The Lipogenic Regulator SREBP2 Induces Transferrin in Circulating Melanoma Cells and Suppresses Ferroptosis

Modeling a mesenchymal cell state by bioprinting for the molecular analysis of dormancy in melanoma

Malignant melanoma is a highly aggressive tumor originating from the pigment producing cells, the melanocytes. It accounts for the majority of skin cancer related deaths worldwide. This is often due to the development of therapy resistance or tumor dormancy, eventually resulting in tumor relapse by yet undefined mechanisms. Tumor dormancy is thought to be mediated by the cellular microenvironment and models taking this factor into account are urgently needed. We 3D bioprinted melanoma cells in the hydrogels Cellink Bioink (CIB) or Matrigel (MG), each as a substitute of the extracellular matrix, and, thereby, induced a quiescent or a proliferative phenotype of the melanoma cell lines, respectively. RNA-Seq with subsequent comprehensive bioinformatical and molecular analyses assigned CIB-cultured cells to a predominantly mesenchymal and Matrigel-cultured cells to a more mitotic phenotype, emphasizing the CIB model as a suitable platform for the investigation of dormancy under consideration of the microenvironment. Melanoma cells in CIB 3D culture reflect a quiescent and migratory active cell state e.g. by revealing significant downregulation of genes associated with replication and cell cycle progression in this setting. Using this model system, we identified the mechanosensory gene FHL2 as one early sensor of changes in the ECM and suggest a FHL2-p21/AP-1 axis contributing to the dormant phenotype of melanoma cells in CIB.

Extracellular vesicles derived from bone marrow mesenchymal stem cells regulate SREBF2/HMGB1 axis by transporting miR-378a-3p to inhibit ferroptosis in intestinal ischemia-reperfusion injury

Intestinal ischemia-reperfusion (II/R) injury represents a life-threatening and complex pathophysiological process that remains challenging to treat clinically, and emerging evidence suggests that ferroptosis plays an essential role in its pathogenesis. This study aimed to investigate whether extracellular vesicles derived from bone marrow mesenchymal stem cells (BMSC-EVs) can mitigate II/R-induced ferroptosis in a murine model. Using a bioinformatics database, we initially identified genes with abnormal expression patterns in II/R injury. Then, we confirmed the association between II/R injury, ferroptosis, and the HMGB1/SREBF2 axis through in vivo and in vitro experiments. To determine the role of HMGB1 in hypoxia/reoxygenation (H/R)-induced ferroptosis in Caco-2 cells, we transfected cells with either sh-HMGB1 or control sh-NC constructs and developed an H/R model in vitro. Subsequently, we examined factors regulating HMGB1-mediated ferroptosis in Caco-2 cells and assessed the effect of BMSC-EVs on this process. To further explore the mechanism underlying the protective effects of BMSC-EVs in II/R injury, we screened for miRNAs with reduced expression during II/R and verified their involvement. Among these, miR-378a-3p was identified as a candidate for regulating ferroptosis. To confirm its functional role, we treated II/R mice with BMSC-EVs overexpressing miR-378a-3p and assessed the outcomes. Our findings revealed that HMGB1, which is a key regulatory factor of ferroptosis, was significantly upregulated during II/R injury, and its knockdown alleviated H/R-induced ferroptosis in Caco-2 cells. We also found that SREBF2 directly regulates HMGB1 expression to promote H/R-induced ferroptosis in vitro. Importantly, BMSC-EVs alleviated II/R injury by suppressing ferroptosis in Caco-2 cells, and mechanistically, miR-378a-3p, a miRNA derived from BMSC-EVs, inhibited II/R-induced ferroptosis by modulating the SREBF2/HMGB1 axis. In conclusion, BMSC-EVs may exert protective effects against II/R injury by delivering miR-378a-3p, which regulates the SREBF2/HMGB1 axis to suppress ferroptosis, providing important insights into the pathological mechanisms underlying II/R injury and potential therapeutic strategies for its management.

The culture and application of circulating tumor cell-derived organoids

Circulating tumor cells (CTCs), which have the heterogeneity and histological properties of the primary tumor and metastases, are shed from the primary tumor and/or metastatic lesions into the vasculature and initiate metastases at remote sites. In the clinic, CTCs are used extensively in liquid biopsies for early screening, diagnosis, treatment, and prognosis. Current research focuses on using CTC-derived models to study tumor heterogeneity and metastasis, with 3D organoids emerging as a promising tool in cancer research and precision oncology. However, isolating and enriching CTCs from blood remains challenging due to their scarcity, exacerbated by the lack of an optimized culture medium for CTC-derived organoids (CTCDOs). In this review, we summarize the origin, isolation, enrichment, culture, validation, and clinical application of CTCs and CTCDOs.

TF and TFRC regulate ferroptosis in swine testicular cells through the JNK signaling pathway

Transferrin (TF) is a serum glycoprotein that plays a critical role in iron metabolism and typically functions through binding to its transferrin receptor (TFRC). TF is also considered a key indicator of sperm quality and, together with TFRC, plays a critical role in regulating spermatogenesis. This study aimed to explore the effects of increased TF and TFRC expression on ferroptosis in swine testicular cells (ST cells). Our findings revealed that the overexpression of either TF or TFRC diminishes ST cell viability, increases cytotoxicity, intensifies oxidative stress damage, decreases mitochondrial activity, and promotes ferroptosis. Transcriptomic analysis suggested that TF and TFRC may influence ST cells through the MAPK signaling pathway. Subsequent experiments revealed that inhibiting the JNK signaling pathway within the MAPK pathway improved mitochondrial activity, reduced oxidative stress damage, and mitigated ferroptosis progression. Moreover, we discovered that TF and TFRC might regulate cellular oxidative phosphorylation via the JNK signaling pathway. In conclusion, increased expression of TF or TFRC increases the sensitivity of ST cells to ferroptosis and modulates mitochondrial DNA transcription and energy metabolism through the JNK signaling pathway. These findings could offer potential therapeutic targets for addressing reproductive toxicity associated with ferroptosis.

TRIM8 enhances chondrocyte ferroptosis by inhibiting YTHDF2-m6A mediated SREBF2 mRNA degradation to promote OA progression

Chondrocyte ferroptosis plays a crucial role in osteoarthritis (OA) progression. Our previous study demonstrated that TRIM8 knockdown alleviated IL-1β-induced chondrocyte injury. However, the involvement of TRIM8 in regulating OA progression through ferroptosis remains unclear. In this study, human OA and normal cartilage samples were collected to examine ferroptosis and TRIM8 expression. We found that both ferroptosis markers and TRIM8 protein levels were elevated in OA cartilage compared to controls. An OA cell model was established by stimulating chondrocytes with IL-1β. TRIM8 knockdown mitigated IL-1β-induced ferroptosis, extracellular matrix (ECM) degradation, and inflammation in chondrocytes. Mechanistically, TRIM8 facilitated the ubiquitylation of YTHDF2 via its RING domain, promoting YTHDF2 protein degradation. This inhibited YTHDF2-m6A-induced SREBF2 mRNA degradation, thereby upregulating SREBF2 expression and enhancing chondrocyte ferroptosis. As expected, SREBF2 overexpression reversed the protective effect of TRIM8 silencing on IL-1β-induced chondrocyte injury. An OA mouse model was established using destabilized medial meniscus surgery, and TRIM8 deficiency alleviated cartilage degradation and synovial inflammation. In conclusion, TRIM8 promotes chondrocyte ferroptosis by suppressing YTHDF2-m6A mediated SREBF2 mRNA degradation, thereby accelerating OA progression.

SREBP2 as a central player in cancer progression: potential for targeted therapeutics

Recent studies have identified the reprogramming of lipid metabolism as a critical hallmark of malignancy. Enhanced cholesterol uptake and increased cholesterol biosynthesis significantly contribute to the rapid growth of tumors, with cholesterol also playing essential roles in cellular signaling pathways. Targeting cholesterol metabolism has emerged as a promising therapeutic strategy in oncology. The sterol regulatory element-binding protein-2 (SREBP2) serves as a primary transcriptional regulator of genes involved in cholesterol biosynthesis and is crucial for maintaining cholesterol homeostasis. Numerous studies have reported the upregulation of SREBP2 across various cancers, facilitating tumor progression. This review aims to provide a comprehensive overview of the structure, biological functions, and regulatory mechanisms of SREBP2. Furthermore, we summarize that SREBP2 plays a crucial role in various cancers and tumor microenvironment primarily by regulating cholesterol, as well as through several non-cholesterol pathways. We also particularly emphasize therapeutic agents targeting SREBP2 that are currently under investigation. This review seeks to enhance our understanding of SREBP2's involvement in cancer and provide theoretical references for cancer therapies that target SREBP2.

Cell Death Modalities in Therapy of Melanoma

Melanoma, one of the most lethal cancers, demands urgent and effective treatment strategies. However, a successful therapeutic approach requires a precise understanding of the mechanisms underlying melanoma initiation and progression. This review provides an overview of melanoma pathogenesis, identifies current pathogenic factors contributing to mortality, and explores targeted therapy and checkpoint inhibitor therapy. Furthermore, we examine melanoma classification and corresponding therapies, along with advancements in various cell death mechanisms for melanoma treatment. We also discuss the current treatment status along with some drawbacks encountered during research stages such as resistance and metastasis.

TCGEx: a powerful visual interface for exploring and analyzing cancer gene expression data

Analyzing gene expression data from the Cancer Genome Atlas (TCGA) and similar repositories often requires advanced coding skills, creating a barrier for many researchers. To address this challenge, we developed The Cancer Genome Explorer (TCGEx), a user-friendly, web-based platform for conducting sophisticated analyses such as survival modeling, gene set enrichment analysis, unsupervised clustering, and linear regression-based machine learning. TCGEx provides access to preprocessed TCGA data and immune checkpoint inhibition studies while allowing integration of user-uploaded data sets. Using TCGEx, we explore molecular subsets of human melanoma and identify microRNAs associated with intratumoral immunity. These findings are validated with independent clinical trial data on immune checkpoint inhibitors for melanoma and other cancers. In addition, we identify cytokine genes that can be used to predict treatment responses to various immune checkpoint inhibitors prior to treatment. Built on the R/Shiny framework, TCGEx offers customizable features to adapt analyses for diverse research contexts and generate publication-ready visualizations. TCGEx is freely available at https://tcgex.iyte.edu.tr , providing an accessible tool to extract insights from cancer transcriptomics data.

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.

Ferritinophagy: a possible new iron-related metabolic target in canine osteoblastic osteosarcoma

Canine osteosarcomas (COS) are the most common bone tumors in dogs, characterized by high metastatic rates, poor prognosis, and poor responsiveness to routine therapies, which highlights the need for new treatment targets. In this context, the metabolism of neoplastic cells represents an increasingly studied element, as cancer cells depend on particular metabolic pathways that are also elements of vulnerability. Among these, tumor cells (TCs) show higher iron requirements to sustain proliferation (so-called iron addiction), which are achieved by increasing iron uptake and/or by activating ferritinophagy, a process mediated by the Nuclear receptor Co-Activator 4 (NCOA4) leading to iron mobilization from ferritin (Ft) deposits. Previous studies have shown that COS cells overexpress Transferrin Receptor 1 (TfR1) to increase iron uptake. In this study we evaluated the immunohistochemical expression of ferritinophagy-related proteins, namely Ferritin Heavy chain (FTH1) and NCOA4, and proliferating cell nuclear antigen (PCNA) in canine normal bone and canine osteoblastic osteosarcoma (COOS) samples. Normal samples revealed negative/weak immunoreactivity for FTH1, NCOA4 and PCNA in <10% of osteocytes. In COOS samples the majority of neoplastic cells showed immunoreactivity to FTH1, NCOA4 and PCNA. Our data suggest that the activation of ferritinophagy by COOS cells responds to the need for feed their "iron addiction." These data, though preliminary, further suggest that targeting iron metabolism represents a new potential strategy worthy of further study to be transferred into clinical practice.

Multi-Omics Analysis of the Anoikis Gene CASP8 in Prostate Cancer and Biochemical Recurrence (BCR)

Background: Prostate cancer, as an androgen-dependent malignant tumor in older men, has attracted the attention of a wide range of clinicians. BCR remains a significant challenge following early prostate cancer treatment. Methods: The specific expression pattern of the Anoikis gene set in prostate cancer cells was first explored by single-cell and spatial transcriptomics analysis. Genes causally associated with prostate cancer were screened using Summary-data-based Mendelian Randomization (SMR). Subsequently, we explored the role and mechanism of CASP8 in prostate cancer cells and defined a new cell type: the CASP8 T cell. We constructed a prediction model that can better predict the BCR of prostate cancer, and explored the differences in various aspects of clinical subgroups, tumor microenvironments, immune checkpoints, drug sensitivities, and tumor-immune circulations between high- and low-risk groups. The results of SMR analysis indicated that CASP8 could increase the risk of prostate cancer. Based on the differential genes of CASP8-positive and -negative T cells, we constructed a four-gene prognostic model with a 5-year AUC of 0.713. Results: The results revealed that high-risk prostate cancer BCR patients had various characteristics such as higher tumor purity, higher BCR rate, downregulated SIRPA immune checkpoints, and unique drug sensitivity. Conclusions: In summary, CASP8 may be a potential biomarker for prostate cancer.

Interactions of Fatty Acid and Cholesterol Metabolism with Cellular Stress Response Pathways in Cancer

Lipids have essential functions as structural components of cellular membranes, as efficient energy storage molecules, and as precursors of signaling mediators. While deregulated glucose and amino acid metabolism in cancer have received substantial attention, the roles of lipids in the metabolic reprogramming of cancer cells are less well understood. However, since the first description of de novo fatty acid biosynthesis in cancer tissues almost 70 years ago, numerous studies have investigated the complex functions of altered lipid metabolism in cancer. Here, we will summarize the mechanisms by which oncogenic signaling pathways regulate fatty acid and cholesterol metabolism to drive rapid proliferation and protect cancer cells from environmental stress. The review also discusses the role of fatty acid metabolism in metabolic plasticity required for the adaptation to changing microenvironments during cancer progression and the connections between fatty acid and cholesterol metabolism and ferroptosis.

Selenoprotein O Promotes Melanoma Metastasis and Regulates Mitochondrial Complex II Activity

Evolutionarily conserved selenoprotein O (SELENOO) catalyzes a posttranslational protein modification known as AMPylation that is essential for the oxidative stress response in bacteria and yeast. Given that oxidative stress experienced in the blood limits survival of metastasizing melanoma cells, SELENOO might be able to affect metastatic potential. However, further work is needed to elucidate the substrates and functional relevance of the mammalian homolog of SELENOO. In this study, we revealed that SELENOO promotes cancer metastasis and identified substrates of SELENOO in mammalian mitochondria. In patients with melanoma, high SELENOO expression was correlated with metastasis and poor overall survival. In a murine model of spontaneous melanoma metastasis, SELENOO deficiency significantly reduced metastasis to distant visceral organs, which could be rescued by treatment with the antioxidant N-acetylcysteine. Mechanistically, SELENOO AMPylated multiple mitochondrial substrates, including succinate dehydrogenase subunit A, one of the four key subunits of mitochondrial complex II. Consistently, SELENOO-deficient cells featured increased mitochondrial complex II activity. Together, these findings demonstrate that SELENOO deficiency limits melanoma metastasis by modulating mitochondrial function and oxidative stress. Significance: SELENOO alters mitochondrial function and supports metastasis in melanoma, highlighting the impact of SELENOO-mediated posttranslational modification of mitochondrial substrates and selenoproteins in cancer progression.

Ferroptosis in Osteoarthritis: Towards Novel Therapeutic Strategy

Osteoarthritis (OA) is a chronic, degenerative joint disease primarily characterised by damage to the articular cartilage, synovitis and persistent pain, and has become one of the most common diseases worldwide. In OA cartilage, various forms of cell death have been identified, including apoptosis, necroptosis and autophagic cell death. Ever-growing observations indicate that ferroptosis, a newly-discovered iron-dependent form of regulated cell death, is detrimental to OA occurrence and progression. In this review, we first analyse the pathogenetic mechanisms of OA by which iron overload, inflammatory response and mechanical stress contribute to ferroptosis. We then discuss how ferroptosis exacerbates OA progression, focusing on its impact on chondrocyte viability, synoviocyte populations and extracellular matrix integrity. Finally, we highlight several potential therapeutic strategies targeting ferroptosis that could be explored for the treatment of OA.

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

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

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

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

Epigenetic Control of Redox Pathways in Cancer Progression

Significance: Growing evidence indicates the importance of redox reactions homeostasis, mediated predominantly by reactive oxygen species (ROS) in influencing the development, differentiation, progression, metastasis, programmed cell death, tumor microenvironment, and therapeutic resistance of cancer. Therefore, reviewing the ROS-linked epigenetic changes in cancer is fundamental to understanding the progression and prevention of cancer. Recent Advances: We review in depth the molecular mechanisms involved in ROS-mediated epigenetic changes that lead to alteration of gene expression by altering DNA, modifying histones, and remodeling chromatin and noncoding RNA. Critical Issues: In cancerous cells, alterations of the gene-expression regulatory elements could be generated by the virtue of imbalance in tumor microenvironment. Various oxidizing agents and mitochondrial electron transport chain are the major pathways that generate ROS. ROS plays a key role in carcinogenesis by activating pro-inflammatory signaling pathways and DNA damage. This loss of ROS-mediated epigenetic regulation of the signaling pathways may promote tumorigenesis. We address all such aspects in this review. Future Directions: Developments in this growing field of epigenetics are expected to contribute to further our understanding of human health and diseases such as cancer and to test the clinical applications of redox-based therapy. Recent studies of the cancer-epigenetic landscape have revealed pervasive deregulation of the epigenetic factors in cancer. Thus, the study of interaction between ROS and epigenetic factors in cancer holds a great promise in the development of effective and targeted treatment modalities. Antioxid. Redox Signal. 00, 000-000.

Transferrin Disassociates TCR from CD3 Signaling Apparatus to Promote Metastasis

Immune recognition and activation by the peptide-laden major histocompatibility complex-T cell receptor (TCR)-CD3 complex is essential for anti-tumor immunity. Tumors may escape immune surveillance by dissembling the complex. Here, we report that transferrin, which is overexpressed in patients with liver metastasis, disassociates TCR from the CD3 signaling apparatus by targeting the constant domain (CD) of T cell receptor α (TCRα), consequently suppresses T cell activation, and inhibits anti-metastatic and anti-tumor immunity. In mouse models of melanoma and lymphoma, transferrin overexpression exacerbates liver metastasis, while its knockdown, antibody, designed peptides, and CD mutation interfering with transferrin-TCRα interaction inhibit metastasis. This work reveals a novel strategy of tumor evasion of immune surveillance by blocking the coupling between TCRs and the CD3 signaling apparatus to suppress TCR activation. Given the conservation of CD and transferrin up-regulation in metastatic tumors, the strategy might be a common metastatic mechanism. Targeting transferrin-TCRα holds promise for anti-metastatic treatment.

Liquid Biopsy and Multidisciplinary Treatment for Esophageal Cancer

Esophageal cancer (EC) is one of the leading causes of cancer-related deaths globally. Surgery is the standard treatment for resectable EC after preoperative chemoradiotherapy or chemotherapy, followed by postoperative adjuvant chemotherapy in certain cases. Upper gastrointestinal endoscopy and computed tomography (CT) are predominantly performed to evaluate the efficacy of these treatments, but their sensitivity and accuracy for evaluating minimal residual disease remain unsatisfactory, thereby requiring the development of alternative methods. In recent years, interest has been increasing in using liquid biopsy to assess treatment responses. Liquid biopsy is a noninvasive technology for detecting cell components in the blood and other body fluids. It involves collecting a small sample of body fluid, which is then analyzed for the presence of components, including circulating tumor DNA (ctDNA), microRNA (miRNA), or circulating tumor cells (CTCs). Further, ctDNA and miRNA are analyzed with various techniques, including digital polymerase chain reaction (dPCR) and next-generation sequencing (NGS). CTCs are isolated by determining surface antigens using immunomagnetic techniques or by filtering the blood according to cell size and rigidity. Several studies indicate that investigating these materials helps predict EC prognosis and recurrence and possibly stratifies high-risk groups. Liquid biopsy may also apply to the selection of cases that have achieved a complete response through preoperative treatment to prevent surgery and preserve the esophagus, as well as identifying the suitability of postoperative chemotherapy and the timing of conversion surgery for unresectable EC. The potential of liquid biopsy to enhance treatment decisions will further advance EC treatment.

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.

Tumor cell-based liquid biopsy using high-throughput microfluidic enrichment of entire leukapheresis product

Circulating Tumor Cells (CTCs) in blood encompass DNA, RNA, and protein biomarkers, but clinical utility is limited by their rarity. To enable tumor epitope-agnostic interrogation of large blood volumes, we developed a high-throughput microfluidic device, depleting hematopoietic cells through high-flow channels and force-amplifying magnetic lenses. Here, we apply this technology to analyze patient-derived leukapheresis products, interrogating a mean blood volume of 5.83 liters from seven patients with metastatic cancer. High CTC yields (mean 10,057 CTCs per patient; range 100 to 58,125) reveal considerable intra-patient heterogeneity. CTC size varies within patients, with 67% overlapping in diameter with WBCs. Paired single-cell DNA and RNA sequencing identifies subclonal patterns of aneuploidy and distinct signaling pathways within CTCs. In prostate cancers, a subpopulation of small aneuploid cells lacking epithelial markers is enriched for neuroendocrine signatures. Pooling of CNV-confirmed CTCs enables whole exome sequencing with high mutant allele fractions. High-throughput CTC enrichment thus enables cell-based liquid biopsy for comprehensive monitoring of cancer.

Sterols in ferroptosis: from molecular mechanisms to therapeutic strategies

Ferroptosis, a novel cell death mode driven by iron-dependent phospholipid (PL) peroxidation, has emerged as a promising therapeutic strategy for the treatments of cancer, cardiovascular diseases, and ischemic-reperfusion injury (IRI). PL peroxidation, the key process of ferroptosis, requires polyunsaturated fatty acid (PUFA)-containing PLs (PL-PUFAs) as substrates, undergoing a chain reaction with iron and oxygen. Cells prevent ferroptosis by maintaining a homeostatic equilibrium among substrates, processes, and detoxification of PL peroxidation. Sterols, lipids abundant in cell membranes, directly participate in PL peroxidation and influence ferroptosis sensitivity. Sterol metabolism also plays a key role in ferroptosis, and targeting sterols presents significant potential for treating numerous ferroptosis-associated disorders. This review elucidates the fundamental mechanisms of ferroptosis, emphasizing how sterols modulate this process and their therapeutic potential.

The interplay between cell death and senescence in cancer

Cellular senescence is a state of permanent proliferative arrest that occurs in response to DNA damage-inducing endogenous and exogenous stresses, and is often accompanied by dynamic molecular changes such as a senescence-associated secretory phenotype (SASP). Accumulating evidence indicates that age-associated increases in the upstream and downstream signals of regulated cell death, including apoptosis, necroptosis, pyroptosis, and ferroptosis, are closely related to the induction of cellular senescence and its phenotype. Furthermore, elevated levels of pro-inflammatory SASP factors with aging can be both a cause and consequence of several cell death modes, suggesting the reciprocal effects of cellular senescence and cells undergoing regulated cell death. Here, we review the critical molecular pathways of the regulated cell death forms and describe the crosstalk between aging-related signals and cancer. In addition, we discuss how targeting regulated cell death could be harnessed in therapeutic interventions for cancer. ABBREVIATIONS: Abbreviations that are not standard in this field are defined at their first occurrence in the article and are used consistently throughout the article.

Circulating Tumor Cells Culture: Methods, Challenges, and Clinical Applications

Circulating tumor cells (CTCs) play a pivotal role in cancer metastasis and hold considerable potential for clinical diagnosis, therapeutic monitoring, and prognostic evaluation. Nevertheless, the limited quantity of CTCs in liquid biopsy samples poses challenges for comprehensive downstream analysis. In vitro culture of CTCs can effectively address the issue of insufficient CTC numbers. Furthermore, research based on CTC cell lines serves as a valuable complement to traditional cancer cell line-based research. While numerous reports exist on CTC in vitro culture and even the establishment of CTC cell lines, the methods used vary, leading to disparate culture outcomes. This review presents the developmental history and current status of CTC in vitro culture research. Additionally, the culture strategies applied in different methods and analyzed the impact of various steps on culture outcomes are compared. Overall, the review indicates that while the short-term culture of CTCs is relatively straightforward, long-term culture success has been achieved for various specific cancer types but still faces challenges. Further optimization of efficient and widely applicable culture strategies is needed. Additionally, ongoing applications of CTC in vitro culture are summarized, highlighting the potential of expanded CTCs for drug susceptibility testing and as therapeutic tools in personalized treatment.

Biofluorescence imaging-guided spatial metabolic tracing: In vivo tracking of metabolic activity in circulating tumor cell-mediated multi-organ metastases

Circulating tumor cells (CTC) are considered metastatic precursors that are shed from the primary or metastatic deposits and navigate the bloodstream before undergoing extravasation to establish distant metastases. Metabolic reprogramming appears to be a hallmark of metastatic progression, yet current methods for evaluating metabolic heterogeneity within organ-specific metastases in vivo are limited. To overcome this challenge, we present Biofluorescence Imaging-Guided Spatial Metabolic Tracing (BIGSMT), a novel approach integrating in vivo biofluorescence imaging, stable isotope tracing, stain-free laser capture microdissection, and liquid chromatography-mass spectrometry. This innovative technology obviates the need for staining or intricate sample preparation, mitigating metabolite loss, and substantially enhances detection sensitivity and accuracy through chemical derivatization of polar metabolites in central carbon pathways. Application of BIGSMT to a preclinical CTC-mediated metastasis mouse model revealed significant heterogeneity in the in vivo carbon flux from glucose into glycolysis and the tricarboxylic acid (TCA) cycle across distinct metastatic sites. Our analysis indicates that carbon predominantly enters the TCA cycle through the enzymatic reaction catalyzed by pyruvate dehydrogenase. Thus, our spatially resolved BIGSMT technology provides fresh insights into the metabolic heterogeneity and evolution during melanoma CTC-mediated metastatic progression and points to novel therapeutic opportunities.

Sphingolipid metabolism and regulated cell death in malignant melanoma

Malignant melanoma (MM) is a highly invasive and therapeutically resistant skin malignancy, posing a significant clinical challenge in its treatment. Programmed cell death plays a crucial role in the occurrence and progression of MM. Sphingolipids (SP), as a class of bioactive lipids, may be associated with many kinds of diseases. SPs regulate various forms of programmed cell death in tumors, including apoptosis, necroptosis, ferroptosis, and more. This review will delve into the mechanisms by which different types of SPs modulate various forms of programmed cell death in MM, such as their regulation of cell membrane permeability and signaling pathways, and how they influence the survival and death fate of MM cells. An in-depth exploration of the role of SPs in programmed cell death in MM aids in unraveling the molecular mechanisms of melanoma development and holds significant importance in developing novel therapeutic strategies.

Propafenone facilitates mitochondrial-associated ferroptosis and synergizes with immunotherapy in melanoma

BACKGROUND

Despite the successful application of immunotherapy, both innate and acquired resistance are typical in melanoma. Ferroptosis induction appears to be a potential strategy to enhance the effectiveness of immunotherapy. However, the relationship between the status of ferroptosis and the effectiveness of immunotherapy, as well as viable strategies to augment ferroptosis, remains unclear.

METHODS

A screening of 200 cardiovascular drugs obtained from the Food and Drug Administration-approved drug library was conducted to identify the potential ferroptosis sensitizer. In vitro and in vivo experiments explored the effects of propafenone on ferroptosis in melanoma. Animal models and transcriptomic analyses evaluated the therapeutic effects and survival benefits of propafenone combined with immune checkpoint blockades (ICBs). The relationship between propafenone targets and the efficacy of ICBs was validated using the Xiangya melanoma data set and publicly available clinical data sets.

RESULTS

Through large-scale drug screening of cardiovascular drugs, we identified propafenone, an anti-arrhythmia medication, as capable of synergizing with ferroptosis inducers in melanoma. Furthermore, we observed that propafenone, in combination with glutathione peroxidase 4 inhibitor RSL3, collaboratively induces mitochondrial-associated ferroptosis. Mechanistically, propafenone transcriptionally upregulates mitochondrial heme oxygenase 1 through the activation of the Jun N-terminal kinase (JNK)/JUN signaling pathway under RSL3 treatment, leading to overloaded ferrous iron and reactive oxygen species within the mitochondria. In xenograft models, the combination of propafenone and ferroptosis induction led to nearly complete tumor regression and prolonged survival. Consistently, propafenone enhances immunotherapy-induced tumorous ferroptosis and antitumor immunity in tumor-bearing mice. Significantly, patients exhibiting high levels of ferroptosis/JUN/HMOX1 exhibited improved efficacy of immunotherapy and prolonged progression-free survival.

CONCLUSIONS

Taken together, our findings suggest that propafenone holds promise as a candidate drug for enhancing the efficacy of immunotherapy and other ferroptosis-targeted therapies in the treatment of melanoma.

Detection of circulating tumor cells in peripheral blood of patients with tongue squamous cell carcinoma and its relationship with clinical features and prognosis: a retrospective study

BACKGROUND

Circulating tumor cells (CTCs) are a promising biomarker for assessment of prognosis. The study was to analyse the relationship between preoperative and postoperative peripheral blood CTC and clinical features and prognosis in patients with tongue squamous cell carcinoma (TSCC).

METHODS

85 with TSCC and 30 tongues with benign disease who underwent surgical treatment from May 2016 to May 2023 were retrospectively analysed. CTC testing was performed twice for TSCC group before and after surgery and only before the surgery for the benign disease group, only one test was performed before surgery.The association of CTCs with clinical features and progression-free survival (PFS) was also analyzed.

RESULTS

The positive rates of CTCs in patients with TSCC were 90.6% before treatment and 72.9% after treatment, respectively. CTCs were not detected in patients with benign disease group before treatment. There was no significant difference in the number of CTCs before and after treatment in patients with disease progression (P > 0.05). However, the number of CTCs after treatment in patients with disease remission (DR) and stable disease (SD) was significantly lower than before treatment, and the difference was statistically significant (P < 0.05). The results of the log-rank test demonstrated that the postoperative CTC was associated with the PFS (P < 0.05), whereas the preoperative CTC was not related to the PFS. The Cox proportional hazard regression model indicated that postoperative CTC and lymph node metastasis were independent risk factors.

CONCLUSIONS

Postoperative CTCs may be an independent risk factor for a poor prognosis in patients with TSCC and CTC may serve as a valuable biomarker for prognostic monitoring for TSCC patients.

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.

Overexpression of NUDT16L1 sustains proper function of mitochondria and leads to ferroptosis insensitivity in colorectal cancer

Cancer research is continuously exploring new avenues to improve treatments, and ferroptosis induction has emerged as a promising approach. However, the lack of comprehensive analysis of the ferroptosis sensitivity in different cancer types has limited its clinical application. Moreover, identifying the key regulator that influences the ferroptosis sensitivity during cancer progression remains a major challenge. In this study, we shed light on the role of ferroptosis in colorectal cancer and identified a novel ferroptosis repressor, NUDT16L1, that contributes to the ferroptosis insensitivity in this cancer type. Mechanistically, NUDT16L1 promotes ferroptosis insensitivity in colon cancer by enhancing the expression of key ferroptosis repressor and mitochondrial genes through direct binding to NAD-capped RNAs and the indirect action of MALAT1. Our findings also reveal that NUDT16L1 localizes to the mitochondria to maintain its proper function by preventing mitochondrial DNA leakage after treatment of ferroptosis inducer in colon cancer cells. Importantly, our orthotopic injection and Nudt16l1 transgenic mouse models of colon cancer demonstrated the critical role of NUDT16L1 in promoting tumor growth. Moreover, clinical specimens revealed that NUDT16L1 was overexpressed in colorectal cancer, indicating its potential as a therapeutic target. Finally, our study shows the therapeutic potential of a NUDT16L1 inhibitor in vitro, in vivo and ex vivo. Taken together, these findings provide new insights into the crucial role of NUDT16L1 in colorectal cancer and highlight its potential as a promising therapeutic target.

Noncoding RNAs regulating ferroptosis in cardiovascular diseases: novel roles and therapeutic strategies

The morbidity and mortality rates of cardiovascular diseases (CVDs) are increasing; thus, they impose substantial health and economic burdens worldwide, and effective interventions are needed for immediate resolution of this issue. Recent studies have suggested that noncoding RNAs (ncRNAs) play critical roles in the occurrence and development of CVDs and are potential therapeutic targets and novel biomarkers for these diseases. Newly discovered modes of cell death, including necroptosis, pyroptosis, apoptosis, autophagy-dependent cell death and ferroptosis, also play key roles in CVD progression. However, ferroptosis, which differs from the other aforementioned forms of regulated cell death in terms of cell morphology, biochemistry and inhereditability, is a unique iron-dependent mode of nonapoptotic cell death induced by abnormal iron metabolism and excessive accumulation of iron-dependent lipid peroxides and reactive oxygen species (ROS). Increasing evidence has confirmed that ncRNA-mediated ferroptosis is involved in regulating tissue homeostasis and CVD-related pathophysiological conditions, such as cardiac ischemia/reperfusion (I/R) injury, myocardial infarction (MI), atrial fibrillation (AF), cardiomyopathy and heart failure (HF). In this review, we summarize the underlying mechanism of ferroptosis, discuss the pathophysiological effects of ncRNA-mediated ferroptosis in CVDs and provide ideas for effective therapeutic strategies.

Ferroptosis in glioma therapy: advancements in sensitizing strategies and the complex tumor-promoting roles

Ferroptosis, an iron-dependent form of non-apoptotic regulated cell death, is induced by the accumulation of lipid peroxides on cellular membranes. Over the past decade, ferroptosis has emerged as a crucial process implicated in various physiological and pathological systems. Positioned as an alternative modality of cell death, ferroptosis holds promise for eliminating cancer cells that have developed resistance to apoptosis induced by conventional therapeutics. This has led to a growing interest in leveraging ferroptosis for cancer therapy across diverse malignancies. Gliomas are tumors arising from glial or precursor cells, with glioblastoma (GBM) being the most common malignant primary brain tumor that is associated with a dismal prognosis. This review provides a summary of recent advancements in the exploration of ferroptosis-sensitizing methods, with a specific focus on their potential application in enhancing the treatment of gliomas. In addition to summarizing the therapeutic potential, this review also discusses the intricate interplay of ferroptosis and its potential tumor-promoting roles within gliomas. Recognizing these dual roles is essential, as they could potentially complicate the therapeutic benefits of ferroptosis. Exploring strategies aimed at circumventing these tumor-promoting roles could enhance the overall therapeutic efficacy of ferroptosis in the context of glioma treatment.

ELK4 targets CHMP6 to inhibit ferroptosis and enhance malignant properties of skin cutaneous melanoma cells

Ferroptosis, a key factor in tumor progression, is poorly understood at the molecular level. This study investigates how ELK4 and CHMP6 regulate skin cutaneous melanoma (SKCM) cell proliferation and ferroptosis. Analysis of TCGA data reveals high expression of ELK4 and CHMP6 in SKCM. Overexpression of ELK4 or CHMP6 enhances cell proliferation, invasion, and migration while reducing ROS and Fe2 + levels. It also increases GPX4 and xCT expression and decreases ACSL4 levels in SKCM cells. The opposite effects are observed with ELK4 or CHMP6 knockdown. ELK4 binds to the CHMP6 promoter, promoting CHMP6 transcription. Knockdown of CHMP6 reverses the oncogenic effects of ELK4 overexpression. In conclusion, ELK4 enhances proliferation, invasion, and migration while inhibiting ferroptosis in SKCM cells by upregulating CHMP6 transcription. This study sheds light on the intricate mechanisms involved in SKCM progression and identifies potential therapeutic targets in melanoma treatment.

Survival mechanisms of circulating tumor cells and their implications for cancer treatment

Metastasis remains the principal trigger for relapse and mortality across diverse cancer types. Circulating tumor cells (CTCs), which originate from the primary tumor or its metastatic sites, traverse the vascular system, serving as precursors in cancer recurrence and metastasis. Nevertheless, before CTCs can establish themselves in the distant parenchyma, they must overcome significant challenges present within the circulatory system, including hydrodynamic shear stress (HSS), oxidative damage, anoikis, and immune surveillance. Recently, there has been a growing body of compelling evidence suggesting that a specific subset of CTCs can persist within the bloodstream, but the precise mechanisms of their survival remain largely elusive. This review aims to present an outline of the survival challenges encountered by CTCs and to summarize the recent advancements in understanding the underlying survival mechanisms, suggesting their implications for cancer treatment.

A novel protein encoded by circFOXP1 enhances ferroptosis and inhibits tumor recurrence in intrahepatic cholangiocarcinoma

CircRNAs participates in the development and occurrence of multiple tumor types. However, the specific effects and underlying mechanisms of circRNA in intrahepatic cholangiocarcinoma (ICC) progression and recurrence remain poorly understood. CircRNA sequencing was performed to screen circRNAs related to ICC recurrence after surgery using 53 ICC frozen tumor specimens. We found that compared with patients who experienced postsurgical recurrence, circFOXP1 had high expression in tumor tissues from patients with no postoperative recurrence. Functional experiments revealed that circFOXP1 inhibited ICC progression in vitro and in vivo. We then found that circFOXP1 inhibited ICC progression via encoding a novel protein, circFOXP1-231aa. Mechanistically, circFOXP1-231aa directly interacted with OTUD4, which regulates NCOA4 protein stability via deubiquitination modification, and thereby enhances ferroptosis of ICC cells. Examination of clinical ICC samples found positive correlations between circFOXP1 expression levels and levels of OTUD4 and NCOA4. These three factors are predictors of prognosis in patients with ICC. Collectively, we identified circFOXP1 encoded circFOXP1-231aa, which interacted with OTUD4 to suppress ubiquitination of NCOA4 and, thereby, promoted ferroptosis and inhibited ICC recurrence.

In vivo vulnerabilities to GPX4 and HDAC inhibitors in drug-persistent versus drug-resistant BRAFV600E lung adenocarcinoma

The current targeted therapy for BRAFV600E-mutant lung cancer consists of a dual blockade of RAF/MEK kinases often combining dabrafenib/trametinib (D/T). This regimen extends survival when compared to single-agent treatments, but disease progression is unavoidable. By using whole-genome CRISPR screening and RNA sequencing, we characterize the vulnerabilities of both persister and D/T-resistant cellular models. Oxidative stress together with concomitant induction of antioxidant responses is boosted by D/T treatment. However, the nature of the oxidative damage, the choice of redox detoxification systems, and the resulting therapeutic vulnerabilities display stage-specific differences. Persister cells suffer from lipid peroxidation and are sensitive to ferroptosis upon GPX4 inhibition in vivo. Biomarkers of lipid peroxidation are detected in clinical samples following D/T treatment. Acquired alterations leading to mitogen-activated protein kinase (MAPK) reactivation enhance cystine transport to boost GPX4-independent antioxidant responses. Similarly to BRAFV600E-mutant melanoma, histone deacetylase (HDAC) inhibitors decrease D/T-resistant cell viability and extend therapeutic response in vivo.

Molecular and therapeutic landscape of ferroptosis in skin diseases

ABSTRACT

Regulated cell death (RCD) is a critical physiological process essential in maintaining skin homeostasis. Among the various forms of RCD, ferroptosis stands out due to its distinct features of iron accumulation, lipid peroxidation, and involvement of various inhibitory antioxidant systems. In recent years, an expanding body of research has solidly linked ferroptosis to the emergence of skin disorders. Therefore, understanding the mechanisms underlying ferroptosis in skin diseases is crucial for advancing therapy and prevention strategies. This review commences with a succinct elucidation of the mechanisms that underpin ferroptosis, embarks on a thorough exploration of ferroptosis's role across a spectrum of skin conditions, encompassing melanoma, psoriasis, systemic lupus erythematosus (SLE), vitiligo, and dermatological ailments precipitated by ultraviolet (UV) exposure, and scrutinizes the potential therapeutic benefits of pharmacological interventions aimed at modulating ferroptosis for the amelioration of skin diseases.

Unveiling the role of AGT in lipid metabolism and regulated cell death in colon cancer

BACKGROUND

Lipid metabolism and regulated cell death (RCD) play a role in the remodeling of tumor immune microenvironment and regulation of cancer progression. Since the underlying immune mechanisms of colon cancer remain elusive, this study aims to identify potential therapeutic target genes.

METHODS

Differential genes related to lipid metabolism and RCD in COAD patients were identified using R language and online tools. Based on the expression of genes, two groups were classified using consensus clustering. CIBERSORT and ssGSEA were used to detect immune infiltration in both groups. Prognostic signature genes for colon cancer were screened using machine learning algorithms. KEGG, GO and GSEA for gene pathway enrichment. In addition, interacting genes in the immune module were obtained using a weighted gene co-expression network (WGCNA). Finally, expression and mutation of key in colon cancer genes were detected using TIMER, HPR, cBioPortal website and qPCR.

RESULTS

The consensus clustering analysis revealed that 231 relevant differential genes were highly associated with immune infiltration. A series of machine learning and website analyses identified AGT as a hub gene linked to lipid metabolism and regulated cell death, which is overexpressed in colon cancer.

CONCLUSION

AGT, as a signature gene of lipid metabolism and regulated cell death, plays a critical role in the development of COAD and is associated with tumor immune infiltration.

Advances in research on immunocyte iron metabolism, ferroptosis, and their regulatory roles in autoimmune and autoinflammatory diseases

Autoimmune diseases commonly affect various systems, but their etiology and pathogenesis remain unclear. Currently, increasing research has highlighted the role of ferroptosis in immune regulation, with immune cells being a crucial component of the body's immune system. This review provides an overview and discusses the relationship between ferroptosis, programmed cell death in immune cells, and autoimmune diseases. Additionally, it summarizes the role of various key targets of ferroptosis, such as GPX4 and TFR, in immune cell immune responses. Furthermore, the release of multiple molecules, including damage-associated molecular patterns (DAMPs), following cell death by ferroptosis, is examined, as these molecules further influence the differentiation and function of immune cells, thereby affecting the occurrence and progression of autoimmune diseases. Moreover, immune cells secrete immune factors or their metabolites, which also impact the occurrence of ferroptosis in target organs and tissues involved in autoimmune diseases. Iron chelators, chloroquine and its derivatives, antioxidants, chloroquine derivatives, and calreticulin have been demonstrated to be effective in animal studies for certain autoimmune diseases, exerting anti-inflammatory and immunomodulatory effects. Finally, a brief summary and future perspectives on the research of autoimmune diseases are provided, aiming to guide disease treatment strategies.

Ursolic acid inhibits the proliferation of triple‑negative breast cancer stem‑like cells through NRF2‑mediated ferroptosis

Ursolic acid (UA), a pentacyclic triterpenoid that has been found in a broad variety of fruits, spices and medicinal plants, has various biological effects such as reducing inflammation, protecting cells from damage, and preserving brain function. However, its impact on ferroptosis in cancer stem‑like cells remains unexplored. The present study investigated the effect of UA on MDA‑MB‑231 and BT‑549 cell‑derived triple‑negative breast CSCs (BCSCs) and its potential ferroptosis pathway. The effects of ferroptosis on BCSCs were demonstrated by the detection of ferroptosis‑related indexes including the intracellular level of glutathione, malondialdehyde, reactive oxygen species and iron. The effects of UA on the biological behaviors of BCSCs were analyzed by Cell Counting Kit‑8, stemness indexes detection and mammosphere formation assay. The mechanism of UA induction on BCSCs was explored by reverse transcription‑quantitative PCR and western blotting. BALB/c‑nude mice were subcutaneously injected with MDA‑MB‑231‑derived BCSCs to establish xenograft models to detect the effects of UA in vivo. The results revealed that BCSCs have abnormal iron metabolism and are less susceptible to ferroptosis. UA effectively reduces the stemness traits and proliferation of BCSCs in spheroids and mice models by promoting ferroptosis. It was observed that UA stabilizes Kelch‑like ECH‑associated protein 1 and suppresses nuclear factor erythroid‑related factor 2 (NRF2) activation. These findings suggested that the ability of UA to trigger ferroptosis through the inhibition of the NRF2 pathway could be a promising approach for treating BCSCs, potentially addressing metastasis and drug resistance in triple‑negative breast cancer (TNBC). This expands the clinical applications of UA and provides a theoretical basis for its use in TNBC treatment.

Glucose metabolism in B cell malignancies: a focus on glycolysis branching pathways

Glucose catabolism, one of the essential pathways sustaining cellular bioenergetics, has been widely studied in the context of tumors. Nevertheless, the function of various branches of glucose metabolism that stem from 'classical' glycolysis have only been partially explored. This review focuses on discussing general mechanisms and pathological implications of glycolysis and its branching pathways in the biology of B cell malignancies. We summarize here what is known regarding pentose phosphate, hexosamine, serine biosynthesis, and glycogen synthesis pathways in this group of tumors. Despite most findings have been based on malignant B cells themselves, we also discuss the role of glucose metabolism in the tumor microenvironment, with a focus on T cells. Understanding the contribution of glycolysis branching pathways and how they are hijacked in B cell malignancies will help to dissect the role they have in sustaining the dissemination and proliferation of tumor B cells and regulating immune responses within these tumors. Ultimately, this should lead to deciphering associated vulnerabilities and improve current therapeutic schedules.

Redox-Regulated Iron Metabolism and Ferroptosis in Ovarian Cancer: Molecular Insights and Therapeutic Opportunities

Ovarian cancer (OC), known for its lethality and resistance to chemotherapy, is closely associated with iron metabolism and ferroptosis-an iron-dependent cell death process, distinct from both autophagy and apoptosis. Emerging evidence suggests that dysregulation of iron metabolism could play a crucial role in OC by inducing an imbalance in the redox system, which leads to ferroptosis, offering a novel therapeutic approach. This review examines how disruptions in iron metabolism, which affect redox balance, impact OC progression, focusing on its essential cellular functions and potential as a therapeutic target. It highlights the molecular interplay, including the role of non-coding RNAs (ncRNAs), between iron metabolism and ferroptosis, and explores their interactions with key immune cells such as macrophages and T cells, as well as inflammation within the tumor microenvironment. The review also discusses how glycolysis-related iron metabolism influences ferroptosis via reactive oxygen species. Targeting these pathways, especially through agents that modulate iron metabolism and ferroptosis, presents promising therapeutic prospects. The review emphasizes the need for deeper insights into iron metabolism and ferroptosis within the redox-regulated system to enhance OC therapy and advocates for continued research into these mechanisms as potential strategies to combat OC.

Ferroptosis in Cancer Therapy: Mechanisms, Small Molecule Inducers, and Novel Approaches

Ferroptosis, a unique form of programmed cell death, is initiated by an excess of iron accumulation and lipid peroxidation-induced damage. There is a growing body of evidence indicating that ferroptosis plays a critical role in the advancement of tumors. The increased metabolic activity and higher iron levels in tumor cells make them particularly vulnerable to ferroptosis. As a result, the targeted induction of ferroptosis is becoming an increasingly promising approach for cancer treatment. This review offers an overview of the regulatory mechanisms of ferroptosis, delves into the mechanism of action of traditional small molecule ferroptosis inducers and their effects on various tumors. In addition, the latest progress in inducing ferroptosis using new means such as proteolysis-targeting chimeras (PROTACs), photodynamic therapy (PDT), sonodynamic therapy (SDT) and nanomaterials is summarized. Finally, this review discusses the challenges and opportunities in the development of ferroptosis-inducing agents, focusing on discovering new targets, improving selectivity, and reducing toxic and side effects.

Boswellia carterii n-hexane extract suppresses breast cancer growth via induction of ferroptosis by downregulated GPX4 and upregulated transferrin

Breast cancer (BC) remains a significant health concern for women globally, prompting the relentless pursuit of novel therapeutic modalities. As a traditional Chinese medicine, Boswellia carterii has been extensively used to treat various cancers, such as BC. However, the anti-BC effect and underlying mechanism of Boswellia carterii remain largely unclear. The aim of this study is to explore the therapeutic effect of Boswellia carterii n-hexane extract (BCHE) against BC as well as its underlying mechanism. The present study showed that BCHE significantly suppressed the viability of human BC cells. Moreover, BCHE exhibited potent anti-BC activity in vivo with no significant toxic effects. Additionally, BCHE induced ferroptosis via increased Transferrin expression and the intracellular accumulation of Fe2+, as well as decreased glutathione peroxidase 4 (GPX4) expression and the upregulation of reactive oxygen species (ROS)-induced lipid peroxidation in BC cells. In vivo experimental results also demonstrated that BCHE effectively induced ferroptosis through GPX4 downregulation and Transferrin upregulation in tumor-bearing mice. Overall, BCHE inhibited the growth of BC cells by inducing ferroptosis mediated by modulating the iron accumulation pathway and the lipid peroxidation pathway. Therefore, BCHE could serve as a potential ferroptosis-targeting drug for treating BC.

Research progress on the mechanism and signalling pathway of ferroptosis and its potential role in dermatosis research

Ferroptosis is a novel type of cell death that is dependent on lipid peroxidation and iron accumulation, which distinguishes it from other types of programmed cell death. Current research indicates a significant association between ferroptosis and various pathological conditions, including cancer, neurological disorders, and cardiovascular diseases, albeit with a relatively unexplored role in dermatological afflictions. This paper elaborates on the mechanisms and signalling pathways of ferroptosis, summarizing the recent studies on ferroptosis and its related factors in dermatosis. Our objective is to shed light on novel perspectives and therapeutic strategies for dermatosis, enhancing the understanding of this under-researched area through this comprehensive review.

Rhythm gene PER1 mediates ferroptosis and lipid metabolism through SREBF2/ALOX15 axis in polycystic ovary syndrome

OBJECTIVE

This work aimed to investigate the role of rhythm gene PER1 in mediating granulosa cell ferroptosis and lipid metabolism of polycystic ovary syndrome (PCOS).

METHODS

We injected dehydroepiandrosterone and Ferrostatin-1 (Fer-1) into mice to explore the mechanism of ferroptosis in PCOS. The effect of PER1 on ferroptosis-like changes in granulosa cells was explored by overexpression of PER1 plasmid transfection and Fer-1 treatment.

RESULTS

We found that Fer-1 ameliorated the characteristic polycystic ovary morphology, suppressed ferroptosis in the PCOS mice. PER1 and ALOX15 were highly expressed in PCOS, whereas SREBF2 was lowly expressed. Overexpression of PER1 decreased granulosa cell viability and inhibited proliferation. Meanwhile, overexpression of PER1 increased lipid reactive oxygen species, 4-Hydroxynonenal (4-HNE), Malondialdehyde (MDA), total Fe, and Fe2+ levels in granulosa cells and decreased Glutathione (GSH) content. Fer-1, SREBF2 overexpression, or ALOX15 silencing treatment reversed the effects of PER1 overexpression on granulosa cells. PER1 binds to the SREBF2 promoter and represses SREBF2 transcription. SREBF2 binds to the ALOX15 promoter and represses ALOX15 transcription. Correlation analysis of clinical trials showed that PER1 was positively correlated with total cholesterol, low-density lipoprotein cholesterol, luteinizing hormone, testosterone, 4-HNE, MDA, total Fe, Fe2+, and ALOX15. In contrast, PER1 was negatively correlated with SREBF2, high-density lipoprotein cholesterol, follicle-stimulating hormone, progesterone, and GSH.

CONCLUSION

This study demonstrates that the rhythm gene PER1 promotes ferroptosis and dysfunctional lipid metabolism in granulosa cells in PCOS by inhibiting SREBF2/ALOX15 signaling.

Exploiting the metabolic vulnerability of circulating tumour cells

Metastasis has a major part in the severity of disease and lethality of cancer. Circulating tumour cells (CTCs) represent a reservoir of metastatic precursors in circulation, most of which cannot survive due to hostile conditions in the bloodstream. Surviving cells colonise a secondary site based on a combination of physical, metabolic, and oxidative stress protection states required for that environment. Recent advances in CTC isolation methods and high-resolution 'omics technologies are revealing specific metabolic pathways that support this selection of CTCs. In this review, we discuss recent advances in our understanding of CTC biology and discoveries of adaptations in metabolic pathways during their selection. Understanding these traits and delineating mechanisms by which they confer acquired resistance or vulnerability in CTCs is crucial for developing successful prognostic and therapeutic strategies in cancer.

Elucidating the Role of Lipid-Metabolism-Related Signal Transduction and Inhibitors in Skin Cancer

Lipids, as multifunctional molecules, play a crucial role in a variety of cellular processes. These include regulating membrane glycoprotein functions, controlling membrane trafficking, influencing apoptotic pathways, and affecting drug transport. In addition, lipid metabolites can alter the surrounding microenvironment in ways that might encourage tumor progression. The reprogramming of lipid metabolism is pivotal in promoting tumorigenesis and cancer progression, with tumors often displaying significant changes in lipid profiles. This review concentrates on the essential factors that drive lipid metabolic reprogramming, which contributes to the advancement and drug resistance in melanoma. Moreover, we discuss recent advances and current therapeutic strategies that employ small-molecule inhibitors to target lipid metabolism in skin cancers, particularly those associated with inflammation and melanoma.

Ficolin 3 promotes ferroptosis in HCC by downregulating IR/SREBP axis-mediated MUFA synthesis

BACKGROUND

Targeting ferroptosis has been identified as a promising approach for the development of cancer therapies. Monounsaturated fatty acid (MUFA) is a type of lipid that plays a crucial role in inhibiting ferroptosis. Ficolin 3 (FCN3) is a component of the complement system, serving as a recognition molecule against pathogens in the lectin pathway. Recent studies have reported that FCN3 demonstrates inhibitory effects on the progression of certain tumors. However, whether FCN3 can modulate lipid metabolism and ferroptosis remains largely unknown.

METHODS

Cell viability, BODIPY-C11 staining, and MDA assay were carried out to detect ferroptosis. Primary hepatocellular carcinoma (HCC) and xenograft models were utilized to investigate the effect of FCN3 on the development of HCC in vivo. A metabonomic analysis was conducted to assess alterations in intracellular and HCC intrahepatic lipid levels.

RESULTS

Our study elucidates a substantial decrease in the expression of FCN3, a component of the complement system, leads to MUFA accumulation in human HCC specimens and thereby significantly promotes ferroptosis resistance. Overexpression of FCN3 efficiently sensitizes HCC cells to ferroptosis, resulting in the inhibition of the oncogenesis and progression of both primary HCC and subcutaneous HCC xenograft. Mechanistically, FCN3 directly binds to the insulin receptor β (IR-β) and its pro-form (pro-IR), inhibiting pro-IR cleavage and IR-β phosphorylation, ultimately resulting in IR-β inactivation. This inactivation of IR-β suppresses the expression of sterol regulatory element binding protein-1c (SREBP1c), which subsequently suppresses the transcription of genes related to de novo lipogenesis (DNL) and lipid desaturation, and consequently downregulates intracellular MUFA levels.

CONCLUSIONS

These findings uncover a novel regulatory mechanism by which FCN3 enhances the sensitivity of HCC cells to ferroptosis, indicating that targeting FCN3-induced ferroptosis is a promising strategy for HCC treatment.

Ferroptosis is an effective strategy for cancer therapy

Ferroptosis is a form of intracellular iron-dependent cell death that differs from necrosis, autophagy and apoptosis. Intracellular iron mediates Fenton reaction resulting in lipid peroxidation production, which in turn promotes cell death. Although cancer cell exhibit's ability to escape ferroptosis by multiple pathways such as SLC7A11, GPX4, induction of ferroptosis could inhibit cancer cell proliferation, migration and invasion. In tumor microenvironment, ferroptosis could affect immune cell (T cells, macrophages etc.) activity, which in turn regulates tumor immune escape. In addition, ferroptosis in cancer cells could activate immune cell activity by antigen processing and presentation. Therefore, ferroptosis could be an effective strategy for cancer therapy such as chemotherapy, radiotherapy, and immunotherapy. In this paper, we reviewed the role of ferroptosis on tumor progression and therapy, which may provide a strategy for cancer treatment.