Targeting de novo lipogenesis and the Lands cycle induces ferroptosis in KRAS-mutant lung cancer

Epithelial-mesenchymal transition promotes metabolic reprogramming to suppress ferroptosis

Epithelial-mesenchymal transition (EMT) is a cellular de-differentiation process that provides cells with the increased plasticity and stem cell-like traits required during embryonic development, tissue remodeling, wound healing and metastasis. Morphologically, EMT confers tumor cells with fibroblast-like properties that lead to the rearrangement of cytoskeleton (loss of stiffness) and decrease of membrane rigidity by incorporating high level of poly-unsaturated fatty acids (PUFA) in their phospholipid membrane. Although large amounts of PUFA in membrane reduces rigidity and offers capabilities for tumor cells with the unbridled ability to stretch, bend and twist in metastasis, these PUFA are highly susceptible to lipid peroxidation, which leads to the breakdown of membrane integrity and, ultimately results in ferroptosis. To escape the ferroptotic risk, EMT also triggers the rewiring of metabolic program, particularly in lipid metabolism, to enforce the epigenetic regulation of EMT and mitigate the potential damages from ferroptosis. Thus, the interplay among EMT, lipid metabolism, and ferroptosis highlights a new layer of intricated regulation in cancer biology and metastasis. Here we summarize the latest findings and discuss these mutual interactions. Finally, we provide perspectives of how these interplays contribute to cellular plasticity and ferroptosis resistance in metastatic tumor cells that can be explored for innovative therapeutic interventions.

Metal-organic framework nanomaterials alter cellular metabolism in bladder cancer

While nanomaterial-mediated metabolic reprogramming emerges as a promising anticancer strategy, the precise mechanisms remain elusive due to limited metabolomics investigations. The objective of this study is to design an aluminum (Al) based metal organic frameworks (Al-MOF) and investigate its cytotoxic effects on bladder cancer cells (T24), and elucidate the specific molecular mechanisms. Comprehensive characterization (scanning electron microscopy, particle size and potential analysis, infrared spectroscopy, powder X-ray diffraction, and N2 desorption/desorption experiment) confirmed the successful preparation of Al-MOF. Subsequently, in vitro assays demonstrated the selective cytotoxicity of Al-MOF, showing an inhibitory effect on the proliferation of T24 compared to human immortalized urothelial cells. At the same time, when the concentration of Al-MOF exceeded 100 μg/mL, it exhibited significant migration inhibition on T24. Then, the effect of Al-MOF on T24 metabolites was investigated using ultra-high performance liquid chromatography quadrupole Orbitrap high-resolution mass spectrometry. After 24 h of incubation, we identified 38 key differential metabolites from expression patterns and metabolic pathways, predominantly in fatty acid synthesis. Research has found that Al-MOF reduced fatty acid biosynthesis by inhibiting FASN expression, thereby inhibiting the progression of T24. This work provides evidence of MOF-mediated intervention in cancer cell metabolism, offering valuable insights for the design of novel multifunctional nanotherapies.

Targeting FASN enhances cisplatin sensitivity via SLC7A11-mediated ferroptosis in cervical cancer

OBJECTIVE

The cisplatin resistance significantly hinders the prospects for curing patients with advanced, recurrent, and metastatic cervical cancer (CC). Our study aims to clarify the mechanisms underlying cisplatin resistance in CC and provide a novel treatment strategy to overcome the cisplatin resistance of CC patients.

METHODS

Intracellular levels of reactive oxygen species, glutathione, malondialdehyde and Fe2+ were measured as indicators of ferroptosis. Biological information analyses, IC50, immunofluorescence assays, qPCR and western blot analyses were conducted to elucidate the functions of FASN in CC. In vivo studies were conducted to examine the antitumor effects of the combination of TVB-2640 and cisplatin.

RESULTS

Fatty acid synthase (FASN) was identified as a key driver of cisplatin resistance in CC through transcriptome sequencing and Gene Expression Omnibus (GEO) data analysis. The clinically safe FASN inhibitor TVB-2640 was found to restore cisplatin sensitivity, resulting in synergistic tumor growth attenuation in xenograft models. Mechanistically, FASN downregulation promoted ferroptosis and reduced solute carrier family 7 member 11 (SLC7A11) expression, both in vitro and in vivo models.

CONCLUSION

Targeting FASN enhances cisplatin sensitivity in CC by promoting SLC7A11-mediated ferroptosis. TVB-2640 combined with cisplatin had superior synergistic antitumor effects in cisplatin-resistant CC models.

Rapid and Noninvasive Early Detection of Lung Cancer by Integration of Machine Learning and Salivary Metabolic Fingerprints Using MS LOC Platform: A Large-Scale Multicenter Study

Most lung cancer (LC) patients are diagnosed at advanced stages due to the lack of effective screening tools. This multicenter study analyzes 1043 saliva samples (334 LC cases and 709 non-LC cases) using a novel high-throughput platform for metabolic fingerprint acquisition. Machine learning identifies 35 metabolic features distinguishing LC from non-LC subjects, enabling the development of a classification model named SalivaMLD. In the validation set and test set, SalivaMLD demonstrates strong diagnostic performance, achieving an area under the curve of 0.849-0.850, a sensitivity of 81.69-83.33%, and a specificity of 74.23-74.39%, outperforming conventional tumor biomarkers. Notably, SalivaMLD exhibits superior accuracy in distinguishing early stage LC patients. Hence, this rapid and noninvasive screening method may be widely applied in clinical practice for LC detection.

Spatial mapping of the brain metabolome lipidome and glycome

Metabolites, lipids, and glycans are fundamental but interconnected classes of biomolecules that form the basis of the metabolic network. These molecules are dynamically channeled through multiple pathways that govern cellular physiology and pathology. Here, we present a framework for the simultaneous spatial analysis of the metabolome, lipidome, and glycome from a single tissue section using mass spectrometry imaging. This workflow integrates a computational platform, the Spatial Augmented Multiomics Interface (Sami), which enables multiomics integration, high-dimensional clustering, spatial anatomical mapping of matched molecular features, and metabolic pathway enrichment. To demonstrate the utility of this approach, we applied Sami to evaluate metabolic diversity across distinct brain regions and to compare wild-type and Ps19 Alzheimer's disease (AD) mouse models. Our findings reveal region-specific metabolic demands in the normal brain and highlight metabolic dysregulation in the Ps19 model, providing insights into the biochemical alterations associated with neurodegeneration.

Xingxiao pills suppresses lung adenocarcinoma progression by modulating lipid metabolism and inhibiting the PLA2G4A-GLI1-SOX2 Axis

BACKGROUND

Lung adenocarcinoma (LUAD) remains a leading cause of cancer mortality due to resistance, metastasis, and recurrence. Unlike conventional cytotoxic therapies, Xingxiao Pills (XXP), a classic traditional Chinese medicine formula, offers a complementary approach to treating LUAD, while its non-cytotoxic anti-cancer mechanisms remain unclear.

PURPOSE

To investigate the effect and mechanism of XXP on LUAD progression and stemness via lipid metabolism regulation.

METHOD

UHPLC-MS/MS was used to analyze the chemical constituents of XXP. The effects of XXP on LUAD cell proliferation, migration, invasion, and stemness were evaluated using CCK-8, Transwell, and tumor sphere assays. A LUAD xenograft model confirmed XXP's anti-tumor effects. Transcriptomics, metabolomics, ELISA, qRT-PCR, and Western blot were used to investigate the underlying mechanisms. Kaplan-Meier (KM) survival analysis and stemness index scores were performed for LUAD patients based on the TCGA dataset. Statistical analyses were performed using Student's t-test, ANOVA, and KM survival analysis (p< 0.05 considered significant).

RESULTS

XXP inhibits LUAD progression in mouse and cell models by targeting lipid metabolism reprogramming. It suppresses FA synthesis, elongation, oxidation, and glycerophospholipid (GPL) metabolism while upregulating arachidonic acid (AA) metabolism. Mechanistic studies revealed that XXP attenuates tumor stemness by inhibiting PLA2G4A (cPLA2), lowering AA release, and disrupting SMO/GLI1/SOX2 signaling, an effect also observed with the cPLA2 inhibitor AACOCF3. KM analysis showed that higher PLA2G4A expression correlated with a worse 5-year prognosis in LUAD (p = 0.0047). The low GPL/high AA group (consistent with XXP's metabolic pattern) had better survival (p = 0.0028) and a lower stemness index (p< 0.0001) than the high GPL/low AA unrelated group.

CONCLUSION

Xingxiao Pill modulates GPL and AA metabolism and downregulates the PLA2G4A (cPLA2)-AA/SMO/GLI1/SOX2 axis. Through this mechanism, XXP effectively inhibits tumor growth and stemness by targeting lipid metabolism.

HHLA3 Silencing Suppresses KRAS-Mutant Non-Small-Cell Lung Cancer Cell Progression Through Triggering MYEOV-Mediated Ferroptosis

KRAS mutation is one of the most common mutational events in non-small-cell lung cancer (NSCLC). However, due to the complex signaling pathways and high biological heterogeneity of KRAS-mutant NSCLC, the current clinical treatment for patients with KRAS mutations still faces many difficulties. The oncogenic effector in KRAS-mutant NSCLC was screened using GEO data sets. CCK-8, colony formation, transwell, and flow cytometry were conducted to assess the malignant phenotype of KRAS-mutant NSCLC cells. The indicators intracellular Fe2+, ROS, GSH, and MDA levels were employed to reflect the ferroptosis of cells. The mechanism of myeloma overexpressed (MYEOV) in KRAS-mutant NSCLC was explored from the perspective of noncoding RNA (ncRNA) and validated by rescue experiments. MYEOV presented a high expression trend in KRAS-mutant NSCLC specimens. MYEOV silencing effectively repressed the malignant phenotype and promoted ferroptosis of NSCLC cells carrying KRAS mutations. Based on bioinformation analysis and a series of rescue experiments, we established the HHLA3/miR-139-5p/MYEOV regulatory network in KRAS-mutant NSCLC cells and disclosed that HHLA3 served as a molecular sponge for miR-139-5p to regulate MYEOV expression. The mechanism of MYEOV and its ncRNA network affecting the progression of KRAS-mutant NSCLC revealed in this study intends to provide a theoretical basis for KRAS-mutant NSCLC treatment.

Caspase-independent cell death in lung cancer: from mechanisms to clinical applications

Caspase-independent cell death (CICD) has recently become a very important mechanism in lung cancer, in particular, to overcome a critical failure in apoptotic cell death that is common to disease progression and treatment failures. The pathways involved in CICD span from necroptosis, ferroptosis, mitochondrial dysfunction, and autophagy-mediated cell death. Its potential therapeutic applications have been recently highlighted. Glutathione peroxidase 4 (GPX4) inhibition-driven ferroptosis has overcome drug resistance in non-small cell lung cancer (NSCLC). In addition, necroptosis involving RIPK1 and RIPK3 causes tumor cell death and modulation of immune responses in the tumor microenvironment (TME). Mitochondrial pathways are critical for CICD through modulation of metabolic and redox homeostasis. Ferroptosis is amplified by mitochondrial reactive oxygen species (ROS) and lipid peroxidation in lung cancer cells, and mitochondrial depolarization induces oxidative stress and leads to cell death. In addition, mitochondria-mediated autophagy, or mitophagy, results in the clearance of damaged organelles under stress conditions, while this function is also linked to CICD when dysregulated. The role of cell death through autophagy regulated by ATG proteins and PI3K/AKT/mTOR pathway is dual: to suppress tumor and to sensitize cells to therapy. A promising approach to enhancing therapeutic outcomes involves targeting mechanisms of CICD, including inducing ferroptosis by SLC7A11 inhibition, modulating mitochondrial ROS generation, or combining inhibition of autophagy with chemotherapy. Here, we review the molecular underpinnings of CICD, particularly on mitochondrial pathways and their potential to transform lung cancer treatment.

Targeting B7-H3 inhibition-induced activation of fatty acid synthesis boosts anti-B7-H3 immunotherapy in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is the most malignant breast cancer, highlighting the need for effective immunotherapeutic targets. The immune checkpoint molecule B7-H3 has recently gained attention as a promising therapeutic target due to its pivotal role in promoting tumorigenesis and cancer progression. However, the therapeutic impact of B7-H3 inhibitors (B7-H3i) remains unclear.

METHODS

Transcriptomic and metabolomic analyses were conducted to explore the underlying mechanisms of B7-H3 inhibition in TNBC. The therapeutic efficacy of the combined treatment strategy was substantiated through comprehensive phenotypic assays conducted in vitro and validated in vivo using animal models.

RESULTS

B7-H3 blockade induces a "primed for death" stress state in cancer cells, leading to distinct alterations in metabolic pathways. Specifically, B7-H3 knockdown activated the AKT signaling pathway and upregulated sterol regulatory element-binding protein 1 (SREBP1), which in turn elevated FASN expression. The simultaneous inhibition of both B7-H3 and FASN more effectively attenuated the malignant progression of TNBC.

CONCLUSIONS

Our findings propose an "immune attack-metabolic compensation" dynamic model and suggest the feasibility of a dual-targeting strategy that concurrently inhibits both B7-H3 and FASN to enhance therapeutic efficacy in TNBC patients.

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.

Lactate dehydrogenase B noncanonically promotes ferroptosis defense in KRAS-driven lung cancer

Ferroptosis is an oxidative, non-apoptotic cell death frequently inactivated in cancer, but the underlying mechanisms in oncogene-specific tumors remain poorly understood. Here, we discover that lactate dehydrogenase (LDH) B, but not the closely related LDHA, subunits of active LDH with a known function in glycolysis, noncanonically promotes ferroptosis defense in KRAS-driven lung cancer. Using murine models and human-derived tumor cell lines, we show that LDHB silencing impairs glutathione (GSH) levels and sensitizes cancer cells to blockade of either GSH biosynthesis or utilization by unleashing KRAS-specific, ferroptosis-catalyzed metabolic synthetic lethality, culminating in increased glutamine metabolism, oxidative phosphorylation (OXPHOS) and mitochondrial reactive oxygen species (mitoROS). We further show that LDHB suppression upregulates STAT1, a negative regulator of SLC7A11, thereby reducing SLC7A11-dependent GSH metabolism. Our study uncovers a previously undefined mechanism of ferroptosis resistance involving LDH isoenzymes and provides a novel rationale for exploiting oncogene-specific ferroptosis susceptibility to treat KRAS-driven lung cancer.

FASN promotes lipid metabolism and progression in colorectal cancer via the SP1/PLA2G4B axis

Abnormal metabolic reprogramming is essential for tumorigenesis, metastasis, and the regulation of immune responses. Fatty acid synthase (FASN), a key enzyme in lipid metabolism, plays a crucial role in these processes. However, the relationship between FASN-mediated lipid reprogramming and the immune response in colorectal cancer (CRC) remains unclear. The present study demonstrated that FASN expression is elevated in CRC tissues and is significantly associated with poor prognosis. Functional experiments revealed that FASN promotes proliferation, migration, invasion, and phosphatidylcholine (PC) production in CRC cells. Additionally, in vivo experiments revealed that FASN knockdown significantly inhibits tumor growth and the spread of CRC cells to the lungs. Mechanistically, FASN, which is upregulated in CRC tissues, drives cancer cell proliferation, metastasis, and PC metabolism through the SP1/PLA2G4B axis, subsequently suppressing the antitumor response of natural killer (NK) cells in a PC-dependent manner. These findings provide new insights into lipid metabolism and the immunobiology of CRC, suggesting potential targets for the treatment and prevention of CRC. Schematic diagram showing the mechanism by which FASN promotes cancer cell proliferation, metastasis, and PC metabolism in CRC via the SP1/PLA2G4B axis, subsequently suppressing the antitumor response of NK cells in a PC-dependent manner. FFA free fatty acid, LPA lysophosphatidic acid, PA phosphatidate, DAG diglyceride, PC phosphatidylcholine, LPC lysophosphatidylcholine, CE cholesterol ester, TAG triacylglycerol.

Microenvironmental arginine restriction sensitizes pancreatic cancers to polyunsaturated fatty acids by suppression of lipid synthesis

Nutrient limitation is a characteristic feature of poorly perfused tumors. In contrast to well-perfused tissues, nutrient deficits in tumors perturb cellular metabolic activity, which imposes metabolic constraints on cancer cells. The metabolic constraints created by the tumor microenvironment can lead to vulnerabilities in cancers. Identifying the metabolic constraints of the tumor microenvironment and the vulnerabilities that arise in cancers can provide new insight into tumor biology and identify promising antineoplastic targets. To identify how the microenvironment constrains the metabolism of pancreatic tumors, we challenged pancreatic cancer cells with microenvironmental nutrient levels and analyzed changes in cell metabolism. We found that arginine limitation in pancreatic tumors perturbs saturated and monounsaturated fatty acid synthesis by suppressing the lipogenic transcription factor SREBP1. Synthesis of these fatty acids is critical for maintaining a balance of saturated, monounsaturated, and polyunsaturated fatty acids in cellular membranes. As a consequence of microenvironmental constraints on fatty acid synthesis, pancreatic cancer cells and tumors are unable to maintain lipid homeostasis when exposed to polyunsaturated fatty acids, leading to cell death by ferroptosis. In sum, arginine restriction in the tumor microenvironment constrains lipid metabolism in pancreatic cancers, which renders these tumors vulnerable to polyunsaturatedenriched fat sources.

Attenuated growth factor signaling during cell death initiation sensitizes membranes towards peroxidation

Cell death programs such as apoptosis and ferroptosis are associated with aberrant redox homeostasis linked to lipid metabolism and membrane function. Evidence for cross-talk between these programs is emerging. Here, we show that cytotoxic stress channels polyunsaturated fatty acids via lysophospholipid acyltransferase 12 into phospholipids that become susceptible to peroxidation under additional redox stress. This reprogramming is associated with altered acyl-CoA synthetase isoenzyme expression and caused by a decrease in growth factor receptor tyrosine kinase (RTK)-phosphatidylinositol-3-kinase signaling, resulting in suppressed fatty acid biosynthesis, for specific stressors via impaired Akt-SREBP1 activation. The reduced availability of de novo synthesized fatty acids favors the channeling of polyunsaturated fatty acids into phospholipids. Growth factor withdrawal by serum starvation mimics this phenotype, whereas RTK ligands counteract it. We conclude that attenuated RTK signaling during cell death initiation increases cells' susceptibility to oxidative membrane damage at the interface of apoptosis and alternative cell death programs.

Harnessing ferroptosis for precision oncology: challenges and prospects

The discovery of diverse molecular mechanisms of regulated cell death has opened new avenues for cancer therapy. Ferroptosis, a unique form of cell death driven by iron-catalyzed peroxidation of membrane phospholipids, holds particular promise for targeting resistant cancer types. This review critically examines current literature on ferroptosis, focusing on its defining features and therapeutic potential. We discuss how molecular profiling of tumors and liquid biopsies can generate extensive multi-omics datasets, which can be leveraged through machine learning-based analytical approaches for patient stratification. Addressing these challenges is essential for advancing the clinical integration of ferroptosis-driven treatments in cancer care.

Multifaceted interplays between the essential players and lipid peroxidation in ferroptosis

Ferroptosis, a type of programmed cell death, represents a distinct paradigm in cell biology. It is characterized by the iron-dependent accumulation of reactive oxygen species, which induce lipid peroxidation (LPO), and is orchestrated by the interplay between iron, lipid peroxides, and glutathione. In this review, we emphasize the frequently overlooked role of iron in LPO beyond the classical iron-driven Fenton reaction in several crucial processes that regulate cellular iron homeostasis, including iron intake and export as well as ferritinophagy, and the emerging roles of endoplasmic reticulum-resident flavoprotein oxidoreductases, especially P450 oxidoreductases, in modulating LPO. We summarize how various types of fatty acids (FAs), including saturated, monounsaturated, and polyunsaturated FAs, differentially influence ferroptosis when incorporated into phospholipids. Furthermore, we highlight the therapeutic potential of targeting LPO to mitigate ferroptosis and discuss the regulatory mechanisms of endogenous lipophilic radical-trapping antioxidants that confer resistance to ferroptosis, shedding light on therapeutic avenues for ferroptosis-associated diseases.

The roles of KRAS in cancer metabolism, tumor microenvironment and clinical therapy

KRAS is one of the most mutated genes, driving alternations in metabolic pathways that include enhanced nutrient uptaking, increased glycolysis, elevated glutaminolysis, and heightened synthesis of fatty acids and nucleotides. However, the beyond mechanisms of KRAS-modulated cancer metabolisms remain incompletely understood. In this review, we aim to summarize current knowledge on KRAS-related metabolic alterations in cancer cells and explore the prevalence and significance of KRAS mutation in shaping the tumor microenvironment and influencing epigenetic modification via various molecular activities. Given that cancer cells rely on these metabolic changes to sustain cell growth and survival, targeting these processes may represent a promising therapeutic strategy for KRAS-driven cancers.

Targeting KRAS: from metabolic regulation to cancer treatment

The Kirsten rat sarcoma viral oncogene homolog (KRAS) protein plays a key pathogenic role in oncogenesis, cancer progression, and metastasis. Numerous studies have explored the role of metabolic alterations in KRAS-driven cancers, providing a scientific rationale for targeting metabolism in cancer treatment. The development of KRAS-specific inhibitors has also garnered considerable attention, partly due to the challenge of acquired treatment resistance. Here, we review the metabolic reprogramming of glucose, glutamine, and lipids regulated by oncogenic KRAS, with an emphasis on recent insights into the relationship between changes in metabolic mechanisms driven by KRAS mutant and related advances in targeted therapy. We also focus on advances in KRAS inhibitor discovery and related treatment strategies in colorectal, pancreatic, and non-small cell lung cancer, including current clinical trials. Therefore, this review provides an overview of the current understanding of metabolic mechanisms associated with KRAS mutation and related therapeutic strategies, aiming to facilitate the understanding of current challenges in KRAS-driven cancer and to support the investigation of therapeutic strategies.

Ferroptosis-related signaling pathways in cancer drug resistance

Ferroptosis is an iron-dependent form of programmed cell death induced by lipid peroxidation. This process is regulated by signaling pathways associated with redox balance, iron metabolism, and lipid metabolism. Cancer cells' increased iron demand makes them especially susceptible to ferroptosis, significantly influencing cancer development, therapeutic response, and metastasis. Recent findings indicate that cancer cells can evade ferroptosis by downregulating key signaling pathways related to this process, contributing to drug resistance. This underscores the possibility of modulating ferroptosis as an approach to counteract drug resistance and enhance therapeutic efficacy. This review outlines the signaling pathways involved in ferroptosis and their interactions with cancer-related signaling pathways. We also highlight the current understanding of ferroptosis in cancer drug resistance, offering insights into how targeting ferroptosis can provide novel therapeutic approaches for drug-resistant cancers. Finally, we explore the potential of ferroptosis-inducing compounds and examine the challenges and opportunities for drug development in this evolving field.

Epithelial-Mesenchymal Transition Suppression by ML210 Enhances Gemcitabine Anti-Tumor Effects on PDAC Cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers in the world. Neoadjuvant chemotherapy (NAC) has become a standard treatment for patients scheduled for surgical resection, but the high rate of postoperative recurrence is a critical problem. Optimization of NAC is desirable to reduce postoperative recurrence and achieve long-term survival. However, if a patient's general condition deteriorates due to NAC toxicity, surgical outcomes may be compromised. Therefore, we aimed to identify drug(s) that can be used in combination with gemcitabine (GEM), a drug widely used for the treatment of PDAC, to inhibit distant metastatic recurrence, particularly after surgery. After several screening steps, ML210, a low molecular weight chemical, was found to suppress the epithelial-mesenchymal transition (EMT) in PDAC cells in combination with GEM. Specifically, low dose ML210 in combination with GEM was sufficient for cell migration without apparent toxicity or cell death. Mechanistically, ML210, which was developed as a glutathione peroxidase 4 (GPX4) inhibitor to induce lipid peroxidation, increased the oxidized lipid concentrations in PDAC cells. The oxidization of the cell membrane lipids may suppress EMT, including cell migration. Since EMT is a major malignant phenotype of PDAC, our findings may lead to the advancement of PDAC therapy, especially in the prevention of postoperative recurrence.

Ferroptosis in Cancer: A new perspective on T cells

T cells occupy a pivotal position in the immune response against cancer by recognizing and eliminating cancer cells. However, the tumor microenvironment often suppresses the function of T cells, leading to immune evasion and cancer progression. Recent research has unveiled novel connections among T cells, ferroptosis, and cancer. Ferroptosis is a type of regulated cell death that relies iron and reactive oxygen species and is distinguished by the proliferation of lipid peroxides. Emerging scientific findings underscore the potential of ferroptosis to modulate the function and survival of T cells in the tumor microenvironment. Moreover, T cells or immunotherapy can also affect cancer by modulating ferroptosis in cancer cells. This review delved into the intricate crosstalk between T cells and ferroptosis in the context of cancer, highlighting the molecular mechanisms involved. We also explored the therapeutic potential of targeting ferroptosis to enhance the anticancer immune response mediated by T cells. Understanding the interplay among T cells, ferroptosis, and cancer may provide new insights into developing innovative cancer immunotherapies.

REV-ERBα inhibitor rescues MPTP/MPP+-induced ferroptosis of dopaminergic neuron through regulating FASN/SCD1 signaling pathway

Circadian disruption is a risk factor for Parkinson's disease (PD). Ferroptosis, a cellular death process, assumes a pivotal role in the degeneration of dopaminergic neurons in PD. Despite its significance, the potential contribution of circadian clock proteins to PD through the modulation of ferroptosis remains elusive. Our investigation unveiled a reduction in the circadian clock protein REV-ERBα in both MPTP/MPP+ and ferroptosis models. REV-ERBα actively promotes ferroptosis by binding to the RORE cis-element and suppressing the transcription of Fasn and Scd1, two genes that inhibit ferroptosis. Notably, inhibiting REV-ERBα exhibited a discernible mitigating effect on ferroptosis and the ensuing dopaminergic neuron damage induced by MPTP/MPP+. Consequently, targeting REV-ERBα emerges as a promising strategy for inhibiting ferroptosis and presents a novel therapeutic avenue for PD.

Calcium signals as regulators of ferroptosis in cancer

The field of ferroptosis research has grown exponentially since this form of cell death was first identified over a decade ago. Ferroptosis, an iron- and ROS-dependent type of cell death, is controlled by various metabolic pathways, including but not limited to redox and calcium (Ca2+) homeostasis, iron fluxes, mitochondrial function and lipid metabolism. Importantly, therapy-resistant tumors are particularly susceptible to ferroptotic cell death, rendering ferroptosis a promising therapeutic strategy against numerous malignancies. Calcium signals are important regulators of both cancer progression and cell death, with recent studies indicating their involvement in ferroptosis. Cells undergoing ferroptosis are characterized by plasma membrane rupture and the formation of nanopores, which facilitate influx of ions such as Ca2+ into the affected cells. Furthermore, mitochondrial Ca²⁺ levels have been implicated in directly influencing the cellular response to ferroptosis. Despite the remarkable progress made in the field, our understanding of the contribution of Ca2+ signals to ferroptosis remains limited. Here, we summarize key connections between Ca²⁺ signaling and ferroptosis in cancer pathobiology and discuss their potential therapeutic significance.

Pharmacological inhibition of SREBP1 suppresses pancreatic cancer growth via inducing GPX4-mediated ferroptosis

Pancreatic cancer (PC) is highly malignancy with poor survival. Ferroptosis offers a novel therapeutic target for cancer treatment and glutathione peroxidase 4 (GPX4) shields tumor cells from ferroptosis damage. Although Sterol regulatory element-binding protein 1 (SREBP1) has been implicated in the development of pancreatic cancer, its underlying mechanisms remain unclear. This research aims to explore the role of SREBP1 in ferroptosis by using its inhibitor Fatostatin. In this study, Fatostatin was found to inhibit the proliferation and clonogenicity of pancreatic cancer cell lines. This was accompanied by a reduction in intracellular lipid synthesis, increased iron accumulation, elevated levels of reactive oxygen species (ROS), and accumulation of malondialdehyde (MDA). The JASPAR database shows that there is a binding site of the SREBP1 on the promoter region of GPX4. What's more, it was verified that SREBP1 can transcriptionally regulate GPX4 by CHIP. In vivo experiments further revealed that Fatostatin could suppress the growth of subcutaneous tumors in nude mice. In conclusion, our study suggests that Fatostatin may inhibit pancreatic cancer cell proliferation by inducing ferroptosis through the SREBP1/GPX4 pathway. These findings shed light on the therapeutic potential of Fatostatin and lay the groundwork for future investigations into its mechanism of action in pancreatic cancer.

High mobility group A1 (HMGA1) promotes the tumorigenesis of colorectal cancer by increasing lipid synthesis

Metabolic reprogramming is a hallmark of cancer, enabling tumor cells to meet the high energy and biosynthetic demands required for their proliferation. High mobility group A1 (HMGA1) is a structural transcription factor and frequently overexpressed in human colorectal cancer (CRC). Here, we show that HMGA1 promotes CRC progression by driving lipid synthesis in a AOM/DSS-induced CRC mouse model. Using conditional knockout (Hmga1△IEC) and knock-in (Hmga1IEC-OE/+) mouse models, we demonstrate that HMGA1 enhances CRC cell proliferation and accelerates tumor development by upregulating fatty acid synthase (FASN). Mechanistically, HMGA1 increases the transcriptional activity of sterol regulatory element-binding protein 1 (SREBP1) on the FASN promoter, leading to increased lipid accumulation in intestinal epithelial cells. Moreover, a high-fat diet exacerbates CRC progression in Hmga1△IEC mice, while pharmacological inhibition of FASN by orlistat reduces tumor growth in Hmga1IEC-OE/+ mice. Our findings suggest that targeting lipid metabolism could offer a promising therapeutic strategy for CRC.

Lipid composition differentiates ferroptosis sensitivity between in vitro and in vivo systems

Ferroptosis is a regulated non-apoptotic cell death process characterized by iron-dependent lipid peroxidation. This process has recently emerged as a promising approach for cancer therapy. Peroxidation of polyunsaturated fatty acid-containing phospholipids (PUFA-PLs) is necessary for the execution of ferroptosis. Ferroptosis is normally suppressed by glutathione peroxidase 4 (GPX4), which reduces lipid hydroperoxides to lipid alcohols. Some evidence indicates that GPX4 may be a useful target for drug development, yet factors that govern GPX4 inhibitor sensitivity in vivo are poorly understood. We find that pharmacological and genetic loss of GPX4 function was sufficient to induce ferroptosis in multiple adherent ("2D") cancer cell cultures. However, reducing GPX4 protein levels did not affect tumor xenograft growth when these cells were implanted in mice. Furthermore, sensitivity to GPX4 inhibition was markedly reduced when cells were cultured as spheroids ("3D"). Mechanistically, growth in 3D versus 2D conditions reduced the abundance of PUFA-PLs. 3D culture conditions upregulated the monounsaturated fatty acid (MUFA) biosynthetic gene stearoyl-CoA desaturase (SCD). SCD-derived MUFAs appear to protect against ferroptosis in 3D conditions by displacing PUFAs from phospholipids. Various structurally related long chain MUFAs can inhibit ferroptosis through this PUFA-displacement mechanism. These findings suggest that growth-condition-dependent lipidome remodeling is an important mechanism governing GPX4 inhibitor effects. This resistance mechanism may specifically limit GPX4 inhibitor effectiveness in vivo .

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.

Online Direct Infusion Mass Spectrometry of Liquid-Liquid Extraction Phases for Metabolite and Lipid Profiling with the Direct Infusion Probe

Background/Objectives: Profiling of metabolites and lipids in biological samples can provide invaluable insights into life-sustaining chemical processes. The ability to detect both metabolites and lipids in the same sample can enhance these understandings and connect cellular dynamics. However, simultaneous detection of metabolites and lipids is generally hampered by chromatographic systems tailored to one molecular type. This void can be filled by direct infusion mass spectrometry (MS), where all ionizable molecules can be detected simultaneously. However, in direct infusion MS, the high chemical complexity of biological samples can introduce limitations in detectability due to matrix effects causing ionization suppression. Methods: Decreased sample complexity and increased detectability and molecular coverage was provided by combining our direct infusion probe (DIP) with liquid-liquid extraction (LLE) and directly sampling the different phases for direct infusion. Three commonly used LLE methods for separating lipids and metabolites were evaluated. Results: The butanol-methanol (BUME) method was found to be preferred since it provides high molecular coverage and have low solvent toxicity. The established BUME DIP-MS method was used as a fast and sensitive analysis tool to study chemical changes in insulin-secreting cells upon glucose stimulation. By analyzing the metabolome at distinct time points, down to 1-min apart, we found high dynamics of the intracellular metabolome. Conclusions: The rapid workflow with LLE DIP-MS enables higher sensitivity of phase separated metabolites and lipids. The application of BUME DIP-MS provides novel information on the dynamics of the intracellular metabolome of INS-1 during the two phases of insulin release for both metabolite and lipid classes.

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

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

The pathological significance and potential mechanism of ACLY in cholangiocarcinoma

Background and aim

Cholangiocarcinoma (CCA) is a rare cancer, yet its incidence and mortality rates have been steadily increasing globally over the past few decades. Currently, there are no effective targeted treatment strategies available for patients. ACLY (ATP Citrate Lyase), a key enzyme in de novo lipogenesis, is aberrantly expressed in several tumors and is associated with malignant progression. However, its role and mechanisms in CCA have not yet been elucidated.

Methods

The expression of ACLY in CCA was assessed using transcriptomic profiles and tissue microarrays. Kaplan-Meier curves were employed to evaluate the prognostic significance of ACLY in CCA. Functional enrichment analysis was used to explore the potential mechanisms of ACLY in CCA. A series of assays were conducted to examine the effects of ACLY on the proliferation and migration of CCA cells. Ferroptosis inducers and inhibitors, along with lipid peroxide probes and MDA assay kits, were utilized to explore the role of ACLY in ferroptosis within CCA. Additionally, lipid-depleted fetal bovine serum and several fatty acids were used to evaluate the impact of fatty acids on ferroptosis induced by ACLY inhibition. Correlation analyses were performed to elucidate the relationship between ACLY and tumor stemness as well as tumor microenvironment.

Results

The expression of ACLY was found to be higher in CCA tissues compared to adjacent normal tissues. Patients with elevated ACLY expression demonstrated poorer overall survival outcomes. ACLY were closed associated with fatty acid metabolism and tumor-initiating cells. Knockdown of ACLY did not significantly impact the proliferation and migration of CCA cells. However, ACLY inhibition led to increased accumulation of lipid peroxides and enhanced sensitivity of CCA cells to ferroptosis inducers. Polyunsaturated fatty acids were observed to inhibit the proliferation of ACLY-knockdown cells; nonetheless, this inhibitory effect was diminished when the cells were cultured in medium supplemented with lipid-depleted fetal bovine serum. Additionally, ACLY expression was negatively correlated with immune cell infiltration and immune scores in CCA.

Conclusion

ACLY promotes ferroptosis by disrupting the balance of saturated and unsaturated fatty acids. ACLY may therefore serve as a potential diagnostic and therapeutic target for CCA.

Darolutamide-mediated phospholipid remodeling induces ferroptosis through the SREBP1-FASN axis in prostate cancer

Darolutamide, an androgen receptor inhibitor, has been approved by the Food and Drug Administration (FDA) for the treatment of prostate cancer (PCa), especially for patients with androgen receptor mutations. Owing to the unique lipidomic profile of PCa and the effect of darolutamide, the relationship between darolutamide and ferroptosis remains unclear. The present study showed that darolutamide significantly induces ferroptosis in AR+ PCa cells. Mechanistically, darolutamide promotes ferroptosis by downregulating SREBP1, which then inhibits the transcription of FASN. FASN knockdown modulates phospholipid remodeling by disrupting the balance between polyunsaturated fatty acids (PUFAs) and saturated fatty acids (SFAs), which induces ferroptosis. Clinically, SREBP1 and FASN are significantly overexpressed in PCa tissues and are related to poor prognosis. Moreover, the synergistic antitumor effect of combination therapy with darolutamide and ferroptosis inducers (FINs) was confirmed in PCa organoids and a mouse xenografts model. Overall, these findings revealed a novel mechanism of darolutamide mediated ferroptosis in PCa, laying the foundation for the combination of darolutamide and FINs as a new therapeutic strategy for PCa patients.

Exploiting ferroptosis vulnerabilities in cancer

Ferroptosis is a distinct lipid peroxidation-dependent form of necrotic cell death. This process has been increasingly contemplated as a new target for cancer therapy because of an intrinsic or acquired ferroptosis vulnerability in difficult-to-treat cancers and tumour microenvironments. Here we review recent advances in our understanding of the molecular mechanisms that underlie ferroptosis and highlight available tools for the modulation of ferroptosis sensitivity in cancer cells and communication with immune cells within the tumour microenvironment. We further discuss how these new insights into ferroptosis-activating pathways can become new armouries in the fight against cancer.

Ferroptosis in health and disease

Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is uncontrolled and overwhelming peroxidation of polyunsaturated fatty acids contained in membrane phospholipids, which eventually leads to rupture of the plasma membrane. Ferroptosis is unique in that it is essentially a spontaneous, uncatalyzed chemical process based on perturbed iron and redox homeostasis contributing to the cell death process, but that it is nonetheless modulated by many metabolic nodes that impinge on the cells' susceptibility to ferroptosis. Among the various nodes affecting ferroptosis sensitivity, several have emerged as promising candidates for pharmacological intervention, rendering ferroptosis-related proteins attractive targets for the treatment of numerous currently incurable diseases. Herein, the current members of a Germany-wide research consortium focusing on ferroptosis research, as well as key external experts in ferroptosis who have made seminal contributions to this rapidly growing and exciting field of research, have gathered to provide a comprehensive, state-of-the-art review on ferroptosis. Specific topics include: basic mechanisms, in vivo relevance, specialized methodologies, chemical and pharmacological tools, and the potential contribution of ferroptosis to disease etiopathology and progression. We hope that this article will not only provide established scientists and newcomers to the field with an overview of the multiple facets of ferroptosis, but also encourage additional efforts to characterize further molecular pathways modulating ferroptosis, with the ultimate goal to develop novel pharmacotherapies to tackle the various diseases associated with - or caused by - ferroptosis.

Oxidative cell death in cancer: mechanisms and therapeutic opportunities

Reactive oxygen species (ROS) are highly reactive oxygen-containing molecules generated as natural byproducts during cellular processes, including metabolism. Under normal conditions, ROS play crucial roles in diverse cellular functions, including cell signaling and immune responses. However, a disturbance in the balance between ROS production and cellular antioxidant defenses can lead to an excessive ROS buildup, causing oxidative stress. This stress damages essential cellular components, including lipids, proteins, and DNA, potentially culminating in oxidative cell death. This form of cell death can take various forms, such as ferroptosis, apoptosis, necroptosis, pyroptosis, paraptosis, parthanatos, and oxeiptosis, each displaying distinct genetic, biochemical, and signaling characteristics. The investigation of oxidative cell death holds promise for the development of pharmacological agents that are used to prevent tumorigenesis or treat established cancer. Specifically, targeting key antioxidant proteins, such as SLC7A11, GCLC, GPX4, TXN, and TXNRD, represents an emerging approach for inducing oxidative cell death in cancer cells. This review provides a comprehensive summary of recent progress, opportunities, and challenges in targeting oxidative cell death for cancer therapy.

Lipid Quality Control and Ferroptosis: From Concept to Mechanism

Cellular quality control systems sense and mediate homeostatic responses to prevent the buildup of aberrant macromolecules, which arise from errors during biosynthesis, damage by environmental insults, or imbalances in enzymatic and metabolic activity. Lipids are structurally diverse macromolecules that have many important cellular functions, ranging from structural roles in membranes to functions as signaling and energy-storage molecules. As with other macromolecules, lipids can be damaged (e.g., oxidized), and cells require quality control systems to ensure that nonfunctional and potentially toxic lipids do not accumulate. Ferroptosis is a form of cell death that results from the failure of lipid quality control and the consequent accumulation of oxidatively damaged phospholipids. In this review, we describe a framework for lipid quality control, using ferroptosis as an illustrative example to highlight concepts related to lipid damage, membrane remodeling, and suppression or detoxification of lipid damage via preemptive and damage-repair lipid quality control pathways.

Spatially and temporally probing distinctive glycerophospholipid alterations in Alzheimer's disease mouse brain via high-resolution ion mobility-enabled sn-position resolved lipidomics

Dysregulated glycerophospholipid (GP) metabolism in the brain is associated with the progression of neurodegenerative diseases including Alzheimer's disease (AD). Routine liquid chromatography-mass spectrometry (LC-MS)-based large-scale lipidomic methods often fail to elucidate subtle yet important structural features such as sn-position, hindering the precise interrogation of GP molecules. Leveraging high-resolution demultiplexing (HRdm) ion mobility spectrometry (IMS), we develop a four-dimensional (4D) lipidomic strategy to resolve GP sn-position isomers. We further construct a comprehensive experimental 4D GP database of 498 GPs identified from the mouse brain and an in-depth extended 4D library of 2500 GPs predicted by machine learning, enabling automated profiling of GPs with detailed acyl chain sn-position assignment. Analyzing three mouse brain regions (hippocampus, cerebellum, and cortex), we successfully identify a total of 592 GPs including 130 pairs of sn-position isomers. Further temporal GPs analysis in the three functional brain regions illustrates their metabolic alterations in AD progression.

Is retrograde menstruation a universal, recurrent, physiological phenomenon? A systematic review of the evidence in humans and non-human primates

STUDY QUESTION

What are the quantitative, qualitative, and temporal patterns of retrograde mentruation?

SUMMARY ANSWER

The extreme quantitative and qualitative heterogeneity of the available studies prevents the definitive conclusion that retrograde menstruation is a universal and consistent phenomenon during the reproductive period.

WHAT IS KNOWN ALREADY

Retrograde menstruation has been defined as a universal, physiological phenomenon that occurs similarly in about 90% of menstruators during the reproductive period. However, uncertainties still exist in terms of the event frequency, total amount, and cellular composition of retrograde menstruation and the differences between individuals with versus those without endometriosis.

STUDY DESIGN SIZE DURATION

Two systematic reviews were performed, one for human studies, and one for non-human primate studies. We retrieved studies from the PubMed and Embase databases published between 1 January 1980 and 1 November 2023. Studies published in the English language were included and identified using a combination of MeSH terms. References from relevant publications were systematically screened and further articles were identified using PubMed's 'similar articles' and 'cited by' functions.

PARTICIPANTS/MATERIALS SETTING METHODS

Results were reported in accordance with the PRISMA guidelines. Studies that did not report original data or provided a review of the field were excluded. Bias analysis was completed for each included human study by using the Newcastle-Ottawa scoring system.

MAIN RESULTS AND THE ROLE OF CHANCE

Fifteen studies were finally included in the human systematic review, mostly with limited sample sizes. The macroscopic visualization of blood in PF during menses was reported with a frequency ranging from 9% to 100%. A prevalence of endometrial cells detected in peritoneal fluid ranging from 8% to 75% was reported in the various studies. Controversial findings were reported in relation to patients with endometriosis. Retrograde menstruation has been evaluated cross-sectionally on single occasions, and no information is available on the course of the phenomenon within an entire cycle and between subsequent cycles. Two studies were included in the non-human primate systematic review; one of them showed that retrograde menstruation was observed more frequently in baboons with naturally occurring endometriosis (83%) than in those with a normal pelvis (51%).

LIMITATIONS REASONS FOR CAUTION

In humans, peritoneal fluid has often been collected at different cycle phases and not systematically during menstruation. The indication for laparoscopy was not always clear for all participants. A wide variety of methods were used to detect endometrial cells, including cytological staining, cell block analysis, immunocytochemistry, and various methods of cell culture.

WIDER IMPLICATION OF THE FINDINGS

The idea that almost all women experience retrograde menstruation regularly and similarly during their reproductive life is currently unsubstantiated. It is an academic notion accepted uncritically. Development of endometriosis may derive from differences in the frequency or severity of the event.

STUDY FUNDING/COMPETING INTERESTS

The review was partially funded by Italian Ministry of Health-Current Research IRCCS. P.Vi. serves as co-editor in Chief of Journal of Endometriosis and Uterine Disorders. E.S. serves as Editor in Chief of Human Reproduction Open and discloses research grants from Ferring, Ibsa, Gedeon Richter, and Theramex, and honoraria from Ibsa and Gedeon Richter. P.Ve. serves as Associate Editor for Human Reproduction Open; is a member of the Editorial Board of the Journal of Obstetrics and Gynaecology Canada, of the Italian Journal of Obstetrics and Gynaecology, and of the International Editorial Board of Acta Obstetricia et Gynecologica Scandinavica; has received royalties from Wolters Kluwer for chapters on endometriosis management in the clinical decision support resource UpToDate; and maintains both a public and private gynecological practice. All other authors declare they have no conflict of interest.

REGISTRATION NUMBER

N/A.

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.

The cell biology of ferroptosis

Ferroptosis is a non-apoptotic cell death mechanism characterized by iron-dependent membrane lipid peroxidation. Here, we review what is known about the cellular mechanisms mediating the execution and regulation of ferroptosis. We first consider how the accumulation of membrane lipid peroxides leads to the execution of ferroptosis by altering ion transport across the plasma membrane. We then discuss how metabolites and enzymes that are distributed in different compartments and organelles throughout the cell can regulate sensitivity to ferroptosis by impinging upon iron, lipid and redox metabolism. Indeed, metabolic pathways that reside in the mitochondria, endoplasmic reticulum, lipid droplets, peroxisomes and other organelles all contribute to the regulation of ferroptosis sensitivity. We note how the regulation of ferroptosis sensitivity by these different organelles and pathways seems to vary between different cells and death-inducing conditions. We also highlight transcriptional master regulators that integrate the functions of different pathways and organelles to modulate ferroptosis sensitivity globally. Throughout this Review, we highlight open questions and areas in which progress is needed to better understand the cell biology of ferroptosis.

Regulation and targeting of SREBP-1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an increasing burden on global public health and is associated with enhanced lipogenesis, fatty acid uptake, and lipid metabolic reprogramming. De novo lipogenesis is under the control of the transcription factor sterol regulatory element-binding protein 1 (SREBP-1) and essentially contributes to HCC progression. Here, we summarize the current knowledge on the regulation of SREBP-1 isoforms in HCC based on cellular, animal, and clinical data. Specifically, we (i) address the overarching mechanisms for regulating SREBP-1 transcription, proteolytic processing, nuclear stability, and transactivation and (ii) critically discuss their impact on HCC, taking into account (iii) insights from pharmacological approaches. Emphasis is placed on cross-talk with the phosphatidylinositol-3-kinase (PI3K)-protein kinase B (Akt)-mechanistic target of rapamycin (mTOR) axis, AMP-activated protein kinase (AMPK), protein kinase A (PKA), and other kinases that directly phosphorylate SREBP-1; transcription factors, such as liver X receptor (LXR), peroxisome proliferator-activated receptors (PPARs), proliferator-activated receptor γ co-activator 1 (PGC-1), signal transducers and activators of transcription (STATs), and Myc; epigenetic mechanisms; post-translational modifications of SREBP-1; and SREBP-1-regulatory metabolites such as oxysterols and polyunsaturated fatty acids. By carefully scrutinizing the role of SREBP-1 in HCC development, progression, metastasis, and therapy resistance, we shed light on the potential of SREBP-1-targeting strategies in HCC prevention and treatment.

Metabolic heterogeneity in tumor microenvironment - A novel landmark for immunotherapy

The surrounding non-cancer cells and tumor cells that make up the tumor microenvironment (TME) have various metabolic rhythms. TME metabolic heterogeneity is influenced by the intricate network of metabolic control within and between cells. DNA, protein, transport, and microbial levels are important regulators of TME metabolic homeostasis. The effectiveness of immunotherapy is also closely correlated with alterations in TME metabolism. The response of a tumor patient to immunotherapy is influenced by a variety of variables, including intracellular metabolic reprogramming, metabolic interaction between cells, ecological changes within and between tumors, and general dietary preferences. Although immunotherapy and targeted therapy have made great strides, their use in the accurate identification and treatment of tumors still has several limitations. The function of TME metabolic heterogeneity in tumor immunotherapy is summarized in this article. It focuses on how metabolic heterogeneity develops and is regulated as a tumor progresses, the precise molecular mechanisms and potential clinical significance of imbalances in intracellular metabolic homeostasis and intercellular metabolic coupling and interaction, as well as the benefits and drawbacks of targeted metabolism used in conjunction with immunotherapy. This offers insightful knowledge and important implications for individualized tumor patient diagnosis and treatment plans in the future.

Emerging targets in lipid metabolism for cancer therapy

Cancer cells perturb lipid metabolic pathways for a variety of pro-tumorigenic functions, and deregulated cellular metabolism is a hallmark of cancer cells. Although alterations in lipid metabolism in cancer cells have been appreciated for over 20 years, there are no FDA-approved cancer treatments that target lipid-related pathways. Recent advances pertaining to cancer cell fatty acid synthesis (FAS), desaturation, and uptake, microenvironmental and dietary lipids, and lipid metabolism of tumor-infiltrating immune cells have illuminated promising clinical applications for targeting lipid metabolism. This review highlights emerging pathways and targets for tumor lipid metabolism that may soon impact clinical treatment.

Ononin triggers ferroptosis-mediated disruption in the triple negative breast cancer both in vitro and in vivo

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is difficult to treat due to a lack of targeted therapies. In this study, we aimed to investigate whether a natural flavonoid compound called ononin could be effective in treating TNBC by triggering ferroptosis in MDA-MB-231 and 4 T1 cell lines, and MDA-MB-231-xenograft nude mice model. Ononin inhibited TNBC through ferroptosis, which was determined by MTT assay, flow cytometry, RT-PCR, immunofluorescence, transmission electron microscopy, histological analysis, western blot and bioluminescence assay. Our results showed that treatment with ononin led to increased levels of malondialdehyde and reactive oxygen species and decreased activity of superoxide dismutase, which are indicatives of ferroptosis. We also found that ononin downregulated two key markers of ferroptosis, SLC7A11 and Nrf2, at both the transcriptional and translational level. Additionally, the administration of ononin resulted in a notable decrease in tumor size and weight in the mouse model. Furthermore, it was observed to enhance the rate of apoptosis in TNBC cells. Importantly, ononin did not induce any histological changes in the kidney, liver, and heart. Taken together, our findings suggest that ononin could be a promising therapeutic strategy for TNBC, and that it works by disrupting the Nrf2/SLC7A11 axis through ferroptosis. These results are encouraging and may lead to the development of new treatments for this challenging cancer subtype.

IL-13 facilitates ferroptotic death in asthmatic epithelial cells via SOCS1-mediated ubiquitinated degradation of SLC7A11

Th2-high asthma is characterized by elevated levels of type 2 cytokines, such as interleukin 13 (IL-13), and its prevalence has been increasing worldwide. Ferroptosis, a recently discovered type of programmed cell death, is involved in the pathological process of Th2-high asthma; however, the underlying mechanisms remain incompletely understood. In this study, we demonstrated that the serum level of malondialdehyde (MDA), an index of lipid peroxidation, positively correlated with IL-13 level and negatively correlated with the predicted forced expiratory volume in 1 s (FEV1%) in asthmatics. Furthermore, we showed that IL-13 facilitates ferroptosis by upregulating of suppressor of cytokine signaling 1 (SOCS1) through analyzing immortalized airway epithelial cells, human airway organoids, and the ovalbumin (OVA)-challenged asthma model. We identified that signal transducer and activator of transcription 6 (STAT6) promotes the transcription of SOCS1 upon IL-13 stimulation. Moreover, SOCS1, an E3 ubiquitin ligase, was found to bind to solute carrier family 7 member 11 (SLC7A11) and catalyze its ubiquitinated degradation, thereby promoting ferroptosis in airway epithelial cells. Last, we found that inhibiting SOCS1 can decrease ferroptosis in airway epithelial cells and alleviate airway hyperresponsiveness (AHR) in OVA-challenged wide-type mice, while SOCS1 overexpression exacerbated the above in OVA-challenged IL-13-knockout mice. Our findings reveal that the IL-13/STAT6/SOCS1/SLC7A11 pathway is a novel molecular mechanism for ferroptosis in Th2-high asthma, confirming that targeting ferroptosis in airway epithelial cells is a potential therapeutic strategy for Th2-high asthma.

Abnormal mitochondrial iron metabolism damages alveolar type II epithelial cells involved in bleomycin-induced pulmonary fibrosis

Rationale: Pulmonary fibrosis is a chronic progressive lung disease with limited therapeutic options. We previously revealed that there is iron deposition in alveolar epithelial type II cell (AECII) in pulmonary fibrosis, which can be prevented by the iron chelator deferoxamine. However, iron in the cytoplasm and the mitochondria has two relatively independent roles and regulatory systems. In this study, we aimed to investigate the role of mitochondrial iron deposition in AECII injury and pulmonary fibrosis, and to find potential therapeutic strategies. Methods: BLM-treated mice, MLE-12 cells, and primary AECII were employed to establish the mouse pulmonary fibrosis model and epithelial cells injury model, respectively. Mitochondrial transplantation, siRNA and plasmid transfection, western blotting (WB), quantitative real-time polymerase chain reaction (RT-qPCR), polymerase chain reaction (PCR), immunofluorescence, immunoprecipitation (IP), MitoSOX staining, JC-1 staining, oxygen consumption rate (OCR) measurement, and Cell Counting Kit-8 (CCK8) assay were utilized to elucidate the role of mitochondrial iron deposition in cell and lung fibrosis and determine its mechanism. Results: This study showed that prominent mitochondrial iron deposition occurs within AECII in bleomycin (BLM)-induced pulmonary fibrosis mouse model and in BLM-treated MLE-12 epithelial cells. Further, the study revealed that healthy mitochondria rescue BLM-damaged AECII mitochondrial iron deposition and cell damage loss. Mitoferrin-2 (MFRN2) is the main transporter that regulates mitochondrial iron metabolism by transferring cytosolic iron into mitochondria, which is upregulated in BLM-treated MLE-12 epithelial cells. Direct overexpression of MFRN2 causes mitochondrial iron deposition and cell damage. In this study, decreased ubiquitination of the ubiquitin ligase F-box/LRR-repeat protein 5 (FBXL5) degraded iron-reactive element-binding protein 2 (IREB2) and promoted MFRN2 expression as well as mitochondrial iron deposition in damaged AECII. Activation of the prostaglandin E2 receptor EP4 subtype (EP4) receptor signaling pathway counteracted mitochondrial iron deposition by downregulating IREB2-MFRN2 signaling through upregulation of FBXL5. This intervention not only reduced mitochondrial iron content but also preserved mitochondrial function and protected against AECII damage after BLM treatment. Conclusion: Our findings highlight the unexplored roles, mechanisms, and regulatory approaches of abnormal mitochondrial iron metabolism of AECII in pulmonary fibrosis. Therefore, this study deepens the understanding of the mechanisms underlying pulmonary fibrosis and offers a promising strategy for developing effective therapeutic interventions using the EP4 receptor activator.

Emerging Therapies in Kirsten Rat Sarcoma Virus (+) Non-Small-Cell Lung Cancer

Kirsten rat sarcoma virus (KRAS) is the most frequently found oncogene in human cancers, including non-small-cell lung cancer (NSCLC). For many years, KRAS was considered "undruggable" due to its structure and difficult targeting. However, the discovery of the switch II region in the KRAS-G12C-mutated protein has changed the therapeutic landscape with the design and development of novel direct KRAS-G12C inhibitors. Sotorasib and adagrasib are FDA-approved targeted agents for pre-treated patients with KRAS-G12C-mutated NSCLC. Despite promising results, the efficacy of these novel inhibitors is limited by mechanisms of resistance. Ongoing studies are evaluating combination strategies for overcoming resistance. In this review, we summarize the biology of the KRAS protein and the characteristics of KRAS mutations. We then present current and emerging therapeutic approaches for targeting KRAS mutation subtypes intending to provide individualized treatment for lung cancer harboring this challenging driver mutation.

Ferroptosis in cancer: From molecular mechanisms to therapeutic strategies

Ferroptosis is a non-apoptotic form of regulated cell death characterized by the lethal accumulation of iron-dependent membrane-localized lipid peroxides. It acts as an innate tumor suppressor mechanism and participates in the biological processes of tumors. Intriguingly, mesenchymal and dedifferentiated cancer cells, which are usually resistant to apoptosis and traditional therapies, are exquisitely vulnerable to ferroptosis, further underscoring its potential as a treatment approach for cancers, especially for refractory cancers. However, the impact of ferroptosis on cancer extends beyond its direct cytotoxic effect on tumor cells. Ferroptosis induction not only inhibits cancer but also promotes cancer development due to its potential negative impact on anticancer immunity. Thus, a comprehensive understanding of the role of ferroptosis in cancer is crucial for the successful translation of ferroptosis therapy from the laboratory to clinical applications. In this review, we provide an overview of the recent advancements in understanding ferroptosis in cancer, covering molecular mechanisms, biological functions, regulatory pathways, and interactions with the tumor microenvironment. We also summarize the potential applications of ferroptosis induction in immunotherapy, radiotherapy, and systemic therapy, as well as ferroptosis inhibition for cancer treatment in various conditions. We finally discuss ferroptosis markers, the current challenges and future directions of ferroptosis in the treatment of cancer.

Metabolism-regulated ferroptosis in cancer progression and therapy

Cancer metabolism mainly includes carbohydrate, amino acid and lipid metabolism, each of which can be reprogrammed. These processes interact with each other to adapt to the complicated microenvironment. Ferroptosis is a regulated cell death induced by iron-dependent lipid peroxidation, which is morphologically different from apoptosis, necrosis, necroptosis, pyroptosis, autophagy-dependent cell death and cuprotosis. Cancer metabolism plays opposite roles in ferroptosis. On the one hand, carbohydrate metabolism can produce NADPH to maintain GPX4 and FSP1 function, and amino acid metabolism can provide substrates for synthesizing GPX4; on the other hand, lipid metabolism might synthesize PUFAs to trigger ferroptosis. The mechanisms through which cancer metabolism affects ferroptosis have been investigated extensively for a long time; however, some mechanisms have not yet been elucidated. In this review, we summarize the interaction between cancer metabolism and ferroptosis. Importantly, we were most concerned with how these targets can be utilized in cancer therapy.

Fatty acid synthase (FASN) signalome: A molecular guide for precision oncology

The initial excitement generated more than two decades ago by the discovery of drugs targeting fatty acid synthase (FASN)-catalyzed de novo lipogenesis for cancer therapy was short-lived. However, the advent of the first clinical-grade FASN inhibitor (TVB-2640; denifanstat), which is currently being studied in various phase II trials, and the exciting advances in understanding the FASN signalome are fueling a renewed interest in FASN-targeted strategies for the treatment and prevention of cancer. Here, we provide a detailed overview of how FASN can drive phenotypic plasticity and cell fate decisions, mitochondrial regulation of cell death, immune escape and organ-specific metastatic potential. We then present a variety of FASN-targeted therapeutic approaches that address the major challenges facing FASN therapy. These include limitations of current FASN inhibitors and the lack of precision tools to maximize the therapeutic potential of FASN inhibitors in the clinic. Rethinking the role of FASN as a signal transducer in cancer pathogenesis may provide molecularly driven strategies to optimize FASN as a long-awaited target for cancer therapeutics.

GSTM3 enhances radiosensitivity of nasopharyngeal carcinoma by promoting radiation-induced ferroptosis through USP14/FASN axis and GPX4

BACKGROUND

Radiotherapy is a critical treatment modality for nasopharyngeal carcinoma (NPC). However, the mechanisms underlying radiation resistance and tumour recurrence in NPC remain incompletely understood.

METHODS

Oxidised lipids were assessed through targeted metabolomics. Ferroptosis levels were evaluated using cell viability, clonogenic survival, lipid peroxidation, and transmission electron microscopy. We investigated the biological functions of glutathione S-transferase mu 3 (GSTM3) in cell lines and xenograft tumours. Co-immunoprecipitation, mass spectrometry, and immunofluorescence were conducted to explore the molecular mechanisms involving GSTM3. Immunohistochemistry was performed to investigate the clinical characteristics of GSTM3.

RESULTS

Ionising radiation (IR) promoted lipid peroxidation and induced ferroptosis in NPC cells. GSTM3 was upregulated following IR exposure and correlated with IR-induced ferroptosis, enhancing NPC radiosensitivity in vitro and in vivo. Mechanistically, GSTM3 stabilised ubiquitin-specific peptidase 14 (USP14), thereby inhibiting the ubiquitination and subsequent degradation of fatty acid synthase (FASN). Additionally, GSTM3 interacted with glutathione peroxidase 4 (GPX4) and suppressed GPX4 expression. Combining IR treatment with ferroptosis inducers synergistically improved NPC radiosensitivity and suppressed tumour growth. Notably, a decrease in GSTM3 abundance predicted tumour relapse and poor prognosis.

CONCLUSIONS

Our findings elucidate the pivotal role of GSTM3 in IR-induced ferroptosis, offering strategies for the treatment of radiation-resistant or recurrent NPC.