Polyamine-mediated ferroptosis amplification acts as a targetable vulnerability in cancer

A ROS-Responsive Dual-Targeting Drug Nanocarrier Serving as a GSI Synergist and Ferroptosis Sensitizer for T-Cell Acute Lymphoblastic Leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is a highly aggressive hematological malignancy for which targeted therapies remain underdeveloped. Oncogenic mutations in Notch1 occur in up to 75% of T-ALL patients. Although γ-secretase inhibitors (GSIs) can block Notch1 activation, their clinical application is limited by side effects and reduced sensitivity. Here, a self-assembling, reactive oxygen species (ROS)-responsive nanotherapeutic strategy-PHD/G-NPs-co-loaded with GSI and controlled released dihydroartemisinin (DHA), and modified with a CD38 antibody is reported. The CD38 antibody specifically targets T-ALL cells, while GSI selectively inhibits Notch1, resulting in a dual-targeting approach. GSI is released first, inhibiting Notch1 activation and inducing the death of a subset of T-ALL cells. To eliminate semi-quiescent T-ALL cells that escape initial therapy by elevating ROS levels, a ROS-sensitive DHA delivery system is employed to enhance ferroptosis and boost GSI efficacy. After elucidating the mechanism of action of PHD/G-NPs in T-ALL cells, PHD/G-NPs are combined with αPD-1, which triggers an anti-tumor immune response in vivo. This dual-targeting strategy using CD38-modified PHD/G-NPs enables controlled drug release, enhances ferroptosis, mitigates GSI-induced gastrointestinal toxicity, and improves therapeutic efficacy. This nanomedical approach offers a novel strategy for targeted T-ALL treatment.

Ferroptosis-activating metabolite acrolein antagonizes necroptosis and anti-cancer therapeutics

Dysregulated cell death leading to uncontrolled cell proliferation is a hallmark of cancer. Chemotherapy-induced cell death is critical for the success of cancer treatment but this process is impaired by metabolic byproducts. How these byproducts interfere with anti-cancer therapy is unclear. Here, we show that the metabolic byproduct acrolein derived from polyamines, tobacco smoke or fuel combustion, induces ferroptosis independently of ZBP1, while suppressing necroptosis in cancer cells by inhibiting the oligomerization of the necroptosis effector MLKL. Loss of the enzyme SAT1, which contributes to intracellular acrolein production, sensitizes cells to necroptosis. In mice, administration of an acrolein-trapping agent relieves necroptosis blockade and enhances the anti-tumor efficacy of the chemotherapeutic drug cyclophosphamide. Human patients with cancer coupled with a higher cell death activity but a lower expression of genes controlling polyamine metabolism exhibit improved survival. These findings highlight that the removal of metabolic byproducts improves the success of certain chemotherapies.

Acyl post-translational modification of proteins by metabolites in cancer cells

The relationship between metabolism and cancer is a major focus of current research, with an increasing number of studies highlighting the significant role of various metabolites in tumor cells, such as lactate, acetic acid, lysine, serine, tryptophan, palmitic acid, succinate, etc. These metabolites are involved in numerous biological processes within tumor cells, including transcription, translation, post-translational modification (PTM) of proteins, cell cycle regulation, and metabolism, thereby modulating tumor proliferation, migration, and drug resistance. Metabolite-mediated PTMs of proteins undoubtedly play a vital role in tumor cells, affecting both histones and non-histone proteins, covering modifications such as lactylation, crotonylation, acetylation, palmitoylation, and succinylation. Therefore, this review aims to elaborate on the abnormal levels of some major metabolites, related metabolic pathways, and the latest protein acyl PTMs they mediate in tumor cells, providing new insights for diagnosis and therapy in the field of oncology.

GPX4-AUTAC induces ferroptosis in breast cancer by promoting the selective autophagic degradation of GPX4 mediated by TRAF6-p62

Emerging evidence indicates that activation of ferroptosis by inhibition of glutathione peroxidase 4 (GPX4) may be exploited as a therapeutic strategy to suppress tumor growth and progression. However, application of GPX4 inhibitors in cancer treatment is hampered by their poor selectivity, which results in unfavorable toxicity. Herein, we identified GPX4 as a candidate for the autophagy pathway. We showed that GPX4 is ubiquitinated by TNF receptor-associated factor 6 (TRAF6), which promotes its recognition by p62 and leads to its selective autophagic degradation. Utilizing targeted protein degradation (TPD) approach, we developed a GPX4-targeted AUTAC and demonstrated that GPX4-AUTAC promoted the ubiquitination of GPX4, and enhanced the binding with GPX4 and p62, leading to the selective autophagy-dependent degradation of GPX4. Furthermore, GPX4-AUTAC treatment strongly induced ferroptosis and exhibited potent anti-cancer activity against breast cancer in vitro, in vivo, and patient-derived organoids (PDOs). Combination treatment of GPX4-AUTAC with sulfasalazine, a ferroptotic inducer, or chemotherapy drugs showed a synergistic anti-cancer effect against breast cancer. These results uncover a new targeted degradation strategy for GPX4 by inducing selective autophagy and provide a rationale for the use of GPX4-AUTAC as a novel therapeutic approach to treatment of breast cancer.

Transcription factor ZNF266 suppresses cancer progression by modulating CA9-mediated intracellular pH alteration in lung adenocarcinoma

BACKGROUND

Lung cancer remains the leading cause of cancer-related mortality globally, with lung adenocarcinoma (LUAD) being the most prevalent subtype. Despite extensive research efforts, the role of transcription factors in LUAD progression remains largely uncharacterized. In this study, we focused on ZNF266, a transcription factor whose impacts on LUAD have not been investigated.

METHODS

Using high-throughput sequencing data, we observed a significant downregulation of ZNF266 expression in LUAD tissues. To validate this finding, we conducted a retrospective analysis of nearly three thousand LUAD patients' data from public databases and our institution. Functional studies were performed using cell lines, organoids, and xenograft models to assess the role of ZNF266 in LUAD progression. RNA sequencing, chromatin immunoprecipitation, DNA pull-down assays, and dual-luciferase reporter assays were employed to elucidate the underlying mechanism. Additionally, adeno-associated virus (AAV)-mediated overexpression of ZNF266 was used to evaluate its therapeutic potential.

RESULTS

Patients with low ZNF266 expression had poorer prognosis compared to those with high expression. ZNF266 inhibits the malignant phenotypes of LUAD, including proliferation, migration, and invasion. Mechanistically, ZNF266 binds to the promoter region of CA9, suppressing its transcription. This leads to a reduction in intracellular pH and subsequent inhibition of the mTOR signaling pathway, which is crucial for cancer cell growth and survival. Furthermore, AAV-mediated overexpression of ZNF266 significantly inhibited tumor growth in patient-derived xenograft models.

CONCLUSIONS

Our study demonstrated that ZNF266 inhibits LUAD progression in a pH-dependent manner via modulating CA9 expression, uncovering its therapeutic significance for LUAD treatment.

Microenvironment-responsive MOF nanozymes armored cryogels promoted wound healing via rapid hemostasis, infection elimination and angiogenesis

Drug-resistant bacterial and biofilm infections, vascularization disorders, and inadequate hemostasis are the key factors that limit chronic diabetic wound healing. Here, we construct a microenvironment-responsive multifunctional platinum-armed iron-based MOF nanocomposite (Pt@FeMOF) to repair chronic wounds. Under acidic conditions (biofilm environment), Pt@FeMOF nanoparticles (NPs) produce reactive oxygen species via a synergistic Fenton reaction to eliminate both drug-resistant bacteria and their biofilms. Furthermore, based on transcriptomic results and ferroptosis marker evaluation, we reveal that the Pt@FeMOF NPs induce ferroptosis in bacteria via lipid peroxidation, GSH depletion, iron overload, and disruption of arginine metabolism. In addition, the Pt@FeMOF NPs promote vascular repair, possibly by inhibiting oxidative stress-mediated endothelial cell senescence in the microenvironment to restore angiogenesis. Finally, the Pt@FeMOF NPs are loaded into GelMA cryogels to further improve their hemostasis and exudate absorption. In vivo experiments demonstrate that Pt@FeMOF NPs-loaded cryogel dressings effectively promote MRSA- and P. aeruginosa-infected diabetic wounds. This ferroptosis-like antibacterial strategy may provide novel insights into the treatment of drug-resistant bacterial infections and fight against biofilm-associated infections. The proposed tactic provides a promising approach for the clinical treatment of diabetic wounds.

The Effect of Microbiome-Derived Metabolites in Inflammation-Related Cancer Prevention and Treatment

Chronic inflammation plays a crucial role in cancer development, yet the mechanisms linking the microbiome to inflammation-related carcinogenesis remain unclear. Emerging evidence suggests that microbiome-derived metabolites influence inflammatory pathways, presenting both challenges and opportunities for therapy. However, a deeper understanding of how these metabolites regulate inflammation and contribute to cancer prevention is still needed. This review explores recent advances in microbiome-derived metabolites and their roles in inflammation-related carcinogenesis. It highlights key molecular mechanisms, emerging therapies, and unresolved challenges. Synthesizing current research, including clinical trials and experimental models, bridges the gap between microbiome science and cancer therapy. Microbial metabolites such as short-chain fatty acids (SCFAs), polyamines, indoles, and bile acids play vital roles in regulating inflammation and suppressing cancer. Many metabolites exhibit potent anti-inflammatory and immunomodulatory effects, demonstrating therapeutic potential. Case studies show promising results, but challenges such as metabolite stability, bioavailability, and individual variability remain. Understanding microbiome-metabolite interactions offers novel strategies for cancer prevention and treatment. This review identifies knowledge gaps and proposes future research directions to harness microbiome-derived metabolites for innovative cancer therapies. Addressing these issues may pave the way for microbiome-targeted cancer interventions.

Spatial multi-omics reveals the potential involvement of SPP1+ fibroblasts in determining metabolic heterogeneity and promoting metastatic growth of colorectal cancer liver metastasis

This study investigates key microscopic regions involved in colorectal cancer liver metastasis (CRLM), focusing on the crucial role of cancer-associated fibroblasts (CAFs) in promoting tumor progression and providing molecular- and metabolism-level insights for its diagnosis and treatment using multi-omics. We followed 12 fresh surgical samples from 2 untreated CRLM patients. Among these, 4 samples were used for spatial transcriptomics (ST), 4 for spatial metabolomics, and 4 for single-cell RNA sequencing (scRNA-seq). Additionally, 92 frozen tissue samples from 40 patients were collected. Seven patients were used for immunofluorescence and RT-qPCR, while 33 patients were used for untargeted metabolomics. ST revealed that the spatial regions of CRLM consists of 7 major components, with fibroblast-dominated regions being the most prominent. These regions are characterized by diverse cell-cell interactions, and immunosuppressive and tumor growth-promoting environments. scRNA-seq identified that SPP1+ fibroblasts interact with CD44+ tumor cells, as confirmed through immunofluorescence. Spatial metabolomics revealed suberic acid and tetraethylene glycol as specific metabolic components of this structure, which was further validated by untargeted metabolomics. In conclusion, an SPP1+ fibroblast-rich spatial region with metabolic reprogramming capabilities and immunosuppressive properties was identified in CRLM, which potentially facilitates metastatic outgrowth through interactions with tumor cells.

FB1 causes barrier damage to vascular endothelial cells through ferroptosis by a PINK1/Parkin mediated mitophagy-dependent mechanism

Fumonisin B1 (FB1) is an environmental mycotoxin produced mainly by fungi of the genus Fusarium. Exposure to FB1 can lead to pulmonary edema in pigs, likely caused by damage to vascular endothelial cells, but the mechanism of FB1-induced damage was unknown. Here, we found that FB1 damages vascular endothelial cells through ferroptosis, marked by iron-dependent membrane lipid peroxidation, and through mitophagy, a selective autophagy that targets mitochondria. FB1 exposure reduced barrier-related gene expression and increased pro-inflammatory factors. Ferroptosis was evidenced by elevated iron, ROS, lipid peroxidation, and ferroptotic markers (TFR, ACSL4), alongside decreased GSH, SLC7A11, and GPX-4 levels in vascular endothelial cells. Importantly, the ferroptosis inhibitor, Ferrostatin-1, reversed the vascular endothelial cells' barrier damage, inflammation, and ferroptosis caused by FB1. FB1-induced mitophagy was demonstrated by detecting decreased mitochondrial membrane potential and increased levels of mitophagy-related proteins. Surprisingly, silencing PINK1 using siRNA not only diminished mitophagy, cellular damage, and inflammatory responses induced by FB1, but also mitigated FB1-induced ferroptosis. In conclusion, this study demonstrates that FB1 causes vascular endothelial cell damage by ferroptosis in a mitophagy-dependent manner. This study thus lays a mechanistic foundation for the study of FB1 causing pulmonary edema in pigs and for exploring options for therapeutic intervention in conditions caused by this mycotoxin, which causes substantial harm to both human and animal health.

Arginine Deprivation Induces Quiescence and Confers Vulnerability to Ferroptosis in Colorectal Cancer

Metabolic reprogramming is a hallmark of cancer. Rewiring of amino acid metabolic processes provides the basis for amino acid deprivation therapies. In this study, we found that arginine biosynthesis is limited in colorectal cancer because of the deficiency of ornithine transcarbamylase. Accordingly, colorectal cancer cells met the demand for arginine by increasing external uptake. The addiction to environmental arginine resulted in the susceptibility of colorectal cancer to arginine deprivation, which dramatically decreased proliferation in colorectal cancer cells and promoted these cells to enter a reversible quiescence state. Arginine deprivation induced quiescence by activating the AMPK-p53-p21 pathway. RNA sequencing data indicated that colorectal cancer cells may be vulnerable to ferroptosis during arginine deprivation and the combination of ferroptosis inducers and arginine deprivation strongly impeded tumor growth in vivo. These findings suggest that dietary modification combined with ferroptosis induction could be a potential therapeutic strategy for colorectal cancer. Significance: Colorectal cancer dependency on arginine uptake creates a metabolic vulnerability to arginine deficiency that causes cell cycle arrest and ferroptosis sensitivity, highlighting arginine deprivation plus ferroptosis induction as a promising treatment.

Overexpression of METTL3 in lung cancer cells inhibits radiation-induced bystander effect

BACKGROUND

Radiation-induced bystander effects (RIBE) increase the complexity of radiation therapy (RT). m6A modification is implicated in ionizing radiation damage. This study aims to investigate the RIBE and the mechanism after promoting m6A modification.

METHODS

Lung adenocarcinoma cells were treated to simulate a hypoxic and 0.5 Gy RT environment. The expression levels of METTL3, METTL14, and YTDHF2 were quantified by RT-qPCR. Paracellular clonogenicity and the expression of 53BP1 and γ-H2AX were assessed by immunofluorescence. The proliferative rate was evaluated by CCK-8. Probes were employed to measure ROS levels. Micronucleus formation was evaluated microscopically. m6A-mRNA/lncRNA microarrays, MERIP-PCR, RT-qPCR, and ELISA were utilized to assess m6A modification levels and the expression of inflammatory factors.

RESULTS

m6A modification levels were significantly diminished under hypoxic, low-dose irradiation conditions. The overexpression of METTL3 in irradiated cancer cells resulted in increased clonogenicity and proliferation of paracellular cells, suppressed the rate of micronucleus formation, and reduced DNA damage by modulating the inflammatory response. m6A-mRNA/lncRNA microarray analyses revealed a higher correlation of inflammatory molecules NF-κB and TRAF6. Further analysis demonstrated that the m6A modification levels of inflammation-related factors such as IL-6, TLR4, NF-κB2, and TRAF6 were significantly up-regulated, while their mRNA expression levels were notably decreased. Additionally, the expression of IL-10 and TGF-β was significantly reduced, with no significant changes observed in IL-1 expression.

CONCLUSION

The overexpression of METTL3 facilitated m6A modification and mitigated the inflammatory response, thereby promoting paracellular cloning and proliferation, inhibiting micronucleus formation, alleviating DNA damage, and achieving the objective of suppression of RIBE.

Amino acids in cancer: Understanding metabolic plasticity and divergence for better therapeutic approaches

Metabolic reprogramming is a hallmark of malignant transformation. While initial studies in the field of cancer metabolism focused on central carbon metabolism, the field has expanded to metabolism beyond glucose and glutamine and uncovered the important role of amino acids in tumorigenesis and tumor immunity as energy sources, signaling molecules, and precursors for (epi)genetic modification. As a result of the development and application of new technologies, a multifaceted picture has emerged, showing that context-dependent heterogeneity in amino acid metabolism exists between tumors and even within distinct regions of solid tumors. Understanding the complexity and flexibility of amino acid metabolism in cancer is critical because it can influence therapeutic responses and predict clinical outcomes. This overview discusses the current findings on the heterogeneity in amino acid metabolism in cancer and how understanding the metabolic diversity of amino acids can be translated into more clinically relevant therapeutic interventions.

Plasma protein levels and hepatocellular carcinoma: a Mendelian randomization study with drug screening implications

BACKGROUND

Hepatocellular carcinoma (HCC) remains a significant cause of cancer-related mortality, highlighting the need for novel therapeutic strategies. Identifying key proteins and potential therapeutic agents is critical for improving treatment outcomes.

METHODS

We employed Mendelian randomization to identify proteins associated with HCC risk and utilized drug enrichment and molecular docking analyses to discover potential therapeutic agents. The efficacy of identified drugs was evaluated in vitro using immune-tumor co-culture systems and in vivo in a murine HCC model. Single-cell expression profiling and clinical sample analyses were conducted to explore expression patterns.

RESULTS

Our analyses identified 16 proteins linked to HCC pathogenesis. Among the therapeutic agents tested, Belinostat significantly enhanced T cell-mediated cytotoxicity against HCC cells and effectively reduced tumor growth in vivo. Single-cell analysis revealed significant modulation of immune cells within the tumor microenvironment, suggesting potential mechanisms for the observed therapeutic effects.

CONCLUSION

This study highlights the potential of Belinostat as a promising therapeutic agent for HCC. By modulating immune responses and tumor growth, Belinostat offers a novel approach to HCC treatment, warranting further clinical investigation to validate its efficacy and therapeutic potential.

METTL16-dependent miR-146b-5p m6A modification remodeling sensitize NSCLC to osimertinib via activating PI3K/AKT signaling

BACKGROUND

Non-small-cell lung cancer (NSCLC) is one of the most common malignant tumors, with poor prognosis and increasing osimertinib therapy resistance. Revealing mechanisms of NSCLC progression and therapy resistance remains critical. The aim of this study was to elucidate the molecular mechanism of miR-146b-5b-5p m6A modification and underlying function in regulating the proliferation and osimertinib resistance of NSCLC.

METHODS

TCGA, GEO datasets were used to analyze the differential expression of miR-146b-5p in NSCLC and adjacent tissues, and its impact on prognosis. Then the effects of miR-146b-5p on the proliferation and osimertinib of A549 and HCC827 cells were investigated through proliferation experiments, colony formation assay and IC50 assay. The regulatory mechanism of miR-146b-5p on the PI3K/AKT signaling pathway and its interaction in cancer progression were investigated through Western blots, dual-luciferase reporter assay, and rescue experiments.

RESULTS

miR-146b-5p was significantly upregulated in NSCLC tissue and represented worse prognosis. miR-146b-5p mimic significantly enhanced proliferation and osimertinib resistance, while miR-146b-5p inhibitor inhibited above phenotype. Through bioinformatic analysis and experimental results, miR-146b-5p interacted directly with PTEN mRNA and activated subsequent signaling pathway activation. PI3K/AKT inhibitor could eliminate the tumorigenic effects of miR-146b-5p mimic on the progression of NSCLC, while PI3K/AKT agonist could rescue the inhibition effect of miR-146b-5p inhibitor group cells. Further, methyltransferase METTL16 is responsible for miR-146b m6A modification. Modified miR-146b-5p promotes osimertinib resistance through downstream PI3K/AKT activation.

CONCLUSIONS

In summary, we found that METTL16 mediated miR-146b-5p m6A modification promoted the proliferation and osimertinib resistance of NSLCL by activating PI3K/AKT signaling pathway. Our study is expected to provide a novel insight and potential therapeutic target for NSCLC osimertinib resistance.

Ferroptosis: when metabolism meets cell death

We present here a comprehensive update on recent advancements in the field of ferroptosis, with a particular emphasis on its metabolic underpinnings and physiological impacts. After briefly introducing landmark studies that have helped to shape the concept of ferroptosis as a distinct form of cell death, we critically evaluate the key metabolic determinants involved in its regulation. These include the metabolism of essential trace elements such as selenium and iron; amino acids such as cyst(e)ine, methionine, glutamine/glutamate, and tryptophan; and carbohydrates, covering glycolysis, the citric acid cycle, the electron transport chain, and the pentose phosphate pathway. We also delve into the mevalonate pathway and subsequent cholesterol biosynthesis, including intermediate metabolites like dimethylallyl pyrophosphate, squalene, coenzyme Q (CoQ), vitamin K, and 7-dehydrocholesterol, as well as fatty acid and phospholipid metabolism, including the biosynthesis and remodeling of ester and ether phospholipids and lipid peroxidation. Next, we highlight major ferroptosis surveillance systems, specifically the cyst(e)ine/glutathione/glutathione peroxidase 4 axis, the NAD(P)H/ferroptosis suppressor protein 1/CoQ/vitamin K system, and the guanosine triphosphate cyclohydrolase 1/tetrahydrobiopterin/dihydrofolate reductase axis. We also discuss other potential anti- and proferroptotic systems, including glutathione S-transferase P1, peroxiredoxin 6, dihydroorotate dehydrogenase, glycerol-3-phosphate dehydrogenase 2, vitamin K epoxide reductase complex subunit 1 like 1, nitric oxide, and acyl-CoA synthetase long-chain family member 4. Finally, we explore ferroptosis's physiological roles in aging, tumor suppression, and infection control, its pathological implications in tissue ischemia-reperfusion injury and neurodegeneration, and its potential therapeutic applications in cancer treatment. Existing drugs and compounds that may regulate ferroptosis in vivo are enumerated.

The dynamic role of ferroptosis in cancer immunoediting: Implications for immunotherapy

Currently, cancer immunotherapy strategies are primarily formulated based on the patient's present condition, representing a "static" treatment approach. However, cancer progression is inherently "dynamic," as the immune environment is not fixed but undergoes continuous changes. This dynamism is characterized by the ongoing interactions between tumor cells and immune cells, which ultimately lead to alterations in the tumor immune microenvironment. This process can be effectively elucidated by the concept of cancer immunoediting, which divides tumor development into three phases: "elimination," "equilibrium," and "escape." Consequently, adjusting immunotherapy regimens based on these distinct phases may enhance patient survival and improve prognosis. Targeting ferroptosis is an emerging area in cancer immunotherapy, and our findings reveal that the antioxidant systems associated with ferroptosis possess dual roles, functioning differently across the three phases of cancer immunoediting. Therefore, this review delve into the dual role of the ferroptosis antioxidant system in tumor development and progression. It also propose immunotherapy strategies targeting ferroptosis at different stages, ultimately aiming to illuminate the significant implications of targeting ferroptosis at various phases for cancer immunotherapy.

Polyamines signalling pathway: A key player in unveiling the molecular mechanisms underlying Huntington's disease

Polyaminesare essential organic cations found in all eukaryotic cells and play an important role in many cellular processes including growth, differentiation, andneuroprotection. This review explores the complex relationship between polyamine signaling and Huntington's disease (HD), an autosomal-dominant neurodegenerative disorder characterized by the progressive degeneration of medium-spiny neurons in the striatum and cortex due to mutations in the huntingtin gene. We provide a comprehensive overview of how polyamines, specificallyputrescine,spermidine, andspermine, regulate important cellular functions such as gene expression, protein synthesis, membrane stability, and ion channel regulation with implications for HD. Dysfunction in polyamine metabolism in HD, reveals how changes in these molecules promote oxidative stress, mitochondrial dysfunction, andexcitotoxicity. Importantly, polyamines interact with mutanthuntingtin protein (mHTT) to affect its aggregationand neurotoxicity. This effect may contribute to the pathophysiological mechanisms underlying HD, suggesting that polyamines may act as potential biomarkers of disease progression. Additionally, we discuss the therapeutic implications of targeting the polyamine signaling pathway to alleviate HD symptoms. By enhancing autophagy and modulating neurotransmitter systems, polyamines mayprovideneuroprotectionagainstmHTT-inducedtoxicity. Moreover, the present review provides new insight into the role of polyamines in the pathogenesis of HDand suggests that regulation of polyamine metabolism may represent a promising therapy to slow the disease progression. Besides this, the review highlights the need for further investigation of the diverse roles of polyamines in neurodegenerative diseases, including HD, paving the way for novel interventions to improve cellular homeostasis andpatient outcomes.

Antitumor potential of polyamines in cancer

The dysregulation of polyamines in tumors has made polyamine metabolism an appealing target for cancer therapy. Gene mutations drive the reprogramming of polyamine metabolism in tumors, presenting promising opportunities for clinical treatment. The proposed strategies involve inhibiting polyamine biosynthesis while also targeting the polyamine transport system as antitumor approaches. A growing number of drugs aimed at polyamine biosynthesis and transport systems are undergoing clinical trials. Polyamine metabolism plays a role in regulating cancer signaling pathways, suggesting potential combination therapies for cancer treatment. Furthermore, supplemental polyamine substances have demonstrated antitumor activity, indicating that combining polyamines with downstream targets or immunotherapy could offer significant clinical benefits. These discoveries open new avenues for leveraging polyamine metabolism in anticancer therapy.

Kinsenoside Suppresses DGAT1-Mediated Lipid Droplet Formation to Trigger Ferroptosis in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) presents limited therapeutic options and is characterized by a poor prognosis. Although Kinsenoside (KIN) possesses a wide range of pharmacological activities, its effect and mechanism in TNBC remain unclear. The objective of this research was to explore the therapeutic effectiveness and the molecular mechanisms of KIN on TNBC. Xenograft experiment was carried out to assess the impact of KIN on TNBC in vivo. The effect of KIN on TNBC in vitro was evaluated through the analysis of cell cytotoxicity and colony formation assays. Oil Red O staining and BODIPY 493/503 fluorescence staining were employed to detect the effect of KIN on lipid droplet (LD) formation. Transcriptomics and inhibitor-rescue experiments were conducted to investigate the role of KIN on TNBC. Mechanistic experiments, including quantitative real-time polymerase chain reaction (RT-qPCR), Western blotting, diacylglycerol acyltransferase 1 (DGAT1) overexpression assay, and flow cytometric assay, were employed to uncover the regulatory mechanisms of KIN on TNBC. KIN inhibited tumor growth without causing obvious toxicity to the liver and kidneys. In vitro experiments demonstrated that KIN significantly inhibited the viability and proliferation of TNBC cells, accompanied by decreased LD formation and lipid content. Polyunsaturated fatty acids (PUFAs) levels were significantly increased by KIN. Furthermore, transcriptomics and inhibitor-rescue experiments revealed that KIN induced ferroptosis in TNBC cells. KIN could significantly regulate ferroptosis-related proteins. Lipid peroxidation, iron accumulation, and GSH depletion also confirmed this. The LD inducer mitigated the KIN-induced ferroptosis in TNBC. The overexpression of DGAT1 attenuated the effects of KIN on cell viability and proliferation. Furthermore, the overexpression of DGAT1 inhibited the effect of KIN to trigger ferroptosis in TNBC cells. Our findings confirmed that KIN could trigger ferroptosis by suppressing DGAT1-mediated LD formation, thereby demonstrating a promising therapeutic effect of KIN in TNBC.

Spermine synthase engages in macrophages M2 polarization to sabotage antitumor immunity in hepatocellular carcinoma

Disturbances in tumor cell metabolism reshape the tumor microenvironment (TME) and impair antitumor immunity, but the implicit mechanisms remain elusive. Here, we found that spermine synthase (SMS) was significantly upregulated in tumor cells, which correlated positively with the immunosuppressive microenvironment and predicted poor survival in hepatocellular carcinoma (HCC) patients. Via "subcutaneous" and "orthotopic" HCC syngeneic mouse models and a series of in vitro coculture experiments, we identified elevated SMS levels in HCC cells played a role in immune escape mainly through its metabolic product spermine, which induced M2 polarization of tumor-associated macrophages (TAMs) and subsequently corresponded with a decreased antitumor functionality of CD8+ T cells. Mechanistically, we discovered that spermine reprogrammed TAMs mainly by activating the PI3K-Akt-mTOR-S6K signaling pathway. Spermine inhibition in combination with immune checkpoint blockade effectively diminished tumor burden in vivo. Our results expand the understanding of the critical role of metabolites in regulating cancer progression and antitumor immunity and open new avenues for developing novel therapeutic strategies against HCC.

Bee Pollen Potential to Modulate Ferroptosis: Phytochemical Insights for Age-Related Diseases

Bee pollen (BP) is one of the richest known natural resources of micronutrients and bioactive phytochemicals. Some captivating bioactivities of BP compounds, although being largely investigated for the latter as individual molecules, remain very scarcely investigated or completely uninvestigated in bee pollen as a whole product. Among the most intriguing of these bioactivities, we identified ferroptosis as a major one. Ferroptosis, a recently discovered form of cell death (connecting oxidative stress and inflammation), is a complex pathophysiological process and one of the most crucial and perplexing events in current challenging human diseases such as cancer, neurodegeneration, and general aging diseases. Many BP compounds were found to intricately modulate ferroptosis depending on the cellular context by inducing this cell death mechanism in malignant cells and preventing it in non-malignant cells. Since research in both fields, i.e., BP and ferroptosis, is still recent, we deemed it necessary to undertake this review to figure out the extent of BP potential in modulating ferroptosis mechanisms. Our research proved that a wide range of BP compounds (polyphenols, phenolamides, carotenoids, vitamins, minerals, and others) substantially modulate diverse ferroptosis mechanisms. Accordingly, these phytochemicals and nutrients showed interesting potential in preclinical studies to lead to ferroptosis-mediated outcomes in important pathophysiological processes, including many aging-related disorders. One of the most paramount challenges that remain to be resolved is to determine how different BP compounds act on ferroptosis in different biological and pathophysiological contexts, either through synergistic or antagonistic behaviors. We hope that our current work constitutes a valuable incentive for future investigations in this promising and very relevant research avenue.

Multiscale Synergy Networks Offer Insights into Disease and Comorbidity Mechanisms

Complex diseases involve extensive metabolic interactions within intricate biological networks. Consequently, it is advantageous to analyze metabolic phenotype data through metabolite interactions rather than focus on individual metabolites in isolation. In this article, we propose a novel analysis strategy called SynNet, which constructs multiscale synergy networks associated with specific metabolic phenotypes, offering new perspectives on the metabolic response mechanisms of diseases, including the mechanisms underlying disease comorbidity. The SynNet strategy begins with the construction of a metabolite-level synergy network (m-SynNet). This network is based on the definition and identification of significant metabolite pair interactions that distinguish disease phenotypes. Subsequently, a pathway synergy effect is defined by mapping these synergistic metabolite pairs onto the predefined metabolic pathways and performing a hypergeometric test to assess the probability of these pairs affecting a given pathway pair. The resulting significant pathway pairs identified form a pathway-level synergy network (p-SynNet). Both m-SynNet and p-SynNet offer complementary insights into disease mechanisms that go beyond conventional metabolomics analysis. For example, nodes with high connectivity in m-/p-SynNet suggest a strong correlation with the phenotype, while shared pathways across different phenotypes offer clues about the mechanisms of disease comorbidity. We applied the SynNet strategy to two real-world metabolomic data sets of disease comorbidity and identified key pathways associated with disease comorbidity from the p-SynNet. The candidate pathways are supported by the existing literature. Thus, the SynNet strategy may represent an alternative approach for metabolomic data analysis, providing novel insights into disease mechanisms and comorbidity.

Targeting ferroptosis: a promising approach for treating lung carcinoma

Lung carcinoma incidence and fatality rates remain among the highest on a global scale. The efficacy of targeted therapies and immunotherapies is commonly compromised by the emergence of drug resistance and other factors, resulting in a lack of durable therapeutic benefits. Ferroptosis, a distinct pattern of cell death marked by the buildup of iron-dependent lipid peroxides, has been shown to be a novel and potentially more effective treatment for lung carcinoma. However, the mechanism and regulatory network of ferroptosis are exceptionally complex, and many unanswered questions remain. In addition, research on ferroptosis in the diagnosis and treatment of lung cancer has been growing exponentially. Therefore, it is necessary to provide a thorough summary of the latest advancements in the field of ferroptosis. Here, we comprehensively analyze the mechanisms underlying the preconditions of ferroptosis, the defense system, and the associated molecular networks. The potential strategies of ferroptosis in the treatment of lung carcinoma are also highlighted. Targeting ferroptosis improves tumor cell drug resistance and enhances the effectiveness of targeted drugs and immunotherapies. These findings may shed fresh light on the diagnosis and management of lung carcinoma, as well as the development of drugs related to ferroptosis.

A Comprehensive Pan-cancer Analysis Identified that TRIB3 was Associated with Immune Cell Infiltration and Poor Prognosis

BACKGROUND

Previous studies have demonstrated that TRIB3 plays a carcinogenic role in tumor progression. However, the exploration of TRIB3 at the pan-cancer level has not been reported.

AIMS

This study aimed to conduct a comprehensive pan-cancer analysis of TRIB3.

OBJECTIVES

We explored the expression pattern and functional mechanism of TRIB3 on the basis of multiple databases.

METHODS

We first explored the expression level of TRIB3 in the TCGA database. Then, the receiver operation characteristic curve (ROC), Kaplan-Meier plotter, and Cox regression were used to estimate the diagnostic and prognostic value of TRIB3, respectively. We also explored the relationship between TRIB3 and the infiltration of tumor immune cells, as well as the expression of immune checkpoint molecules. Gene enrichment and protein interaction network analysis were carried out to identify possible carcinogenic molecular mechanisms and functional pathways. Finally, we compared the non-promoter region methylation of TRIB3 in normal and tumor tissues and explored potential systems with unique functions in TRIB3-mediated tumorigenesis.

RESULTS

The expression level of TRIB3 was elevated in multiple tumor types, and the high expression of TRIB3 was associated with poor prognosis. TRIB3 had a higher frequency of genetic changes in several tumors and showed varying trends in TRIB3 methylation levels. Additionally, high expression of TRIB3 was also associated with infiltration of cancer-related fibroblasts and different types of immune cells and was positively correlated with the expression of immune checkpoint molecules. Furthermore, gene enrichment analysis suggested that TRIB3 may play a role in the malignant progression of cancer by participating in protein post-translational modifications and activating transcription initiation factors.

CONCLUSION

Our pan-cancer analysis provided the potential carcinogenic role of TRIB3 in tumors and verified a promising target for clinical immune treatment.

Recent advances in crosstalk between immune cells and cancer cells with ferroptosis

Ferroptosis, a regulated form of cell death distinct from apoptosis and necrosis. Key hallmarks include iron-dependent lipid peroxidation, glutathione depletion, and intracellular iron accumulation, all of which are counteracted by specific cellular defenses. However, the immunosuppressive effects of ferroptosis induction in cancer immunotherapy remain unresolved. This review summarizes the recent advancements in ferroptosis research, focusing on its defensive mechanisms. It analyzes how ferroptosis affects both cancer and immune cells, highlighting its potential inhibitory effects on anti-tumor immunity and possible promotion of pro-tumor immune responses. Finally, this review briefly introduces case studies that combined ferroptosis induction with immunotherapy, offering novel perspectives for cancer treatment.

Administration of Spermidine and Eugenol Demonstrates Anti-Tumorigenic Efficacy on Metastatic SW620 and Primary Caco-2 Colorectal Cancer Spheroids

The anti-cancer potential of eugenol (EUG) is well recognized, whereas that of spermidine (SPD) is subject to dispute and requires further research. The anti-tumorigenic potential of wheat germ SPD (150 µM) and clove EUG (100 µM), alone, in combination as SPD+EUG (50 µM + 100 µM) and, as a supplement (SUPPL; 0.6 µM SPD + 50 µM EUG), was investigated on both metastatic SW620 and primary Caco-2 colorectal cancer (CRC) spheroids. Compared to untreated controls, all treatments significantly reduced the vitality and spheroid area, increased the necrotic area, and induced apoptosis on both cell-type spheroids after 96 h, with a reduced migration evident in 2D (two-dimensional) cultures after 48 h. The comparable anti-CRC effects of the SPD+EUG and the SUPPL reflected a wide-range dose efficacy of SPD and EUG. It is of note that SPD+EUG induced a synergistic effect on the increased caspase-3 expression and reduced the migration percentage in SW620. In more physiologically relevant intestinal equivalents (healthy enterocytes [NCM460], fibroblasts [L929], and monocytes [U937]) containing embedded SW620/Caco-2 spheroids, SPD+EUG administration significantly reduced the spheroid CEA marker and proliferation, whilst simultaneously increasing occludin, autophagy LC3-II expression, and monocyte differentiation, compared to the control models. Exogenous SPD, alone and in combination with EUG, displayed an anti-CRC potential on tumor growth and metastasis, and warrants further investigation.

Single-cell expression and immune infiltration analysis of polyamine metabolism in breast cancer

Breast cancer is one of the most threatening women health diseases worldwide and its molecular heterogeneity offers a range of response to therapy. The role of polyamine metabolism is receiving increasing attention. Polyamine metabolism not only plays an important role in the occurrence and development of breast cancer, but also interacts with tumor immune microenvironment. In this work, we applied single-cell RNA-sequencing (scRNA-seq) and systems immunological approaches to interrogate immune cell infiltration gene-to-gene co-expressions in the bulk tumor transcriptomes of breast cancer. We acquired breast cancer sample data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), evaluated the infiltration status of 22 immune cell types using CIBERSORTx tool, respectively. By leveraging the Retrospective Breast sample of various technologies including gene expression and methylation, we identified 46 breast cancer proliferation-associated co-expression modules using weighted gene coexpression network analysis (WGCNA) approach along with machine learning models which in turn delineated single cell level expressions features that these selected module possessed. We observed substantial cellular heterogeneity in the breast cancer microenvironment, where lineage-specific gene expression patterns were highly associated with tumor progression. Moreover, we also identified the gene modules correlated with immune cell infiltration level that could function as regulators in response to tumors for immune therapy. Moreover, risk scores were correlated with immune cell function in different patient groups defined by high- and low-risk. The findings of this study shed a new light upon molecular classification prognostic assessment and personalized treatment in breast cancer.

Ferroptosis as a new tool for tumor suppression through lipid peroxidation

As a newly defined type of programmed cell death, ferroptosis is considered a potent weapon against tumors due to its distinct mechanism from other types of programmed cell death. Ferroptosis is triggered by the uncontrolled accumulation of hydroperoxyl polyunsaturated fatty acid-containing phospholipids, also called lipid peroxidation. The lipid peroxidation, generated through enzymatic and non-enzymatic mechanisms, drives changes in cell morphology and the destruction of membrane integrity. Here, we dissect the mechanisms of ferroptosis induced enzymatically or non-enzymatically, summarize the major metabolism pathways in modulating lipid peroxidation, and provide insights into the relationship between ferroptosis and tumor suppression. In this review, we discuss the recent advances of ferroptosis in tumor microenvironments and the prospect of potential therapeutic application.

Protein degradation of antizyme depends on the N-terminal degrons

Antizyme (AZ) is a regulatory protein that plays a crucial role in modulating the activity of ornithine decarboxylase (ODC), which is the initial and rate-limiting enzyme in the complex pathway of polyamine biosynthesis. AZ facilitates the swift degradation of ODC, thereby modulating the levels of cellular polyamines. This study unveils a new ubiquitin-independent mechanism for AZ degradation, emphasizing the essential role of N-terminal degrons. Contrary to traditional ubiquitin-dependent degradation, our findings reveal that AZ degradation is significantly influenced by its N-terminal region. By conducting a series of experiments, including in vitro degradation assays, cycloheximide chase experiments, differential scanning calorimetry, and measurement of cellular concentrations of polyamines, we demonstrate that N-terminal truncation significantly enhances AZ's stability and facilitates the reduction of polyamine levels by accelerating ODC degradation. The removal of the N-terminal portion of AZ results in a reduced degradation rate and enhanced thermal stability of the protein, leading to a more efficient inhibition of polyamine synthesis. These findings are corroborated by the analysis of AZ isoforms, AZ1, AZ2, and AZ3, which display differential degradation patterns based on the specific N-terminal segments. This substantiates a degradation mechanism driven by an intrinsically disordered N-terminal region acting as a degron, independent of lysine ubiquitination. These results underscore the significant regulatory function of the N-terminal domain in the activity of AZ and the maintenance of polyamine homeostasis.

Targeting ALDH1A1 to enhance the efficacy of KRAS-targeted therapy through ferroptosis

KRAS is among the most commonly mutated oncogenes in human malignancies. Although the advent of sotorasib and adagrasib, has lifted the "undruggable" stigma of KRAS, the resistance to KRAS inhibitors quickly becomes a major issue. Here, we reported that aldehyde dehydrogenase 1 family member A1 (ALDH1A1), an enzyme in retinoic acid biosynthesis and redox balance, increases in response to KRAS inhibitors and confers resistance in a range of cancer types. KRAS inhibitors' efficacy is significantly improved in sensitive or drug-resistant cells, patient-derived organoids (PDO), and xenograft models by ALDH1A1 knockout, loss of enzyme function, or inhibitor. Furthermore, we discovered that ALDH1A1 suppresses the efficacy of KRAS inhibitors by counteracting ferroptosis. ALDH1A1 detoxicates deleterious aldehydes, boosts the synthesis of NADH and retinoic acid (RA), and improves RARA function. ALDH1A1 also activates the CREB1/GPX4 pathway, stimulates the production of lipid droplets in a pH-dependent manner, and subsequently prevents ferroptosis induced by KRAS inhibitors. Meanwhile, we established that GTF2I is dephosphorylated at S784 via ERK by KRAS inhibitors, which hinders its nuclear translocation and mediates ALDH1A1's upregulation in response to KRAS inhibitors. In summary, the results offer valuable insights into targeting ALDH1A1 to enhance the effectiveness of KRAS-targeted therapy through ferroptosis in cancer treatment.

MDH2 Promotes Hepatocellular Carcinoma Growth Through Ferroptosis Evasion via Stabilizing GPX4

The crosstalk between tumor progression and ferroptosis is largely unknown. Here, we identify malate dehydrogenase 2 (MDH2) as a key regulator of ferroptosis. MDH2 deficiency inhibits the growth of hepatocellular carcinoma (HCC) cells and enhances their sensitivity to ferroptosis induced by RAS-selective lethal 3 (RSL3), a compound known to cause ferroptosis. MDH2 knock-down enhances RSL3-induced intracellular reactive oxygen species, free iron ions and lipid per-oxides levels, leading to HCC ferroptotic cell death which is rescued by ferrostatin-1 and iron chelator deferiprone. Importantly, the inhibition of HCC cell growth caused by MDH2 deficiency is partially rescued by ferroptosis blockade. Mechanistically, MDH2 resists RSL3-induced ferroptosis sensitivity dependent on glutathione peroxidase 4 (GPX4), an enzyme responsible for scavenging lipid peroxides, which is stabilized by MDH2 in HCC. The protein expressions of MDH2 and GPX4 are positively correlated with each other in HCC cell lines. Furthermore, through our UALCAN website analysis, we found that MDH2 and GPX4 are highly expressed in HCC samples. These findings reveal a critical mechanism by which HCC evades ferroptosis via MDH2-mediated stabilization of GPX4 to promote tumor progression and underscore the potential of MDH2 inhibition in combi-nation with ferroptosis inducers for the treatment of HCC.

Methionine-SAM metabolism-dependent ubiquinone synthesis is crucial for ROS accumulation in ferroptosis induction

Ferroptosis is a cell death modality in which iron-dependent lipid peroxides accumulate on cell membranes. Cysteine, a limiting substrate for the glutathione system that neutralizes lipid peroxidation and prevents ferroptosis, can be converted by cystine reduction or synthesized from methionine. However, accumulating evidence shows methionine-based cysteine synthesis fails to effectively rescue intracellular cysteine levels upon cystine deprivation and is unable to inhibit ferroptosis. Here, we report that methionine-based cysteine synthesis is tissue-specific. Unexpectedly, we find that rather than inhibiting ferroptosis, methionine in fact plays an essential role during cystine deprivation-induced ferroptosis. Methionine-derived S-adenosylmethionine (SAM) contributes to methylation-dependent ubiquinone synthesis, which leads to lipid peroxides accumulation and subsequent ferroptosis. Moreover, SAM supplementation synergizes with Imidazole Ketone Erastin in a tumor growth suppression mouse model. Inhibiting the enzyme that converts methionine to SAM protects heart tissue from Doxorubicin-induced and ferroptosis-driven cardiomyopathy. This study broadens our understanding about the intersection of amino acid metabolism and ferroptosis regulation, providing insight into the underlying mechanisms and suggesting the methionine-SAM axis is a promising therapeutic strategy to treat ferroptosis-related diseases.

Prognostic modeling and Emerging therapeutic targets Unveiled through single-cell sequencing in esophageal squamous Cell carcinoma

ESCC presents a significant global health challenge due to its high mortality rates and varying responses to treatment. This underscores the critical need for novel diagnostic and predictive biomarkers to improve treatment outcomes. Initially, we conducted single-cell transcriptome sequencing on a total of 128,688 cells obtained from 10 patients as part of our research. Utilizing machine learning and cross-validation techniques, we developed a model incorporating 12 genes that distinguish malignant cells from non-malignant ones. In vitro, we explored the effects of IGFBP2 knockdown on the proliferation, invasion, and migration of ESCC cells. The clinical relevance of IGFBP2 was confirmed through IHC and Kaplan-Meier survival analyses. Furthermore, using bioinformatics tools such as GSVA and xCell on public databases, we discovered that high expression of IGFBP2 is associated with an immunosuppressive tumor microenvironment in ESCC, characterized by reduced CD8+ T cell infiltration. This was validated then through IHC. In summary, our study integrates single-cell sequencing and sophisticated computational techniques to highlight IGFBP2 as a promising biomarker and therapeutic target in ESCC.

Lysosomal iron accumulation and subsequent lysosomes-mitochondria iron transmission mediate PFOS-induced hepatocyte ferroptosis

Perfluorooctane sulfonate (PFOS) is known as a persistent organic pollutant. A significant correlation between PFOS and liver ferroptosis has been unveiled, but the precise mechanism needs to be elucidated. In prior research, we found that PFOS treatment provoked mitochondrial iron overload. In this study, we observed a gradual increase in lysosomal iron in L-O2 cells after exposure to PFOS for 0.5-24 h. In PFOS-exposed L-O2 cells, suppressing autophagy relieved the lysosomal iron overload. Inhibiting transient receptor potential mucolipin 1 (TRPML1), a calcium efflux channel on the lysosomal membrane, led to a further rise in lysosomal iron levels and decreased mitochondrial iron overload during PFOS treatment. Suppressing VDAC1, a subtype of voltage-dependent anion-selective channels (VDACs) on the outer mitochondrial membrane, had no impact on PFOS-triggered mitochondrial iron overload, whereas restraining VDAC2/3 relieved this condition. Although silencing VDAC2 relieved PFOS-induced mitochondrial iron overload, it had no effect on PFOS-triggered lysosomal iron overload. Silencing VDAC3 alleviated PFOS-mediated mitochondrial iron overload and led to an additional increase in lysosomal iron. Therefore, we regarded VDAC3 as the specific VDACs subtype that mediated the lysosomes-mitochondria iron transfer. Additionally, in the presence of PFOS, an enhanced association between TRPML1 and VDAC3 was found in mice liver tissue and L-O2 cells. Our research unveils a novel regulatory mechanism of autophagy on the iron homeostasis and the effect of TRPML1-VDAC3 interaction on lysosomes-mitochondria iron transfer, giving an explanation of PFOS-induced ferroptosis and shedding some light on the role of classic calcium channels in iron transmission.

miR-30c-5p inhibits esophageal squamous cell carcinoma progression by repressing the PI3K/AKT signaling pathway

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors, with high incidence and poor prognosis. Revealing mechanisms of ESCC progression and developing new therapeutic targets remains crucial. The aim of this study was to elucidate the molecular mechanism of miR-30c-5p in regulating the malignant progression of ESCC.

METHODS

TCGA, GEO, and other datasets were used to analyze the differential expression of miR-30c-5p in ESCC and adjacent tissues, and its impact on prognosis. Then the effects of miR-30c-5p on the proliferation, migration, and invasion of TE-1 and Eca9706 cells were investigated through proliferation experiments, transwell and wounding healing assays. The regulatory mechanism of miR-30c-5p on the PI3K/AKT signaling pathway and its interaction in cancer progression were investigated through Western blots, dual-luciferase reporter assay, and rescue experiments.

RESULTS

miR-30c-5p was significantly downregulated in ESCC tissue and represented a poor prognosis. miR-30c-5p mimic significantly inhibited the proliferation, migration, and invasion ability of ESCC, while miR-30c-5p inhibitor significantly promoted tumor cell progression. Through bioinformatic analysis and experimental results, miR-30c-5p interacted directly with PIK3CA mRNA and inhibited subsequent signaling pathway activation. PIK3CA activator could eliminate the inhibitory effects of miR-30c-5p mimic on the progression of ESCC, while PIK3CA inhibitors could rescue the promoting effect of miR-30c-5p inhibitor group cells.

CONCLUSIONS

In summary, we found that miR-30c-5p inhibited the proliferation, invasion and migration of ESCC by inhibiting PI3K/AKT signaling pathway for the first time, and this study is expected to provide a novel insight and potential therapeutic target for managing ESCC.

Polyamine Pathway Inhibitor DENSPM Suppresses Lipid Metabolism in Pheochromocytoma Cell Line

Pheochromocytomas (PCCs) are tumors arising from chromaffin cells in the adrenal medulla, and paragangliomas (PGLs) are tumors derived from extra-adrenal sympathetic or parasympathetic paraganglia; these tumors are collectively referred to as PPGL cancer. Treatment for PPGL primarily involves surgical removal of the tumor, and only limited options are available for treatment of the disease once it becomes metastatic. Human carriers of the heterozygous mutations in the succinate dehydrogenase subunit B (SDHB) gene are susceptible to the development of PPGL. A physiologically relevant PCC patient-derived cell line hPheo1 was developed, and SDHB_KD cells carrying a stable short hairpin knockdown of SDHB were derived from it. An untargeted metabolomic approach uncovered an overactive polyamine pathway in the SDHB_KD cells that was subsequently fully validated in a large set of human SDHB-mutant PPGL tumor samples. We previously reported that treatment with the polyamine metabolism inhibitor N1,N11-diethylnorspermine (DENSPM) drastically inhibited growth of these PCC-derived cells in culture as well as in xenograft mouse models. Here we explored the mechanisms underlying DENSPM action in hPheo1 and SDHB_KD cells. Specifically, by performing an RNAseq analysis, we have identified gene expression changes associated with DENSPM treatment that broadly interfere with all aspects of lipid metabolism, including fatty acid (FA) synthesis, desaturation, and import/uptake. Furthermore, by performing an untargeted lipidomic liquid chromatography-mass spectrometry (LC/MS)-based analysis we uncovered specific groups of lipids that are dramatically reduced as a result of DENSPM treatment. Specifically, the bulk of plasmanyl ether lipid species that have been recently reported as the major determinants of cancer cell fate are notably decreased. In summary, this work suggests an intersection between active polyamine and lipid pathways in PCC cells.

Regulatory mechanisms of amino acids in ferroptosis

Ferroptosis, an iron-dependent non-apoptotic regulated cell death process, is associated with the pathogenesis of various diseases. Amino acids, which are indispensable substrates of vital activities, significantly regulate ferroptosis. Amino acid metabolism is involved in maintaining iron and lipid homeostasis and redox balance. The regulatory effects of amino acids on ferroptosis are complex. An amino acid may exert contrasting effects on ferroptosis depending on the context. This review systematically and comprehensively summarized the distinct roles of amino acids in regulating ferroptosis and highlighted the emerging opportunities to develop clinical therapeutic strategies targeting amino acid-mediated ferroptosis.

Silver nanoparticles induce liver inflammation through ferroptosis in zebrafish

As the most widely employed artificial nanomaterials, silver nanoparticles (AgNPs) have been implicated in oxidative stress-induced liver injury. Despite these observations, the precise mechanisms underpinning AgNPs-induced hepatotoxicity have yet to be fully elucidated. This study embarked on an intersectional analysis of the GEO dataset (GSE139560), which encompassed murine liver tissues subjected to AgNPs, alongside datasets related to ferroptosis. Through this approach, three pivotal ferroptosis-associated genes (Arrdc3, Txnip, and Egfr) were identified. Further integration with disease model analysis from GSE111407 and GSE183158 unveiled a significant association between AgNPs exposure and alterations in glucose metabolism and insulin signaling pathways, intricately linked with the identified key ferroptosis genes. This correlation fostered the hypothesis that ferroptosis significantly contributed to the hepatotoxicity triggered by AgNPs. Subsequent Gene Set Enrichment Analysis (GSEA) pointed to the activation of ferroptosis-associated pathways, specifically MAPK and PPAR, under AgNPs exposure. Examination of the miRNA-mRNA interaction network revealed co-regulated upstream miRNAs targeting these pivotal genes, establishing a nexus to ferroptosis and heightened liver susceptibility. Experimental validation employing an adult zebrafish model exposed to AgNPs from 90 to 120 dpf demonstrated elevated levels of Fe2+ and MDA in the zebrafish livers, along with conspicuous mitochondrial morphological alterations, thereby reinforcing the notion that AgNPs precipitate liver dysfunction predominantly through the induction of ferroptosis. These insights collectively underscore the role of ferroptosis in mediating the adverse effects of AgNPs on liver glucose metabolism and insulin sensitivity, culminating in liver dysfunction. Overall, these results enhance the understanding of nanomaterial-induced hepatotoxicity and inform strategies to mitigate such health risks.

Involvement of mammalian SoLute Carriers (SLC) in the traffic of polyamines

Polyamines interact with different molecular targets to regulate a vast range of cellular processes. A network of enzymes and transport systems is crucial for the maintenance of polyamine homeostasis. Indeed, polyamines after synthesis must be distributed to the various tissues and some intracellular organelles. Differently from the well characterized enzymes devoted to polyamine synthesis, the transport systems are not unequivocally identified or characterized. Besides some ATPases which have been identified as polyamine transporters, much less is known about solute carriers (SLC) involved in the transport of these compounds. Only two SLCs have been unequivocally identified as polyamine transporters: SLC18B1 (VPAT) and SLC22A4 (OCTN1). Transport studies have been performed with cells transfected with the cDNAs encoding the two and other SLCs or, in the case of OCTN1, also by in vitro assay using proteoliposomes harboring the recombinant human protein. According to the role proposed for OCTN1, polyamines have been associated with prolonged and quality of life. This review provides an update on the most recent findings concerning the polyamine transporters or the prediction of the putative ones.

BACH1 inhibits senescence, obesity, and short lifespan by ferroptotic FGF21 secretion

Ferroptosis is a type of regulated cell death characterized by iron-dependent lipid peroxidation. A model cell system is constructed to induce ferroptosis by re-expressing the transcription factor BACH1, a potent ferroptosis inducer, in immortalized mouse embryonic fibroblasts (iMEFs). The transfer of the culture supernatant from ferroptotic iMEFs activates the proliferation of hepatoma cells and other fibroblasts and suppresses cellular senescence-like features. The BACH1-dependent secretion of the longevity factor FGF21 is increased in ferroptotic iMEFs. The anti-senescent effects of the culture supernatant from these iMEFs are abrogated by Fgf21 knockout. BACH1 activates the transcription of Fgf21 by promoting ferroptotic stress and increases FGF21 protein expression by suppressing its autophagic degradation through transcriptional Sqstm1 and Lamp2 repression. The BACH1-induced ferroptotic FGF21 secretion suppresses obesity in high-fat diet-fed mice and the short lifespan of progeria mice. The inhibition of these aging-related phenotypes can be physiologically significant regarding ferroptosis.

Oxidative Metabolism as a Cause of Lipid Peroxidation in the Execution of Ferroptosis

Ferroptosis is a type of nonapoptotic cell death that is characteristically caused by phospholipid peroxidation promoted by radical reactions involving iron. Researchers have identified many of the protein factors that are encoded by genes that promote ferroptosis. Glutathione peroxidase 4 (GPX4) is a key enzyme that protects phospholipids from peroxidation and suppresses ferroptosis in a glutathione-dependent manner. Thus, the dysregulation of genes involved in cysteine and/or glutathione metabolism is closely associated with ferroptosis. From the perspective of cell dynamics, actively proliferating cells are more prone to ferroptosis than quiescent cells, which suggests that radical species generated during oxygen-involved metabolism are responsible for lipid peroxidation. Herein, we discuss the initial events involved in ferroptosis that dominantly occur in the process of energy metabolism, in association with cysteine deficiency. Accordingly, dysregulation of the tricarboxylic acid cycle coupled with the respiratory chain in mitochondria are the main subjects here, and this suggests that mitochondria are the likely source of both radical electrons and free iron. Since not only carbohydrates, but also amino acids, especially glutamate, are major substrates for central metabolism, dealing with nitrogen derived from amino groups also contributes to lipid peroxidation and is a subject of this discussion.

Ferroptosis: principles and significance in health and disease

Ferroptosis, an iron-dependent form of cell death characterized by uncontrolled lipid peroxidation, is governed by molecular networks involving diverse molecules and organelles. Since its recognition as a non-apoptotic cell death pathway in 2012, ferroptosis has emerged as a crucial mechanism in numerous physiological and pathological contexts, leading to significant therapeutic advancements across a wide range of diseases. This review summarizes the fundamental molecular mechanisms and regulatory pathways underlying ferroptosis, including both GPX4-dependent and -independent antioxidant mechanisms. Additionally, we examine the involvement of ferroptosis in various pathological conditions, including cancer, neurodegenerative diseases, sepsis, ischemia-reperfusion injury, autoimmune disorders, and metabolic disorders. Specifically, we explore the role of ferroptosis in response to chemotherapy, radiotherapy, immunotherapy, nanotherapy, and targeted therapy. Furthermore, we discuss pharmacological strategies for modulating ferroptosis and potential biomarkers for monitoring this process. Lastly, we elucidate the interplay between ferroptosis and other forms of regulated cell death. Such insights hold promise for advancing our understanding of ferroptosis in the context of human health and disease.