CD8+ T cells and fatty acids orchestrate tumor ferroptosis and immunity via ACSL4

Circ-0069561 as a novel diagnostic biomarker for progression of diabetic kidney disease

BACKGROUND

Circular RNAs (circRNAs) are non-coding RNAs that are key regulators of the initiation and progression of various human diseases. However, the role of circRNAs in diabetic kidney disease (DKD) remains unknown.

METHODS

Whole high-throughput RNA sequencing (RNA-seq) was performed on kidney tissues from clinical DKD patients and controls. Circ-0069561 with significantly up-regulated expression level was selected by real-time PCR (RT-PCR) analysis. RT-PCR and fluorescent in situ hybridization (FISH) further validated the expression and subcellular localization of circ-0069561 in type 2 diabetic mice and DKD patients. The clinical significance of circ-0069561 in DKD was evaluated. The circRNA-miRNA-ferroptosis associated mRNA network was constructed. The biological function of circ-0069561 in mouse podocyte clone 5 (MPC5) was analyzed.

RESULTS

The top 10 up-regulated circular RNAs were selected by RT-PCR validation, and the results demonstrated a significant elevation in the expression level of circ-0069561. The RT-PCR and FISH results demonstrated that the expression of circ-0069561 was elevated in renal tissues of type 2 diabetic mice and DKD patients, with a predominant localization in glomerulus. The ROC curves showed that circ-0069561 had a good diagnostic value in massive proteinuria (area under the curve = 0.889). Kaplan-Meier analysis showed that high expression of circ-0069561 was associated with an increased risk of primary endpoints. The circRNA-miRNA-mRNA network indicated that ferroptosis might be involved in the pathogenesis of DKD. In vitro experiments demonstrated that circ-0069561 aggravated glucose-induced podocyte damage and ferroptosis.

CONCLUSION

Circ-0069561 has the potential to be an ideal biomarker and therapeutic target for DKD progression.

Ferroptosis meets inflammation: A new frontier in cancer therapy

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a critical player in cancer pathogenesis. Concurrently, inflammation, a key biological response to tissue injury or infection, significantly influences cancer development and progression. The interplay between ferroptosis and inflammation represents a promising yet underexplored area of research. This review synthesizes recent advances in understanding the molecular mechanisms governing their interaction, emphasizing how ferroptosis triggers inflammatory responses and how inflammatory mediators, such as TNF-α, regulate ferroptosis through iron metabolism and lipid peroxidation pathways. Key molecular targets within the ferroptosis-inflammation axis, including GPX4, ACSL4, and the NF-κB signaling pathway, offer therapeutic potential for cancer treatment. By modulating these targets, it may be possible to enhance ferroptosis and fine-tune inflammatory responses, thereby improving therapeutic outcomes. Additionally, this review explores the broader implications of targeting the ferroptosis-inflammation interplay in disease treatment, highlighting opportunities for developing innovative strategies to combat cancer. By bridging the gap in current knowledge, this review provides a comprehensive resource for researchers and clinicians, offering insights into the therapeutic potential of this intricate biological relationship.

Epigenetic regulation of ferroptosis in gastrointestinal cancers (Review)

Ferroptosis is a type of iron‑dependent cell death characterized by excessive lipid peroxidation and may serve as a potential therapeutic target in cancer treatment. While the mechanisms governing ferroptosis continue to be explored and elucidated, an increasing body of research highlights the significant impact of epigenetic modifications on the sensitivity of cancer cells to ferroptosis. Epigenetic processes, such as DNA methylation, histone modifications and non‑coding RNAs, have been identified as key regulators that modulate the expression of ferroptosis‑related genes. These alterations can either enhance or inhibit the sensitivity of gastrointestinal cancer (GIC) cells to ferroptosis, thereby affecting the fate of GICs. Drugs that target epigenetic markers for advanced‑stage cancer have shown promising results in enhancing ferroptosis and inhibiting tumor growth. This review explores the intricate relationship between epigenetic regulation and ferroptosis in GICs. Additionally, the potential of leveraging epigenetic modifications to trigger ferroptosis in GICs is investigated. This review highlights the importance of further research to elucidate the specific mechanisms underlying epigenetic control of ferroptosis and to advance the development of novel therapeutic approaches.

Deep transfer learning approach for automated cell death classification reveals novel ferroptosis-inducing agents in subsets of B-ALL

Ferroptosis is a recently described type of regulated necrotic cell death whose induction has anti-cancer therapeutic potential, especially in hematological malignancies. However, efforts to uncover novel ferroptosis-inducing therapeutics have been largely unsuccessful. In the current investigation, we classified brightfield microscopy images of tumor cells undergoing defined modes of cell death using deep transfer learning (DTL). The trained DTL network was subsequently combined with high-throughput pharmacological screening approaches using automated live cell imaging to identify novel ferroptosis-inducing functions of the polo-like kinase inhibitor volasertib. Secondary validation showed that subsets of B-cell acute lymphoblastic leukemia (B-ALL) cell lines, namely 697, NALM6, HAL01, REH and primary patient B-ALL samples were sensitive to ferroptosis induction by volasertib. This was accompanied by an upregulation of ferroptosis-related genes post-volasertib treatment in cell lines and patient samples. Importantly, using several leukemia models, we determined that volasertib delayed tumor growth and induced ferroptosis in vivo. Taken together, we have applied DTL to automated live-cell imaging in pharmacological screening to identify novel ferroptosis-inducing functions of a clinically relevant anti-cancer therapeutic.

Organelles Ca2+ redistribution contributes to cadmium-induced EMT of renal cancer cells through p-cPLA2-mediated arachidonic acid release

Cadmium ion (Cd2+) is a non-essential metal that can increase cancer risk, including potentially renal cell carcinoma (RCC), though this link is not definitive. Cd2+ exposure impairs fatty acid metabolism in the kidneys, particularly affecting arachidonic acid (AA) levels, which are crucial for health. Previous studies have suggested that Cd2+-altered the AA metabolism associates with renal dysfunction. However, the role and mechanism of Cd2+-regulated AA source in promoting RCC progression are still unclear. This study aims to investigate how Cd2+ exposure affects AA levels in renal cancer cells and its role in promoting cell migration. Cd2+ exposure increases AA levels through cPLA2-mediated release. It also induces calcium ion (Ca2+) redistribution from the endoplasmic reticulum (ER) to mitochondria, activating the p38 MAPK/cPLA2 signaling pathway, and epithelial-mesenchymal transition (EMT) of Caki-1 cells. Cd2+-induced ER Ca2+ release, p38 MAPK/cPLA2 signaling activation, AA levels, and EMT of Caki-1 cells were effectively reversed by siRNA knockdown of IP3R. Both exogenous AA treatments and Cd2+-induced AA metabolite PGD2 promoted EMT and cell migration of Caki-1 cells. This study highlights Cd2+'s impact on fatty acid metabolism and organelle function in renal cancer cells, identifying potential therapeutic targets for RCC.

HSPB1/KDM1 A facilitates ANXA2 expression via hypomethylated DNA promoter to inhibit ferroptosis and enhance gemcitabine resistance in pancreatic cancer

Chemotherapy resistance contributes to the unsatisfied prognosis in pancreatic cancer (PC) patients. Heat shock protein beta-1 (HSPB1) plays a tumor promoting role in PC by inhibiting ferroptosis. This study aims to explore whether high expression of HSPB1 was responsible for ferroptosis and gemcitabine (GEM) resistance in PC. Here, we found that HSPB1 was upregulated in GEM-resistant PC cells and tumor tissues, as confirmed by RT-qPCR and Western blotting assays. Knockdown of HSPB1 enhanced GEM sensitivity, decreased the abilities of proliferation and invasion, and promoted apoptosis in GEM-resistant PC cells. Utilizing commercial kits, HSPB1 inhibition triggered ferroptosis, as indicated by increased levels of reactive oxygen species, malondialdehyde, and Fe2+, along with reduced glutathione (GSH) levels. Furthermore, the methylation specific PCR (MSP) results demonstrated a significant decrease in the methylation level of annexin A2 (ANXA2) CpG. The Chromatin immunoprecipitation (ChIP), ChIP-Re-ChIP, and Co-IP experiments revealed that HSPB1 interacts with lysine-specific histone demethylase 1A (KDM1A), recruiting KDM1A-CoREST complex to the ANXA2 promoter to enhance ANXA2 expression through demethylation of H3K9me2. Additionally, ANXA2 depletion further inhibited cell proliferation and invasion and induced ferroptosis in KDM1A-silenced cells, whereas ANXA2 overexpression produced the opposite effects. Finally, HSPB1 overexpression reduced gemcitabine sensitivity by promoting tumor growth in nude mice. Altogether, HSPB1 promoted ANXA2 expression by facilitating H3K9me2 demethylation through the recruitment of KDM1A-CoREST complex to the ANXA2 promoter, thereby inhibiting ferroptosis and enhancing GEM resistance in PC. These data provided a new insight for overcoming GEM-resistant PC.

Mitochondria-specific GPX4 inhibition enhances ferroptosis and antitumor immunity

Ferroptosis is gaining attention as a potential cancer immunotherapy strategy, as it can stimulate antitumor responses by enhancing dendritic cell (DC) activation and the infiltration of cytotoxic T cells (CTLs). However, cancer cells often develop resistance to ferroptosis, reducing the effectiveness of existing treatments. This study demonstrates a novel mitochondria-targeted ferroptosis inducer, designated mitoFePDA@R, which is engineered to achieve a "closed-loop" cancer immunotherapy strategy of ferroptosis induction, antitumor immune activation, and ferroptosis enhancement. In this strategy, mitoFePDA@R is designed to release Fe2+ and the mitoGPX4 inhibitor RSL3 within tumor mitochondria, thereby effectively inducing ferroptosis and activating strong antitumor immune responses. Additionally, interferon γ (IFN-γ) released from CTLs inhibits GSH synthesis, which further enhances the ferroptosis sensitivity of tumor cells to form a "closed-loop" strategy. In vitro studies indicated that mitoFePDA@R induced strong ferroptosis in tumor cells by accumulating lipid peroxides (LPO) in mitochondria (which lacks mitochondria targeting). Animal studies confirmed that mitoFePDA@R effectively triggered ferroptosis and activated subsequent antitumor immune responses, leading to significant tumor growth inhibition. This provides a viable and effective strategy for ferroptosis-associated cancer immunotherapy.

Development of a machine learning-based predictive risk model combining fatty acid metabolism and ferroptosis for immunotherapy response and prognosis in prostate cancer

Prostate cancer (PCa) remains a leading cause of cancer-related mortality, necessitating robust prognostic models and personalized therapeutic strategies. This study integrated bulk RNA sequencing, single-cell RNA sequencing (scRNA-seq), and spatial transcriptomics to construct a prognostic model based on genes shared between ferroptosis and fatty acid metabolism (FAM). Using the TCGA-PRAD dataset, we identified 73 differentially expressed genes (DEGs) at the intersection of ferroptosis and FAM, of which 19 were significantly associated with progression-free survival (PFS). A machine learning-based prognostic model, optimized using the Lasso + Random Survival Forest (RSF) algorithm, achieved a high C-index of 0.876 and demonstrated strong predictive accuracy (1-, 2-, and 3-year AUCs: 0.77, 0.75, and 0.78, respectively). The model, validated in the DFKZ cohort, stratified patients into high- and low-risk groups, with the high-risk group exhibiting worse PFS and higher tumor mutation burden (TMB). Functional enrichment analysis revealed distinct pathway activities, with high-risk patients showing enrichment in immune-related and proliferative pathways, while low-risk patients were enriched in metabolic pathways. Immune microenvironment analysis revealed heightened immune activity in high-risk patients, characterized by increased infiltration of CD8 + T cells, regulatory T cells, and M2 macrophages, alongside elevated TIDE scores, suggesting immune evasion and resistance to immunotherapy. In contrast, low-risk patients exhibited higher infiltration of plasma cells and neutrophils and demonstrated better responses to immune checkpoint inhibitors (ICIs). Spatial transcriptomics and scRNA-seq further elucidated the spatial distribution of model genes, highlighting the central role of macrophages in mediating risk stratification. Additionally, chemotherapy sensitivity analysis identified potential therapeutic agents, such as Erlotinib and Picolinic acid, for low-risk patients. In vitro experiments showed that overexpression of CD38 in the PC-3 cell line led to elevated lipid peroxidation (C11-BODIPY) and reactive oxygen species (ROS), suggesting increased cell ferroptosis. These findings provide a comprehensive framework for risk stratification and personalized treatment in PCa, bridging molecular mechanisms with clinical outcomes.

Long-chain fatty acyl CoA synthetase 4 expression in pancreatic cancer: a marker for malignant lesions and prognostic indicator for recurrence

BACKGROUND

Long-chain fatty acyl CoA synthetase 4 (ACSL4) is crucial for lipid metabolism, primarily catalyzing the formation of 12-20 carbon chain fatty acids. ACSL4 is upregulated in various cancers and linked to aggressive behavior and poor survival. A bioinformatics study showing ACSL4 upregulation in pancreatic cancer. However, utility for actual pathological diagnosis and clinical significance in pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasm (IPMN) are unexplored. This study aimed to investigate ACSL4 expression in PDAC and IPMN, and evaluate its clinical implications.

METHODS

We examined ACSL4 expression using immunohistochemistry in 165 patients with PDAC and IPMN. Differences in ACSL4 expression between malignant and benign lesions were evaluated using the Pearson χ2 test. The association between ACSL4 expression, pathological parameters, and survival was assessed through Kaplan-Meier and Cox regression analyses in 96 patients with invasive cancer.

RESULTS

Compared to normal pancreatic ducts, low-grade pancreatic intraepithelial neoplasm, and intraductal papillary mucinous adenoma (IPMA) (3.3%, 3.4%, and 2.7%, respectively), ACSL4 expression was significantly higher in invasive PDAC, noninvasive intraductal papillary mucinous carcinoma (IPMC), and invasive IPMC (77%, 86.7%, and 93.9%, respectively). In invasive cancers, low ACSL4 expression was associated with a higher frequency of lymphovascular invasion and recurrence and shorter disease-free survival (P = 0.006). Additionally, low ACSL4 expression was an independent prognostic factor for shorter disease-free survival in multivariable Cox regression analysis (HR = 2.409, 95% CI: 1.121-5.180, P = 0.024).

CONCLUSION

ACSL4 expression helps differentiate cancerous from precancerous lesions in pancreatic cancer, but low expression is linked to a higher frequency of lymphovascular invasion and shorter disease-free survival in invasive cases. Due to the limited sample size and broad confidence intervals, the findings of this study should be interpreted with caution and require validation in larger, independent cohorts.

Targeting PSMD14 combined with arachidonic acid induces synthetic lethality via FADS1 m6A modification in triple-negative breast cancer

Dysregulation of deubiquitination is essential for cancer growth. However, the role of 26S proteasome non-ATPase regulatory subunit 14 (PSMD14) in the progression of triple-negative breast cancer (TNBC) remains to be determined. Gain- and loss-of-function experiments showed that silencing PSMD14 notably attenuated the growth, invasion, and metastasis of TNBC cells in vitro and in vivo. Overexpression of PSMD14 produced the opposite results. Mechanistically, PSMD14 decreased K63-linked ubiquitination on SF3B4 protein to de-ubiquitin and stabilize SF3B4 protein. Then, SF3B4/HNRNPC complex bound to FADS1 mRNA and promoted exon inclusion in the target mRNA through m6A site on FADS1 mRNA recognized by HNRNPC, thereby up-regulating the expression of FADS1 and activating Akt/mTOR signaling. Exogenous arachidonic acid supplementation combined with PSMD14 knockdown induced synthetic lethality, which was further confirmed in TNBC organoid (PDO) and TNBC patient-derived xenograft (PDX) mouse models. Overall, our findings reveal an oncogenic role of PSMD14 in TNBC progression, which indicates a potential biomarker and ferroptosis-mediated therapeutic strategy for TNBC.

NANS suppresses NF-κB signaling to promote ferroptosis by perturbing iron homeostasis

Metastatic colorectal cancer (CRC) cells endure survival challenges, including treatment-induced ferroptosis. While adaptation to ferroptosis stress facilitates metastasis, reciprocal regulatory mechanisms remain unclear. Here, a CRISPR-Cas9 screen identifies N-acetylneuraminate synthase (NANS) as a ferroptosis promoter in CRC, regardless of its metabolic function. NANS expression is downregulated and correlates with poor prognosis in patients with CRC. Under ferroptotic stress, cyclin-dependent kinase 1 (CDK1) phosphorylates NANS at serine 275 (S275), triggering its dissociation from TAK1. Phosphorylated NANS is ubiquitinated by UBE2N at K246, leading to degradation, which activates TAK1-NF-κB signaling and upregulates the ferroptosis inhibitor FTH1, enabling metastasis via ferroptosis resistance. NANS pS275 levels are associated with tumor aggressiveness and clinical outcomes in patients with CRC. These findings indicate that NANS suppresses CRC metastasis by enhancing ferroptosis susceptibility, while CDK1-mediated phosphorylation at S275 drives adaptive resistance. Targeting this phosphorylation axis may improve ferroptosis-inducing therapies to restrict metastatic progression in CRC.

Increased fatty acid delivery by tumor endothelium promotes metastatic outgrowth

Metastatic outgrowth in distant microscopic niches requires sufficient nutrients, including fatty acids (FAs), to support tumor growth and to generate an immunosuppressive tumor microenvironment (TME). However, despite the important role of FAs in metastasis, the regulation of FA supply in metastatic niches has not been defined. In this report, we show that tumor endothelium actively promotes outgrowth and restricts antitumor cytolysis by transferring FAs into developing metastatic tumors. We describe a process of transendothelial FA delivery via endosomes that requires mTORC1 activity. Thus, endothelial cell-specific targeted deletion of Raptor (RptorECKO), a unique component of the mTORC1 complex, significantly reduced metastatic tumor burden that was associated with improved markers of T cell cytotoxicity. Low-dose everolimus that selectively inhibited endothelial mTORC1 improves immune checkpoint responses in metastatic disease models. This work reveals the importance of transendothelial nutrient delivery to the TME, highlighting a future target for therapeutic development.

Comprehensive analysis of ferroptosis-related long non-coding RNA and its association with tumor progression and ferroptosis in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors with a poor prognosis. Ferroptosis is an distinct type of non-apoptotic cell death that is closely associated with tumor prognosis. Thus, we aimed to develop an novel prognosis risk model based on ferroptosis-related lncRNAs and excavate novel diagnostic markers. In this study, eight ferroptosis-related lncRNAs were obtained for constructing the prognosis model in GC based on TCGA database. The patients in the high-risk group had worse survival than those in the low-risk group, and the risk-grouping could be used as an independent prognostic factor for OS. Receiver operating characteristic curve analysis demonstrated this risk model was superior to traditional clinicopathological features in predicting GC prognosis. GSEA revealed that these lncRNAs were mainly involved in cell adhesion, cancer pathways, and immune function regulation. The key gene HAGLR of this risk signature was up-regulated in GC tissues and cells. Function assays showed that knockdown of HAGLR could effectively inhibit the GC cells proliferation and migration, whereas silencing HAGLR accelerated apoptosis and ferroptosis cell death process. In conclusion, we established a novel ferroptosis-related prognostic risk signature including eight lncRNAs, which may improve prognostic predictive accuracy for patients with GC.

IFN-γ could induce ferroptosis in keloid fibroblasts by inhibiting the expression of serpine2

Keloids are common pathological scars resulting from previous trauma or inflammation. Interferon-gamma (IFN-γ) has shown significant therapeutic effects when used alone or in combination with other agents. While IFN-γ has been found to regulate ferroptosis in tumor cells, its ability to regulate ferroptosis in keloid fibroblasts (KFs) is unclear. Here, we have demonstrated a direct causal relationship between IFN-γ levels and ferroptosis in KFs. To explore the intrinsic mechanism, we performed genome-wide RNA and proteomics sequencing and found that serpine2 was the most significantly downregulated gene in KFs after exogenous overexpression of IFN-γ. Serpine2, which belongs to a family of serine protease inhibitors, has been shown to play an important role in fibrotic diseases. Therefore, we hypothesized that serpine2 is a downstream gene in the regulation of ferroptosis in KFs by IFN-γ. Our results showed that serpine2 overexpression promotes collagen synthesis, which in turn promotes the proliferation, migration, and invasive functions of KFs. We further demonstrated that serpine2 overexpression promoted system Xc- transporter expression, cystine uptake, and glutathione synthesis, enhanced GPX4 activity; and inhibited reactive oxygen species generation. This resulted in a reduction in intracellular lipid peroxidation and the levels of its metabolite malondialdehyde, as well as inhibited ferroptosis in KFs. IFN-γ reversed these effects of serpine2 overexpression. These results were largely confirmed in in vivo keloid models too. These findings imply that IFN-γ not only directly induces ferroptosis in KFs but also enhances their sensitivity to ferroptosis by inhibiting the synthesis of SLC7A11 and SLC3A2 through downregulation of serpine2. In summary, we suggest that the serpine2-system Xc- axis is a promising therapeutic target for the treatment of keloids.

Targeting pyroptosis for cancer immunotherapy: mechanistic insights and clinical perspectives

Pyroptosis is a distinct form of programmed cell death characterized by the rupture of the cell membrane and robust inflammatory responses. Increasing evidence suggests that pyroptosis significantly affects the tumor microenvironment and antitumor immunity by releasing damage-associated molecular patterns (DAMPs) and pro-inflammatory mediators, thereby establishing it as a pivotal target in cancer immunotherapy. This review thoroughly explores the molecular mechanisms underlying pyroptosis, with a particular focus on inflammasome activation and the gasdermin family of proteins (GSDMs). It examines the role of pyroptotic cell death in reshaping the tumor immune microenvironment (TIME) involving both tumor and immune cells, and discusses recent advancements in targeting pyroptotic pathways through therapeutic strategies such as small molecule modulators, engineered nanocarriers, and combinatory treatments with immune checkpoint inhibitors. We also review recent advances and future directions in targeting pyroptosis to enhance tumor immunotherapy with immune checkpoint inhibitors, adoptive cell therapy, and tumor vaccines. This study suggested that targeting pyroptosis offers a promising avenue to amplify antitumor immune responses and surmount resistance to existing immunotherapies, potentially leading to more efficacious cancer treatments.

Metal-modulated T cell antitumor immunity and emerging metalloimmunotherapy

In recent years, increasing evidence has shown that metals play important roles in both innate and adaptive immunity. An emerging concept of metalloimmunotherapy has been proposed, which may accelerate the development of immunotherapy for cancers. Here, we discuss how metals affect T cell function through different signaling pathways. Metals impact the fate of T cells, including their activation, proliferation, cytotoxicity, and differentiation. Most importantly, metals also participate in mitochondrial operation by regulating energy production and reactive oxygen species homeostasis in T cells. We also identified the metal-based mutual effects between tumor cells and T cells in the tumor microenvironment. Overall, the antitumor effect of T cells can be improved by targeting metal metabolism and metalloimmunotherapy, which will be a step forward in the treatment of cancers.

Comprehensive analysis based on IFN-γ and SASP related genes, bulk RNA and single-cell sequencing to evaluate the prognosis and immune landscape of stomach adenocarcinoma

BACKGROUND

Stomach adenocarcinoma (STAD) represents the predominant subtype of gastric cancer, known for its drug resistance, unfavorable prognosis, and low cure rates. IFN-γ serves as a cytokine generated by immune cells, instrumental in tumor immune clearance and essential to the tumor microenvironment. The aging-associated secretory phenotype (SASP) can modify the local tissue environment, facilitating gastric cancer progression and chemotherapy resistance.

OBJECTIVE

This study intends to identify STAD subtypes based on IFN-γ and SASP-related genes and to develop a risk prognostic model for predicting patient survival, tumor immune microenvironment, and responses to drug treatment.

METHODS

The genomic and clinical datasets originate from the Cancer Genome Atlas (TCGA) database, while the genes associated with IFN-γ and SASP come from pertinent scholarly articles. We discovered the prognostic genes linked to IFN-γ and SASP in STAD using Cox regression analysis. Next, we applied non-negative matrix factorization (NMF) to categorize LIHC into distinct molecular subtypes, identifying differentially expressed genes across these subtypes. Following this, we developed a predictive model using Cox and LASSO regression analyses to stratify patients into specific risk categories, validating the model to assess the prognostic significance of the identified signatures. Lastly, we integrated single-cell data to elucidate the immune landscape of STAD and identified potential drugs along with their sensitivity profiles.

RESULTS

We identified 17 prognostic genes related to IFN-γ and SASP, successfully classifying patients into two distinct molecular subtypes. These subtypes exhibited notable differences in immune profiles and prognostic outcomes. We pinpointed three differentially expressed genes to establish risk characteristics and created a prognostic model capable of accurately predicting patient outcomes. Our findings revealed a strong association between STAD and the extracellular matrix, low-risk group exhibited favorable prognosis, and may derive greater benefits from immunotherapy.

CONCLUSION

We developed a risk model using IFN-γ and SASP-associated genes to predict the prognosis of STAD patients more accurately. Additionally, we assessed the immune landscape of STAD by integrating bulk RNA and single-cell sequencing analyses. This approach may yield valuable insights for clinical decision-making and immunotherapy strategies in STAD.

Lipotoxicity, lipid peroxidation and ferroptosis: a dilemma in cancer therapy

The vulnerability of tumor cells to lipid peroxidation, driven by redox imbalance and lipid overabundance within the tumor microenvironment (TME), has become a focal point for novel antitumor strategies. Ferroptosis, a form of regulated cell death predicated on lipid peroxidation, is emerging as a promising approach. Beyond their role in directly eliminating tumor cells, lipid peroxidation and its products, such as 4-hydroxynonenal (HNE), exert an additional influence by damaging DNA and shaping an environment conducive to tumor growth and metastasis. This process polarizes macrophages towards a pro-inflammatory phenotype, dampens the antigen-presenting capacity of dendritic cells (DCs), and undermines the cytotoxic functions of T and NK cells. Furthermore, it transforms neutrophils into pro-tumorigenic polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). The lipid peroxidation of stroma cells also contributes to tumor progression. Although advanced nanotherapies have shown the ability to target tumor cells precisely, they often overlook the nuanced effects of lipid peroxidation products. In this review, we highlight a synergistic mechanism in which lipid peroxidation products and ferroptosis contribute to an immunosuppressive state that is temporally distinct from cell death. This insight broadens our understanding of ferroptosis-derived immunosuppression, encompassing all types of immune cells within the TME. This review aims to catalyze further research in this underexplored area, emphasizing the potential of lipid peroxidation products to hinder the clinical translation of ferroptosis-based therapies.

PSAT1 impairs ferroptosis and reduces immunotherapy efficacy via GPX4 hydroxylation

Tumor cells adapt to the inflammatory tumor microenvironment (TME) and develop resistance to immunotherapy, with ferroptosis being a major form of tumor cell death. However, the mechanisms by which tumor cells coordinate TME stimuli and their unique metabolic traits to evade ferroptosis and develop resistance to immunotherapy remain unclear. Here we showed that interferon-γ (IFNγ)-activated calcium/calmodulin-dependent protein kinase II phosphorylates phosphoserine aminotransferase 1 (PSAT1) at serine 337 (S337), allowing it to interact with glutathione peroxidase 4 (GPX4) and stabilize the protein, counteracting ferroptosis. PSAT1 elevates GPX4 stability by promoting α-ketoglutarate-dependent PHD3-mediated GPX4 proline 159 (P159) hydroxylation, disrupting its binding to HSC70 and inhibiting autophagy-mediated degradation. In mice, reconstitution of PSAT1 S337A or GPX4 P159A promotes ferroptosis and suppresses triple-negative breast cancer (TNBC) progression. Blocking PSAT1 pS337 with CPP elevates IFNγ-induced ferroptosis and enhances the efficacy of programmed cell death protein 1 (PD-1) antibodies in TNBC. Additionally, PSAT1-mediated GPX4 hydroxylation correlates with poor immunotherapy outcomes in patients with TNBC, highlighting PSAT1's noncanonical role in suppressing ferroptosis and immunotherapy sensitivity.

An atlas of ferroptosis-induced secretomes

Cells undergoing regulated necrosis systemically communicate with the immune system via the release of protein and non-protein secretomes. Ferroptosis is a recently described iron-dependent type of regulated necrosis driven by massive lipid peroxidation. While membrane rupture occurs during ferroptosis, a comprehensive appraisal of ferroptotic secretomes and their potential biological activity has been lacking. Here, we apply a multi-omics approach to provide an atlas of ferroptosis-induced secretomes and reveal a novel function in macrophage priming. Proteins with assigned DAMP and innate immune system function, such as MIF, heat shock proteins (HSPs), and chaperones, were released from ferroptotic cells. Non-protein secretomes with assigned inflammatory function contained oxylipins as well as TCA- and methionine-cycle metabolites. Interestingly, incubation of bone marrow-derived macrophages (BMDMs) with ferroptotic supernatants induced transcriptional reprogramming consistent with priming. Indeed, exposure to ferroptotic supernatants enhanced LPS-induced cytokine production. These results define a catalog of ferroptosis-induced secretomes and identify a biological activity in macrophage priming with important implications for the fine-tuning of inflammatory processes.

Sarcosine sensitizes lung adenocarcinoma to chemotherapy by dual activation of ferroptosis via PDK4/PDHA1 signaling and NMDAR-mediated iron export

BACKGROUND

Ferroptosis, a regulated cell death driven by iron-dependent lipid peroxidation, is associated with chemoresistance in lung adenocarcinoma (LUAD). This study aims to investigate the role of sarcosine in ferroptosis and its underlying mechanisms.

METHODS

An RSL3-induced ferroptosis model was used to screen a library of 889 human endogenous metabolites and metabolomic profiling was harnessed to identify metabolites associated with ferroptosis. Cell viability, lipid-reactive oxygen species (ROS), ferrous iron, malondialdehyde (MDA), and mitochondrial integrity were assessed to evaluate sarcosine's effects on ferroptosis. Metabolic fate was studied using 15N-labeled sarcosine. Next, we used untargeted metabolomic profiling and next-generation sequencing to dissect metabolic and transcriptomic changes upon sarcosine supplementation. The effects of sarcosine on ferroptosis and chemotherapy were further validated in patient-derived organoids (PDOs), xenograft models, and LUAD tissues.

RESULTS

Sarcosine emerged as a potent ferroptosis inducer in the metabolic library screening, which was further confirmed via cell viability, lipid-ROS, ferrous iron, and MDA measurements. Metabolic flux analysis showed limited conversion of sarcosine to other metabolites in LUAD cells, while untargeted metabolomic profiling and seahorse assays indicated a metabolic shift from glycolysis to oxidative phosphorylation. Sarcosine enhanced pyruvate dehydrogenase activity to generate more ROS by interacting with PDK4, reducing PDHA1 phosphorylation. As a co-activator of N-methyl-D-aspartate receptor (NMDAR), sarcosine also exerted its pro-ferroptosis effect via regulating ferrous export through the NMDAR/MXD3/SLC40A1 axis. Given the significance of ferroptosis in chemotherapy, we validated that sarcosine enhanced the sensitization of cisplatin by promoting ferroptosis in LUAD cells, PDOs, and xenograft models.

CONCLUSION

Sarcosine promotes ferroptosis and enhances chemosensitivity, suggesting its potential as a therapeutic agent in treating LUAD.

DHODH modulates immune evasion of cancer cells via CDP-Choline dependent regulation of phospholipid metabolism and ferroptosis

The ability of cancer cells to evade immune destruction is governed by various intrinsic factors including their metabolic state. Here we demonstrate that inactivation of dihydroorotate dehydrogenase (DHODH), a pyrimidine synthesis enzyme, increases cancer cell sensitivity to T cell cytotoxicity through induction of ferroptosis. Lipidomic and metabolomic analyses reveal that DHODH inhibition reduces CDP-choline level and attenuates the synthesis of phosphatidylcholine (PC) via the CDP-choline-dependent Kennedy pathway. To compensate this loss, there is increased synthesis from phosphatidylethanolamine via the phospholipid methylation pathway resulting in increased generation of very long chain polyunsaturated fatty acid-containing PCs. Importantly, inactivation of Dhodh in cancer cells promotes the infiltration of interferon γ-secreting CD8+ T cells and enhances the anti-tumor activity of PD-1 blockade in female mouse models. Our findings reveal the importance of DHODH in regulating immune evasion through a CDP-choline dependent mechanism and implicate DHODH as a promising target to improve the efficacy of cancer immunotherapies.

Fatty acid metabolism: The crossroads in intestinal homeostasis and tumor

Fatty acids (FAs) have various functions on cell regulation considering their abundant types and metabolic pathways. In addition, the relation between FA and other nutritional metabolism makes their functions more complex. As the first place for diet-derived FA metabolism, intestine is significantly influenced despite lack of clear conclusions due to the inconsistent findings. In this review, we discuss the regulation of fatty acid metabolism on the fate of intestinal stem cells in homeostasis and disorders, and also focus on the intestinal tumor development and treatment from the aspect of gut microbiota-epithelium-immune interaction. We summarize that the balances between FA oxidation and glycolysis, between oxidative phosphorylation and ketogenesis, between catabolism and anabolism, and the specific roles of individual FA types determine the diverse effects of intestinal FA metabolism in different cases. We hope this will inspire further dissection and suggest precise dietary/metabolic intervention for different demands related to intestinal health.

The suppressive role of GLS in radiosensitivity and irradiation-induced immune response in LUAD: integrating bioinformatics and experimental insights

Background

Radiotherapy elicits immune activation, thereby synergistically enhancing systemic tumor control when combined with immunotherapy. Glutaminase (GLS), a key enzyme for glutamine metabolism, has been found to regulate glutamine availability within tumor microenvironment (TME). However, the precise mechanisms through which GLS modulates radiosensitivity and irradiation-induced immune responses in lung adenocarcinoma (LUAD) and its clinical value remain to be fully elucidated.

Methods

We employed bulk RNA-seq and single-cell transcriptomics to explore the role of GLS expression in radiosensitivity and immune infiltration. The bioinformatic results were validated by in vitro and in vivo experiments. Co-culture assays and flow cytometry were used to validate the impact of GLS expression on CD8+ T cell activation and cytotoxicity. Moreover, a GLS-DSBr (double strand break repair) prognostic model was developed using machine learning with data from 2,066 LUAD patients.

Results

In vitro and in vivo experiments demonstrated that GLS silence inhibited DSB repair and promoted ferroptosis, therefore enhancing radiosensitivity. Single-cell and spatial transcriptomics revealed the immunomodulatory effects of GLS expression in the TME. Further, Co-culture assays and flow cytometry experiments indicated that silencing GLS in LUAD cells potentiated the activation and cytotoxicity of CD8+ T cells in the context of radiotherapy. The GLS-DSBr model demonstrated robust predictive performance for overall survival, as well as the efficacy of radiotherapy and immunotherapy in LUAD. The applicability of GLS-DSBr model was further validated through pan-cancer analysis.

Conclusion

In the contexts of radiotherapy, GLS downregulation exerts dual regulatory effects by modulating ferroptosis and remodeling the immune landscapes, particularly enhancing CD8+ T cell cytotoxicity. Our work suggests that strategies preferentially targeting GLS in tumor cells may represent promising and translatable therapeutic approaches to promote antitumor efficacy of radiotherapy plus immune checkpoint blockade in LUAD patients. Furthermore, the established GLS-DSBr model serves as a robust predictive tool for prognosis and effects of radiotherapy and immunotherapy, which assists personalized treatment optimization in LUAD.

Iron, lipid peroxidation, and ferroptosis play pathogenic roles in atherosclerosis

Oxidation of lipids, excessive cell death, and iron deposition are prominent features of human atherosclerotic plaques. While extensive research has established the detrimental roles of lipid oxidation and apoptosis in atherosclerosis development, the involvement of iron in atherogenesis is not yet fully understood. With the emergence of an iron-dependent form of cell death termed ferroptosis, new attention has been brought to the complex inter-play among iron, ferroptosis, and atherosclerosis. Mechanistically, ferroptosis is caused by the lethal accumulation of iron-mediated lipid peroxides. Emerging studies have underscored ferroptosis as a contributor to worsened atherosclerosis. Herein, we review the evidence that oxidative damage and iron overload in the context of atherosclerosis may promote ferroptosis within plaques. Furthermore, we summarize recent findings of lipid peroxidation, thereby potentially ferroptosis, in various plaque cell types-such as endothelial cells, macrophages, dendritic cells, T cells, and vascular smooth muscle cells-across different stages of atherosclerosis. Understanding how these processes influence atherosclerotic plaque progression may permit targeting stage-dependent ferroptosis in each cell population and could provide a rationale for developing cell type-specific intervention strategies to mitigate atherogenic ferroptosis effectively.

Immunogenic Cell Death and Metabolic Reprogramming in Cancer: Mechanisms, Synergies, and Innovative Therapeutic Strategies

Immunogenic cell death (ICD) is a promising cancer therapy where dying tumor cells release damage-associated molecular patterns (DAMPs) to activate immune responses. Recent research highlights the critical role of metabolic reprogramming in tumor cells, including the Warburg effect, oxidative stress, and lipid metabolism, in modulating ICD and shaping the immune microenvironment. These metabolic changes enhance immune activation, making tumors more susceptible to immune surveillance. This review explores the molecular mechanisms linking ICD and metabolism, including mitochondrial oxidative stress, endoplasmic reticulum (ER) stress, and ferroptosis. It also discusses innovative therapeutic strategies, such as personalized combination therapies, metabolic inhibitors, and targeted delivery systems, to improve ICD efficacy. The future of cancer immunotherapy lies in integrating metabolic reprogramming and immune activation to overcome tumor immune evasion, with multi-omics approaches and microbiome modulation offering new avenues for enhanced treatment outcomes.

Exploring Immune-Related Ferroptosis Genes in Thyroid Cancer: A Comprehensive Analysis

Background: The increasing incidence and poor outcomes of recurrent thyroid cancer highlight the need for innovative therapies. Ferroptosis, a regulated cell death process linked to the tumour microenvironment (TME), offers a promising antitumour strategy. This study explored immune-related ferroptosis genes (IRFGs) in thyroid cancer to uncover novel therapeutic targets. Methods: CIBERSORTx and WGCNA were applied to data from TCGA-THCA to identify hub genes. A prognostic model composed of IRFGs was constructed using LASSO Cox regression. Pearson correlation was employed to analyse the relationships between IRFGs and immune features. Single-cell RNA sequencing (scRNA-seq) revealed gene expression in cell subsets, and qRT-PCR was used for validation. Results: Twelve IRFGs were identified through WGCNA, leading to the classification of thyroid cancer samples into three distinct subtypes. There were significant differences in patient outcomes among these subtypes. A prognostic risk score model was developed based on six key IRFGs (ACSL5, HSD17B11, CCL5, NCF2, PSME1, and ACTB), which were found to be closely associated with immune cell infiltration and immune responses within the TME. The prognostic risk score was identified as a risk factor for thyroid cancer outcomes (HR = 14.737, 95% CI = 1.95-111.65; p = 0.009). ScRNA-seq revealed the predominant expression of these genes in myeloid cells, with differential expression validated using qRT-PCR in thyroid tumour and normal tissues. Conclusions: This study integrates bulk and single-cell RNA sequencing data to identify IRFGs and construct a robust prognostic model, offering new therapeutic targets and improving prognostic evaluation for thyroid cancer patients.

Ferroptosis: a novel perspective on tumor immunotherapy

Ferroptosis is a novel form of programmed cell death characterized by iron-dependent accumulation of reactive oxygen species (ROS) and lipid peroxidation. The execution of ferroptosis is intricately linked to both iron and lipid metabolism. Intriguingly, iron and lipid metabolism are also pivotal for maintaining the physiological function of immune cells. Research has revealed that ferroptosis can potentiate the immunogenicity of tumor cells and engage in intricate interactions with immune cells. Certain ferroptosis inducers have the capacity to augment the efficacy of immunotherapy by modulating the tumor immune microenvironment. Ferroptosis holds immense potential in cancer immunotherapy and is anticipated to emerge as a novel therapeutic target in the future landscape of cancer treatment. In this review, we primarily delineate the ferroptosis signaling pathways and metabolic processes pertinent to immune cells, and further summarize the roles of ferroptosis in tumor-infiltrating immune cells. Ultimately, we anticipate further elucidation of the mechanisms of ferroptosis in immunotherapy and envision that strategies targeting ferroptosis and immunotherapy will be expeditiously applied in clinical oncology practice.

p38 mediated ACSL4 phosphorylation drives stress-induced esophageal squamous cell carcinoma growth through Src myristoylation

The comprehension of intricate molecular mechanisms underlying how external stimuli promote malignancy is conducive to cancer early prevention. Esophageal squamous cell carcinoma (ESCC) is considered as an external stimuli (hot foods, tobacco, chemo-compounds) induced cancer, characterized by stepwise progression from hyperplasia, dysplasia, carcinoma in situ and invasive carcinoma. However, the underlying molecular mechanism governing the transition from normal epithelium to neoplastic processes in ESCC under persistent external stimuli has remained elusive. Herein, we show that a positive correlation between p38 and ERK1/2 activation during the progression of ESCC. We identify that phosphorylation of ACSL4 at T679 by p38 enhances its enzymatic activity, resulting in increased production of myristoyl-CoA (C14:0 CoA). This subsequently promotes Src myristoylation and activates downstream ERK signaling. Our results partially elucidate the role of ACSL4 in mediating stress-induced signaling pathways that activate growth cascades and contribute to tumorigenesis.

miR-145-5p regulates hepatocellular carcinoma malignant advancement and immune escape via down-regulation of AcylCoA synthase ACSL4

Hepatocellular carcinoma (HCC) exhibits a subtle onset, high incidence rates, and low survival rates, becoming a substantial threat to human health. Hence, it is crucial to discover fresh biomarkers and treatment targets for the early detection and management of HCC. CCK-8, scratch-wound, and transwell assays were used to evaluate the biological properties of HCC cell lines (Huh-7 and Hep3B). Bioinformatics analysis identified the downstream target mRNA of miR-145-5p as acyl-CoA synthetase long-chain family member 4 (ACSL4). RT-qPCR was used to test miR-145-5p and ACSL4 levels. Transwell chambers were used to co-incubate purified CD8+ T cells and HCC cells for 48 h, and the effect of CD8+ T cells on apoptosis in HCC cells was detected by flow cytometry. A subcutaneous graft tumor model was constructed, and ELISA kits were used to assess cytokine levels and CD8+ T cell activation markers. HCC cells showed a decline in miR-145-5p levels and a rise in ACSL4 levels. Overexpression of miR-145-5p hindered HCC cell proliferation, migration, and invasion, while stimulating CD8+ T cell activation. Conversely, overexpression of ACSL4 enhanced the malignant biological properties of HCC cells and reduced the effect of CD8+ T cells, while silencing ACSL4 had the opposite effect. miR-145-5p targeted and downregulated ACSL4, while overexpression of miR-145-5p weakened the promotion of HCC malignant progression caused by ACSL4 overexpression. Additionally, overexpression of miR-145-5p and silencing ACSL4 were effective in inhibiting tumor growth in vivo. In conclusion, miR-145-5p targets and downregulates ACSL4, leading to the inhibition of HCC malignant progression and preventing immune escape in HCC cells.

VIPAS39 confers ferroptosis resistance in epithelial ovarian cancer through exporting ACSL4

BACKGROUND

The high mortality rate associated with epithelial ovarian cancer (EOC) is primarily due to recurrence and chemoresistance, underscoring the urgent need for innovative therapeutic approaches that leverage newly identified vulnerabilities in cancer cells. While conventional chemotherapies induce apoptosis by targeting DNA or mitotic machinery, ferroptosis represents a new distinct form of programmed cell death characterised by the accumulation of lipid peroxides.

METHODS

The sensitivity of different EOC cell lines to ferroptosis inducers was evaluated using cell viability assays and lipid peroxidation measurements. Live-cell imaging with the pH-sensitive CD63-pHuji reporter was performed to track the extracellular export of acyl-CoA synthetase long-chain family member 4 (ACSL4) via exosomes. The upstream regulator of ACSL4 were identified through immunoprecipitation-mass spectrometry (IP-MS) and validated using protein binding assays. Finally, cell-derived xenograft (CDX) and patient-derived xenograft (PDX) models were utilised to evaluate the therapeutic potential overcoming ferroptosis resistance.

FINDINGS

In this study, we found that interferon (IFN)-γ combined with arachidonic acid (AA), which are endogenous ferroptosis inducers, could initiate ferroptosis in most EOC cells. However, some EOC cells displayed significant resistance. Contrary to the typical increase in ACSL4 protein observed in ferroptosis-sensitive cells, resistant EOC cells exhibited surprisingly low levels of this pro-ferroptotic lipid metabolic protein. Intriguingly, this reduction is attributed to the exosomal expulsion of ACSL4 protein, revealing a distinct cellular mechanism to evade ferroptosis. We further identified VIPAS39 as a pivotal regulator in sorting ACSL4 into late endosomes, thereby facilitating their subsequent release as exosomes. Notably, targeting VIPAS39 not only overcomes the resistance to ferroptotic cell death but also markedly suppresses tumour growth.

INTERPRETATION

Our findings uncover the crucial role of VIPAS39 in ferroptosis evasion by facilitating the exporting of ACSL4 protein via exosomes, highlighting VIPAS39 as a promising target for ferroptosis-based anti-cancer therapy.

FUNDING

Funded by Beijing Municipal Natural Science Foundation (Key program Z220011), National Natural Science Foundation of China (NSFC) (T2225006, T2488301, 82272948), Peking University Medicine Youth Science and Technology Innovation 'Sail Plan' Project Type B Medical Interdisciplinary Seed Fund (71006Y3171), GuangDong Basic and Applied Basic Research Foundation (2021A1515110820), and the special fund of the National Clinical Key Speciality Construction Program, P. R. China (2023).

Exploring lipid metabolism-associated gene biomarkers and their regulatory mechanisms in nasopharyngeal carcinoma

BackgroundNasopharyngeal carcinoma (NPC) is a neoplasm that arises from the mucosal lining of the nasopharynx. Recent investigations have underscored that reprogramming of lipid metabolism is a salient metabolic alteration in neoplastic cells. Consequently, identifying lipid metabolism-associated biomarkers in NPC is of paramount importance.MethodsUtilizing transcriptomic datasets, differentially expressed genes (DEGs) were identified from GSE12452, contrasting NPC specimens with normal controls. The Weighted Gene Co-expression Network Analysis (WGCNA) was employed to discern key module genes pertinent to NPC. Lipid metabolism-related differentially expressed genes (LMR-DEGs) were ascertained by intersecting DEGs, key module genes linked to NPC, and lipid metabolism-related genes (LMRGs) using a Venn diagram approach. Subsequently, the MCODE algorithm was applied within the protein-protein interaction (PPI) framework to pinpoint lipid metabolism-centric biomarkers for NPC. The diagnostic potential of these biomarkers was assessed through ROC analysis. In the concluding phase, a 'TF-mRNA-miRNA' interaction network was delineated using Cytoscape.ResultsIn our analysis, a total of 5026 DEGs were discerned when contrasting NPC specimens with normal controls. From this pool, 1835 genes were pinpointed as key module genes pertinent to NPC. Through a Venn diagram approach, 64 LMR-DEGs were isolated. Further analysis led to the identification of six lipid metabolism-centric biomarkers for NPC, namely GALC, SPTLC2, SMPD2, DEGS2, DEGS1, and SMPD3. Notably, these biomarkers demonstrated robust diagnostic efficacy. We found that DEGS1 was negatively correlated with SMPD2 and DEGS2. A comparative expression analysis revealed diminished expression levels of GALC, SPTLC2, SMPD2, DEGS2, and SMPD3 in the NPC cohort relative to the control group. In the terminal phase of our study, the 'TF-mRNA-miRNA' regulatory network was delineated, comprising 309 nodes and 360 interaction pairs.ConclusionIn summary, our investigation identified six lipid metabolism-associated biomarkers (GALC, SPTLC2, SMPD2, DEGS2, DEGS1, and SMPD3) linked to NPC, providing a foundational framework for potential therapeutic interventions for NPC.

Do physiological changes in fatty acid composition alter cellular ferroptosis susceptibility and influence cell function?

Ferroptosis is an iron-dependent form of cell death driven by the excessive peroxidation of poly-unsaturated fatty acids (PUFAs) within membrane phospholipids. Ferroptosis is a hallmark of many diseases and preventing or inducing ferroptosis has considerable therapeutic potential. Like other forms of cell death, the pathological importance and therapeutic potential of ferroptosis is well appreciated. However, while cell death modalities such as apoptosis and necroptosis have critical physiological roles, such as in development and tissue homeostasis, whether ferroptosis has important physiological roles is largely unknown. In this regard, key questions for field are as follows: Is ferroptosis used for physiological processes? Are certain cell-types purposely adapted to be either resistant or sensitive to ferroptosis to be able to function optimally? Do physiological perturbations such as aging and diet impact ferroptosis susceptibility? Herein, we have reviewed emerging evidence that supports the idea that being able to selectively and controllably induce or resist ferroptosis is essential for development and cell function. While several factors regulate ferroptosis, it appears that the ability of cells and tissues to control their lipid composition, specifically the abundance of phospholipids containing PUFAs, is crucial for cells to be able to either resist or be sensitized to ferroptosis. Finally, aging and diets enriched in specific PUFAs lead to an increase in cellular PUFA levels which may sensitize cells to ferroptosis. Therefore, changes in dietary PUFAs or againg may impact the pathogenesis of diseases where ferroptosis is involved.

Cross-talks of GSH, mitochondria, RNA m6A modification, NRF2, and p53 between ferroptosis and cuproptosis in HCC: A review

Hepatocellular carcinoma (HCC) is a common malignant tumor with high morbidity and mortality, as well as poor prognosis. Therefore, it is imperative to explore alternative therapeutic targets for HCC treatment. Ferroptosis and cuproptosis have recently been identified as metal-dependent cell death mechanisms that play significant roles in HCC treatment. This study identified potential cross-talk between ferroptosis and cuproptosis, including the common hub glutathione, common site of occurrence, mitochondria, shared epigenetic modification mode, RNA N6 methyladenosine modification, mutual inhibitor, nuclear factor erythroid 2-related factor 2, and dual regulator, p53. These findings provide a theoretical foundation for the joint induction of HCC cell death and effective inhibition of HCC progression. However, some immune cells are susceptible to ferroptosis or cuproptosis, which may impair or enhance anti-cancer immune function. We propose strategies to target specific targets molecules such as tripartite motif containing 25, ferroptosis suppressor protein 1, and peroxisome proliferator-activated receptor gamma or exploit the unique acidic environment surrounding cancer cells to precisely induce ferroptosis in cancer cells. This approach aims to advance the development of precision medicine for HCC treatment.

Injectable Nanocomposite Hydrogels for Intervertebral Disc Degeneration: Combating Oxidative Stress, Mitochondrial Dysfunction, and Ferroptosis

Intervertebral disc degeneration (IVDD) is a major cause of low back pain, where oxidative stress and mitochondrial dysfunction are key contributors. Additionally, ferroptosis, an iron-dependent form of cell death, is identified as a critical mechanism in IVDD pathogenesis. Herein, the therapeutic potential of gallic acid (GA)-derived PGA-Cu nanoparticles, enhanced with functional octapeptide (Cys-Lys-His-Gly-d-Arg-d-Tyr-Lys-Phe, SS08) to build the mitochondria-targeted nanoparticles (PGA-Cu@SS08), and embedded within a hydrogel matrix to form a nanocomposite hydrogel, is explored. The nanoparticles show targeted localization within mitochondria, effectively scavenging reactive oxygen species and preserving mitochondrial function. The abundant phenolic hydroxyl groups present on the nanoparticle surface, along with the histidine residue of the SS08 peptide, endow these entities with the capacity to chelate iron. Through RNA sequencing analysis, it is discovered that PGA-Cu@SS08 activates the NRF2 signaling pathway, mitigating ferroptosis. It also reduces iron overload by inhibiting the autophagy of iron storage proteins. Additionally, the nanocomposite hydrogels exhibit excellent biocompatibility and biodegradability, along with enhanced mechanical properties that improve intervertebral disc (IVD) performance. PGA-Cu@SS08 is continuously released from these hydrogels, restoring IVD height and maintaining tissue hydration levels, thus facilitating future applications for alleviating IVDD.

Lipid metabolic reprogramming and associated ferroptosis in osteosarcoma: From molecular mechanisms to potential targets

Osteosarcoma is a common bone tumor in adolescents, which is characterized by lipid metabolism disorders and plays a key role in tumorigenesis and disease progression. Ferroptosis is an iron-dependent form of programmed cell death associated with lipid peroxidation. This review provides an in-depth analysis of the complex relationship between lipid metabolic reprogramming and associated ferroptosis in OS from the perspective of metabolic enzymes and metabolites. We discussed the molecular basis of lipid uptake, synthesis, storage, lipolysis, and the tumor microenvironment, as well as their significance in OS development. Key enzymes such as adenosine triphosphate-citrate lyase (ACLY), acetyl-CoA synthetase 2 (ACSS2), fatty acid synthase (FASN) and stearoyl-CoA desaturase-1 (SCD1) are overexpressed in OS and associated with poor prognosis. Based on specific changes in metabolic processes, this review highlights potential therapeutic targets in the lipid metabolism and ferroptosis pathways, and in particular the HMG-CoA reductase inhibitor simvastatin has shown potential in inducing apoptosis and inhibiting OS metastasis. Targeting these pathways provides new strategies for the treatment of OS. However, challenges such as the complexity of drug development and metabolic interactions must be overcome. A comprehensive understanding of the interplay between dysregulation of lipid metabolism and ferroptosis is essential for the development of innovative and effective therapies for OS, with the ultimate goal of improving patient outcomes.

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.

Targeting aldehyde dehydrogenase ALDH3A1 increases ferroptosis vulnerability in squamous cancer

Ferroptosis is a unique modality of regulated cell death induced by excessive lipid peroxidation, playing a crucial role in tumor suppression and providing potential therapeutic strategy for cancer treatment. Here, we find that aldehyde dehydrogenase-ALDH3A1 tightly links to ferroptosis in squamous cell carcinomas (SCCs). Functional assays demonstrate the enzymatic activity-dependent regulation of ALDH3A1 in protecting SCC cells against ferroptosis through catalyzing aldehydes and mitigating lipid peroxidation. Furthermore, a specific covalent inhibitor of ALDH3A1-EN40 significantly enhances the ferroptosis sensitivity induced by the ferroptosis inducer. The combination of EN40 and a ferroptosis inducer exhibits a synergistic effect, effectively inhibiting the proliferation of SCC cells/organoids and suppressing tumor growth both in vitro and in vivo. On mechanism, high expression of ALDH3A1 is transcriptionally governed by TP63, which binds to super-enhancer of ALDH3A1. Collectively, our findings reveal a yet-unrecognized function of ALDH3A1 exploited by SCC cells to evade ferroptosis, and targeting ALDH3A1 may enhance the effect of ferroptosis-induced therapy in SCCs.

Exploring the Role of Ferroptosis-Related Circular RNAs in Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular event associated with high mortality and significant morbidity. Recent studies have highlighted the emerging role of ferroptosis, a novel form of regulated cell death, in the pathogenesis of SAH. Circular RNAs (circRNAs), have been found to play essential roles in various cellular processes, including gene regulation and disease pathogenesis. The expression profile of circRNAs in neural tissues, particularly in the brain, suggests their critical role in synaptic function and neurogenesis. Moreover, the interplay between circRNAs and ferroptosis-related pathways, such as iron metabolism and lipid peroxidation, is explored in the context of SAH. Understanding the functional roles of specific circRNAs in the context of SAH may provide potential therapeutic targets to attenuate ferroptosis-associated brain injury. Furthermore, the potential of circRNAs as diagnostic biomarkers for SAH severity, prognosis, and treatment response is discussed. Overall, this review highlights the significance of studying the intricate interplay between circRNAs and ferroptosis in the context of SAH. Unraveling the mechanisms by which circRNAs modulate ferroptotic cell death may pave the way for the development of novel therapeutic strategies and diagnostic approaches for SAH management, ultimately improving patient outcomes and quality of life.

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.

Lipid peroxidation and immune activation: TRAF3's double-edged strategy against glioblastoma

Glioblastoma (GBM), the most aggressive type of primary brain tumor, continues to defy therapeutic advances with its metabolic adaptability and resistance to treatment. In this issue of the JCI, Zeng et al. delve into a pivotal mechanism underpinning this adaptability. They identified an important role for TNF receptor-associated factor 3 (TRAF3) in regulating lipid metabolism through its interaction with enoyl-CoA hydratase 1 (ECH1). These findings elucidate a unique signaling axis that shields GBM cells from lipid peroxidation and antitumor immunity, advancing therapeutic strategies for GBM that may also carry over to other cancers with similar metabolic vulnerabilities.

Dying to survive: harnessing inflammatory cell death for better immunotherapy

Immunotherapy has transformed cancer treatment paradigms, but its effectiveness depends largely on the immunogenicity of the tumor. Unfortunately, the high resemblance of cancer to normal tissues makes most tumors immunologically 'cold', with a poor response to immunotherapy. Danger signals are critical for breaking immune tolerance and mobilizing robust, long-lasting antitumor immunity. Recent studies have identified inflammatory cell death modalities and their power in providing danger signals to trigger optimal tumor suppression. However, key mediators of inflammatory cell death are preferentially silenced during early tumor immunoediting. Strategies to rejuvenate inflammatory cell death hold great promise for broadening immunotherapy-responsive tumors. In this review, we examine how inflammatory cell death enhances tumor immunogenicity, how it is suppressed during immunoediting, and the potential of harnessing it for improved immunotherapy.

Ferroptosis: CD8+T cells' blade to destroy tumor cells or poison for self-destruction

Ferroptosis represents an emerging, iron-dependent form of cell death driven by lipid peroxidation. In recent years, it has garnered significant attention in the realm of cancer immunotherapy, particularly in studies involving immune checkpoint inhibitors. This form of cell death not only enhances our comprehension of the tumor microenvironment but is also considered a promising therapeutic strategy to address tumor resistance, investigate immune activation mechanisms, and facilitate the development of cancer vaccines. The combination of immunotherapy with ferroptosis provides innovative targets and fresh perspectives for advancing cancer treatment. Nevertheless, tumor cells appear to possess a wider array of ferroptosis evasion strategies compared to CD8+T cells, which have been conclusively shown to be more vulnerable to ferroptosis. Furthermore, ferroptosis in the TME can create a favorable environment for tumor survival and invasion. Under this premise, both inducing tumor cell ferroptosis and inhibiting T cell ferroptosis will impact antitumor immunity to some extent, and even make the final result run counter to our therapeutic purpose. This paper systematically elucidates the dual-edged sword role of ferroptosis in the antitumor process of T cells, briefly outlining the complexity of ferroptosis within the TME. It explores potential side effects associated with ferroptosis-inducing therapies and critically considers the combined application of ferroptosis-based therapies with ICIs. Furthermore, it highlights the current challenges faced by this combined therapeutic approach and points out future directions for development.

SIRT6 mitigates oxidative stress and RSL3-induced ferroptosis in HTR-8/SVneo cells

Dysregulation in placental trophoblast cells frequently results in oxidative stress, culminating in pregnancy-related complications. While iron is essential for fetal development, cellular ferroptosis due to elevated iron levels might mediate the emergence of preeclampsia (PE), presenting significant risks during gestation. We found abnormally activated oxidative stress and increased iron concentration in the placental tissues of PE patients. Subsequently, we treated placental trophoblasts with hydrogen peroxide and RSL3 to induce oxidative stress and ferroptosis models. The results revealed that SIRT6 overexpression activates the Nrf2/HO-1 pathway, restores the oxidative imbalance of the cells, and protects the cells from ferroptosis. Meanwhile, activation of the Nrf2/HO-1 pathway alone showed similar results. Thus, we posit that SIRT6, via the Nrf2/HO-1 pathway, alleviates cellular oxidative stress and diminishes ferroptosis, offering a novel therapeutic avenue for PE.

Reciprocal regulation between ferroptosis and STING-type I interferon pathway suppresses head and neck squamous cell carcinoma growth through dendritic cell maturation

Head and neck squamous cell carcinoma (HNSCC) presents a serious clinical challenge mainly due to its resistance to conventional therapies and its complex, immunosuppressive tumor microenvironment. While recent studies have identified ferroptosis as a new therapeutic option, its impact on the immune microenvironment in HNSCC remains controversial, which may hinder its translational application. Although the role of the stimulator of interferon genes (STING)-type I interferon (IFN-I) pathway in antitumor immune responses has been widely investigated, its relationship with ferroptosis in HNSCC has not been fully explored. In this study, we discovered that ferroptosis in HNSCC inhibited tumor growth, activated STING-IFN-I pathway and subsequently improved recruitment and maturation of dendritic cells. We further demonstrated that IFN-I could enhance ferroptosis by inhibiting xCT-glutathione peroxidase 4 (GPX4) antioxidant system. To harness this positive feedback loop, we treated HNSCC tumors with both ferroptosis inducer and STING agonist, resulting in significant tumor suppression, elevated ferroptosis levels and enhanced dendritic cell infiltration. Overall, our findings reveal a mutually regulatory relationship between ferroptosis and the intrinsic STING-IFN-I pathway, providing novel insights into immune-mediated tumor suppression and suggesting its potential as therapeutic approach in HNSCC.

Simvastatin inhibits PD-L1 via ILF3 to induce ferroptosis in gastric cancer cells

The treatment of gastric cancer remains challenging, with immunotherapy serving as a critical component of the holistic approach to its treatment. The results of this study indicated that statins could decrease the serum levels of interleukin-enhancing binding factor 3 (ILF3) and programmed cell death ligand 1(PD-L1) in GC patients and improve their prognosis. Functional experiments demonstrated that simvastatin induced ferroptosis by inhibiting ILF3 in GC cells and enhanced the killing effect of activated CD8+ T cells on GC cells. The CUT&Tag assay revealed that, mechanistically, simvastatin inhibited ILF3 expression by reducing the acetylation level at residue site H3K14 in ILF3. Next-generation sequencing and Kyoto Encyclopedia of Genes and Genomes analysis revealed that ILF3 regulated PD-L1 expression through the DEPTOR/mTOR signaling pathway. Overall, simvastatin induced ferroptosis in GC cells by inhibiting ILF3 expression while promoting the activation of CD8+ T cells to augment antitumor immune responses, thereby facilitating synergistic immunotherapy.

Research progress of ferroptosis pathway and its related molecular ubiquitination modification in liver cancer

As a new type of programmed cell death, ferroptosis is characterized by iron metabolism disorder and reactive oxygen species (ROS) accumulation, and is involved in regulating the occurrence and development of cancer cells. Especially in the field of liver cancer treatment, ferroptosis shows great potential because it can induce tumor cell death. Ubiquitination is a process of protein post-translational modification, which can affect the stability of proteins and regulate the progress of ferroptosis. This article reviews the research progress of ubiquitination modification of molecules related to ferroptosis pathway in the regulation of liver cancer, providing a new strategy for the treatment of liver cancer.

Role of long non-coding RNAs in the regulation of ferroptosis in tumors

Normal cells begin to grow indefinitely and immortalize to form tumor cells after an external stimulus resulting in a genetic mutation. Effective killing of tumor cells is the basis of various cancer therapies. Ferroptosis is a class of cell death types dependent on iron and cellular lipid peroxidation. Tumors themselves are iron-dependent, and conventional radiotherapy also sensitizes cancer cells to ferroptosis. Increasing the sensitivity of tumor cells to ferroptosis may be a potential therapeutic strategy to overcome the resistance mechanisms of conventional cancer therapy. Long noncoding RNAs (LncRNAs) are a class of transcripts more than 200 nucleotides in length that regulate gene expression at multiple levels and are involved in biological processes such as cell differentiation, cell cycle arrest, and maintenance of tumor stemness. Recent studies have found that lncRNAs regulate ferroptosis of tumor cells through multiple mechanisms and may influence or ameliorate tumor resistance to chemotherapeutic agents. With the continuous maturation of nanomaterials technology, it may provide new means for cancer treatment by regulating the levels of ferroptosis-related lncRNAs inside tumors as well as increasing the levels of Fe2+ and ROS inside tumors. In this paper, we systematically introduce the regulatory mechanism of lncRNAs in ferroptosis, the role of ferroptosis in tumor immunotherapy and the application of lncRNAs combined with ferroptosis in nanomaterials, which provides new perspectives for tumor therapy.

Lipid availability influences ferroptosis sensitivity in cancer cells by regulating polyunsaturated fatty acid trafficking

Ferroptosis is a form of cell death caused by lipid peroxidation that is emerging as a target for cancer therapy, highlighting the need to identify factors that govern ferroptosis susceptibility. Lipid peroxidation occurs primarily on phospholipids containing polyunsaturated fatty acids (PUFAs). Here, we show that even though extracellular lipid limitation reduces cellular PUFA levels, lipid-starved cancer cells are paradoxically more sensitive to ferroptosis. Using mass spectrometry-based lipidomics with stable isotope fatty acid labeling, we show that lipid limitation induces a fatty acid trafficking pathway in which PUFAs are liberated from triglycerides to synthesize highly unsaturated PUFAs such as arachidonic and adrenic acid. These PUFAs then accumulate in phospholipids, including ether phospholipids, to promote ferroptosis sensitivity. Therefore, PUFA levels within cancer cells do not necessarily correlate with ferroptosis susceptibility. Rather, how cancer cells respond to extracellular lipid levels by trafficking PUFAs into proper phospholipid pools contributes to their sensitivity to ferroptosis.