ACSL family: The regulatory mechanisms and therapeutic implications in cancer

OTUB1 enhances fatty acid oxidation in APAP-induced liver injury by mediating ACSL5 deubiquitination

Overdosing on acetaminophen (APAP) is the primary cause of drug-induced liver injury. Recent studies have demonstrated that dysregulated lipid metabolism, particularly decreased fatty acid oxidation (FAO), is a key contributor to APAP-induced acute liver injury (AILI). OTU domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1), a crucial member of the OTU deubiquitinase family, has been involved in the metabolic progression of multiple diseases. Nevertheless, its involvement in AILI as well as FAO remains unclear. Here, we aimed to elucidate the effects of OTUB1 on the regulation of FAO in AILI. Our investigation revealed decreased OTUB1 expression in AILI. OTUB1 overexpression not only alleviated liver injury but also improved FAO in vivo and in vitro. Conversely, opposite biochemical changes were observed in hepatocytes with OTUB1 knockdown. Mechanistically, long-chain acyl-CoA synthase 5 (ACSL5), which plays a crucial role in regulating FAO, was identified as a novel substrate of OTUB1 in AILI via mass spectrometry analysis. OTUB1 interacts with ACSL5 and promotes its deubiquitination and stability. Moreover, the protective effect of OTUB1 on FAO in AILI occurred via the deubiquitination of ACSL5. Overall, the present study revealed that the OTUB1-ACSL5 axis plays an essential role in regulating FAO during AILI progression and might be a novel target for therapeutic intervention.

Emerging roles for fatty acid oxidation in cancer

Fatty acid oxidation (FAO) denotes the mitochondrial aerobic process responsible for breaking down fatty acids (FAs) into acetyl-CoA units. This process holds a central position in the cancer metabolic landscape, with certain tumor cells relying primarily on FAO for energy production. Over the past decade, mounting evidence has underscored the critical role of FAO in various cellular processes such as cell growth, epigenetic modifications, tissue-immune homeostasis, cell signal transduction, and more. FAO is tightly regulated by multiple evolutionarily conserved mechanisms, and any dysregulation can predispose to cancer development. In this view, we summarize recent findings to provide an updated understanding of the multifaceted roles of FAO in tumor development, metastasis, and the response to cancer therapy. Additionally, we explore the regulatory mechanisms of FAO, laying the groundwork for potential therapeutic interventions targeting FAO in cancers within the metabolic landscape.

Fate of polystyrene micro- and nanoplastics in zebrafish liver cells: Influence of protein corona on transport, oxidative stress, and glycolipid metabolism

Micro- and nanoplastics (MNPs) form protein corona (PC) upon contact with biological fluids, but their impact on the intracellular transport, distribution, and toxicity of MNPs remains unclear. Fetal bovine serum (FBS) and bovine serum albumin (BSA) were used to simulate in vivo environment, this study explored their influence on the transport and toxicity of polystyrene (PS) MNPs in zebrafish liver (ZFL) cells. Results showed PS MNPs were wrapped by proteins into stable complexes. Nanoparticles (NP, 50 nm) and their protein complexes (NP@PC) were internalized by cells within 6 h, with PC formation enhancing NP uptake. NP primarily entered cells through clathrin- and caveolae-mediated endocytosis, while NP@PC via clathrin-mediated pathways. Internalized particles were predominantly in lysosomes where PC degraded and some were also in mitochondria. Eventually, particles were expelled from cells through energy-dependent lysosomal pathways and energy-independent membrane penetration mechanisms. Notably, PC formation limited the clearance of NP. In toxicity, NP had a more severe impact than microplastics (MP, 5 μm). FBS more effectively mitigated PS MNPs-induced reactive oxygen species accumulation, subcellular structural damage, and dysregulation of glycolipid metabolism than BSA did. This study elucidates the modulatory role of PC on biological effects of MNPs, providing safety and risk management strategies.

Methotrexate loaded extracellular vesicles attenuate periodontitis by suppressing ACSL1 and promoting anti-inflammatory macrophage

Macrophages are crucial immune cells in periodontal tissues, which play key roles in both the destruction and repair of associated with periodontitis. Targeted modulation of macrophage function has emerged as a potentially effective approach to influence periodontitis progression. This study investigates the effects of methotrexate-loaded extracellular vesicles (MTX-EVs) on inflammatory macrophage polarization both in vivo and in vitro. In a murine periodontitis model, MTX-EVs inhibited alveolar bone resorption, suppressed pro-inflammatory macrophage activation, and promoted anti-inflammatory macrophages. Mechanistically, MTX-EVs reduced acyl-CoA synthetase-1 (ACSL1) expression, which was elevated during inflammation. Inhibition of ACSL1 with triacsin-C in macrophages suppressed the inflammatory phenotype through the promotion of the oxidative phosphorylation (OXPHOS). In contrast, MTX-EVs counteracted the effects of ACSL1 overexpression on macrophage polarization and metabolism. Our findings suggest that targeting ACSL1 via MTX-EVs represents a therapeutic strategy for modulating macrophage polarization and improving periodontitis treatment outcomes.

The cGAS-STING-mediated ROS and ferroptosis are involved in manganese neurotoxicity

Manganese (Mn) has been characterized as an environmental pollutant. Excessive releases of Mn due to human activities have increased Mn levels in the environment over the years, posing a threat to human health and the environment. Long-term exposure to high concentrations of Mn can induce neurotoxicity. Therefore, toxicological studies on Mn are of paramount importance. Mn induces oxidative stress through affecting the level of reactive oxygen species (ROS), and the overabundance of ROS further triggers ferroptosis. Additionally, Mn2+ was found to be a novel activator of the cyclic guanosine-adenosine synthase (cGAS)-stimulator of interferon genes (STING) pathway in the innate immune system. Thus, we speculate that Mn exposure may promote ROS production by activating the cGAS-STING pathway, which further induces oxidative stress and ferroptosis, and ultimately triggers Mn neurotoxicity. This review discusses the mechanism between Mn-induced oxidative stress and ferroptosis via activation of the cGAS-STING pathway, which may offer a prospective direction for future in-depth studies on the mechanism of Mn neurotoxicity.

Targeting Acyl-CoA synthetase long-chain family member 4: a potential approach for the treatment of cerebral ischemia/reperfusion injury

Cerebral ischemia/reperfusion injury causes high rates of morbidity and death. Recent studies have shown that ferroptosis, a type of controlled cell death brought on by lipid peroxidation, worsens cerebral ischemia/reperfusion injury. Acyl-CoA synthetase long-chain family member 4 (ACSL4) has emerged as a crucial enzyme in lipid metabolism and ferroptosis in the context of ischemia/reperfusion injury, influencing neuronal cell death. Increased vulnerability to ferroptosis and worsening ischemia/reperfusion injury outcomes are linked to elevated ACSL4 levels. Comprehending the molecular processes underlying ACSL4-mediated ferroptosis may result in novel approaches to treating cerebral ischemia/reperfusion injury. The present review discusses ACSL4 as a potential target for treating cerebral ischemia/reperfusion injury, focusing on ACSL4-mediated ferroptosis and signal transduction.

Circ_0002638 drives squamous cell lung cancer (LUSC) progression and chemotherapy resistance by inhibiting ferroptosis via SENP1-mediated deSUMOylation of ACSL4

AIMS

Chemotherapy is the first-line treatment for LUSC, but chemotherapy resistance often leads to tumor recurrence, significantly affecting the prognosis of patients. We sought to investigate the potential involvement of circRNAs in chemotherapy-resistant LUSC.

MAIN METHODS

qRT-PCR and circRNA sequencing were employed to assess the level of circRNAs in LUSC patients treated with chemotherapy, and the role of circ_0002638 in LUSC was explored in vivo and in vitro. RNA pulldown, mass spectrometry, and co-IP assays were performed to evaluate the underlying mechanism by which circ_0002638 promotes the progression of LUSC.

KEY FINDINGS

The expression of circ_0002638 is significantly upregulated in LUSC patients with PD (progressive disease) compared to those with PR (partial remission) after chemotherapy. Furthermore, upregulation of circ_0002638 enhanced the tumor progression. Mechanistically, circ_0002638 acts as a scaffold promoting the binding of SENP1 to ACSL4 and facilitates the process of deSUMOylation of ACSL4 was shown to protect LUSC from ferroptosis. Importantly, a combination of SENP1-IN-1 with chemotherapy has a synergistic effect in inhibiting tumor growth.

SIGNIFICANCE

This study offers novel perspectives on the function of circ_0002638 in LUSC, and provided a therapeutic target to enhance the chemotherapy sensitivity of LUSC.

Exosomal miR-196a-5p Secreted by Bone Marrow Mesenchymal Stem Cells Inhibits Ferroptosis and Promotes Drug Resistance of Acute Myeloid Leukemia

Background: Ferroptosis is a nonapoptotic type of cell death characterized by an increase in lipid reactive oxygen species (ROS). Acute myeloid leukemia (AML)-derived bone marrow mesenchymal stem cells (AML-BMSCs) support the progression and drug resistance of AML by secreting various bioactive substances, including exosomes. However, the role of BMSCs in regulating lipid metabolism and ferroptosis in AML remains unexplored. Results: Exosomes secreted by AML-BMSCs increased the expression of miR-196a-5p in AML cells. MiR-196a-5p promoted the proliferation of AML cells, reduced lipid ROS and ferroptosis, and was associated with poor prognosis in AML patients. Mechanistically, miR-196a-5p inhibited the expression level of neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L). Co-immunoprecipitation (CO-IP) analysis showed that NEDD4L was bound to long-chain acyl-CoA synthetase (ACSL)3 and promoted ubiquitin-mediated degradation of ACSL3 protein. In addition, we also demonstrated that AML-BMSCs highly expressed Ras-associated binding protein 7A (RAB7A), which was associated with exosomal miR-196a-5p release. Importantly, cytarabine (Ara-C) activated the expression of RAB7A and promoted the secretion of exosomal miR-196a-5p, which weakened the ubiquitination of ACSL3 by NEDD4L, leading to ferroptosis inhibition and Ara-C resistance in AML. Innovation: This is the first time that exosomes secreted by BMSCs (BMSCs-exos) have been linked to ferroptosis in AML cells, thereby expanding our understanding of the mechanism of drug resistance in AML cells. High miR-196a-5p expression reduced lipid ROS levels and ferroptosis in AML cells by inhibiting NEDD4L-mediated ubiquitination of ACSL3. Conclusion: This study identified a new network through which BMSCs-exos regulate ferroptosis in AML cells. We combined BMSCs and AML cells to provide new ideas for drug research targeting exosome secretion and ferroptosis. Antioxid. Redox Signal. 00, 000-000.

Oxidative complexity: The role of ROS in the tumor environment and therapeutic implications

Reactive oxygen species (ROS) constitutes a group of reactive molecules that play a critical role in biological processes. Varying ROS levels have been frequently observed in cancer cells and the tumor microenvironment (TME). The role of ROS displays significant complexity in cancer development and therapy. Elevated ROS levels can induce metabolic reprogramming and promote the proliferation, invasion, and metastasis of cancer cells, resulting in cancer progression. However, excessive ROS accumulation leads to the occurrence of apoptosis, pyroptosis, necroptosis, and ferroptosis in cancer cells, which restrains tumor development. In the TME, ROS frequently promotes angiogenesis and remodels the extracellular matrix (ECM) by enhancing the differentiation of cancer-associated fibroblasts (CAFs), thereby supporting tumor growth. Concurrently, high ROS levels favour immunosuppressive cells, including M2-polarized macrophages, and regulatory T cells (Tregs), while impairing the antitumor capabilities of T cells. In the aspect of cancer therapy, it is overly simplistic to merely combine chemoradiotherapy with antioxidants as a therapeutic strategy. Instead, highlighting targeted therapies that modulate ROS is essential, given their inherent complexity. Fortunately, a variety of innovative treatments have emerged, including nanodrug delivery systems (NDDS), proteolysis-targeting chimeras (PROTAC), and adoptive cell therapy (ADT), which not only exhibit synergistic effects with immune checkpoint therapy (ICT), but also enhance the antitumor capabilities of the TME. In this paper, we elucidate the mechanism of ROS production, enumerate the role of ROS in cancer development and the TME, and discuss advancements in ROS-targeted cancer therapeutics.

Lipid droplet - organelle crosstalk and its implication in cancer

Lipid droplets (LDs) store lipids in cells, provide phospholipids for membrane synthesis, and maintain the intracellular balance of energy and lipid metabolism. Undoubtedly, the crosstalk between LDs and other organelles is the foundation for performing functions. Many studies indicate that LDs promote tumor progression. LD accumulation has been observed in a variety of cancers, and high LD content is associated with malignant phenotype and poor prognosis of cancers. In this paper, we summarized the intimate crosstalk between LDs and intracellular organelles, including endoplasmic reticulum (ER), mitochondria, lysosomes and peroxisomes, and addressed the effects of LD-organelle crosstalk on cancer initiation and progression. We also integrated the changes of LD-organelle interactions in cancers to provide an insightful knowledge for cancer therapeutics.

A correlation of ineffective erythropoiesis and dysregulated signaling pathways in myelodysplastic syndromes/neoplasms

Over 90% of patients with myelodysplastic syndromes/neoplasms (MDS) exhibit anemia at diagnosis, primarily due to ineffective erythropoiesis. This is characterized by abnormal proliferation and differentiation of erythroid cells influenced by signaling pathways including heme synthesis, ferroptosis, senescence and apoptosis. Despite widespread anemia, the specific mechanisms and pathway alterations at different disease stages are not well understood. This study employed the NUP98-HOXD13 (NHD13) transgenic mouse model, which mimicked the erythroid changes observed in MDS patients, to explore these dynamic pathway changes during disease progression. Based on the severity of anemia and changes in mean corpuscular volume (MCV), four time points were selected: 6 weeks (non-anemic), 12 weeks (mild anemia), 16 weeks (obvious anemia) and 20 weeks (severe macrocytic anemia). The findings indicated that a reduction in erythroid-committed progenitors and impaired erythroid maturation were linked to ineffective erythropoiesis. As the disease progressed, signaling pathways dynamically changed. Heme metabolism and ferroptosis pathways were significantly upregulated in the pre-disease and early disease stages, while senescence and cell cycle pathways were activated in the early stage. The prominent roles of apoptosis, pyroptosis and inflammasome signaling pathways were observed in the late stage. Notably, changes in Gpx4 and Ncoa4 expression, along with transmission electron microscopy analysis, suggested that ferroptosis played a critical role in the early stage of the disease. To our knowledge, this is the first report of the signaling pathway dynamics associated with ineffective erythropoiesis during the pathogenesis and progression of MDS, highlighting potential targets for therapeutic intervention at various stages of the disease.

Visceral adipocyte metabolic dysfunction in obesity related to altered chromatin accessibility to thyroid hormone receptor

OBJECTIVE

To explore the alterations in visceral adipose tissue (VAT) during obesity and identify the underlying mechanism causing the onset of VAT dysfunction.

METHODS

Histological staining on human VAT was utilized. VAT samples were collected from individuals with normal weight (n = 3, BMI 21.77 ± 0.709) and obesity (n = 3, BMI 32.95 ± 1.815). RNA-seq and ATAC-seq were employed. In vitro cell experiment, Chromatin immunoprecipitation (CHIP) assay and RNA interference were conducted.

RESULTS

Our research identified differentially expressed genes (DEGs) of VAT from individuals with normal wight or obesity enriched in pathways related to adipocyte metabolic function, thyroid hormone receptor binding sites were discovered in the accessible chromatin regions of these DEGs, including STAT5B. Motif enrichment, CHIP assay and in vitro cell experiments confirmed the decreased activation of STAT5B by triiodothyronine (T3) through binding with thyroid hormone receptor alpha (THRa) in obesity. In addition, RNA interference revealed STAT5B as a key transcription factor in maintaining the metabolic function of VAT.

CONCLUSION

In obesity, VAT metabolic function impairment is related to altered chromatin accessibility to thyroid hormone receptor. STAT5B is a key transcription factor at the core of the disrupted thyroid-adipose signaling and might be a promising target to improve obesity.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

A study on the microbiome within oropharyngeal cancer tissues

Oropharyngeal cancer (OPC), a prevalent head and neck malignancy, is witnessing a rise in incidence and mortality rates annually. Our study aimed to understand the microbial composition within OPC tissue, utilizing the 2bRAD-M technique to analyze microbiome characteristics of tissue samples from 46 OPC patients and 31 with tonsillitis, followed by bioinformatics analysis. We identified higher relative abundances of Selenomonas sputigena, Nocardia farcinica, and other species in the OPC group compared to the tonsillitis group. KEGG functional prediction revealed enrichment in bile secretion, type II polyketide backbone biosynthesis, staurosporine biosynthesis, and cGMP-PKG signaling pathways. HPV-positive OPC patients showed greater abundances of Pseudomonas and other species, with differential gene enrichment in "ATP-binding cassette" and "ACSL" processes. These microbial disparities may offer potential biomarkers for OPC prediction and insight into its progression, informing treatment strategies for HPV-positive and HPV-negative patients.

A novel approach to cancer rehabilitation: assessing the influence of exercise intervention on postoperative recovery and survival rates

Cancer rehabilitation is the crucial process by which cancer patients regain their physical abilities and enhance their quality of life through diverse methods following treatment. As the cure rate of cancer continues to rise, the need for postoperative rehabilitation is becoming increasingly evident. This is particularly crucial for enhancing patient survival rates and minimizing the chances of cancer recurrence. Exercise intervention has become increasingly popular and widely used as a proactive rehabilitation therapy in recent years. This article examines the influence of exercise intervention on the recovery and survival rates of cancer patients after surgery. It specifically investigates the effects and mechanisms of various exercise interventions, such as aerobic exercise, strength training, and flexibility training, on patients with lung cancer, gastric cancer, colorectal cancer, and other forms of cancer. Exercise therapies before and after surgery can greatly boost patients' physical abilities, decrease postoperative problems, minimize hospital stays, and improve overall quality of life. In addition, implementing exercise intervention can enhance the long-term survival rates of patients. Future studies should investigate the most effective exercise programs and their suitability for various types of cancer, with the goal of offering better evidence-based clinical advice.

LIBX-A401: A Novel Selective Inhibitor of Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) and Its Binding Mode

Acyl-coenzyme A synthetase long-chain family member 4 (ACSL4), a pivotal enzyme in lipid metabolism, has emerged as a therapeutic target for ferroptosis-related conditions and cancer. However, its reference inhibitor, rosiglitazone, has off-target activity on peroxisome proliferator-activated receptor gamma (PPARγ), a key regulator of lipid homeostasis. Here, the discovery of LIBX-A401, a potent ACSL4 inhibitor derived from rosiglitazone devoid of PPARγ activity, is reported. Its binding to ACSL4 is ATP-dependent, stabilizing the C-terminal domain and altering the fatty acid gate region, as shown by Hydrogen-Deuterium Exchange Mass Spectrometry. Photoaffinity labeling identified A329 within the fatty acid binding site, while molecular dynamics and mutagenesis highlighted Q302 as critical for LIBX-A401 binding. LIBX-A401 exhibits anti-ferroptotic properties in cells, supported by target engagement. These findings establish LIBX-A401 as a valuable tool to study ACSL4 in ferroptosis and cancer, while its elucidated binding mode paves the way for the rational design of improved inhibitors.

METTL3 promotes infantile pneumonia-induced lung injury by the m6A-TBL1XR1-ACSL1 axis

BACKGROUND

Methyltransferase-like 3 (METTL3) is the catalytic subunit of methyltransferase complex that catalyzes mRNA methylation and has been identified to be involved in lipopolysaccharide (LPS)-induced lung cell injury. In this study, we investigated whether METTL3 is involved in the progression of infantile pneumonia (IP)-induced lung injury and its underlying mechanism.

METHODS

WI-38 cells were exposed to LPS to induce in vitro proliferation, inflammation, apoptosis, and ferroptosis. The mRNA and protein levels of METTL3, TBL1XR1, IGF2BP1/2/3, and ACSL1 were measured by qRT-PCR and western blotting, respectively. The N6-methyladenosine (m6A) modification was analyzed using a methylated RNA immunoprecipitation assay. Protein interactions were determined using a Co-IP assay. LPS-induced pneumonia in mice was used for the in vivo analysis.

RESULTS

METTL3 was highly expressed in IP and LPS-induced WI-38 cells. Knockdown of METTL3 reversed LPS-induced apoptosis, inflammation, and ferroptosis in vitro and in vivo and improved LPS-induced lung injury and collagen deposition in lung tissues of IP mice. Mechanistically, METTL3 induces TBL1XR1 m6A modifications and stabilizes its expression in an m6A-IGF2BP1-dependent manner. Functionally, the protective effects mediated by METTL3 silencing in LPS-treated WI-38 cells were reversed by TBL1XR1 overexpression. In addition, TBL1XR1 interacts with ACSL1, and METTL3 regulates ACSL1 expression via TBL1XR1. Further functional analysis showed that TBL1XR1 deficiency suppressed LPS-induced apoptosis, inflammation, and ferroptosis, which were abolished by ACSL1 up-regulation.

CONCLUSION

METTL3 stabilized TBL1XR1 expression through IGF2BP1-m6A methylation, promoting LPS-induced IP lung injury by upregulating ACSL1 expression.

Chlamydia trachomatis regulates ferroptosis through the p53/SLC7A11 pathway to promote reproduction

Genital tract Chlamydia trachomatis (Ct) infection is one of the most prevalent sexually transmitted infections (STIs) worldwide. However, its clinical progression is often insidious and prolonged. Understanding the mechanisms by which Ct influences cell death pathways is crucial for elucidating the pathogenic processes of this intracellular bacterium. Ferroptosis, a newly identified form of programmed cell death, is characterized by the iron-dependent accumulation of lipid peroxides. Despite its relevance, the interaction between Ct and ferroptosis remains poorly studied. In the present study, we first performed bioinformatics analysis based on RNA sequencing data under an in vitro model of Ct acute infection. Bioinformatics analysis revealed significant enrichment of differentially expressed genes in ferroptosis and p53 signaling pathways. Subsequently, we validated the hypothesis that Ct inhibits host ferroptosis by expression assays of ferroptosis-related proteins. Further cell proliferation, intracellular ferrous iron fluorescence, and lipid peroxidation assays multifaceted observations of the phenotype. Mechanistically, we found that Ct inhibition of ferroptosis acts by regulating the host p53/SLC7A11 pathway. Finally, indirect immunofluorescence assays demonstrated that ferroptosis decreases inclusion forming units (IFUs) of Ct progeny and thus affects its reproduction, which partly explains Ct's survival strategy of resisting host ferroptosis.

Isolation and Characterization of the Adamantinomatous Craniopharyngioma Primary Cells with Cancer-Associated Fibroblast Features

Backgrounds: Adamantinomatous craniopharyngiomas (ACPs) are benign intracranial tumors that behave aggressively due to their location, infiltration of the surrounding nervous tissue and high capacity for recurrence. In this study, we aimed to construct ACP primary cell models for further investigation of tumorigenic and recurrent mechanisms. Methods: Primary cells were isolated from primary (one case) and recurrent (one case) ACP. Short tandem repeat (STR) analysis was used to clarify the identity of the ACP primary cells we isolated. Whole exome sequencing (WES), immunofluorescence (IF) and immunohistochemistry (IHC) were performed on primary cells and corresponding ACP tissues, to determine the mutational profile and to clarify the tissue origin and phenotypic of primary cells. Transcriptome RNA-seq was performed to obtain the gene expression characteristics of ACP primary cells. Subsequently, a heterotopic ACP xenograft mouse model was established to confirm the tumorigenesis capacity of ACP primary cells. Results: ACP primary cells were successfully cultured. The genetic variants were similar to the original tumor tissue, and they owned expression of cancer-associated fibroblast (CAF) markers (FSP1/S100A4, Vimentin) and nuclear translocation β-catenin. Meanwhile, they had an high level expression of extracellular matrix components (Fibronectin). The tumor formation ability of ACP primary cells was verified. The transcriptional signatures of ACP primary cells were also explored. Conclusions: We successfully isolated and characterized ACP primary cells that acquired multiple CAF features and demonstrated stable propagation through dozens of passages. These PDC models laid the foundation for further research on ACP.

A gene-based predictive model for lymph node metastasis in cervical cancer: superior performance over imaging techniques

OBJECTIVE

Lymph node metastasis (LNM) critically impacts the prognosis and treatment decisions of cervical cancer patients. The accuracy and sensitivity of current imaging techniques, such as CT and MRI, are limited in assessing lymph node status. This study aims to develop a more accurate and efficient method for predicting LNM.

METHODS

Three independent cohorts were merged and divided into training and internal validation groups, with our cohort and those from other centers serving as external validation. A predictive model for LNM in cervical cancer was established using the LASSO regression and multivariate logistic regression. The diagnostic performance of the predictive model was compared with that of CT/MRI in terms of accuracy, sensitivity, specificity, and AUC.

RESULTS

Using RNA-seq data, four independent predictive genes (MAPT, EPB41L1, ACSL5, and PRPF4B) were identified through LASSO regression and multivariate logistic regression, and a predictive model was constructed to calculate the LNM risk score. Compared with CT/MRI, the model demonstrated higher diagnostic efficiency, with an accuracy of 0.840 and sensitivity of 0.804, compared to CT/MRI's accuracy of 0.713 and sensitivity of 0.587. The predictive model corrected 81% of misdiagnoses by CT/MRI, demonstrating significant improvements in accuracy and sensitivity.

CONCLUSION

The predictive model developed in this study, based on gene expression data, significantly improves the preoperative assessment accuracy of LNM in cervical cancer. Compared to traditional imaging techniques, this model shows superior sensitivity and accuracy. This study provides a robust foundation for developing precise diagnostic tools, paving the way for future clinical applications in individualized treatment planning.

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.

The role of ACSL4 in stroke: mechanisms and potential therapeutic target

Stroke, as a neurological disorder with a poor overall prognosis, has long plagued the patients. Current stroke therapy lacks effective treatments. Ferroptosis has emerged as a prominent subject of discourse across various maladies in recent years. As an emerging therapeutic target, notwithstanding its initial identification in tumor cells associated with brain diseases, it has lately been recognized as a pivotal factor in the pathological progression of stroke. Acyl-CoA synthetase long-chain family member 4 (ACSL4) is a potential target and biomarker of catalytic unsaturated fatty acids mediating ferroptosis in stroke. Specifically, the upregulation of ACSL4 leads to heightened accumulation of lipid peroxidation products and reactive oxygen species (ROS), thereby exacerbating the progression of ferroptosis in neuronal cells. ACSL4 is present in various tissues and involved in multiple pathways of ferroptosis. At present, the pharmacological mechanisms of targeting ACSL4 to inhibit ferroptosis have been found in many drugs, but the molecular mechanisms of targeting ACSL4 are still in the exploratory stage. This paper introduces the physiopathological mechanism of ACSL4 and the current status of the research involved in ferroptosis crosstalk and epigenetics, and summarizes the application status of ACSL4 in modern pharmacology research, and discusses the potential application value of ACSL4 in the field of stroke.

Core Molecular Clock Factors Regulate Osteosarcoma Stem Cell Survival and Behavior via CSC/EMT Pathways and Lipid Droplet Biogenesis

The circadian clock, an intrinsic 24 h cellular timekeeping system, regulates fundamental biological processes, including tumor physiology and metabolism. Cancer stem cells (CSCs), a subpopulation of cancer cells with self-renewal and tumorigenic capacities, are implicated in tumor initiation, recurrence, and metastasis. Despite growing evidence for the circadian clock's involvement in regulating CSC functions, its precise regulatory mechanisms remain largely unknown. Here, using a human osteosarcoma (OS) model (143B), we have shown that core molecular clock factors are critical for OS stem cell survival and behavior via direct modulation of CSC and lipid metabolic pathways. In single-cell-derived spheroid formation assays, 143B OS cells exhibited robust spheroid-forming capacity under 3D culture conditions. Furthermore, siRNA-mediated depletion of core clock components (i.e., BMAL1, CLOCK, CRY1/2, PER1/2)-essential positive and negative elements of the circadian clock feedback loop-significantly reduced spheroid formation in 143B CSCs isolated from in vivo OS xenografts. In contrast, knockdown of the secondary clock-stabilizing factor genes NR1D1 and NR1D2 had little effect. We also found that knockdown of BMAL1, CLOCK, or CRY1/2 markedly impaired the migration and invasion capacities of 143B CSCs. At the molecular level, silencing of BMAL1, CLOCK, or CRY1/2 distinctly altered the expression of genes associated with stem cell properties and the epithelial-mesenchymal transition (EMT) in 143B CSCs. In addition, disruption of BMAL1, CLOCK, or CRY1/2 expression significantly reduced lipid droplet formation by downregulating the expression of genes involved in lipogenesis (e.g., DGAT1, FASN, ACSL4, PKM2, CHKA, SREBP1), which are closely linked to CSC/EMT processes. Furthermore, transcriptomic analysis of human OS patient samples revealed that compared with other core clock genes, CRY1 was highly expressed in OS tumors relative to controls, and its expression exhibited strong positive correlations with patient prognosis, survival, and LD biogenesis gene expression. These findings highlight the critical role of the molecular circadian clock in regulating CSC properties and metabolism, underscoring the therapeutic potential of targeting the core clock machinery to enhance OS treatment outcomes.

eIF3f promotes tumour malignancy by remodelling fatty acid biosynthesis in hepatocellular carcinoma

BACKGROUND & AIMS

Fatty acid metabolism is closely associated with hepatocellular carcinoma (HCC). Elucidating the molecules that influence fatty acid metabolism in HCC is important for developing precision therapies. However, uncovering the precise molecular mechanisms underlying changes in fatty acid metabolism in tumour cells is challenging. In this study, we aimed to determine the characteristics of fatty acid metabolism in HCC.

METHODS

We employed organoid models, single-cell RNA sequencing, and spatial transcriptomics to identify key genes involved in tumour fatty acid metabolism. Metabolomics, proteomics, metabolic flux analysis, and transmission electron microscopy were utilized to evaluate this metabolic process. Tumour malignancy was characterized using multi-species models. Changes in the immune microenvironment were analysed by time-of-flight mass cytometry and multiplexed immunohistochemistry. Gene knockdown targeting the liver was achieved using lipid nanoparticles.

RESULTS

Eukaryotic translation initiation factor 3 subunit f (eIF3f) is upregulated in HCC tissues and is associated with poor prognosis. eIF3f directly interacted with and stabilised long chain acyl CoA synthetase 4 (ACSL4) through K48-linked deubiquitination, promoting fatty acid biosynthesis and malignancy. The increased fatty acid levels in the tumour microenvironment indirectly reduced CD8+ T-cell infiltration. In addition, phosphorylated eIF3f enhanced the interaction between eIF3f and ACSL4.

CONCLUSIONS

Targeting the eIF3f-ACSL4-fatty acid biosynthesis axis could decelerate the progression of HCC and enhance anti-programmed cell death-1 efficacy, implicating eIF3f as a potential target for precision therapy in HCC.

IMPACT AND IMPLICATIONS

Fatty acid metabolism is closely associated with hepatocellular carcinoma (HCC), yet the underlying mechanisms involved remain unclear. Here, we found that eIF3f is upregulated in HCC and is associated with poor prognosis. eIF3f interacts with and stabilizes ACSL4, thereby promoting fatty acid biosynthesis. Additionally, increased fatty acid levels reduce CD8+ T-cell infiltration and activation. These findings are of significant importance for clinicians and researchers in the field of HCC treatment, as eIF3f inhibition combined with anti-PD-1 therapy significantly improved anti-tumour efficacy in a mouse model and could offer therapeutic benefits for patients. These findings have practical implications, as eIF3f could serve as a novel therapeutic target in HCC. However, further clinical studies are needed to confirm the efficacy of eIF3f targeting in human patients.

The Protective Effect of Limosilactobacillus fermentum FZU501 Against Alcohol-Induced Liver Injury in Mice via Gut Microbiota-Liver Axis

As a probiotic strain isolated from Hongqu rice wine (a traditional Chinese fermented food), Limosilactobacillus fermentum FZU501 (designated as Lf) demonstrates exceptional gastric acid and bile salt tolerance, showing potential application as a functional food. The aim of this study was to investigate the protective effect of dietary Lf intervention on alcohol-induced liver injury (ALI) in mice. The results demonstrated that oral administration of Lf effectively ameliorated alcohol-induced lipid metabolism disorders by reducing the serum levels of TC, TG and LDL-C and increasing the serum levels of HDL-C. In addition, oral administration of Lf effectively prevented alcohol-induced liver damage by increasing the hepatic activities of antioxidant enzymes (CAT, SOD, GSH-Px) and alcohol-metabolizing enzymes (ADH and ALDH). Interestingly, 16S amplicon sequencing showed that oral administration of Lf increased the number of Prevotella, Lachnospiraceae_NK4A136_group and Lactobacillus, but decreased the proportion of Faecalibaculum, Adlercreutzia and Alistipes in the intestines of mice that consumed excessive alcohol, which was highly associated with improved liver function. As revealed by liver untargeted metabolomics studies, oral Lf clearly changed liver metabolic profiles, with the signature biomarkers mainly involving purine metabolism, taurine metabolism, tryptophan, alanine, aspartic acid and glutamate metabolism, etc. Additionally, Lf intervention regulated liver gene transcription in over-drinking mice for cholesterol metabolism, bile acid metabolism, fatty acid β-oxidation, alcohol metabolism and oxidative stress. Taken together, the above research results provide solid scientific support for the biological activity of Lf in ameliorating alcohol-induced liver metabolism disorder and intestinal microbiota imbalance.

Identification of methionine metabolism related prognostic model and tumor suppressive functions of BHMT in hepatocellular carcinoma

Given the resistance to conventional treatments and limitations of immune checkpoint blockade therapy in hepatocellular carcinoma (HCC), it is imperative to explore novel prognostic models and biomarkers. The dependence of cancer cell on exogenous methionine, known as Hoffman effect, is a hallmark of HCC, with numerous studies reporting a strong correlation between methionine metabolism and tumor development. Betaine-homocysteine S-methyltransferase (BHMT), a critical component of methionine metabolism pathway, has polymorphisms linking to poor prognosis in multiple cancers. Nevertheless, there is little literature regarding the relationship between methionine metabolism and incidence, mortality of HCC, as well as the function of BHMT in HCC progression. In this study, by analyzing multiple datasets, we constructed a methionine metabolism-related prognostic model and thoroughly investigated the influence of BHMT on the prognosis of HCC. Bioinformatics analysis revealed a marked decrease in BHMT expression in HCC, which was linked to adverse clinical outcomes. CIBERSORT results suggest that BHMT promotes infiltration of M1 macrophages. Our results suggest its potential as an ideal prognostic biomarker for anti PD-L1 immunotherapy. In summary, this study innovatively provides first methionine metabolism-related prognostic model and unveils the tumor suppressive function of BHMT in HCC, providing potential mechanism by which BHMT exert its function.

Monounsaturated fatty acids promote cancer radioresistance by inhibiting ferroptosis through ACSL3

Radioresistance is a major challenge in tumor radiotherapy and involves in a mixture of cellular events, including ferroptosis, a new type of programmed cell death characterized by the excess accumulation of iron-dependent lipid peroxides. In the present study, we observed that surviving cancer tissues and cells after radiotherapy had significantly greater glutathione to oxidized glutathione (GSH/GSSG) ratios and lower lipid reactive oxygen species (ROS) and malondialdehyde (MDA) levels than nonirradiated tumors and cells. Untargeted lipidomic analyses revealed that oleic acid (OA) and palmitoleic acid (POA) were the most significantly upregulated unsaturated fatty acids in irradiated surviving cancer cells compared with those in control cancer cells irradiated with IR. Both OA and POA could protect cancer cells from the killing effects of the ferroptosis inducer erastin and RSL3, and OA had a stronger protective effect than POA, resulting in lower lipid ROS production than POA. Mechanistically, OA protected cells from ferroptosis caused by the accumulation of polyunsaturated fatty acid-containing phospholipids in an ACSL3-dependent manner. A mouse model demonstrated that ACSL3 knockdown combined with imidazole ketone erastin synergistically enhanced antitumor effects in radiation-resistant tumors in vivo. Our study reveals previously undiscovered associations between radiation and fatty acid metabolism and ferroptosis, providing a novel treatment strategy for overcoming cancer radioresistance.

HAT1/HDAC2 mediated ACSL4 acetylation confers radiosensitivity by inducing ferroptosis in nasopharyngeal carcinoma

Protein acetylation modification plays important roles in various aspects of tumor progression. Ferroptosis driven by lethal lipid peroxidation is closely related to tumor development. Targeting ferroptosis has become a promising strategy. However, the crosstalk between protein acetylation and ferroptosis remains unclear. In present study, we found that the acetylation of acyl-CoA synthase long-chain family member 4 (ACSL4) enhances its protein stability and a double-edged sword regulation in nasopharyngeal carcinoma (NPC). On the one hand, ACSL4 could promote the malignant progress of tumors; on the other hand, it enhanced radiosensitivity by endowing NPC cells with ferroptosis-sensitive properties in vitro and in vivo. Mechanistically, histone acetyltransferase 1 (HAT1) directly promotes the acetylation of ACSL4 at lysine 383, and deacetylase sirtuin 3 (SIRT3) mediates the deacetylation of ACSL4. Meanwhile, another deacetylase histone deacetylase 2 (HDAC2) enhances ACSL4 acetylation through inhibiting the transcription of SIRT3. Acetylation of ACSL4 inhibits F-box protein 10 (FBXO10)-mediated K48-linked ubiquitination, resulting in enhanced protein stability of ACSL4. This study reveals the novel regulatory mechanism of ferroptosis-related protein from the perspective of protein acetylation, and provides a novel method for the radiosensitivity of NPC.

Host lipid metabolism influences the variation in resistance of Pekin ducks to duck hepatitis A virus genotype 3

Duck viral hepatitis (DVH) is a common and serious acute infectious disease that has a significantly impact on the duck farming industry. Duck hepatitis A virus type 3 (DHAV-3) is the major causative agent of DVH in East Asia. Host factor indicators of resistance to DHAV-3 in Pekin ducks were investigated using resistant (Z7R) and susceptible (Z7S) duck lines. Before DHAV-3 infection, Z7R had significantly higher HDL-C and LDL-C levels than Z7S. The results of population verification showed that Pekin ducks with HDL-C and/or LDL-C concentrations within their maximum 5 % confidence interval were highly resistant to DHAV-3. RNA-seq identified fifteen differentially expressed genes, primarily involved in lipid metabolism. Additionally, lipidomics identified one hundred distinct metabolites involved in glycerophospholipid metabolism. The ACSL6 gene was found to be significantly associated with PC and PE. ACSL6, PE, PC, HDL-C and LDL-C co-regulated hepatic lipid metabolism. In conclusion, our results reveal that HDL-C and LDL-C may serve as markers of anti-DHAV-3 infection and lipid metabolism may be related to a potential mechanism of antiviral activity in Pekin ducks, providing a theoretical basis for future studies on the interaction between lipid metabolism and DHAV-3.

BPDE induces ferroptosis in hippocampal neurons through ACSL3 suppression

Benzo(a)pyrene (B[a]P) and its ultimate active metabolite, benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), are known to have neurotoxic effects that can damage hippocampal neurons and cause cognitive impairments. Ferroptosis, a form of programmed cell death distinct from apoptosis, is associated with multiple neurodegenerative conditions. Recently, we have found that BPDE triggers ferroptosis in hippocampal neurons, though the underlying molecular mechanism remains unclear. Here, we firstly identified ACSL3 as the target of BPDE-induced ferroptosis through transcriptomics, and then investigated its role in ferroptosis using gene transfection technology in HT22 cells and primary hippocampal neurons. Our results showed that BPDE treatment caused significant transcriptional changes in HT22 cells, notably decreasing ACSL3 expression, which was further validated in both HT22 cells and primary hippocampal neurons. Furthermore, overexpression of ACSL3 effectively rescued the ferroptosis induced by BPDE in HT22 cells and primary mouse hippocampal neurons, characterized by increased cell viability, enhanced glutathione and glutathione peroxidase activities, and reduced levels of intracellular free Fe2+, reactive oxygen species, and malondialdehyde. In summary, our findings demonstrated that BPDE induces ferroptosis in hippocampal neurons by inhibiting ACSL3 expression, providing new insights into the toxicological mechanisms underlying BPDE-induced neurotoxicity.

Prostate Cancer: De-regulated Circular RNAs With Efficacy in Preclinical In Vivo Models

Therapy resistance, including castration-resistance and metastasis, remains a major hurdle in the treatment of prostate cancer. In order to identify novel therapeutic targets and treatment modalities for prostate cancer, we conducted a comprehensive literature search on PubMed to identify de-regulated circular RNAs that influence treatment efficacy in preclinical prostate cancer-related in vivo models. Our analysis identified 49 circular RNAs associated with various processes, including treatment resistance, transmembrane and secreted proteins, transcription factors, signaling cascades, human antigen R, nuclear receptor binding, ubiquitination, metabolism, epigenetics and other target categories. The identified targets and circular RNAs can be further scrutinized through target validation approaches. Down-regulated circular RNAs are candidates for reconstitution therapy, while up-regulated RNAs can be inhibited using small interfering RNA (siRNA), antisense oligonucleotides (ASO) or clustered regularly interspaced short palindromic repeats/CRISPR associated (CRISPR-CAS)-related approaches.

Parkin inhibits iron overload-induced cardiomyocyte ferroptosis by ubiquitinating ACSL4 and modulating PUFA-phospholipids metabolism

Iron overload is strongly associated with heart disease. Ferroptosis is a new form of regulated cell death indicated in cardiac ischemia-reperfusion (I/R) injury. However, the specific molecular mechanism of myocardial injury caused by iron overload in the heart is still unclear, and the involvement of ferroptosis in iron overload-induced myocardial injury is not fully understood. In this study, we observed that ferroptosis participated in developing of iron overload and I/R-induced cardiomyopathy. Mechanistically, we discovered that Parkin inhibited iron overload-induced ferroptosis in cardiomyocytes by promoting the ubiquitination of long-chain acyl-CoA synthetase 4 (ACSL4), a crucial protein involved in ferroptosis-related lipid metabolism pathways. Additionally, we identified p53 as a transcription factor that transcriptionally suppressed Parkin expression in iron-overloaded cardiomyocytes, thereby regulating iron overload-induced ferroptosis. In animal studies, cardiac-specific Parkin knockout mice (Myh6-CreER T2 /Parkin fl/fl ) fed a high-iron diet presented more severe myocardial damage, and the high iron levels exacerbated myocardial I/R injury. However, the ferroptosis inhibitor Fer-1 significantly suppressed iron overload-induced ferroptosis and myocardial I/R injury. Moreover, Parkin effectively protected against impaired mitochondrial function and prevented iron overload-induced mitochondrial lipid peroxidation. These findings unveil a novel regulatory pathway involving p53-Parkin-ACSL4 in heart disease by inhibiting of ferroptosis.

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.

AURKB inhibition induces rhabdomyosarcoma apoptosis and ferroptosis through NPM1/SP1/ACSL5 axis

Rhabdomyosarcoma (RMS) is one of the most common solid tumors in children and adolescents. Patients with relapsed/refractory RMS have limited treatment options, highlighting the urgency for the identification of novel therapeutic targets for RMS. In the present study, aurora kinase B (AURKB) was found to be highly expressed in RMS and associated with unfavorable prognosis of patients. Functional experiments indicated that inhibition of AURKB significantly reduced RMS cell proliferation, induced apoptosis and ferroptosis, and suppressed RMS growth in vivo. The highly expressed AURKB in RMS contributes to the apoptosis and ferroptosis resistance of tumor cells through the nucleophosmin 1 (NPM1)/Sp1 transcription factor (SP1)/acyl-CoA synthetase long-chain family member 5 (ACSL5) axis. Furthermore, inhibition of AURKB exerted an anti-RMS effect together with vincristine both in vitro and in vivo, with tolerable toxicity. The above findings provide insights we believe are new into the tumorigenesis of RMS, especially with regard to apoptosis or ferroptosis resistance, indicating that AURKB may be a potential target for clinical intervention in patients with RMS.

EZH2 suppresses IR-induced ferroptosis by forming a co-repressor complex with HIF-1α to inhibit ACSL4: Targeting EZH2 enhances radiosensitivity in KDM6A-deficient esophageal squamous carcinoma

The mutation status of the lysine demethylase 6 A (KDM6A), a gene antagonist to Enhancer of zeste homolog 2 (EZH2), is closely related to the therapeutic efficacy of EZH2 inhibitors in several malignancies. However, the mutational landscape of KDM6A and the therapeutic targetability of EZH2 inhibitors in esophageal squamous carcinoma (ESCC) remain unreported. Here, we found that approximately 9.18% (9/98) of our study ESCC tissues had KDM6A mutations of which 7 cases resulted in a complete loss of expression and consequent loss of demethylase function. We found that KDM6A-deficient ESCC cells exhibited increased sensitivity to EZH2 inhibitor, and the radiosensitizing activity of EZH2 inhibitor was evident in KDM6A-dficient ESCC cells. Further transcriptome analysis revealed that ferroptosis is implicated in the radiosensitizing effect exerted by EZH2 inhibition on KDM6A-deficient ESCC cells. The following Chromatin Immunoprecipitation (ChIP), co-immunoprecipitation, and luciferase reporter assays demonstrated that in KDM6A-deficient ESCC cells, (1) Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) is the target gene for EZH2 to regulate ferroptosis; (2) The IR-induced hypoxia inducible factor 1 subunit alpha (HIF-1α) is a predominant mediator of EZH2 to repress ACSL4; (3) the HRE7-8 regions of the ACSL4 promoter are required for the repressive function of EZH2 on ACSL4; (4) EZH2 regulates ACSL4 by forming a co-repressive complex with HIF-1α. Our study provides preclinical evidence supporting that EZH2 inhibitors may confer therapeutic benefit in KDM6A-deficient ESCC patients.

LRP11 facilitates lipid metabolism and malignancy in hepatocellular carcinoma by stabilizing RACK1 through USP5 regulation

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide and a major public health challenge. Lipid metabolism plays a crucial role in the metabolic reprogramming observed in HCC, although the underlying mechanisms are still being elucidated. Nile red staining and lipid assays showed that LRP11 knockdown significantly reduces lipid accumulation in HCC cells, with a concurrent decrease in key lipid metabolism markers such as FSAN, ACLY and ACSL4, as demonstrated by Western blotting. Mass spectrometry (MS) and co-immunoprecipitation (Co-IP) revealed that LRP11 recruits USP5, enhancing USP5-mediated deubiquitination of RACK1. Truncation analysis identified LRP11 residues 309-500 as critical for interaction with the RACK1 residues 91-231. These findings suggest that LRP11 may influence lipid metabolism and progression in HCC through USP5-mediated stabilization of RACK1. Based on these results, LRP11 emerges as a potential target for further exploration in HCC therapy. Targeting LRP11 or disrupting its interactions with USP5 or RACK1 could offer new avenues for treatment, though additional research is required to validate these therapeutic possibilities.

Ergosterol alleviates hepatic steatosis and insulin resistance via promoting fatty acid β-oxidation by activating mitochondrial ACSL1

Sterols target sterol-sensing domain (SSD) proteins to lower cholesterol and circulating and hepatic triglyceride levels, but the mechanism remains unclear. In this study, we identify acyl-coenzyme A (CoA) synthetase long-chain family member 1 (ACSL1) as a direct target of ergosterol (ES). The C-terminal domain of ACSL1 undergoes conformational changes from closed to open, and ES may target the drug-binding pocket in the acetyl-CoA synthetase-like domain 1 (ASLD1) of ACSL1 to stabilize the closed conformation and maintain its activity. Moreover, ES is mainly enriched in the mitochondria and promotes fatty acid β-oxidation through ACSL1 allosteric activation. Structure-activity relationship analysis reveals how different structural sterols interact with the sterol-sensing domain-containing protein (SCAP) and ACSL1, explaining their regulatory effects on lipid metabolism. Moreover, our findings reveal that the combination of SCAP inhibitor 25-hydroxycholesterol (25-HC) and ES has a stronger lipid-lowering effect than alone.

Inhibition of acyl-CoA synthetase long-chain isozymes decreases multiple myeloma cell proliferation and causes mitochondrial dysfunction

Multiple myeloma (MM) is an incurable cancer of plasma cells with a 5-year survival rate of 59%. Dysregulation of fatty acid (FA) metabolism is associated with MM development and progression; however, the underlying mechanisms remain unclear. Herein, we explore the roles of long-chain fatty acid coenzyme A ligase (ACSL) family members in MM. ACSLs convert free long-chain fatty acids into fatty acyl-CoA esters and play key roles in catabolic and anabolic fatty acid metabolism. Analysis of the Multiple Myeloma Research Foundation (MMRF) CoMMpassSM study showed that high ACSL1 and ACSL4 expression in myeloma cells are both associated with worse clinical outcomes for MM patients. Cancer Dependency Map (DepMap) data showed that all five ACSLs have negative Chronos scores, and ACSL3 and ACSL4 were among the top 25% Hallmark Fatty Acid Metabolism genes that support myeloma cell line fitness. Inhibition of ACSLs in myeloma cell lines in vitro, using the pharmacological inhibitor Triacsin C (TriC), increased apoptosis, decreased proliferation, and decreased cell viability, in a dose- and time-dependent manner. RNA-sequencing analysis of MM.1S cells treated with TriC showed a significant enrichment in apoptosis, ferroptosis, and endoplasmic reticulum (ER) stress, and proteomic analysis of these cells revealed enriched pathways for mitochondrial dysfunction and oxidative phosphorylation. TriC also rewired mitochondrial metabolism by decreasing mitochondrial membrane potential, increasing mitochondrial superoxide levels, decreasing mitochondrial ATP production rates, and impairing cellular respiration. Overall, our data support the hypothesis that suppression of ACSLs in myeloma cells is a novel metabolic target in MM that inhibits their viability, implicating this family as a promising therapeutic target in treating myeloma.

Methyltransferase-like 7B participates in bladder cancer via ACSL3 m6A modification in a ferroptosis manner

BACKGROUND

Bladder cancer (BC) is a malignant tumor. Methyltransferase-like 7B (MEETL7B) is a methyltransferase and its role in BC has not yet been revealed.

METHOD

Stable METTL7B knockdown or overexpression were achieved by lentiviral transduction in SW780 and TCCSUP cell lines. Xenografts tumors were established via subcutaneous injection of stable transfectants in BALB/c mice.

RESULTS

A database search indicated that METTL7B was elevated in BC and it was validated in BC cell lines. METTL7B silencing suppressed cell proliferation and tumorigenesis in vitro and in vivo. Besides, METTL7B knockdown induced cell cycle arrest in G1 phase with a reduction in cyclin D1(CCND1), CDK4, and CDK6 levels and an elevation in CDKN2D levels in cells. Considering that ferroptosis is emerging as a therapeutic target for cancer, and the possible relationship between METTL7B and antioxidant enzymes. We, here, examined that ectopic METTL7B expression abolished ferroptosis markers in cells raised by Erastin treatment, including the production of lipid ROS, the increased cellular iron and MDA content, the decreased gene expression of ACSL3, FANCD2, and FADS2, as well as the mitochondrial injury observed by electron microscopy. Mechanically, ectopic METTL7B expression promoted m6A modification on ACSL3 mRNA. Gain of functional experiment exhibited that METTL7B inhibited Erastin-induced ferroptosis via ACSL3. Overexpressed PLAGL2 is identified as a possible independent predictor in BC and bioinformatics predicted the potential binding sites between PLAGL2 and METTL7B promoter region. Dual luciferase and chromatin immunoprecipitation analysis provided evidence that PLAGL2 directly binds to METTL7B promoter region.

CONCLUSIONS

METTL7B is involved in BC development and progression. METTL7B may mediate m6A modification on ACSL3 mRNA to negatively regulate ferroptosis in BC cells, which provides a potential therapeutic target for BC via ferroptosis.

Ferroptosis genes and ST-segment elevation myocardial infarction outcomes: A predictive signature

Objective

The aim of this paper is to discover differentially expressed genes related to ferroptosis (DEFRGs) in patients with ST-segment elevation myocardial infarction (STEMI) and to construct a reliable prognostic signature that incorporates key DEFRGs and easily accessible clinical factors.

Methods

We did a systematic review of Gene Expression Omnibus datasets and picked datasets SE49925, GSE60993, and GSE61144 for analysis. We applied GEO2R to find DEFRGs and overlapped them among the picked datasets. We performed functional enrichment analysis to explore their biological functions. We built an optimal model with least absolute shrinkage and selection operator (LASSO) penalized Cox proportional hazards regression. We tested the clinical value of the signature with survival analysis, ROC curve, decision curve analysis and a prognostic nomogram. We also confirmed the model externally with plasma samples from our center's patients.

Results

A prognostic signature combining three overexpressed DEFRGs (ACSL1, ACSL4, TSC22D3) and two clinical variables (serum creatinine level, Gensini score) was established. The signature effectively classified patients into low- and high-risk groups. Survival analysis, ROC curve analysis, and DCA showed its robust predictive performance and clinical utility of the signature within two years after the onset of the disease. The external validation cohort confirmed the significant difference in major adverse cardiovascular events (MACEs) between the low- and high-risk groups.

Conclusion

This study revealed DEFRGs in patients with STEMI and developed a prognostic signature that integrates gene expression levels and clinical factors for stratifying patients and predicting the risk of MACEs.

Dysregulation of genes involved in the long-chain fatty acid transport in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive lethal malignancy with limited options for treatment and a 5-year survival rate of 11% in the United States. As for other types of tumors, such as colorectal cancer, aberrant de novo lipid synthesis and reprogrammed lipid metabolism have been suggested to be associated with PDAC development and progression.

AIM

To identify the possible involvement of lipid metabolism in PDAC by analyzing in tumoral and non-tumoral tissues the expression level of the most relevant genes involved in the long-chain fatty acid (FA) import into cell.

METHODS

A gene expression analysis of FASN, CD36, SLC27A1, SLC27A2, SLC27A3, SLC27A4, SLC27A5, ACSL1, and ACSL3 was performed by qRT-PCR in 24 tumoral PDAC tissues and 11 samples from non-tumoral pancreatic tissues obtained via fine needle aspiration or via surgical resection. The genes were considered significantly dysregulated between the groups when the p value was < 0.05 and the fold change (FC) was ≤ 0.5 and ≥ 2.

RESULTS

We found that three FA transporters and two long-chain acyl-CoA synthetases genes were significantly upregulated in the PDAC tissue compared to the non-tumoral tissue: SLC27A2 (FC = 5.66; P = 0.033), SLC27A3 (FC = 2.68; P = 0.040), SLC27A4 (FC = 3.13; P = 0.033), ACSL1 (FC = 4.10; P < 0.001), and ACSL3 (FC = 2.67; P = 0.012). We further investigated any possible association between the levels of the analyzed mRNAs and the specific characteristics of the tumors, including the anatomic location, the lymph node involvement, and the presence of metastasis. A significant difference in the expression of SLC27A3 (FC = 3.28; P = 0.040) was found comparing patients with and without lymph nodes involvement with an overexpression of this transcript in 17 patients presenting tumoral cells in the lymph nodes.

CONCLUSION

Despite the low number of patients analyzed, these preliminary results seem to be promising. Addressing lipid metabolism through a broad strategy could be a beneficial way to treat this malignancy. Future in vitro and in vivo studies on these genes may offer important insights into the mechanisms linking PDAC with the long-chain FA import pathway.

ACSL4 accelerates osteosarcoma progression via modulating TGF-β/Smad2 signaling pathway

Osteosarcoma (OS) is a malignant bone sarcoma arising from mesenchymal stem cells. The biological role of Acyl-CoA synthetase long-chain family member 4 (ACSL4), recently identified as an oncogene in numerous tumor types, remains largely unclear in OS. In this study, we investigated the expression of ACSL4 in OS tissues using immunohistochemistry staining (IHC) staining of a human tissue microarray and in OS cells by qPCR assay. Our findings revealed a significant up-regulation of ACSL4 in both OS tissues and cells. To further understand its biological effects, we conducted a series of loss-of-function experiments using ACSL4-depleted MNNG/HOS and U-2OS cell lines, focusing on OS cell proliferation, migration, and apoptosis in vitro. Our results demonstrated that ACSL4 knockdown remarkably suppressed OS cell proliferation, arrested cells in the G2 phase, induced cell apoptosis, and inhibited cell migration. Additionally, a subcutaneous xenograft mice model was established to validate the in vivo impact of ACSL4, revealing ACSL4 silencing impaired tumor growth in the OS xenograft mice. Additionally, we discovered that ACSL4 could regulate the phosphorylation level of Smad2 through cooperative interactions, and treatment with a TGF-β inhibitor weakened the promoting effects of ACSL4 overexpression. In short, ACSL4 regulated OS progression by modulating TGF-β/Smad2 signaling pathway. These findings underscore ACSL4 as a promising therapeutic target for OS patients and contribute novel insights into the pathogenesis of OS.

Quercetin and its derivatives from lotus (Nelumbo nucifera) seedpod extract combat radioresistance by suppressing ACSL4

Radioresistance poses a significant obstacle in cancer treatment. Lotus seedpod extract (LSE) has demonstrated anticancer effects in various cancer cells. However, its potential against radioresistant tumors remains unclear. In this study, we aimed to investigate the effect of LSE on radioresistant breast cancer cells, explore the underlying mechanism, and identify the major constituents responsible for its cytotoxic effect. LSE, extracted using 70% ethanol, exhibited selective cytotoxic effects against radioresistant breast cancer cells compared with their parental cells. Chemical analysis identified quercetin and its derivatives, hyperoside and miquelianin, as the major constituents responsible for these selective effects. Notably, quercetin displayed the most potent cytotoxicity against radioresistant breast cancer cells compared with hyperoside and miquelianin. Further investigation revealed that these compounds inhibited the activation of DNA repair systems, leading to the accumulation of DNA damage and the induction of apoptosis. Importantly, they efficiently suppressed the expression of ACSL4, a factor previously associated with radioresistance. In an in vivo study, quercetin exhibited a significant suppression of tumor growth in radioresistant tumor-bearing mice. Taken together, our findings highlight the potential of LSE and its major constituents, quercetin and its derivatives, in overcoming radioresistance in breast cancer. This study provides compelling evidence to support the use of LSE as a medicinal source for the future adjunctive therapy to combat radioresistance in breast cancers.

Prognostic feature based on androgen-responsive genes in bladder cancer and screening for potential targeted drugs

OBJECTIVES

Bladder cancer (BLCA) is a tumor that affects men more than women. The biological function and prognostic value of androgen-responsive genes (ARGs) in BLCA are currently unknown. To address this, we established an androgen signature to determine the prognosis of BLCA.

METHODS

Sequencing data for BLCA from the TCGA and GEO datasets were used for research. The tumor microenvironment (TME) was measured using Cibersort and ssGSEA. Prognosis-related genes were identified and a risk score model was constructed using univariate Cox regression, LASSO regression, and multivariate Cox regression. Drug sensitivity analysis was performed using Genomics of drug sensitivity in cancer (GDSC). Real-time quantitative PCR was performed to assess the expression of representative genes in clinical samples.

RESULTS

ARGs (especially the CDK6, FADS1, PGM3, SCD, PTK2B, and TPD52) might regulate the progression of BLCA. The different expression patterns of ARGs may lead to different immune cell infiltration. The risk model indicates that patients with higher risk scores have a poorer prognosis, more stromal infiltration, and an enrichment of biological functions. Single-cell RNA analysis, bulk RNA data, and PCR analysis support the reliability of this risk model, and a nomogram was also established for clinical use. Drug prediction analysis showed that high-risk patients had a better response to fludarabine, AZD8186, and carmustine.

CONCLUSION

ARGs played an important role in the progression, immune infiltration, and prognosis of BLCA. The ARGs model has high accuracy in predicting the prognosis of BLCA patients and provides more effective medication guidelines.

Molecular mechanisms of ferroptosis in cardiovascular disease

Ferroptosis is a newly recognized type of regulated cell death that is characterized by the accumulation of iron and lipid peroxides in cells. Studies have shown that ferroptosis plays a significant role in the pathogenesis of various diseases, including cardiovascular diseases. In cardiovascular disease, ferroptosis is associated with ischemia-reperfusion injury, myocardial infarction, heart failure, and atherosclerosis. The molecular mechanisms underlying ferroptosis include the iron-dependent accumulation of lipid peroxidation products, glutathione depletion, and dysregulation of lipid metabolism, among others. This review aims to summarize the current knowledge of the molecular mechanisms of ferroptosis in cardiovascular disease and discuss the potential therapeutic strategies targeting ferroptosis as a treatment for cardiovascular disease.

DHRS2-induced SPHK1 downregulation contributes to the cell growth inhibition by Trichothecin in colorectal carcinoma

BACKGROUND

Deregulation of lipid metabolism is one of the most prominent metabolic features in cancer. The activation of sphingolipid metabolic pathways affects the proliferation, invasion, angiogenesis, chemoresistance, and immune escape of tumors, including colorectal cancer (CRC). Dehydrogenase/reductase member 2 (DHRS2), which belongs to the short-chain dehydrogenase/reductase (SDR) family, has been reported to participate in the regulation of lipid metabolism and impact on cancer progression. Trichothecin (TCN) is a sesquiterpenoid metabolite originating from an endophytic fungus of the herbal plant Maytenus hookeri Loes. Studies have shown that TCN exerts a broad-spectrum antitumor activity.

METHODS

We evaluated the proliferative ability of CRC cells by CCK8 and colony formation assays. A metabolite profiling using liquid chromatography coupled with mass spectrometry (LC/MS) was adopted to identify the proximal metabolite changes linked to DHRS2 overexpression. RNA stability assay and RNA immunoprecipitation (RIP) experiments were applied to determine the post-transcriptional regulation of SPHK1 expression by DHRS2. We used flow cytometry to detect changes in cell cycle and cell apoptosis of CRC cells in the absence or presence of TCN.

RESULTS

We demonstrate that DHRS2 hampers the sphingosine kinases 1 (SPHK1)/sphingosine 1-phosphate (S1P) metabolic pathway to inhibit CRC cell growth. DHRS2 directly binds to SPHK1 mRNA to accelerate its degradation in a post-transcriptionally regulatory manner. Moreover, we illustrate that SPHK1 downregulation induced by DHRS2 contributes to TCN-induced growth inhibition of CRC.

CONCLUSIONS

The present study provides a mechanistic connection among metabolic enzymes, metabolites, and the malignant progression of CRC. Moreover, TCN could be developed as a potential pharmacological tool against CRC by the induction of DHRS2 and targeting SPHK1/S1P metabolic pathway.

Ferroptosis in Cancer: Epigenetic Control and Therapeutic Opportunities

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a critical pathway in cancer biology. This review delves into the epigenetic mechanisms that modulate ferroptosis in cancer cells, focusing on how DNA methylation, histone modifications, and non-coding RNAs influence the expression and function of essential genes involved in this process. By unraveling the complex interplay between these epigenetic mechanisms and ferroptosis, the article sheds light on novel gene targets and functional insights that could pave the way for innovative cancer treatments to enhance therapeutic efficacy and overcome resistance in cancer therapy.

ACSL1 improves pulmonary fibrosis by reducing mitochondrial damage and activating PINK1/Parkin mediated mitophagy

Pulmonary fibrosis is a chronic interstitial lung disease with no curative therapeutic treatment, leading to significant mortality. The aims of this study were to investigate the regulatory mechanisms of mitophagy in the progression of pulmonary fibrosis. Through bioinformatics analysis, we identified the downregulation of long-chain fatty acyl-CoA synthetase 1 (ACSL1) as being associated with the severity of pulmonary fibrosis. A pulmonary fibrosis model was established through bleomycin (BLM) exposure both in vivo and in vitro. Mitoquinone (MitoQ) pretreatment significantly decreased redox damage, stabilized mitochondrial membrane potential (MMP), improved mitochondrial dynamics, and activated PINK1/Parkin-mediated mitophagy, thereby alleviating pulmonary fibrosis. In vitro, overexpression of ACSL1 mitigated mitochondrial damage and restored PINK1/Parkin-mediated mitophagy under BLM exposure. In contrast, ACSL1 inhibition exacerbated pulmonary fibrosis, and these adverse effects could not be reversed by MitoQ treatment. Taken together, our study reveals a novel mechanism underlying the pathogenesis of pulmonary fibrosis and suggests a potential therapeutic target for its treatment.

Targeting ACSLs to modulate ferroptosis and cancer immunity

Five acyl-CoA synthetase long-chain family members (ACSLs) are responsible for catalyzing diverse long-chain fatty acids (LCFAs) into LCFA-acyl-coenzyme A (CoA) for their subsequent metabolism, including fatty acid oxidation (FAO), lipid synthesis, and protein acylation. In this review, we focus on ACSLs and their LCFA substrates and introduce their involvement in regulation of cancer proliferation, metastasis, and therapeutic resistance. Along with the recognition of the decisive role of ACSL4 in ferroptosis - an immunogenic cell death (ICD) initiated by lipid peroxidation - we review the functions of ACSLs on regulating ferroptosis sensitivity. Last, we discuss the current understanding of ACSL on the antitumor immune response. We emphasize the necessity to explore the functions of immune cells expressing ACSLs for developing novel strategies to augment immunotherapy by targeting ACSL.

Self-Healing Photothermal Nanotherapeutics for Enhanced Tumor Therapy through Triple Ferroptosis Amplification and Cascade Inflammation Inhibition

The therapeutic effectiveness of photothermal therapy (PTT) is limited by heat tolerance and PTT-induced inflammation, which increases the risk of tumor metastasis and recurrence. Ferroptosis combined with PTT can achieve significant therapeutic effects. In this work, we designed self-healing photothermal nanotherapeutics to achieve effective PTT with triple-amplified ferroptosis and cascade inflammation inhibition after photothermal treatment. After the ferroptosis-inducing ability of mangiferin (MF) was first elucidated, the nanocomplex PFeM, coordinated by Fe3+ and MF with polyvinylpyrrolidone (PVP) modification, was prepared by a one-pot self-assembly method. PFeM with laser irradiation could induce intensified ferroptosis by integrating the functions of MF to deactivate glutathione peroxidase 4, Fe3+/Fe2+ to generate lethal reactive oxygen species via the Fenton reaction, and the photothermal effect to amplify ferroptosis. More importantly, the released MF could achieve cascade inflammation inhibition, thereby reversing the proinflammatory microenvironment caused by PTT. The in vivo antitumor and anti-inflammatory effects of PFeM were further confirmed in a 4T1 tumor-bearing mouse model. This study expounding the ferroptosis-inducing effects of MF and utilizing the strategy of chelating MF with iron ions can provide a new idea for developing photothermal nanoagents with clinically convertible safety ingredients and a green preparation process that improve efficacy and reduce adverse reactions during PTT.