Peroxidation of n-3 and n-6 polyunsaturated fatty acids in the acidic tumor environment leads to ferroptosis-mediated anticancer effects

Mitochondrial metabolism in laryngeal cancer: therapeutic mechanisms and prospects

Tumours reprogram pathways that regulate nutrient uptake and metabolism to meet the biosynthetic, bioenergetic, and redox requirements of cancer cells. This phenomenon is known as metabolic reprogramming and is edited by the deletion of oncogenes and the activation of proto-oncogenes. This article highlights the pathological mechanisms associated with metabolic reprogramming in laryngeal cancer (LC), including enhanced glycolysis, tricarboxylic acid cycle, nucleotide synthesis, lipid synthesis and metabolism, and amino acid metabolism, with a special emphasis on glutamine, tryptophan, and arginine metabolism. All these changes are regulated by HPV infection, hypoxia, and metabolic mediators in the tumour microenvironment. We analyzed the function of metabolic reprogramming in the development of drug resistance during standard LC treatment, which is challenging. In addition, we revealed recent advances in targeting metabolic strategies, assessing the strengths and weaknesses of clinical trials and treatment programs to attack resistance. This review summarises some currently important biomarkers and lays the foundation for therapeutic pathways in LC.

Divergent ferroptotic pathways in breast cancer cells: IGFBP6-regulated mitochondrial lipid peroxidation under erastin and omega-3 DHA treatment

Breast cancer remains a major challenge and new therapeutic approaches are needed for its treatment. Ferroptosis is considered a promising alternative cell death mechanism to eliminate resistant cancer cells. In previous works, we identified that lower IGFBP6 gene expression in tumor tissue corresponds to a worse prognosis for breast cancer patients and, at the same, time makes them more sensitive to ferroptosis. In this study, we further investigated the mechanism of ferroptosis induction in IGFBP6 knockdown and control MDA-MB-231 breast cancer cells by the canonical ferroptosis inducer erastin and omega-3 docosahexaenoic acid (DHA). Our results indicate that there is a significant overlap between the mechanisms of action of both of these molecules, as they regulate the same subset of genes, and their action can be inhibited by canonical ferroptosis inhibitors. On the other hand, we also observed significant differences between the effects of erastin and DHA. The most notable of these are the additional activation of apoptosis-related genes by DHA and its minor peroxidation of mitochondrial lipid membranes. Interestingly, our kinetic analysis of ferroptosis induction showed that IGFBP6 knockdown cells began to die earlier and could hardly be rescued from erastin-induced ferroptosis by mitochondrial antioxidant SkQ1, in contrast to control cells. Overall, our data suggest that the action of DHA is less dependent on mitochondrial membrane peroxidation during ferroptosis induction, and this molecule can be a promising candidate for the treatment of breast cancer, especially in the case of reduced IGFBP6 gene expression in cancer cells.

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.

Comparative lipidomics analysis of human colostrum, mature milk and yak mature milk

Yak milk is a promising lipid source substitute for infant formulas designed to mimic human milk. However, comparative studies on the lipid profiles between human and yak milk are scarce. To address this gap, in this study, we thoroughly analysed and compared the lipidome and fatty acid (FA) composition of human colostrum, human mature milk and yak mature milk. A total of 2686 lipid species from 30 lipid classes were identified in the three milk types. Notably, yak mature milk surpassed both human milk stages in the total content of lipid species, triglycerides (TG) and saturated FA. In particular, three potential lipid biomarkers, namely TG(6,0_8,0_14:0) + NH4, TG(16,0_6,0_8:0) + NH4 and TG(10,0_12,0_12,0) + NH4, were identified to differentiate yak mature milk from human colostrum and mature milk. Moreover, upon analysing the lipid metabolic pathways, it was found that the lipids involved in the pathways of acetylcholine synthesis, as well as starch and sucrose metabolism, may not manifest notable differences between yak mature milk and human colostrum, indicating the presence of similar neurodevelopment-regulating and metabolic characteristics in yak milk as in colostrum. Therefore, this comprehensive comparison offers novel insights into the potential of yak mature milk lipids to enhance the humanisation of infant formulas.

Ferroptosis: A Targetable Vulnerability for Melanoma Treatment

Melanoma is a devastating form of skin cancer characterized by a high mutational burden, limited treatment success, and dismal prognosis. Although immunotherapy and targeted therapies have significantly revolutionized melanoma treatment, the majority of patients fail to achieve durable responses, highlighting the urgent need for novel therapeutic strategies. Ferroptosis, an iron-dependent form of regulated cell death driven by the overwhelming accumulation of lipid peroxides, has emerged as a promising therapeutic approach in preclinical melanoma models. A deeper understanding of the ferroptosis landscape in melanoma based on its biology characteristics, including phenotypic plasticity, metabolic state, genomic alterations, and epigenetic changes, as well as the complex role and mechanisms of ferroptosis in immune cells could provide a foundation for developing effective treatments. In this review, we outline the molecular mechanisms of ferroptosis, decipher the role of melanoma biology in ferroptosis regulation, reveal the therapeutic potential of ferroptosis in melanoma, and discuss the pressing questions that should guide future investigations into ferroptosis in melanoma.

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

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

Parenteral nutrition with n-3 polyunsaturated fatty acids on nutrition inflammatory and immune status of gastrointestinal cancer patients: Meta-analysis

BACKGROUND

The incidence of malignant tumors in the digestive system is increasing and is a threat to human health. However, the long duration from tumor detection to radical resection, stress responses due to surgical trauma, and insufficient nutritional intake increases the risk of malnutrition, immune function reduction, postoperative complications, and intestinal dysfunction among patients.

AIM

To systematically investigate the association of parenteral nutrition enriched with n-3 polyunsaturated fatty acids (PUFAs) with the nutritional status of patients after gastrointestinal treatment.

METHODS

Randomized controlled trials associated with PUFA-enriched parenteral nutrition administration in patients with digestive system malignancies were retrieved from online databases such as PubMed, EMBASE, ScienceDirect, Cochrane Library, China Knowledge Network, China VIP, Wanfang, and China Biomedical Literature Database, with the retrieval time from database inception to present. Two researchers independently extracted data. Each article’s bias risk was assessed by referring to the Cochrane Handbook version 5.3 criteria and RevMan5.4 was used for data analysis.

RESULTS

This meta-analysis involved six randomized controlled trials involving a total of 505 cases. Random-effects model analysis indicated remarkably better improvements in various inflammatory factors in the study group (P < 0.05). Meta-analysis of nutritional indicators revealed that the study group had higher total protein, albumin, and prealbumin levels, as well as lower transferrin levels compared to the control group (P < 0.05). Meanwhile, meta-analysis of T-cell subsets revealed no remarkable inter-group difference in post-treatment CD8⁺ cells (P > 0.05). Moreover, the meta-analysis identified a notably lower incidence of adverse reactions in the study group (P < 0.05).

CONCLUSION

Administration of PUFAs helps improve the nutritional status of patients with digestive malignancies in the perioperative period. It promotes immune function recovery, reduces the inflammatory response, and decreases the risk of adverse effects. These beneficial effects make it worth investigating and promoting their use in appropriate patient populations. However, further validation via high-quality studies with long intervention time and extended follow-up periods is required.

Turning Waste into Treasure: Radiation Byproduct-Induced Fe(III)/Fe(II) Conversion for Efficient Ferroptosis to Improve Iodine-131-Based Transarterial Radioembolization for Liver Tumors

Transarterial radioembolization (TARE) is a primary palliative treatment for advanced liver cancer. Nonetheless, its therapeutic efficacy is frequently hindered by resistance to tumor cell apoptosis induced by inter-radiotherapy. Induction of multiple cell death modalities provides a potential solution to this challenge. Ferroptosis, a distinct form of cell death from apoptosis, is dependent on the intracellular Fe2+-mediated Fenton reaction for the production of hydroxyl radicals (·OH) and is gaining recognition as a promising approach for cancer treatment. In this study, we synthesized a therapeutic radionuclide iodine-131 (131I)-based TARE agent by combining 131I-labeled iron-based MIL-88B(Fe) nanoparticles (NPs) (abbreviated as 131I-MIL-88B(Fe)) with Lipiodol to achieve a combined apoptosis-ferroptosis tumor therapy. Specifically, a mixture of Lipiodol and 131I-MIL-88B(Fe) NPs was injected into the liver tumors through the hepatic artery. Lipiodol blocks the arterial blood supply of the tumor, causing tumor tissue necrosis, whereas 131I inter-radiotherapy damages deoxyribonucleic acid (DNA) through direct action or indirectly via the production of ·OH through H2O radiolysis, leading to tumor cell apoptosis. Importantly, hydrated electrons (eaq-), a byproduct of H2O radiolysis, promoted the conversion of Fe3+ to Fe2+ in MIL-88B(Fe) NPs, enhancing the efficacy of the Fenton reaction and triggering ferroptosis. In vitro experiments demonstrated that compared to 131I alone, 131I-MIL-88B(Fe) NPs significantly enhanced ferroptosis-mediated tumor cell death due to 131I-induced Fe2+ production, which increased catalytic activity in the Fenton reaction. In a rat model bearing orthotopic N1S1 liver tumors, TARE with Lipiodol and 131I-MIL-88B(Fe) NPs induced tumor cell necrosis, apoptosis, and ferroptosis, resulting in improved therapeutic outcomes. This study leverages eaq- to facilitate Fe3+/Fe2+ conversion for efficient ferroptosis, turning waste into a valuable resource. This demonstrated the innovative integration of multiple treatment strategies to augment the efficacy of TARE in liver cancer therapy.

Disrupting lipid homeostasis with CAV2 in OSCC triggers apoptosis, lipolysis, and mitochondrial dysfunction by transcriptional repression of PPARγ

BACKGROUND

Abnormal lipid droplet (LD) dynamics in oral squamous cell carcinoma (OSCC) indicate lipid metabolism alterations that facilitate malignancy progression. However, the specific mechanisms by which disruptions in lipid homeostasis affect malignancy processes remain poorly understood. This study investigated the role of LD-associated protein Caveolin2 (CAV2) in OSCC lipid homeostasis and progression.

METHODS

The clinical relevance of CAV2 in OSCC was assessed through transcriptomics, single-cell sequencing, and functional validation in OSCC cells. CAV2 knockdown via shRNA was used to analyze its effects on growth, apoptosis, lipid homeostasis, and mitochondrial function. RNA sequencing, lipidomics, and molecular docking elucidated mechanisms of lipid metabolic disruption. Lipolysis was evaluated via glycerol release, lipidomics, and expression of related genes and proteins. Seahorse assays were used to evaluate mitochondrial dysfunction by analyzing mitochondrial respiration, while additional experiments assessed ROS levels, MMP, morphology, mass, and organelle interactions. In vivo, studies examined tumor progression in nude mice implanted with CAV2-knockdown OSCC cells. The regulatory role of PPARγ on CAV2 was explored through bioinformatics, correlation analysis, and dual-luciferase assays. Coimmunoprecipitation assessed CAV2 and NCOR1 binding with PPARγ, while the PPARγ inverse agonist T0070907 was used to enhance NCOR1-mediated repression of CAV2.

RESULTS

CAV2 was upregulated in OSCC and correlated with poor clinical outcomes. CAV2 knockdown increased apoptosis, reduced proliferation, and disrupted lipid homeostasis, elevating polyunsaturated fatty acids (PUFAs). Regulatory networks responsible for PUFA accumulation were mapped in CAV2-knockdown OSCC cells, from upstream regulators to downstream effects. Furthermore, lipolysis and mitochondrial dysfunction were also enhanced following CAV2 silencing. In vivo, CAV2 knockdown suppressed OSCC progression. Mechanistically, PPARγ regulated CAV2 transcription via NCOR1, but OSCC cells disrupted this repression. The PPARγ inverse agonist T0070907 restored NCOR1-mediated repression, synergistically enhancing the effects of CAV2 knockdown on apoptosis, lipolysis, and mitochondrial dysfunction.

CONCLUSIONS

Alteration of CAV2 disrupted lipid homeostasis and inhibited OSCC progression by affecting key processes, including apoptosis, lipolysis, and mitochondrial dysfunction. The disruption was driven by the dysregulation of the PPARγ/NCOR1 axis, highlighting the potential of targeting CAV2 and its interaction with PPARγ as a therapeutic strategy for OSCC.

Dynamic regulation and targeted interventions of macrophages in ischemia-reperfusion injury

BACKGROUND

Ischemia-Reperfusion Injury (IRI) is a complex pathophysiological process characterized by oxidative stress and inflammatory responses during tissue reperfusion, leading to severe organ dysfunction. Macrophages, as key immune cells, play a pivotal role in the pathogenesis of IRI, exhibiting dynamic functions that influence both tissue damage and repair. Despite extensive research, the precise mechanisms underlying macrophage-mediated IRI remain incompletely understood, necessitating a comprehensive review to explore their multifaceted roles and potential therapeutic targets.

AIM OF REVIEW

This review aims to elucidate the diverse roles of macrophages in IRI, focusing on their involvement in programmed cell death mechanisms, communication with other immune cells, and regulatory effects on key organs affected by IRI. The review also explores potential therapeutic strategies targeting macrophages to mitigate IRI-induced injury. Key Scientific Concepts of Review: This article reviews the multifaceted roles of macrophages in IRI and explores various modes of macrophage programmed cell death induced by IRI, including gasdermin D-mediated pyroptosis, lipid peroxidation-associated ferroptosis, PARP-1-mediated PAR-dependent cell death, PANoptosis regulated by the PANoptosome, and the formation of macrophage extracellular traps (METs) induced by both reactive oxygen species-dependent and -independent pathways. Additionally, it discusses intercellular communication between macrophages and other immune cells in IRI, focusing on the bidirectional regulatory effects between macrophages and neutrophils, as well as their synergistic role in resolving inflammation. Moreover, the regulatory mechanisms of macrophages in IRI affecting key organs, such as the brain, lung, heart, kidneys and liver, have been systematically summarized. Finally, innovative therapeutic strategies targeting macrophages, including precise approaches such as regulating cell polarization, inhibiting excessive METs formation, and utilizing nano-drug delivery systems, are thoroughly analyzed. This review provides a significant theoretical foundation for clinical translational research on IRI.

Inhalable biomimetic polyunsaturated fatty acid-based nanoreactors for peroxynitrite-augmented ferroptosis potentiate radiotherapy in lung cancer

The limited efficacy and poor tumor accumulation remain crucial challenges for radiotherapy against lung cancer. To address these limitations, we rationally developed a polyunsaturated fatty acid (PUFA)-based nanoreactor (DHA-N@M) camouflaged with macrophage cell membrane to improve tumoral distribution and achieve peroxynitrite-augment ferroptosis for enhanced radiotherapy against lung cancer. After nebulization, the nanoreactors exhibited superior pulmonary accumulation in orthotopic lung cancer-bearing mice, with 70-fold higher than intravenously injected nanoreactors at 12 h post-administration, and distributed deeply in the tumors. DHA-N@M selectively released nitric oxide (NO) in glutathione (GSH)-enriched tumor cells, with consumption of GSH and subsequent inactivation of glutathione peroxidase 4 (GPX4). Under radiation, NO reacted with radiotherapy-induced reactive oxygen species (ROS) to generate peroxynitrite (ONOO-), resulting in redox homeostasis disruption. Combined with docosahexaenoic acid (DHA)-induced lipid metabolism disruption, overwhelming ferroptosis was induced both in vitro and in vivo. Notably, DHA-N@M mediated ferroptosis-radiotherapy significantly suppressed tumor growth with a 93.91% inhibition in orthotopic lung cancer models. Therefore, this design provides a nebulized ferroptosis-radiotherapy strategy for lung cancer.

Charged dendrimers reduce glioblastoma viability by modulating lysosomal activity and HMGB1-RAGE interaction

Dendrimers and dendrimer-based self-assembly systems have emerged as promising nanocarriers for a variety of applications, including anti-cancer therapies, modulation of the tumor microenvironment, and imaging. Here, we explored the therapeutic potential of two charged dendrimers, dendritic polyglycerol sulfate (dPGS) and dendritic polyglycerol amine (dPGA), in the context of glioblastoma multiforme (GBM). Docosahexaenoic acid (DHA) has shown potential in GBM. We therefore examined dPGS and dPGA effects alone and in combination with DHA. Using 2D cell models and 3D tumoroids, we showed that DHA with dPGA reduced tumor integrity and cell viability. dPGS reduced oxidative stress, whereas dPGA reduced lysosomal acidification, contributing to cellular dysfunction. Both dendrimers influence the interaction between high mobility group box 1 (HMGB1) and the receptor for advanced glycation end products (RAGE). The surfaces of the HMGB1-RAGE complex provide binding sites for interactions of charged molecules like dPGS and dPGA, suggesting the contribution of these interactions to cytotoxicity. In summary, our findings show that combining DHA with charged dendrimers (dPGS and dPGA) enhances GBM cytotoxicity through several mechanisms, involving lysosomal alkalinization, lipid peroxidation and modulation of the HMGB1-RAGE complex.

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.

Omega-3 polyunsaturated fatty acids alleviate renal fibrosis in chronic kidney disease by reducing macrophage activation and infiltration through the JAG1-NOTCH1/2 pathway

In recent years, the global incidence of chronic kidney disease (CKD) has been rising. As CKD progresses, it frequently involves inflammatory cell infiltration, contributing to renal fibrosis. Current research indicates that abnormalities in lipid metabolism play a role in this fibrotic process. However, the specific effects of various dietary fatty acids on renal inflammation and fibrosis remains largely unexplored. Our study demonstrates that dietary intake of omega-3 polyunsaturated fatty acids can inhibit macrophage activation and infiltration in a mouse model of unilateral ureteral obstruction (UUO), thus reducing the severity of renal fibrosis. Omega-3 polyunsaturated fatty acids, particularly α-linolenic acid (α-LA), mitigate damage to HK-2 cells and macrophages by targeting the JAG1-NOTCH1/2 pathway and by downregulating the expression of the chemokine MCP-1 and its receptor CCR2. This modulation attenuates macrophage activation and infiltration, reducing the inflammatory response. Furthermore, these fatty acids inhibit fibroblast chemotaxis, reduce fibroblast activation, and mitigate the deposition of extracellular matrix (ECM), thus slowing the progression of renal fibrosis. Our findings underscore the protective effects of omega-3 polyunsaturated fatty acids, such as α-LA, in preventing injury, inhibiting macrophage activation, and alleviating fibrosis. These results suggests that adjusting the dietary balance of fatty acids may offer a promising strategy to enhance the efficacy of CKD treatment.

Peroxisomal membrane protein PMP70 confers drug resistance in colorectal cancer

Metabolic reprogramming is a key contributor to cancer therapeutic resistance. Peroxisomes are highly metabolic organelles essential for lipid metabolism and reactive oxygen species (ROS) turnover. Recent studies pointed out that targeting peroxisomal genes could be a promising strategy for treating therapy-resistant cells. However, the role of peroxisomes in CRC chemoresistance remains largely unexplored. This study aimed to investigate the function of peroxisomes in CRC chemoresistance and uncover the underlying mechanisms. Our results showed that the protein level of peroxisome marker PMP70 was strongly correlated with oxaliplatin (LOHP)-treated tumor recurrence in CRC. LOHP was confirmed to induce pexophagy in CRC cells, whereas LOHP-resistant cells maintained stable peroxisome levels and resisted this selective autophagy. Moreover, depletion of PMP70 significantly reduced the viability of resistant CRC cells in response to LOHP, both in vitro and in vivo. Mechanistically, PMP70 acted as a potential protector against excessive lipid peroxidation (LPO) in PMP70High and LOHP-resistant CRC cells. Additionally, PMP70-depleted cells exhibited an altered metabolic profile, characterized by reduced neutral lipids, fewer lipid droplets (LDs), and cell cycle arrest, indicating that PMP70 downregulation resulted in metabolic impairment. In conclusion, our study unveiled the pivotal role of PMP70-mediated peroxisomal functions in conferring chemoresistance, particularly in the context of LOHP resistance in CRC.

Mechanisms of ferroptosis sensitization and resistance

Ferroptosis is an iron-dependent and oxidative form of non-apoptotic cell death with roles in development, homeostasis, and disease. Ferroptosis sensitivity can vary between cells, often for reasons that are not well understood. In this perspective, we describe the core ferroptosis mechanism and outline how changes in iron, redox, and lipid metabolism can alter ferroptosis sensitivity. We propose the concept of a ferroptosis sensitivity-resistance continuum to describe how different intrinsic and extrinsic factors interact to push cells toward a more ferroptosis-sensitive or ferroptosis-resistant state, with effects on development and diseases such as cancer.

Jacaric Acid Empowers RSL3-Induced Ferroptotic Cell Death in Two- and Three-Dimensional Breast Cancer Cell Models

Ferroptosis has recently emerged as a promising strategy to combat therapy-resistant cancers. As lipid peroxidation is a key trigger of ferroptotic cell death, enhancing cancer cell susceptibility through the supply of highly peroxidisable fatty acids represents a novel therapeutic approach. Conjugated linolenic acids (CLnAs) fulfill this requirement, exhibiting a peroxidation propagation rate eight times higher than their non-conjugated counterpart, α-linolenic acid. This study evaluates jacaric acid (JA), a plant-derived CLnA, as a ferroptotic inducer, both as a monotherapy and in combination with RAS-selective lethal 3 (RSL3), a canonical ferroptosis inducer, in 2D and 3D breast cancer cell models. JA treatment significantly reduced cell viability across all models, primarily through lipid peroxidation driven by JA incorporation into cellular lipids rather than alterations in anti-ferroptotic gene expression. Moreover, JA synergistically enhanced RSL3 cytotoxicity under 2D and several 3D conditions. Similar effects were observed with punicic acid, another plant-derived CLnA isomer. Our study exploits a common feature of cancer metabolism, increased fatty acid uptake, to turn it into a vulnerability. The incorporation of JA into breast cancer cells creates a highly peroxidisable environment that increases cancer cell sensitivity to RSL3, potentially reducing required doses and minimising side effects.

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.

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.

PRMT5-mediated arginine methylation stabilizes GPX4 to suppress ferroptosis in cancer

The activation of ferroptosis has shown great potential for cancer therapy from an unconventional perspective, but revealing the mechanisms underlying the suppression of tumour-intrinsic ferroptosis to promote tumorigenesis remains a challenging task. Here we report that methionine is metabolized into S-adenosylmethionine, which functions as a methyl-group donor to trigger symmetric dimethylation of glutathione peroxidase 4 (GPX4) at the conserved arginine 152 (R152) residue, along with a prolonged GPX4 half-life. Inhibition of protein arginine methyltransferase 5 (PRMT5), which catalyses GPX4 methylation, decreases GPX4 protein levels by impeding GPX4 methylation and increasing ferroptosis inducer sensitivity in vitro and in vivo. This methylation prevents Cullin1-FBW7 E3 ligase binding to GPX4, thereby abrogating the ubiquitination-mediated GPX4 degradation. Notably, combining PRMT5 inhibitor treatment with ferroptotic therapies markedly suppresses tumour progression in mouse tumour models. In addition, the levels of GPX4 are negatively correlated with the levels of FBW7 and a poor prognosis in patients with human carcinoma. In summary, we found that PRMT5 functions as a target for improving cancer therapy efficacy, by acting to reduce the counteraction of ferroptosis by tumour cells by means of PRMT5-enhanced GPX4 stability.

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.

PLAGL2-STAU1-NCOA4 axis enhances gastric cancer peritoneal metastasis by resisting ferroptosis via ferritinophagy

Peritoneal metastasis (PM) is the primary site of distant metastasis in gastric cancer (GC) and is associated with an advanced disease stage and poor prognosis. Due to its high resistance to chemotherapy, disseminated peritoneal lesions are often untreatable. A primary reason for therapy resistance in cancer cells is often their defective cell death execution mechanisms. Ferroptosis, a newly identified type of regulated cell death, is strongly linked to the emergence and formation of tumors. Earlier studies have demonstrated the significant role of RNA-binding proteins in ferroptosis. Nevertheless, the fundamental process linking Staufen Double-Stranded RNA Binding Protein 1 (STAU1) to ferroptosis in the peritoneal metastasis of gastric cancer is yet to be clarified. This study shows that the RNA-binding protein STAU1 is crucial for regulating ferroptosis in gastric cancer cells. Elevated levels of STAU1 are linked to unfavorable outcomes in individuals diagnosed with gastric cancer. STAU1 was up-regulated by PLAGL2 and decreased the stability of NCOA4 mRNA by binding to the 3'-untranslated region. Decreased NCOA4 expression inhibits the accumulation of reactive iron, the occurrence of the Fenton reaction, and cellular ROS generation in the GC cells. Additionally, we showed that NCOA4 is crucial in the process of ferritinophagy triggered by the reduction of STAU1 in gastric cancer cells. Ultimately, the process safeguards GC cells from ferroptosis. These findings elucidate the function of PLAGL2/STAU1/NCOA4 in the ferroptosis of gastric cancer cells and provide theoretical backing for possible diagnostic markers and treatment targets for peritoneal metastasis in gastric cancer.

Acidosis overrides molecular heterogeneity to shape therapeutically targetable metabolic phenotypes in colon cancers

Colorectal cancer (CRC) represents a prototypical example of a cancer type for which inter- and intra-tumor heterogeneities remain major challenges for the clinical management of patients. Besides genotype-mediated phenotypic alterations, tumor microenvironment (TME) conditions are increasingly recognized to promote intrinsic diversity and phenotypic plasticity and sustain disease progression. In particular, acidosis is a common hallmark of solid tumors, including CRC, and it is known to induce aggressive cancer cell phenotypes. In this study, we report that long-term adaptation to acidic pH conditions is associated with common metabolic alterations, including a glycolysis-to-respiration switch and a higher reliance on the activity of phosphoglycerate dehydrogenase (PHGDH), in CRC cells initially displaying molecularly heterogeneous backgrounds. Pharmacological inhibition of PHGDH activity or mitochondrial respiration induces greater growth-inhibitory effects in acidosis-exposed CRC cells in 2D and 3D culture conditions, and in patient-derived CRC organoids. These data pave the way for drugs targeting the acidic tumor compartment as a "one-size-fits-all" therapeutic approach to delay CRC progression.

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.

Tools to Dissect Lipid Droplet Regulation, Players, and Mechanisms

Spurred by the authors' own recent discovery of reactive metabolite-regulated nexuses involving lipid droplets (LDs), this perspective discusses the latest knowledge and multifaceted approaches toward deconstructing the function of these dynamic organelles, LD-associated localized signaling networks, and protein players. Despite accumulating knowledge surrounding protein families and pathways of conserved importance for LD homeostasis surveillance and maintenance across taxa, much remains to be understood at the molecular level. In particular, metabolic stress-triggered contextual changes in LD-proteins' localized functions, crosstalk with other organelles, and feedback signaling loops and how these are specifically rewired in disease states remain to be illuminated with spatiotemporal precision. We hope this perspective promotes an increased interest in these essential organelles and innovations of new tools and strategies to better understand context-specific LD regulation critical for organismal health.

Tumor microenvironment acidosis favors pancreatic cancer stem cell properties and in vivo metastasis

The acidic tumor microenvironment (TME) favors cancer aggressiveness via incompletely understood pathways. Here, we asked whether adaptation to environmental acidosis (pH 6.5) selects for human pancreatic cancer stem cell (CSC) properties. RNA sequencing (RNA-seq) of acid-adapted (AA) Panc-1 cells revealed CSC pathway enrichment and upregulation of CSC markers. AA Panc-1 cells exhibited classical CSC characteristics including increased aldehyde dehydrogenase (ALDH) activity and β-catenin activity. Panc-1, PaTu8988s, and MiaPaCa-2 cells all exhibited increased pancreatosphere-forming efficiency after acid adaptation but differed in CSC marker expression and did not exhibit typical flow cytometric CSC populations. However, single-nucleus sequencing revealed the acid adaptation-induced emergence of Panc-1 cell subpopulations with clear CSC characteristics. In orthotopic mouse tumors, AA Panc-1 cells exhibited enhanced aggressiveness, liver and lung metastasis, compared to controls. Collectively, our work suggests that acid adaptation enriches for pancreatic CSC phenotypes with unusual traits via several trajectories, providing new insight into how acidic microenvironments favor cancer aggressiveness.

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.

Lipid metabolism: the potential therapeutic targets in glioblastoma

Glioblastoma is a highly malignant tumor of the central nervous system with a high mortality rate. The mechanisms driving glioblastoma onset and progression are complex, posing substantial challenges for developing precise therapeutic interventions to improve patient survival. Over a century ago, the discovery of the Warburg effect underscored the importance of abnormal glycolysis in tumors, marking a pivotal moment in cancer research. Subsequent studies have identified mitochondrial energy conversion as a fundamental driver of tumor growth. Recently, lipid metabolism has emerged as a critical factor in cancer cell survival, providing an alternative energy source. Research has shown that lipid metabolism is reprogrammed in glioblastoma, playing a vital role in shaping the biological behavior of tumor cells. In this review, we aim to elucidate the impact of lipid metabolism on glioblastoma tumorigenesis and explore potential therapeutic targets. Additionally, we provide insights into the regulatory mechanisms that govern lipid metabolism, emphasizing the critical roles of key genes and regulators involved in this essential metabolic process.

The Impact of Polyunsaturated Fatty Acids in Cancer and Therapeutic Strategies

PURPOSE OF REVIEW

Cancer is a disease influenced by both genetic and environmental factors, with dietary lipids being a significant contributing factor. This review summarizes the role of polyunsaturated fatty acids (PUFAs) in the mechanism of tumor occurrence and development, and elucidate the role of PUFAs in tumor treatment.

RECENT FINDINGS

PUFAs exert their impact on cancer through altering lipid composition in cell membranes, interacting with cell membrane lipid receptors, directly modulating gene expression in the cell nucleus, and participating in the metabolism of lipid mediators. Most omega-3 PUFAs are believed to inhibit cell proliferation, promote cancer cell death, suppress cancer metastasis, alter energy metabolism, inhibit tumor microenvironment inflammation, and regulate immune responses involving macrophages, T cells, NK cells, and others. However, certain omega-6 PUFAs exhibit weaker anti-tumor effects and may even promote tumor development, such as by fostering inflammatory tumor microenvironment and enhancing tumor cell proliferation. PUFAs play important roles in hallmarks of cancer including tumor cell proliferation, cell death, migration and invasion, energy metabolism remodeling, epigenetics, and immunity. These findings provide insights into the mechanisms of cancer development and offers options for dietary management of cancer.

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.

Gallic acid alleviates ferroptosis by negatively regulating APOC3 and improves nerve function deficit caused by traumatic brain injury

Traumatic brain injury (TBI) is more common than ever and is becoming a global public health issue. A variety of secondary brain injuries occur after TBI, including ferroptosis characterized by iron-dependent lipid peroxidation. Gallic acid is a kind of traditional Chinese medicine, which has many biological effects such as anti-inflammatory and antioxidant. We further investigated whether Gallic acid can improve the neurological impairment caused by ferroptosis after TBI by targeting APOC3. Weighted gene coexpression network analyses (WGCNA) and 3 kinds of machine-learning algorithms were used to find the potential biomarkers. Then the HERB database was used to select the Chinese herb that acted on the target gene APOC3. Finally, we selected Gallic acid as a drug targeting APOC3 and verified by Western blotting. The effect of Gallic acid on the improvement of neurological function was studied by Nissl staining and FJB staining. Finally, the effect of Gallic acid on the cognitive ability of TBI mice was explored through behavioral experiments. Gallic acid can inhibit the expression level of APOC3 and thus inhibit the level of ferroptosis after TBI. It can also reduce the degeneration of nerve tissue by inhibiting ferroptosis and improve the neurological function deficit. The behavioral experiment proved that Gallic acid can alleviate the behavioral cognitive impairment caused by TBI. Gallic acid can reduce ferroptosis by inhibiting APOC3, and then alleviate neurological impairment after TBI.

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

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

Adipocyte-derived ferroptotic signaling mitigates obesity

Ferroptosis is characterized as an iron-dependent and lipophilic form of cell death. However, it remains unclear what role ferroptosis has in adipose tissue function and activity. Here, we find a lower ferroptotic signature in the adipose tissue of individuals and mice with obesity. We further find that activation of ferroptotic signaling by a non-lethal dose of ferroptosis agonists significantly reduces lipid accumulation in primary adipocytes and high-fat diet (HFD)-fed mice. Notably, adipocyte-specific overexpression of acyl-coenzyme A synthetase long-chain family member 4 (Acsl4) or deletion of ferritin heavy chain (Fth) protects mice from HFD-induced adipose expansion and metabolic disorders via activation of ferroptotic signaling. Mechanistically, we find that 5,15-dihydroxyeicosatetraenoic acid (5,15-DiHETE) activates ferroptotic signaling, resulting in the degradation of hypoxia-inducible factor-1α (HIF1α), thereby derepressing a thermogenic program regulated by the c-Myc-peroxisome proliferator-activated receptor gamma coactivator-1 beta (Pgc1β) pathway. Our findings suggest that activating ferroptosis signaling in adipose tissues might help to prevent and treat obesity and its related metabolic disorders.

Mechanism of Guishao Yigong decoction in treating colorectal cancer based on network pharmacology and experimental validation

OBJECTIVES

To explore the effective components of Guishao Yigong decoction (GYD) in the treatment of colorectal cancer and reveal its potential mechanism of action.

METHODS

Through network pharmacology, the main target and signaling pathway of GYD therapy for colorectal cancer (CRC) were found. Subsequently, the effect of GYD was verified by in vitro cell viability measurements, colony formation, and scratch healing tests. The effects of GYD on metabolic pathways in vivo were found through plasma metabolomics. Finally, flow cytometry and qPCR experiments were used to verify the cycle-blocking effect of GYD on CRC cells.

KEY FINDINGS

Based on the network pharmacological analysis and molecular docking technology, it was found that GYD could restrain the growth of CRC cells by affecting lipid metabolic pathways and mitogen-activated protein kinase (MAPK) signaling pathways. A series of cell experiments showed that GYD could inhibit the proliferation, migration and clonogenic ability of CRC cells. Furthermore, the plasma metabolomics results showed that GYD could affect the production of unsaturated fatty acids in mice. Flow cytometry and qPCR experiments further proved that GYD blocked the CRC cells in the G1 phase and modulated the expression of cell cycle-related targets, such as AKT, TP53, CDKN1A, and CDK2.

CONCLUSIONS

All the results indicated that GYD could regulate the related metabolism of unsaturated fatty acids. Thus, the cell cycle was blocked and the expressions of the key proteins such as AKT and TP53 were regulated, which achieved the purpose of intervention in colorectal cancer.

Hypoxia-responsive micelles deprive cofactor of stearoyl-CoA desaturase-1 and sensitize ferroptotic ovarian cancer therapy

Ferroptosis has been recognized as a promising therapeutic strategy for cancer due to its unique mechanism of action. However, the upregulation of stearoyl-CoA desaturase 1 (SCD1) in ovarian cancer leads to resistance to ferroptotic therapy. Zinc ion (Zn2+) serves as the cofactor of SCD1. It was hypothesized that selective deprivation of Zn2+ from SCD1 could sensitize ferroptotic ovarian cancer therapy. Here, we report a hypoxia-responsive polymer micelle for enhanced ferroptosis of ovarian cancer cells. A SCD1 inhibitor, PluriSIn 1 (Plu), and a ferroptosis inducer, Auranofin (Aur), were co-encapsulated in nitroimidazole-bearing micelles. Under the hypoxic tumor microenvironment, the conversion of nitroimidazole to aminoimidazole triggered the cargo release and induced the depletion of antioxidant molecules (e.g., glutathione, thioredoxin, and NADPH). Meanwhile, because of the strong coordination between aminoimidazole and Zn2+ compared to that of histidine and Zn2+, such conversion can deprive the metal cofactor of SCD1, hence sensitizing the action of Plu and Aur. The proof-of-concept was demonstrated in cell and animal models with minimal systemic toxicity. The current work integrates ferroptosis induction with SCD1 inhibition in a hypoxia-responsive vehicle, offering a promising strategy for addressing the ferroptosis resistance and opening novel avenues for managing the difficult-to-treat ovarian cancer.

Acceptor Elongation Boosted Intersystem Crossing Affords Efficient NIR Type-I and AIE-Active Photosensitizers for Targeting Ferroptosis-Based Cancer Therapy

Photosensitizers (PSs) featuring type I reactive oxygen species (ROS) generation and aggregation-induced emission (AIE) activity offer a promising solution to achieve non-invasive and precise theranostics. However, the reported AIE luminogens (AIEgens) with both AIE characteristic and strong type-I ROS generation are still scarce and the structure-property relationship is still unclear. Herein, an innovative acceptor elongation boosted intersystem crossing (AEBIC) design strategy has been proposed to endow the AIEgen strong type-I ROS producibility. The results indicate that the obtained AIEgen exhibit type-I ROS and aggregation-enhanced ROS efficacy, which has been verified by both experimental and theoretical results. Mechanistic study reveal that the acceptor elongation has promoted a dual-channel intersystem crossing pathway to enhance the intersystem crossing (ISC) process due to the differences in triplet configurations, which can be further amplified by aggregation. The afforded type-I AIE-PS show lipid droplet-anchored characteristic and can induce the ferroptosis through destroying the cellular redox homeostasis and increasing lethal levels of lipid peroxidation. Finally, targeting ferroptosis-based cancer therapy can be realized with excellent anti-tumor effect.

Orchestrated desaturation reprogramming from stearoyl-CoA desaturase to fatty acid desaturase 2 in cancer epithelial-mesenchymal transition and metastasis

BACKGROUND

Adaptative desaturation in fatty acid (FA) is an emerging hallmark of cancer metabolic plasticity. Desaturases such as stearoyl-CoA desaturase (SCD) and fatty acid desaturase 2 (FADS2) have been implicated in multiple cancers, and their dominant and compensatory effects have recently been highlighted. However, how tumors initiate and sustain their self-sufficient FA desaturation to maintain phenotypic transition remains elusive. This study aimed to explore the molecular orchestration of SCD and FADS2 and their specific reprogramming mechanisms in response to cancer progression.

METHODS

The potential interactions between SCD and FADS2 were explored by bioinformatics analyses across multiple cancer cohorts, which guided subsequent functional and mechanistic investigations. The expression levels of desaturases were investigated with online datasets and validated in both cancer tissues and cell lines. Specific desaturation activities were characterized through various isomer-resolved lipidomics methods and sensitivity assays using desaturase inhibitors. In-situ lipid profiling was conducted using multiplex stimulated Raman scattering imaging. Functional assays were performed both in vitro and in vivo, with RNA-sequencing employed for the mechanism verification.

RESULTS

After integration of the RNA-protein-metabolite levels, the data revealed that a reprogramming from SCD-dependent to FADS2-dependent desaturation was linked to cancer epithelial-mesenchymal transition (EMT) and progression in both patients and cell lines. FADS2 overexpression and SCD suppression concurrently maintained EMT plasticity. A FADS2/β-catenin self-reinforcing feedback loop facilitated the degree of lipid unsaturation, membrane fluidity, metastatic potential and EMT signaling. Moreover, SCD inhibition triggered a lethal apoptosis but boosted survival plasticity by inducing EMT and enhancing FA uptake via adenosine monophosphate-activated protein kinase activation. Notably, this desaturation reprogramming increased transforming growth factor-β2, effectively sustaining aggressive phenotypes and metabolic plasticity during EMT.

CONCLUSIONS

These findings revealed a metabolic reprogramming from SCD-dependent to FADS2-dependent desaturation during cancer EMT and progression, which concurrently supports EMT plasticity. Targeting desaturation reprogramming represents a potential vulnerability for cancer metabolic therapy.

Crosstalk between gut microbiotas and fatty acid metabolism in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy globally and the second leading cause of cancer-related mortality. Its development is a multifactorial and multistage process influenced by a dynamic interplay between gut microbiota, environmental factors, and fatty acid metabolism. Dysbiosis of intestinal microbiota and abnormalities in microbiota-associated metabolites have been implicated in colorectal carcinogenesis, highlighting the pivotal role of microbial and metabolic interactions. Fatty acid metabolism serves as a critical nexus linking dietary patterns with gut microbial activity, significantly impacting intestinal health. In CRC patients, reduced levels of short-chain fatty acids (SCFAs) and SCFA-producing bacteria have been consistently observed. Supplementation with SCFA-producing probiotics has demonstrated tumor-suppressive effects, while therapeutic strategies aimed at modulating SCFA levels have shown potential in enhancing the efficacy of radiation therapy and immunotherapy in both preclinical and clinical settings. This review explores the intricate relationship between gut microbiota, fatty acid metabolism, and CRC, offering insights into the underlying mechanisms and their potential translational applications. Understanding this interplay could pave the way for novel diagnostic, therapeutic, and preventive strategies in the management of CRC.

Muscle loss in cancer cachexia: what is the basis for nutritional support?

Cancer cachexia (CC) is characterized by significant skeletal muscle wasting, and contributes to diminished quality of life, while being associated with poorer response to treatment and with reduced survival. Chronic inflammation plays a central role in driving CC progression, within a complex interplay favoring catabolism. Although cachexia cannot be fully reversed by conventional nutritional support, nutritional intervention shows promise for the prevention and treatment of the syndrome. Of special interest are nutrients with antioxidant and anti-inflammatory potential and those that activate pathways involved in muscle mass synthesis and/or in the inhibition of muscle wasting. Extensive research has been carried out on novel nutritional supplements' power to mitigate CC impact, while the mechanisms through which some nutrients or bioactive compounds exert beneficial effects on muscle mass are still not totally clear. Here, we discuss the most studied supplements and nutritional strategies for dealing with muscle loss in CC.

Medium-Chain Fatty Acids Selectively Sensitize Cancer Cells to Ferroptosis by Inducing CD36 and ACSL4

BACKGROUND

Inducing ferroptosis in cancer cells is a promising therapeutic strategy. It has been shown that certain types of fatty acids can induce ferroptosis in multiple types of cancer cells.

METHODS

Here, we employed crystal violet staining and CCK8 to assess cell viability, a Liperfluo probe and commercial kit to measure lipid peroxides, and western blotting and RNA interference to detect protein levels.

RESULTS

This study demonstrates for the first time that the medium-chain fatty acids lauric acid (LA-m), octanoic acid (OA-m), and decanoic acid (DA-m) selectively sensitize various cancer cell types to ferroptosis induced by either RSL3, a well-known inducer of ferroptosis, or linoleic acid (LA-l), a ω-6 polyunsaturated fatty acid (PUFA). Mechanistically, the ferroptosis-sensitizing effect of medium-chain fatty acids is associated with their ability to upregulate cluster of differentiation 36 (CD36) and acyl-CoA synthetase long-chain family member 4 (ACSL4) expression.

CONCLUSIONS

These findings suggest that medium-chain fatty acids could be developed as novel ferroptosis sensitizers to enhance ferroptosis-based cancer therapy.

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.

Reprogramming of fatty acid metabolism: a hidden force regulating the occurrence and progression of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a malignant tumor that originates from the bile duct epithelium and with a poor outcome due to lack of effective early diagnostic methods. Surgical resection is the preferred method for cure, but treatment options are limited for advanced diseases, such as distant metastatic or locally progressive tumors. Therefore, it is urgent to explore other new treatment methods. As modern living standards rise, the acceptance of high-fat, high-protein, and high-carbohydrate diets is growing among the public, and the resulting metabolic abnormalities are intimately linked to the initiation and spread of tumors. Metabolic reprogramming is a key mechanism in the process of tumor development and progression and is closely related to cancer cell proliferation, metastasis and drug resistance. Fatty acid (FA) metabolism, an integral component of cancer cell metabolism, can provide an energy source for cancer cells and participate in cell signaling, the regulation of the immune response and the maintenance of homeostasis of the internal environment, which are closely linked to the development and progression of CCA. Therefore, a better understanding of FA metabolism may provide promising strategies for early diagnosis, prognostic assessment and targeted therapy for CCA patients. In this paper, we review the effects of FA metabolism on CCA development and progression, summarize related mechanisms and the existing clinical applications of targeted lipid metabolism in CCA, and explore new targets for CCA metabolic therapy.

Advances in understanding ferroptosis mechanisms and their impact on immune cell regulation and tumour immunotherapy

Ferroptosis is a novel mode of iron-dependent non-apoptotic cell death that occurs mainly due to excessive accumulation of lipid peroxides. Numerous studies in recent years have shown that ferroptosis plays a vital role in the organism and has important interactions with immune cells. Ferroptosis has been shown to have great potential in tumour therapy through studying its mechanism of action. In addition, ferroptosis plays a major role in many types of tumour cells that can potently suppress the tumourigenesis and metastasis, provide a basis for the treatment of many malignant tumour diseases and become a novel therapeutic modality of antitumour immunity in the clinic. Current tumour immunotherapy for ferroptosis in combination with other conventional oncological modalities is not well elaborated. In this paper, we mainly discuss the connection of ferroptosis with immune cells and their mediated tumour immunotherapy in order to provide a better theoretical basis and new thinking about ferroptosis mediated antitumour immunity.

TIPE Inhibits Ferroptosis in Colorectal Cancer Cells by Regulating MGST1/ALOX5

TIPE is a protein highly expressed in various cancers that promotes ferroptosis in colorectal cancer cells. Ferroptosis is a nonapoptotic cell death caused by lipid peroxidation, and microsomal glutathione transferase 1 (MGST1) is a critical enzyme that resists lipid peroxidation. This study explored how TIPE regulates MGST1 expression to inhibit ferroptosis and promote colorectal cancer proliferation. TIPE was highly expressed in colorectal cancer tissues and positively correlated with the proliferation of human colorectal cancer cells. We measured levels of reactive oxygen species and lipid reactive oxygen species in colorectal cancer cells with differential expression of TIPE and detected ferroptosis using transmission electron microscopy. Bioinformatics analysis revealed a positive correlation of expression patterns between TIPE and MGST1 in colorectal cancer. TIPE regulated the expression of MGST1 by activating the phosphorylation of ERK1/2. Coimmunoprecipitation revealed binding between MGST1 and ALOX5. This binding inhibited the phosphorylation of ALOX5, inhibiting ferroptosis and promoting the proliferation of colorectal cancer cells. A tumor formation experiment in nude mice supported our findings that TIPE regulates the proliferation of colorectal cancer by regulating ferroptosis. Implications: TIPE inhibits colorectal cancer ferroptosis via an MGST1-ALOX5 interaction to promote colorectal cancer proliferation. These findings suggest future colorectal cancer treatment strategies.

Lipid metabolism in ferroptosis: Unraveling key mechanisms and therapeutic potential in cancer

Ferroptosis, a form of iron-dependent cell death driven by lipid peroxidation, has emerged as a critical area of research for cancer therapy. This review delves into the intricate relationship between lipid metabolism and ferroptosis, emphasizing the impact of lipidome remodeling on cancer cell susceptibility. We explore key mechanisms, such as the role of polyunsaturated fatty acids and phosphatidylethanolamines in ferroptosis induction, alongside the protective effects of monounsaturated fatty acids and their regulatory enzymes. We also discuss the influence of dietary fatty acids, lipid droplets, and the epithelial-to-mesenchymal transition on ferroptosis and cancer resistance. By integrating current findings on enzymatic regulation, lipid peroxidation pathways, and metabolic adaptations, this review highlights potential therapeutic strategies targeting lipid metabolism to enhance ferroptosis-based cancer treatments. Our goal is to provide a comprehensive overview that underscores the significance of lipid metabolic pathways in ferroptosis and their implications for developing novel cancer therapies.

PPARα-mediated lipid metabolism reprogramming supports anti-EGFR therapy resistance in head and neck squamous cell carcinoma

Anti-epidermal growth factor receptor (EGFR) therapy (cetuximab) shows a limited clinical benefit for patients with locally advanced or recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), due to the frequent occurrence of secondary resistance mechanisms. Here we report that cetuximab-resistant HNSCC cells display a peroxisome proliferator-activated receptor alpha (PPARα)-mediated lipid metabolism reprogramming, with increased fatty acid uptake and oxidation capacities, while glycolysis is not modified. This metabolic shift makes cetuximab-resistant HNSCC cells particularly sensitive to a pharmacological inhibition of either carnitine palmitoyltransferase 1A (CPT1A) or PPARα in 3D spheroids and tumor xenografts in mice. Importantly, the PPARα-related gene signature, in human clinical datasets, correlates with lower response to anti-EGFR therapy and poor survival in HNSCC patients, thereby validating its clinical relevance. This study points out lipid metabolism rewiring as a non-genetic resistance-causing mechanism in HNSCC that may be therapeutically targeted to overcome acquired resistance to anti-EGFR therapy.

Exogenous dihomo-γ-linolenic acid triggers ferroptosis via ACSL4-mediated lipid metabolic reprogramming in acute myeloid leukemia cells

Ferroptosis is a novel type of programmed cell death caused by excessive iron-dependent lipid peroxidation. According to various studies, there may be a link between ferroptosis and lipid metabolism. However, few studies have been reported on the lipid metabolism of ferroptosis in acute myeloid leukemia (AML). Here, we analyzed the relationship between lipid metabolism and ferroptosis in AML cells to explore new clinical treatment strategies. This study found that 12 fatty acids were significantly changed in acute myeloid leukemia cell ferroptosis, including dihomo-γ-linolenic acid (DGLA), arachidonic acid (AA), docosahexaenoic acid (DHA), etc. Exogenous DGLA substantially increases the sensitivity to ferroptosis and induces ferroptosis alone in AML cells. In addition, acyl-CoA synthetase long-chain family member 4 (ACSL4) knockout significantly inhibited DGLA-induced AML cells ferroptosis, and ACSL4 regulates DGLA-associated lipid synthesis to affect the sensitivity of AML cells to ferroptosis. Collectively, our studies indicate that a DGLA-enriched diet significantly restricted the growth of leukemia cells as well as induced ferroptosis in vivo.