depletion. The released digitonin simultaneously downregulates multiple immune checkpoints in cancer cells and T cells through cholesterol depletion. As a result, Th-Ir-DBB/dig plus X-ray irradiation induces strong antitumor immunity to effectively inhibit tumor growth in mouse models of colon and breast cancer.

Cisplatin Resistance and Metabolism: Simplification of Complexity

Cisplatin is one of the most well-known anti-cancer drugs and has demonstrated efficacy against numerous tumor types for many decades. However, a key challenge with cisplatin, as with any chemotherapeutic agent, is the development of resistance with a resultant loss of efficacy. This resistance is often associated with metabolic alterations that allow insensitive cells to divide and survive under treatment. These adaptations could vary greatly among different tumor types and may seem questionable and incomprehensible at first glance. Here we discuss the disturbances in glucose, lipid, and amino acid metabolism in cisplatin-resistant cells as well as the roles of ferroptosis and autophagy in acquiring this type of drug intolerance.

New aspects of redox signaling mediated by supersulfides in health and disease

Oxygen molecules accept electrons from the respiratory chain in the mitochondria and are responsible for energy production in aerobic organisms. The reactive oxygen species formed via these oxygen reduction processes undergo complicated electron transfer reactions with other biological substances, which leads to alterations in their physiological functions and cause diverse biological and pathophysiological consequences (e.g., oxidative stress). Oxygen accounts for only a small proportion of the redox reactions in organisms, especially under aerobic or hypoxic conditions but not under anaerobic and hypoxic conditions. This article discusses a completely new concept of redox biology, which is governed by redox-active supersulfides, i.e., sulfur-catenated molecular species. These species are present in abundance in all organisms but remain largely unexplored in terms of redox biology and life science research. In fact, accumulating evidence shows that supersulfides have extensive redox chemical properties and that they can be readily ionized or radicalized to participate in energy metabolism, redox signaling, and oxidative stress responses in cells and in vivo. Thus, pharmacological intervention and medicinal modulation of supersulfide activities have been shown to benefit the regulation of disease pathogenesis as well as disease control.

A novel model combining genes associated with disulfidptosis and glycolysis to predict breast cancer prognosis, molecular subtypes, and treatment response

Breast cancer (BC) is a heterogeneous malignancy with a dismal prognosis. Disulfidptosis is a novel type of regulated cell death that happens in the presence of glucose deficiency and is linked to the metabolic process of glycolysis. However, the mechanism of action of disulfidptosis and glycolysis-related genes (DGRG) in BC, as well as their prognostic value in BC patients, remain unknown. After identifying the differentially expressed DGRG in normal and BC tissues, a number of machine learning algorithms were utilized to select essential prognostic genes to develop a model, including SLC7A11, CACNA1H, SDC1, CHST1, and TFF3. The expression characteristics of these genes were then examined using single-cell RNA sequencing, and BC was classified into three clusters using "ConsensusClusterPlus" based on these genes. The DGRG model's median risk score can categorize BC patients into high-risk and low-risk groups. Furthermore, we investigated variations in clinical landscape, immunoinvasion analysis, tumor immune dysfunction and rejection (TIDE), and medication sensitivity in patients in the DGRG model's high- and low-risk groups. Patients in the low-risk group performed better on immunological and chemotherapeutic therapies and had lower TIDE scores. In conclusion, the DGRG model we developed has significant clinical application potential because it can accurately predict the prognosis of BC, TME, and pharmacological treatment responses.

Identification of druggable host dependency factors shared by multiple SARS-CoV-2 variants of concern

The high mutation rate of SARS-CoV-2 leads to the emergence of multiple variants, some of which are resistant to vaccines and drugs targeting viral elements. Targeting host dependency factors, e.g. cellular proteins required for viral replication, would help prevent the development of resistance. However, it remains unclear whether different SARS-CoV-2 variants induce conserved cellular responses and exploit the same core host factors. To this end, we compared three variants of concern and found that the host transcriptional response was conserved, differing only in kinetics and magnitude. Clustered regularly interspaced short palindromic repeats screening identified host genes required for each variant during infection. Most of the genes were shared by multiple variants. We validated our hits with small molecules and repurposed the US Food and Drug Administration-approved drugs. All the drugs were highly active against all the tested variants, including new variants that emerged during the study (Delta and Omicron). Mechanistically, we identified reactive oxygen species production as a key step in early viral replication. Antioxidants such as N-acetyl cysteine (NAC) were effective against all the variants in both human lung cells and a humanized mouse model. Our study supports the use of available antioxidant drugs, such as NAC, as a general and effective anti-COVID-19 approach.

Upregulation of GPX4 drives ferroptosis resistance in scleroderma skin fibroblasts

The pathogenesis of systemic sclerosis (SSC) fibrosis involves the rapid proliferation of skin fibroblasts, and current anti-fibrotic treatments are limited. This study investigated the relationship between ferroptosis and SSC skin fibroblasts. We observed that erastin-induced ferroptosis was suppressed in SSC fibroblasts. RSL3, a direct inhibitor of Glutathione Peroxidase 4 (GPX4), significantly reduced the viability of the fibroblasts, and upregulation of GPX4 in the SSC fibroblasts contributed to ferroptosis resistance. Furthermore, we demonstrated that transferrin receptor 1 (TfR1) was a crucial transporter for iron deposition in the fibroblasts. Collectively, our results highlight that GPX4 inhibition could enhance the sensitivity to ferroptosis by SSC fibroblasts, which showed distinct characteristics of iron metabolism that were not observed in normal fibroblasts in this study. Taken together, these results suggest that targeting ferroptosis could be a therapeutic strategy for the treatment of SSC.

Ferroptosis in the adjuvant treatment of lung cancer-the potential of selected botanical drugs and isolated metabolites

Ferroptosis represents a distinct form of cell death that is not associated with necrosis, autophagy, apoptosis, or pyroptosis. It is characterised by intracellular iron-dependent lipid peroxidation. The current literature indicates that a number of botanical drugs and isolated metabolites can modulate ferroptosis, thereby exerting inhibitory effects on lung cancer cells or animal models. The aim of this review is to elucidate the mechanisms through which botanical drugs and isolated metabolites regulate ferroptosis in the context of lung cancer, thereby providing potential insights into lung cancer treatment. It is crucial to highlight that these preclinical findings should not be interpreted as evidence that these treatments can be immediately translated into clinical applications. In the future, we will continue to study the pharmacology, pharmacokinetics and toxicology of these drugs, as well as evaluating their efficacy and safety in clinical trials, with the aim of providing new approaches to the development of new agents for the treatment of lung cancer.

Glutathione-Dependent Pathways in Cancer Cells

The most abundant tripeptide-glutathione (GSH)-and the major GSH-related enzymes-glutathione peroxidases (GPxs) and glutathione S-transferases (GSTs)-are highly significant in the regulation of tumor cell viability, initiation of tumor development, its progression, and drug resistance. The high level of GSH synthesis in different cancer types depends not only on the increasing expression of the key enzymes of the γ-glutamyl cycle but also on the changes in transport velocity of its precursor amino acids. The ability of GPxs to reduce hydroperoxides is used for cellular viability, and each member of the GPx family has a different mechanism of action and site for maintaining redox balance. GSTs not only catalyze the conjugation of GSH to electrophilic substances and the reduction of organic hydroperoxides but also take part in the regulation of cellular signaling pathways. By catalyzing the S-glutathionylation of key target proteins, GSTs are involved in the regulation of major cellular processes, including metabolism (e.g., glycolysis and the PPP), signal transduction, transcription regulation, and the development of resistance to anticancer drugs. In this review, recent findings in GSH synthesis, the roles and functions of GPxs, and GST isoforms in cancer development are discussed, along with the search for GST and GPx inhibitors for cancer treatment.

Supersulfide catabolism participates in maladaptive remodeling of cardiac cells

The atrophic myocardium resulting from mechanical unloading and nutritional deprivation is considered crucial as maladaptive remodeling directly associated with heart failure, as well as interstitial fibrosis. Conversely, myocardial hypertrophy resulting from hemodynamic loading is perceived as compensatory stress adaptation. We previously reported the abundant presence of highly redox-active polysulfide molecules, termed supersulfide, with two or more sulfur atoms catenated in normal hearts, and the supersulfide catabolism in pathologic hearts after myocardial infarction correlated with worsened prognosis of heart failure. However, the impact of supersulfide on myocardial remodeling remains unclear. Here, we investigated the involvement of supersulfide metabolism in cardiomyocyte remodeling, using a model of adenosine 5'-triphosphate (ATP) receptor-stimulated atrophy and endothelin-1 receptor-stimulated hypertrophy in neonatal rat cardiomyocytes. Results revealed contrasting changes in intracellular supersulfide and its catabolite, hydrogen sulfide (H2S), between cardiomyocyte atrophy and hypertrophy. Stimulation of cardiomyocytes with ATP decreased supersulfide activity, while H2S accumulation itself did not affect cardiomyocyte atrophy. This supersulfide catabolism was also involved in myofibroblast formation of neonatal rat cardiac fibroblasts. Thus, unraveling supersulfide metabolism during myocardial remodeling may lead to the development of novel therapeutic strategies to improve heart failure.

Bridging the Gap in Cancer Research: Sulfur Metabolism of Leukemic Cells with a Focus on L-Cysteine Metabolism and Hydrogen Sulfide-Producing Enzymes

Leukemias are cancers of the blood-forming system, representing a significant challenge in medical science. The development of leukemia cells involves substantial disturbances within the cellular machinery, offering hope in the search for effective selective treatments that could improve the 5-year survival rate. Consequently, the pathophysiological processes within leukemia cells are the focus of critical research. Enzymes such as cystathionine beta-synthase and sulfurtransferases like thiosulfate sulfurtransferase, 3-mercaptopyruvate sulfurtransferase, and cystathionine gamma-lyase play a vital role in cellular sulfur metabolism. These enzymes are essential to maintaining cellular homeostasis, providing robust antioxidant defenses, and supporting cell division. Numerous studies have demonstrated that cancerous processes can alter the expression and activity of these enzymes, uncovering potential vulnerabilities or molecular targets for cancer therapy. Recent laboratory research has indicated that certain leukemia cell lines may exhibit significant changes in the expression patterns of these enzymes. Analysis of the scientific literature and online datasets has confirmed variations in sulfur enzyme function in specific leukemic cell lines compared to normal leukocytes. This comprehensive review collects and analyzes available information on sulfur enzymes in normal and leukemic cell lines, providing valuable insights and identifying new research pathways in this field.

uL3 Regulates Redox Metabolism and Ferroptosis Sensitivity of p53-Deleted Colorectal Cancer Cells

Despite advancements in therapeutic strategies, the development of drug resistance and metastasis remains a serious concern for the efficacy of chemotherapy against colorectal cancer (CRC). We have previously demonstrated that low expression of ribosomal protein uL3 positively correlates with chemoresistance in CRC patients. Here, we demonstrated that the loss of uL3 increased the metastatic capacity of CRC cells in chick embryos. Metabolomic analysis revealed large perturbations in amino acid and glutathione metabolism in resistant uL3-silenced CRC cells, indicating that uL3 silencing dramatically triggered redox metabolic reprogramming. RNA-Seq data revealed a notable dysregulation of 108 genes related to ferroptosis in CRC patients. Solute Carrier Family 7 Member 11 (SLC7A11) is one of the most dysregulated genes; its mRNA stability is negatively regulated by uL3, and its expression is inversely correlated with uL3 levels. Inhibition of SLC7A11 with erastin impaired resistant uL3-silenced CRC cell survival by inducing ferroptosis. Of interest, the combined treatment erastin plus uL3 enhanced the chemotherapeutic sensitivity of uL3-silenced CRC cells to erastin. The antimetastatic potential of the combined strategy was evaluated in chick embryos. Overall, our study sheds light on uL3-mediated chemoresistance and provides evidence of a novel therapeutic approach, erastin plus uL3, to induce ferroptosis, establishing individualized therapy by examining p53, uL3 and SLC7A11 profiles in tumors.