Stabilization of phosphofructokinase 1 platelet isoform by AKT promotes tumorigenesis

Diversity of metabolic features and relevance to clinical subtypes of gliomas

Gliomas carry a dismal prognosis and have proven difficult to treat. Current treatments and efforts to target individual signaling pathways have failed. This is thought to be due to genetic and epigenetic heterogeneity and resistance. Therefore, interest has grown in developing a deeper understanding of the metabolic alterations that represent drivers and dependencies in gliomas. Therapies that target glioma-specific metabolic dependencies overcome the challenges of disease heterogeneity. Here, we present the diverse metabolic features of each current clinical subtype of glioma. We believe that this approach will enable the development of novel strategies to specifically target the various clinical and molecular subtypes of glioma using these metabolic features.

Post-translational modifications and the reprogramming of tumor metabolism

Metabolic reprogramming occurs alongside tumor development. As cancers advance from precancerous lesions to locally invasive tumors and then to metastatic tumors, metabolic patterns exhibit distinct changes, including mutations in metabolic enzymes and modifications in the activity of metabolic regulatory proteins. Alterations in metabolic patterns can influence tumor evolution, either establishing or alleviating metabolic burdens and facilitating cancer growth. To fully understand how metabolic reprogramming helps tumors grow and find the metabolic activities that are most useful for treating tumors, we need to have a deeper understanding of how metabolic patterns are controlled as tumors grow. Post-translational modifications (PTMs), a critical mechanism in the regulation of protein function, can influence protein activity, stability, and interactions in several ways. In tumor cells, PTMs-mediated metabolic reprogramming is a crucial mechanism for adapting to the challenging microenvironment and sustaining fast growth. This article will deeply explore the intricate regulatory mechanism of PTMs on metabolic reprogramming and its role in tumor progression, with the expectation of providing new theoretical basis and potential targets for tumor treatment.

Unveiling the multifaceted functions of TRIM proteins in glioma pathogenesis

Gliomas, the most prevalent malignant primary brain tumors in adults, represent a heterogeneous group of neoplasms characterized by poor prognosis and limited therapeutic options, particularly in high-grade cases. Understanding the molecular mechanisms underlying glioma pathogenesis is crucial for developing novel and effective treatment strategies. In recent years, increasing attention has been directed toward the tripartite motif (TRIM) family of proteins, a class of E3 ubiquitin ligases, due to their significant roles in glioma development and progression. This review comprehensively explores the diverse functions of TRIM proteins in gliomas, including their expression patterns, prognostic significance, and mechanisms of action that are both ubiquitination-dependent and -independent. By synthesizing current knowledge, we aim to elucidate the role of TRIM proteins in glioma pathogenesis and identify potential therapeutic targets within this protein family.

Targeting SAMD1 enhances the effect of anti-PD-1 plus lenvatinib therapy in hepatocellular carcinoma by increasing ferroptosis sensitivity and immune response

BACKGROUND

Combination therapy of anti-PD-1 plus lenvatinib has shown effective anti-tumour effects for unresectable hepatocellular carcinoma (HCC), but the overall prognosis of HCC is still unsatisfactory. Elucidating the molecular mechanism underlying HCC progression contributes to develop new effective treatment in order to enhances the response of anti-PD-1 plus lenvatinib therapy and improve the patients prognosis.

METHOD AND RESULTS

Here, we reported that targeting SAMD1 in HCC cells via small interference RNA-containing ZIF-90@HA (ATP/acid-responsive) Nanoparticles (ZIF-90@siRNA@HA NPs, ZSH NPs) significantly enhanced the anti-tumour effects of anti-PD-1 plus lenvatinib in vivo. Targeting SAMD1 in HCC cells not only increased cellular ROS abundance by inhibiting glycolysis and enhancing oxidative phosphorylation (OXPHOS) to increase ferroptosis sensitivity, but also inhibited the expression of CCL28, thereby reducing the recruitment of Treg cells, and improving the immunosuppression of tumour microenvironment. Mechanistically, SAMD1 suppression inhibits the expression of NUAK2 via Hippo pathway, thereby decreasing the phosphorylation of PFKP Ser386 and promoting the ubiquitination degradation of PFKP in HCC. Further study demonstrated that SAMD1 inhibition increased the expression of ITIH5 by regulating H3K4me3 demethylation at the ITIH5 promoter and then regulates Hippo pathway.

CONCLUSIONS

Our study revealed the potential application of targeting SAMD1 in HCC treatment by enhancing ferroptosis sensitivity and immune response.

ERK-USP9X-coupled regulation of thymidine kinase 1 promotes both its enzyme activity-dependent and its enzyme activity-independent functions for tumor growth

Thymidine kinase 1 (TK1), a crucial enzyme in DNA synthesis, is highly expressed in various cancers. However, the mechanisms underlying its elevated expression and the implications for tumor metabolism remain unclear. Here we demonstrate that activation of growth factor receptors enhances TK1 expression. Treatment with epidermal growth factor or insulin-like growth factor 1 induces the binding of ERK1/2 to TK1 and subsequent TK1 S13/231 phosphorylation by ERK1/2. This modification recruits ubiquitin carboxyl-terminal hydrolase 9X to deubiquitylate TK1, preventing its proteasomal degradation. Stabilized TK1 not only enhances its enzyme activity-dependent deoxythymidine monophosphate production for DNA synthesis but also promotes glycolysis independently of its enzymatic activity by upregulating phosphofructokinase/fructose bisphosphatase type 3 expression. This dual role of TK1 drives the proliferation of human hepatocellular carcinoma cells and liver tumor growth in mice. Our findings reveal a crucial mechanism by which growth factors promote tumor development through TK1-mediated DNA synthesis and glycolysis and highlight TK1 as a potential molecular target for cancer treatment.

Role of ubiquitination-driven metabolisms in oncogenesis and cancer therapy

Ubiquitination represents one of the most critical post-translational modifications, comprising a multi-stage enzyme process that plays a pivotal role in a myriad of cellular biological activities. The deregulation of the processes of ubiquitination and deubiquitination is associated with the development of cancers and other diseases. This typescript reviews the impact of ubiquitination on metabolic processes, elucidating the regulatory functions of ubiquitination on pivotal enzymes within metabolic pathways in pathological contexts. It underscores the role of ubiquitination-driven metabolism disorders in the etiology of cancers, and oncogenesis, and highlights the potential therapeutic efficacy of targeting ubiquitination-driven enzymes in cancer metabolism, their combination with immune checkpoint inhibitors, and their clinical applications.

Friend or foe of tripartite motif-containing protein 21 in cardiovascular disease: A review

As an E3 ubiquitin ligase and an Fc receptor, tripartite motif-containing protein 21 (TRIM21) plays a crucial role in immune defense, signal transduction, and cellular regulation. TRIM21 is widely expressed in various tissues, but it is particularly abundant in cardiovascular tissues and is involved in the pathogenesis of various cardiovascular diseases (CVDs). However, although TRIM21 is involved in the regulation of several key molecular pathways in the immune system, its specific role in CVD remains unclear. In this review, we comprehensively summarize the regulatory role of TRIM21 in signaling pathways and discuss the function of TRIM21 in CVD, to provide a systematic understanding of this important protein in CVD and offer insights for further research into the pathogenesis of CVD and its potential applications.

Mapping the Interactome of OSCC Prognostic-Associated Proteins NDRG1 and PGK1 Through Proximity Labeling Using TurboID

Oral squamous cell carcinoma (OSCC) is a prevalent type of head and neck cancer, comprising over 90% of all oral malignancies worldwide. The identification of diagnostic and prognostic markers for OSCC is crucial for improving patient outcomes, as early detection and treatment are critical for the successful management of this disease. Previously, we demonstrated that N-myc downstream-regulated gene 1 (NDRG1) and phosphoglycerate kinase 1 (PGK1) are prognostic markers for OSCC; however, their role in OSCC development remains unclear. To investigate this, we used TurboID-based proximity labeling to identify the interactomes of NDRG1 and PGK1 in HEK293 cells. Herein, protein abundance patterns from three time points were used for clustering 364 proteins with a "fast" or "slow" response to biotin. Of these, 65 proteins were also identified in neoplastic islands of OSCC patients from our previous study, and 28 of these proteins have their gene expression associated with prognostic features, including death, metastasis, and relapse. PRM-MS enabled the quantification of 17 of these proteins, providing further evidence of their presence in the OSCC prognostic interactome. Finally, we characterized a prognostic-associated interactome composed of 28 proteins, which enabled the prioritization of candidates that can be further explored in OSCC progression. The mass spectrometry data generated in this study have been deposited in ProteomeXchange with the data set identifier PXD048046.

Hydroxymethyltransferase 2 promotes the development of glioblastoma by mediating WTAP regulation of PTEN N6-methyladenosine modification

Characterized by rapid proliferation and therapeutic resistance, glioblastoma (GBM) represents the deadliest primary CNS neoplasm, demonstrating a low survival rate and high mortality rate in patients. This is mainly related to the development of GBM more specifically due to the abnormal metabolism within cells. SHMT2 (serine hydroxymethyltransferase 2) acts as a pivotal metabolic regulator in neoplastic cells, driving one-carbon unit transfer essential for nucleotide biosynthesis. Here, we explored the mechanism of SHMT2 mediated GBM occurrence. In this study, SHMT2 expression was assessed in GBM cells and tissues. In vitro experiments were performed to investigate the functional role of SHMT2. The detailed mechanisms of SHMT2-mediated cell metabolism were addressed. Xenograft model analysis explored the influence of SHMT2 on GBM development. The expression level of SHMT2 in GBM clinical tissues and cell lines is higher than that in normal tissues. The downregulation of SHMT2 inhibits the proliferation ability and metabolic process of GBM cell lines. Mechanism dissection revealed that SHMT2 enhanced phosphatase and tensin homolog (PTEN) N6-methyladenosine (m6A) modification through the endogenous methyl donor SAM mediated by SHMT2 via serine/glycine one carbon metabolic networks. In addition, Xenograft model analysis showed that knockdown of SHMT2 inhibited the development of GBM tumors. SHMT2 promotes the tumorigenesis of glioblastoma by regulating the m6A modification of PTEN.

Utilizing bioinformatics to identify biomarkers and analyze their expression in relation to immune cell ratios in femoral head necrosis

Background

Necrosis of the Femoral Head (NFH) represents a challenging orthopedic condition, characterized by elusive early detection and rapid progression, predominantly in the middle-aged demographic. Current research on the pathophysiological and immunoregulatory mechanisms underpinning immune cell infiltration in NFH is sparse. This study employs bioinformatics analysis of publicly available RNA sequencing databases to elucidate the pivotal molecules and pathways implicated in NFH progression.

Methods

The NFH-related dataset GSE123568 was obtained from the Gene Expression Omnibus (GEO). Subsequently, CIBERSORT was utilized to assess the proportion and distribution of immune cell types, followed by the identification of critical Hub immune cells using LASSO and RFE algorithms. The dataset GSE123568 was then explored to identify significantly differentially expressed genes (DEGs). These genes were further refined by intersecting with death-associated genes reported in existing literature. GO and KEGG pathway enrichment analyses were conducted to elucidate their underlying molecular mechanism. A protein-protein interaction (PPI) network was constructed using the STRING database and visualized via Cytoscape. Hub genes were identified using the CytoHubba plugin, followed by enrichment analysis, and their expression levels were evaluated using the ROC curve. In addition, we performed expression data visualization and ROC curve analysis on the external dataset GSE74089 to further evaluate the discriminative power of the hub genes. Moreover, the study analyzed the correlation between the identified hub genes and Hub immune cells. Finally, we verified the hub genes utilizing real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry.

Results

Four types of immune cells (Neutrophil, Mast cell resting, Myeloid dendritic cell activated, Macrophage M0) were identified. Fourteen pivotal genes (BCL2L1, BIRC2, NFKBIA, XIAP, CFLAR, AKT1, BIRC3, IKBKB, RIPK1, CASP8, TNFRSF1A, IL1B, CASP1, STAT3) were identified, and the findings were validated using the external dataset GSE74089. Among these, STAT3 exhibited the most pronounced positive correlation with neutrophils (r = 0.6804, p = 3.525e-05). Conversely, XIAP displayed the most significant negative correlation with Myeloid dendritic cell activated (r = -0.3610, p = 0.04003). In experiments, the experimental outcomes for five hub genes (CASP8, TNFRSF1A, AKT1, XIAP and STAT3) were congruent with the results obtained from bioinformatics analysis.

Conclusion

Our study identified CASP8, TNFRSF1A, AKT1, XIAP, STAT3 and BCL2L1 as potential biomarkers for NFH patients and elucidated the immune cell types with the strongest association to these markers. These insights may be crucial for the early diagnosis, understanding of the pathophysiological mechanisms, and the development of treatment strategies for NFH.

Moonlighting functions of glucose metabolic enzymes and metabolites in cancer

Glucose metabolic enzymes and their metabolites not only provide energy and building blocks for synthesizing macromolecules but also possess non-canonical or moonlighting functions in response to extracellular and intracellular signalling. These moonlighting functions modulate various cellular activities, including gene expression, cell cycle progression, DNA repair, autophagy, senescence and apoptosis, cell proliferation, remodelling of the tumour microenvironment and immune responses. These functions integrate glucose metabolism with other essential cellular activities, driving cancer progression. Targeting these moonlighting functions could open new therapeutic avenues and lead to cancer-specific treatments.

Study on the mechanism of 17-Hydroxy-jolkinolide B on anaplastic thyroid cancer cell

BACKGROUND

Anaplastic thyroid cancer (ATC) has a dismal prognosis, and the optimal treatment has not yet been confirmed. Euphorbia fischeriana Steud has been proven to exhibit pharmacological properties, including various antitumor effects, that can be used to treat numerous diseases and has been used to treat cancer. 17-Hydroxy-jolkinolide B (17-HJB) is one of the major diterpenoids produced from plants, but little research has investigated how it affects cancer.

METHODS

MTT assays, glucose and lactate concentration detection, Annexin V-FITC detection via cytometry, and Western blotting were performed to research the mechanism of 17-HJB.

RESULTS

Cell viability was inhibited in a concentration-dependent manner after 17-HJB treatment. 17-HJB inhibited glucose consumption and lactate production, and the expression of the glucose transporter GLUT1 and proteins associated with glycolysis, HK2, PFK1, and PKM2, was significantly downregulated. 17-HJB induced apoptosis, and the expression of signaling proteins related to apoptosis, such as Caspase-3 and cleaved Caspase-3, was upregulated. In vivo, 17-HJB effectively inhibited the growth of ATC tumors. The results of the expression of glycolysis-related enzyme proteins and apoptosis signaling proteins were consistent with those in vitro.

CONCLUSIONS

17-HJB inhibited the growth of ATCs both in vivo and in vitro. The mechanism may be related to the effects on glucose metabolism and the inhibition of aerobic glycolysis. 17-HJB also induced ATC apoptosis.

GNAO1 overexpression promotes neural differentiation of glioma stem-like cells and reduces tumorigenicity through TRIM21/CREB/HES1 axis

Inducing tumor cell differentiation is a promising strategy for treating malignant cancers, including glioma, yet the critical regulator(s) underlying glioma cell differentiation is poorly understood. Here, we identify G Protein Subunit Alpha O1 (GNAO1) as a critical regulator of neural differentiation of glioma stem-like cells (GSCs). GNAO1 expression was lower in gliomas than in normal neuronal tissues and high expression of GNAO1 correlated with a better prognosis. GNAO1 overexpression markedly promoted neural differentiation of GSCs, leading to decreased cell proliferation and colony formation. Mechanistically, GNAO1 recruited TRIM21 and facilitated TRIM21-mediated ubiquitination. This ubiquitination resulted in the degradation of CREB and further reduced p300-mediated H3K27ac levels of the HES1 promoter. As a result, GNAO1 overexpression downregulated HES1 expression, which reinforced neuronal differentiation. In addition, knockdown of METTL3, a key writer of the N6-methyladenosine (m6A), enhanced GNAO1 mRNA stability. Treatment with GNAO1 adenovirus increased neuronal differentiation of tumor cells and reduced tumor cell proliferation in orthotopic GSC xenografts and temozolomide further enhanced GNAO1 adenovirus effects, resulting in extended animal survival. Our study presents that engineering GNAO1 overexpression-inducing neural differentiation of GSCs is a potential therapy strategy via synergistic inhibition of malignant proliferation and chemotherapy resistance.

Hexokinase detachment from mitochondria drives the Warburg effect to support compartmentalized ATP production

Hexokinase (HK) catalyzes the synthesis of glucose-6-phosphate, marking the first committed step of glucose metabolism. Most cancer cells express two homologous isoforms (HK1 and HK2) that can each bind to the outer mitochondrial membrane (OMM). CRISPR screens across hundreds of cancer cell lines indicate that both are dispensable for cell growth in traditional culture media. By contrast, HK2 deletion impairs cell growth in Human Plasma-Like Medium (HPLM). Here, we find that HK2 is required to maintain sufficient cytosolic (OMM-detached) HK activity under conditions that enhance HK1 binding to the OMM. Notably, OMM-detached rather than OMM-docked HK promotes "aerobic glycolysis" (Warburg effect), an enigmatic phenotype displayed by most proliferating cells. We show that several proposed theories for this phenotype cannot explain the HK2 dependence and instead find that HK2 deletion severely impairs glycolytic ATP production with little impact on total ATP yield for cells in HPLM. Our results reveal a basis for conditional HK2 essentiality and suggest that demand for compartmentalized ATP synthesis underlies the Warburg effect.

ACSS2 acts as a lactyl-CoA synthetase and couples KAT2A to function as a lactyltransferase for histone lactylation and tumor immune evasion

Lactyl-coenzyme A (CoA)-dependent histone lysine lactylation impacts gene expression and plays fundamental roles in biological processes. However, mammalian lactyl-CoA synthetases and their regulation of histone lactylation have not yet been identified. Here, we demonstrate that epidermal growth factor receptor (EGFR) activation induces extracellular signal-regulated kinase (ERK)-mediated S267 phosphorylation of acetyl-CoA synthetase 2 (ACSS2) and its subsequent nuclear translocation and complex formation with lysine acetyltransferase 2A (KAT2A). Importantly, ACSS2 functions as a bona fide lactyl-CoA synthetase and converts lactate to lactyl-CoA, which binds to KAT2A as demonstrated by a co-crystal structure analysis. Consequently, KAT2A acts as a lactyltransferase to lactylate histone H3, leading to the expression of Wnt/β-catenin, NF-κB, and PD-L1 and brain tumor growth and immune evasion. A combination treatment with an ACSS2-KAT2A interaction-blocking peptide and an anti-PD-1 antibody induces an additive tumor-inhibitory effect. These findings uncover ACSS2 and KAT2A as hitherto unidentified lactyl-CoA synthetase and lactyltransferase, respectively, and the significance of the ACSS2-KAT2A coupling in gene expression and tumor development.

ENO2-Regulated Glycolysis in Endothelial Cells Contributes to FGF2-Induced Retinal Neovascularization

Purpose

Ocular neovascularization is a major cause of blindness. Although fibroblast growth factor-2 (FGF2) has been implicated in the pathophysiology of angiogenesis, the underlying mechanisms remain incompletely understood. The purpose of this study was to investigate the role of FGF2 in retinal neovascularization and elucidate its underlying mechanisms.

Methods

The oxygen-induced retinopathy mouse model was used to study the pathogenesis of retinal neovascularization. Immunofluorescence was used to quantify the neovascularization in retina. Data-independent acquisition proteomics were performed to quantify differentially expressed proteins in human retinal microvascular endothelial cells stimulated with FGF2 and associated pathways were analyzed. We carried out qRT-PCR and Western Blot assays to detect the expression of genes at mRNA and protein levels. The angiogenesis abilities of human retinal microvascular endothelial cells were measured by transwell, EdU and tube formation assays.

Results

FGF2 was significantly upregulated in retinal tissues of the oxygen-induced retinopathy mouse model and it markedly enhanced tube formation, migration, and proliferation abilities of human retinal microvascular endothelial cells in vitro. The proteomic analysis identified 287 differentially expressed proteins in endothelial cells in response to FGF2 stimulation, characterized by a notable upregulation of the glycolysis pathway, among which we confirmed that the enolase 2 (ENO2) levels were elevated after FGF2 stimulation, and its knockdown resulted in diminished glycolytic activity and impaired angiogenic processes. Furthermore, the use of the ENO2 inhibitor AP-Ⅲ-a4 alleviated angiogenesis in vivo and in vitro.

Conclusions

Our findings underscore the pivotal role of ENO2-mediated glycolysis in FGF2-induced angiogenesis, suggesting that ENO2 may serve as a promising therapeutic target for managing pathological neovascularization.

Eye on the horizon: The metabolic landscape of the RPE in aging and disease

To meet the prodigious bioenergetic demands of the photoreceptors, glucose and other nutrients must traverse the retinal pigment epithelium (RPE), a polarised monolayer of cells that lie at the interface between the outer retina and the choroid, the principal vascular layer of the eye. Recent investigations have revealed a metabolic ecosystem in the outer retina where the photoreceptors and RPE engage in a complex exchange of sugars, amino acids, and other metabolites. Perturbation of this delicate metabolic balance has been identified in the aging retina, as well as in age-related macular degeneration (AMD), the leading cause of blindness in the Western world. Also common in the aging and diseased retina are elevated levels of cytokines, oxidative stress, advanced glycation end-products, increased growth factor signalling, and biomechanical stress - all of which have been associated with metabolic dysregulation in non-retinal cell types and tissues. Herein, we outline the role of these factors in retinal homeostasis, aging, and disease. We discuss their effects on glucose, mitochondrial, lipid, and amino acid metabolism in tissues and cell types outside the retina, highlighting the signalling pathways through which they induce these changes. Lastly, we discuss promising avenues for future research investigating the roles of these pathological conditions on retinal metabolism, potentially offering novel therapeutic approaches to combat age-related retinal disease.

PKC phospho-activated PFK1 is required for PBAN regulated sex pheromone biosynthesis in Helicoverpa armigera

The enzyme 6-phosphofructokinase-1 (PFK1) acts as the primary rate-limiting enzyme in glycolysis, catalyzing the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. This glycolytic process provides essential substrates for the synthesis of sex pheromones. However, the specific function of PFK1 in sex pheromone biosynthesis remains unidentified. This study aimed to investigate the detailed mechanism by which PFK1 influences pheromone biosynthesis activating neuropeptide (PBAN)-regulated sex pheromone biosynthesis in Hecoverpa armigera. Findings revealed the presence of two PFK genes in pheromone glands (PGs). Further investigation demonstrated that RNAi-mediated knockdown of PFK1 significantly reduced sex pheromone production, mating success and the female ability to attract males, whereas PFK2 did not influence sex pheromone biosynthesis. Importantly, PFK1 was activated by PBAN in both isolated PGs and Sf9 cells. However, PBAN-induced activation of PFK1 could be attenuated by chelerythrine chloride (CC), a specific inhibitor of protein kinase C (PKC). Furthermore, the phosphorylation levels of PFK1 significantly increased in response to PBAN challenge, while CC treatment significantly mitigated this phosphorylation. PFK1 activity was found to depend on phosphorylation at the S135 and S676 sites in response to PBAN stimulation. Mutants at these sites abolished PFK1 phosphorylation and its activity. Overall, our findings unveil a critical mechanism by which the PBAN signaling recruits PKC to phosphorylate PFK1 at S135 and S676 sites, thereby activating PFK1. This activation ensures the normal progression of the glycolysis pathway, ultimately facilitating sex pheromone biosynthesis.

RNF123 inhibits cell viability, cell cycle and colony formation of breast cancer by inhibiting glycolysis via ubiquitination of PFKP

E3 ubiquitin ligases have the potential to modulate key oncogenic pathways. RING finger protein 123 (RNF123), as an E3 ubiquitin ligase, has been functioned as a tumor suppressor. This study was designed to explore the role of RNF123 in breast cancer. Immunohistochemistry was applied to examine protein expression in breast cancer tissues. Western blot and Quantitative Real-time PCR were performed to gauge protein and mRNA levels. Lentivirus transduction was used to overexpress or silence genes of interest. Cell Counting Kit-8, flow cytometry, and colony formation assays were used to assess cell viability, cell cycle, and colony formation. Extracellular acidification rate, lactic acid and adenosine triphosphate were used for glycolysis assay. Co-immunoprecipitation (Co-IP) and ubiquitination analysis were used to explore the interaction between RNF123 and 6-Phosphofructo-2-kinase (PFKP). In vivo experiments were performed with xenograft tumor models. RNF123 was downregulated in tumor tissues and cells, overexpression of which significantly decreased the viability and colony-forming ability of tumor cells, suppressed the progression of the cell cycle and glycolytic activity, and suppressed tumor growth in vivo. Co-IP and ubiquitination analysis revealed that there was an interaction between RNF123 and PFKP, and RNF123 could induce ubiquitination of PFKP. PFKP could reverse the effects of RNF123 on tumor cells. RNF123 inhibited cell viability, cell cycle and colony formation of breast cancer cells by inhibiting glycolysis via ubiquitination of PFKP.

Unveiling the Mechanisms and Therapeutic Effects of Xiaoyao Sanjie Decoction in Triple-Negative Breast Cancer: A Network Pharmacology and Experimental Validation Approach

Purpose

Triple-negative breast cancer (TNBC) is a disease associated with high incidence and high mortality, which is a major problem threatening women's health. Xiaoyao Sanjie Decoction (XYSJD) exhibits remarkable therapeutic efficacy on TNBC; however, the underlying mechanism is unclear. This study verified the efficacy of XYSJD and its active component in the treatment of TNBC and explored its potential mechanism.

Methods

Ultra-high performance liquid chromatography-hybrid quadrupole orbitrap mass spectrometry (UHPLC-Q Exactive HFX-MS) was applied to explore the main chemical constituents of XYSJD. The key targets and potential mechanisms of XYSJD in the treatment of TNBC were predicted through network pharmacology, bioinformatics analysis and molecular docking. The effects of XYSJD against TNBC cells were evaluated by CCK-8 assay, EdU assay, wound healing assay, transwell assay, Hoechst-PI staining and flow cytometry. The mechanism of action was validated by Western blot analysis. Finally, the effect and mechanism of XYSJD and Que on TNBC were further verified by the tumor formation model.

Results

UHPLC-Q Exactive HFX-MS identified a total of 9 compounds in XYSJD. Network pharmacological methods identified 206 targets for anti-TNBC. Bioinformatics analysis suggests that the EZH2/AKT1 signaling pathway might play an important role in the effects of XYSJD against TNBC. Gene Ontology enrichment analysis showed that the biological process of XYSJD in TNBC treatment mainly involved apoptosis. XYSJD and Que were observed to have a good anticancer effect in vivo and in vitro. In addition, quercetin could induce the apoptosis of TNBC cells by decreased the expression levels of EZH2/AKT1 signaling pathway. Furthermore, AKT1 overexpression, treatment with the AKT activator (SC79) and EZH2 overexpression could reverse apoptosis induced by quercetin in TNBC cells.

Conclusion

This study revealed the anti-TNBC efficacy of XYSJD. Quercetin, the effective component of XYSJD, promoted apoptosis of TNBC cells via blockade of the EZH2/AKT1 signaling pathway. These findings aim to provide a more reliable basis for the clinical application of XYSJD in the treatment of TNBC.

PFKP Lactylation Promotes the Ovarian Cancer Progression Through Targeting PTEN

Ovarian cancer (OC) ranks among the most prevalent malignancies affecting females globally and is a leading cause of cancer-related mortality in women. This study sought to elucidate the influence of phosphofructokinase P (PFKP) on the progression of OC. A cohort of sixty OC patients was enrolled. OC cells were exposed to both normoxic and hypoxic conditions. Expression levels of PFKP and phosphatase and tensin homolog (PTEN) were quantified using real time quantitative polymerase chain reaction (RT-qPCR) and Western blot analyses. Immunofluorescence confirmed these protein expression patterns. Glycolysis-related parameters, encompassing glucose uptake, extracellular lactate levels, extracellular acidification rates, and oxygen consumption rates, were assessed using commercially available kits. Lactylation status of PFKP was evaluated via immunoprecipitation followed by Western blot analysis. An OC xenograft mouse model was also established. Findings indicated elevated PFKP expression in OC tissues and cells. Additionally, PFKP knockdown attenuated glycolysis and counteracted the hypoxia-induced enhancement of glycolytic activity in OC cells. Mutation of the lysine (K) residue at position 392 diminished PFKP lactylation. Further investigations revealed that PFKP depletion upregulated PTEN expression in hypoxia-treated OC cells. Besides, PTEN suppression increased the glycolysis in hypoxia-treated OC cells. Animal study results demonstrated that PFKP inhibition curtailed OC tumor growth by modulating PTEN expression. Collectively, these results suggested that lactylation of PFKP at the K392 residue promoted glycolysis in OC cells by regulating PTEN, thereby facilitating the disease's progression.

Effect of lncRNA XIST on acute myeloid leukemia cells via miR-142-5p-PFKP axis

Acute myeloid leukemia (AML) is the common blood cancer in hematopoietic system-related diseases and has a poor prognosis. Studies have shown that long non-coding RNAs (lncRNAs) are closely related to the pathogenesis of a variety of diseases, including AML. However, the specific molecular mechanism remains unclear. Hence, the objective of this study was to investigate the effect and mechanism of lncRNA X inactive specific transcript (lncRNA XIST) on AML. To achieve our objective, some tests were performed. Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect the expression of lncRNA XIST, miR-142-5p and the platelet isoform of phosphofructokinase (PFKP). The targeting relationship between miR-142-5p and lncRNA XIST and PFKP was verified by Pearson correlation analysis, dual-luciferase reporter assay, and pull-down assay. Functional experiments were used to analyze the effect and mechanism of action of knocking down lncRNA XIST on THP-1 and U937 cells. Compared with bone marrow cells, lncRNA XIST and PFKP expression levels were up-regulated and miR-142-5p expression levels were down-regulated in AML. Further analysis revealed that lncRNA XIST targeted and bound to miR-142-5p, and PFKP was a target gene of miR-142-5p. Knockdown of lncRNA XIST significantly promoted miR-142-5p expression to down-regulate PFKP in THP-1 and U937 cells, while the cell proliferation, cell viability, and cell cycle arrest were inhibited and apoptosis was increased. Knockdown of miR-142-5p reversed the functional impact of lncRNA XIST knockdown on AML cells. In conclusion, down-regulation of lncRNA XIST can affect the progression of AML by regulating miR-142-5p.

Protein kinase N1 deficiency results in upregulation of cerebral energy metabolism and is highly protective in in vivo and in vitro stroke models

BACKGROUND AND AIM

We recently identified protein kinase N1 (PKN1) as a master regulator of brain development. However, its function in the adult brain has not been clearly established. In this study, we assessed the cerebral energetic phenotype of wildtype (WT) and global Pkn1 knockout (Pkn1-/-) animals under physiological and pathophysiological conditions.

METHODS

Cerebral energy metabolism was analyzed by 13C6-glucose tracing in vivo and real time seahorse analysis of extracellular acidification rates as well as mitochondrial oxygen consumption rates (OCR) of brain slice punches in vitro. Isolated WT and Pkn1-/- brain mitochondria were tested for differences in OCR with different substrates. Metabolite levels were determined by mass spectrometric analysis in brain slices under control and energetic stress conditions, induced by oxygen-glucose deprivation and reperfusion, an in vitro model of ischemic stroke. Differences in enzyme activities were assessed by enzymatic assays, western blotting and bulk RNA sequencing. A middle cerebral artery occlusion stroke model was used to analyze lesion volumes and functional recovery in WT and Pkn1-/- mice.

RESULTS

Pkn1 deficiency resulted in a remarkable upregulation of cerebral energy metabolism, in vivo and in vitro. This was due to two separate mechanisms involving an enhanced glycolytic flux and higher pyruvate-induced mitochondrial OCR. Mechanistically we show that Pkn1-/- brain tissue exhibits an increased activity of the glycolysis rate-limiting enzyme phosphofructokinase. Additionally, glucose-1,6-bisphosphate levels, a metabolite that increases mitochondrial pyruvate uptake, were elevated upon Pkn1 deficiency. Consequently, Pkn1-/- brain slices had more ATP and a greater accumulation of ATP degradation metabolites during energetic stress. This translated into increased phosphorylation and activity of adenosine monophosphate (AMP)-activated protein kinase (AMPK) during in vitro stroke. Accordingly, Pkn1-/- brain slices showed a post-ischemic transcriptional upregulation of energy metabolism pathways and Pkn1 deficiency was strongly protective in in vitro and in vivo stroke models. While inhibition of mitochondrial pyruvate uptake only moderately affected the protective phenotype, inhibition of AMPK in Pkn1-/- slices increased post-ischemic cell death in vitro.

CONCLUSION

This is the first study to comprehensively demonstrate an essential and unique role of PKN1 in cerebral energy metabolism, regulating glycolysis and mitochondrial pyruvate-induced respiration. We further uncovered a highly protective phenotype of Pkn1 deficiency in both, in vitro and in vivo stroke models, validating inhibition of PKN1 as a promising new therapeutic target for the development of novel stroke therapies.

PFKP silencing suppresses tumor growth via the AXL-MET axis

PFKP (Phosphofructokinase, Platelet Type isoform), as an essential metabolic enzyme, contributes to the high glycolysis rates seen in cancers while its role in oncogenic pathways, especially from a non-metabolic aspect, is not fully understood. We found that PFKP was highly expressed in NSCLC and was related to poor patient survival. Knockdown of PFKP significantly inhibited cell proliferation, colony formation, invasion, and migration of NSCLC cells. Nanoparticles-mediated PFKP silencing can inhibit tumor growth in vivo. Mechanistically, we found that PFKP can bind with AXL and promote its phosphorylation at Y779, thus activating the AXL signaling pathway and promoting MET phosphorylation. In addition, several glycolysis, glutaminolysis, and TCA cycle proteins were downregulated following PFKP silencing. PFKP has an oncogenic role in cancer progression in vitro and in vivo. Beyond its known role in glycolysis, PFKP also has a non-metabolic function in affecting lung cancer progression by interacting with the AXL-MET axis, thus indicating a potential therapeutic target for lung cancer.

Growth Signaling Networks Orchestrate Cancer Metabolic Networks

Normal cells grow and divide only when instructed to by signaling pathways stimulated by exogenous growth factors. A nearly ubiquitous feature of cancer cells is their capacity to grow independent of such signals, in an uncontrolled, cell-intrinsic manner. This property arises due to the frequent oncogenic activation of core growth factor signaling pathway components, including receptor tyrosine kinases, PI3K-AKT, RAS-RAF, mTORC1, and MYC, leading to the aberrant propagation of pro-growth signals independent of exogenous growth factors. The growth of both normal and cancer cells requires the acquisition of nutrients and their anabolic conversion to the primary macromolecules underlying biomass production (protein, nucleic acids, and lipids). The core growth factor signaling pathways exert tight regulation of these metabolic processes and the oncogenic activation of these pathways drive the key metabolic properties of cancer cells and tumors. Here, we review the molecular mechanisms through which these growth signaling pathways control and coordinate cancer metabolism.

Glycolysis, the sweet appetite of the tumor microenvironment

Cancer cells display an altered metabolic phenotype, characterised by increased glycolysis and lactate production, even in the presence of sufficient oxygen - a phenomenon known as the Warburg effect. This metabolic reprogramming is a crucial adaptation that enables cancer cells to meet their elevated energy and biosynthetic demands. Importantly, the tumor microenvironment plays a pivotal role in shaping and sustaining this metabolic shift in cancer cells. This review explores the intricate relationship between the tumor microenvironment and the Warburg effect, highlighting how communication within this niche regulates cancer cell metabolism and impacts tumor progression and therapeutic resistance. We discuss the potential of targeting the Warburg effect as a promising therapeutic strategy, with the aim of disrupting the metabolic advantage of cancer cells and enhancing our understanding of this complex interplay within the tumor microenvironment.

Casting Light on the Janus-Faced HMG-CoA Reductase Degradation Protein 1: A Comprehensive Review of Its Dualistic Impact on Apoptosis in Various Diseases

Nowadays, it is well recognized that apoptosis, as a highly regulated cellular process, plays a crucial role in various biological processes, such as cell differentiation. Dysregulation of apoptosis is strongly implicated in the pathophysiology of numerous disorders, making it essential to comprehend its underlying mechanisms. One key factor that has garnered significant attention in the regulation of apoptotic pathways is HMG-CoA reductase degradation protein 1, also known as HRD1. HRD1 is an E3 ubiquitin ligase located in the endoplasmic reticulum (ER) membrane. Its primary role involves maintaining the quality control of ER proteins by facilitating the ER-associated degradation (ERAD) pathway. During ER stress, HRD1 aids in the elimination of misfolded proteins that accumulate within the ER. Therefore, HRD1 plays a pivotal role in the regulation of apoptotic pathways and maintenance of ER protein quality control. By targeting specific protein substrates and affecting apoptosis-related pathways, HRD1 could be an exclusive therapeutic target in different disorders. Dysregulation of HRD1-mediated processes contributes significantly to the pathophysiology of various diseases. The purpose of this review is to assess the effect of HRD1 on the pathways related to apoptosis in various diseases from a therapeutic perspective.

Development of a biomarker prediction model for post-trauma multiple organ failure/dysfunction syndrome based on the blood transcriptome

BACKGROUND

Multiple organ failure/dysfunction syndrome (MOF/MODS) is a major cause of mortality and morbidity among severe trauma patients. Current clinical practices entail monitoring physiological measurements and applying clinical score systems to diagnose its onset. Instead, we aimed to develop an early prediction model for MOF outcome evaluated soon after traumatic injury by performing machine learning analysis of genome-wide transcriptome data from blood samples drawn within 24 h of traumatic injury. We then compared its performance to baseline injury severity scores and detection of infections.

METHODS

Buffy coat transcriptome and linked clinical datasets from blunt trauma patients from the Inflammation and the Host Response to Injury Study ("Glue Grant") multi-center cohort were used. According to the inclusion/exclusion criteria, 141 adult (age ≥ 16 years old) blunt trauma patients (excluding penetrating) with early buffy coat (≤ 24 h since trauma injury) samples were analyzed, with 58 MOF-cases and 83 non-cases. We applied the Least Absolute Shrinkage and Selection Operator (LASSO) and eXtreme Gradient Boosting (XGBoost) algorithms to select features and develop models for MOF early outcome prediction.

RESULTS

The LASSO model included 18 transcripts (AUROC [95% CI]: 0.938 [0.890-0.987] (training) and 0.833 [0.699-0.967] (test)), and the XGBoost model included 41 transcripts (0.999 [0.997-1.000] (training) and 0.907 [0.816-0.998] (test)). There were 16 overlapping transcripts comparing the two panels (0.935 [0.884-0.985] (training) and 0.836 [0.703-0.968] (test)). The biomarker models notably outperformed models based on injury severity scores and sex, which we found to be significantly associated with MOF (APACHEII + sex-0.649 [0.537-0.762] (training) and 0.493 [0.301-0.685] (test); ISS + sex-0.630 [0.516-0.744] (training) and 0.482 [0.293-0.670] (test); NISS + sex-0.651 [0.540-0.763] (training) and 0.525 [0.335-0.714] (test)).

CONCLUSIONS

The accurate assessment of MOF from blood samples immediately after trauma is expected to aid in improving clinical decision-making and may contribute to reduced morbidity, mortality and healthcare costs. Moreover, understanding the molecular mechanisms involving the transcripts identified as important for MOF prediction may eventually aid in developing novel interventions.

Structural basis for allosteric regulation of human phosphofructokinase-1

Phosphofructokinase-1 (PFK1) catalyzes the rate-limiting step of glycolysis, committing glucose to conversion into cellular energy. PFK1 is highly regulated to respond to the changing energy needs of the cell. In bacteria, the structural basis of PFK1 regulation is a textbook example of allostery; molecular signals of low and high cellular energy promote transition between an active R-state and inactive T-state conformation, respectively. Little is known, however, about the structural basis for regulation of eukaryotic PFK1. Here, we determine structures of the human liver isoform of PFK1 (PFKL) in the R- and T-state by cryoEM, providing insight into eukaryotic PFK1 allosteric regulatory mechanisms. The T-state structure reveals conformational differences between the bacterial and eukaryotic enzyme, the mechanisms of allosteric inhibition by ATP binding at multiple sites, and an autoinhibitory role of the C-terminus in stabilizing the T-state. We also determine structures of PFKL filaments that define the mechanism of higher-order assembly and demonstrate that these structures are necessary for higher-order assembly of PFKL in cells.

Genome-wide CRISPR screening identifies critical role of phosphatase and tensin homologous (PTEN) in sensitivity of acute myeloid leukemia to chemotherapy

Although significant progress has been made in the development of novel targeted drugs for the treatment of acute myeloid leukemia (AML) in recent years, chemotherapy still remains the mainstay of treatment and the overall survival is poor in most patients. Here, we demonstrated the antileukemia activity of a novel small molecular compound NL101, which is formed through the modification on bendamustine with a suberanilohydroxamic acid (SAHA) radical. NL101 suppresses the proliferation of myeloid malignancy cells and primary AML cells. It induces DNA damage and caspase 3-mediated apoptosis. A genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) library screen revealed that phosphatase and tensin homologous (PTEN) gene is critical for the regulation of cell survival upon NL101 treatment. The knockout or inhibition of PTEN significantly reduced NL101-induced apoptosis in AML and myelodysplastic syndrome (MDS) cells, accompanied by the activation of protein kinase B (AKT) signaling pathway. The inhibition of mammalian target of rapamycin (mTOR) by rapamycin enhanced the sensitivity of AML cells to NL101-induced cell death. These findings uncover PTEN protein expression as a major determinant of chemosensitivity to NL101 and provide a novel strategy to treat AML with the combination of NL101 and rapamycin.

Transcriptional regulation and post-translational modifications in the glycolytic pathway for targeted cancer therapy

Cancer cells largely rely on aerobic glycolysis or the Warburg effect to generate essential biomolecules and energy for their rapid growth. The key modulators in glycolysis including glucose transporters and enzymes, e.g. hexokinase 2, enolase 1, pyruvate kinase M2, lactate dehydrogenase A, play indispensable roles in glucose uptake, glucose consumption, ATP generation, lactate production, etc. Transcriptional regulation and post-translational modifications (PTMs) of these critical modulators are important for signal transduction and metabolic reprogramming in the glycolytic pathway, which can provide energy advantages to cancer cell growth. In this review we recapitulate the recent advances in research on glycolytic modulators of cancer cells and analyze the strategies targeting these vital modulators including small-molecule inhibitors and microRNAs (miRNAs) for targeted cancer therapy. We focus on the regulation of the glycolytic pathway at the transcription level (e.g., hypoxia-inducible factor 1, c-MYC, p53, sine oculis homeobox homolog 1, N6-methyladenosine modification) and PTMs (including phosphorylation, methylation, acetylation, ubiquitination, etc.) of the key regulators in these processes. This review will provide a comprehensive understanding of the regulation of the key modulators in the glycolytic pathway and might shed light on the targeted cancer therapy at different molecular levels.

Single-Cell Analyses Reveal the Metabolic Heterogeneity and Plasticity of the Tumor Microenvironment during Head and Neck Squamous Cell Carcinoma Progression

Metabolic reprogramming is a hallmark of cancer. In addition to metabolic alterations in the tumor cells, multiple other metabolically active cell types in the tumor microenvironment (TME) contribute to the emergence of a tumor-specific metabolic milieu. Here, we defined the metabolic landscape of the TME during the progression of head and neck squamous cell carcinoma (HNSCC) by performing single-cell RNA sequencing on 26 human patient specimens, including normal tissue, precancerous lesions, early stage cancer, advanced-stage cancer, lymph node metastases, and recurrent tumors. The analysis revealed substantial heterogeneity at the transcriptional, developmental, metabolic, and functional levels in different cell types. SPP1+ macrophages were identified as a protumor and prometastatic macrophage subtype with high fructose and mannose metabolism, which was further substantiated by integrative analysis and validation experiments. An inhibitor of fructose metabolism reduced the proportion of SPP1+ macrophages, reshaped the immunosuppressive TME, and suppressed tumor growth. In conclusion, this work delineated the metabolic landscape of HNSCC at a single-cell resolution and identified fructose metabolism as a key metabolic feature of a protumor macrophage subpopulation. Significance: Fructose and mannose metabolism is a metabolic feature of a protumor and prometastasis macrophage subtype and can be targeted to reprogram macrophages and the microenvironment of head and neck squamous cell carcinoma.

PA28γ coordinates the cross-talk between cancer-associated fibroblasts and tumor cells to promote OSCC progression via HDAC1/E2F3/IGF2 signaling

PA28γ overexpression is aberrant and accompanied by poor patient prognosis in various cancers, the precise regulatory mechanism of this crucial gene in the tumor microenvironment remains incompletely understood. In this study, using oral squamous cell carcinoma as a model, we demonstrated that PA28γ exhibits high expression in cancer-associated fibroblasts (CAFs), and its expression significantly correlates with the severity of clinical indicators of malignancy. Remarkably, we found that elevated levels of secreted IGF2 from PA28γ+ CAFs can enhance stemness maintenance and promote tumor cell aggressiveness through the activation of the MAPK/AKT pathway in a paracrine manner. Mechanistically, PA28γ upregulates IGF2 expression by stabilizing the E2F3 protein, a transcription factor of IGF2. Further mechanistic insights reveal that HDAC1 predominantly mediates the deacetylation and subsequent ubiquitination and degradation of E2F3. Notably, PA28γ interacts with HDAC1 and accelerates its degradation via a 20S proteasome-dependent pathway. Additionally, PA28γ+ CAFs exert an impact on the tumor immune microenvironment by secreting IGF2. Excitingly, our study suggests that targeting PA28γ+ CAFs or secreted IGF2 could increase the efficacy of PD-L1 therapy. Thus, our findings reveal the pivotal role of PA28γ in cell interactions in the tumor microenvironment and propose novel strategies for augmenting the effectiveness of immune checkpoint blockade in oral squamous cell carcinoma.

A positive feedback loop between PFKP and c-Myc drives head and neck squamous cell carcinoma progression

BACKGROUND

The aberrant expression of phosphofructokinase-platelet (PFKP) plays a crucial role in the development of various human cancers by modifying diverse biological functions. However, the precise molecular mechanisms underlying the role of PFKP in head and neck squamous cell carcinoma (HNSCC) are not fully elucidated.

METHODS

We assessed the expression levels of PFKP and c-Myc in tumor and adjacent normal tissues from 120 HNSCC patients. A series of in vitro and in vivo experiments were performed to explore the impact of the feedback loop between PFKP and c-Myc on HNSCC progression. Additionally, we explored the therapeutic effects of targeting PFKP and c-Myc in HNSCC using Patient-Derived Organoids (PDO), Cell Line-Derived Xenografts, and Patients-Derived Xenografts.

RESULTS

Our findings indicated that PFKP is frequently upregulated in HNSCC tissues and cell lines, correlating with poor prognosis. Our in vitro and in vivo experiments demonstrate that elevated PFKP facilitates cell proliferation, angiogenesis, and metastasis in HNSCC. Mechanistically, PFKP increases the ERK-mediated stability of c-Myc, thereby driving progression of HNSCC. Moreover, c-Myc stimulates PFKP expression at the transcriptional level, thus forming a positive feedback loop between PFKP and c-Myc. Additionally, our multiple models demonstrate that co-targeting PFKP and c-Myc triggers synergistic anti-tumor effects in HNSCC.

CONCLUSION

Our study demonstrates the critical role of the PFKP/c-Myc positive feedback loop in driving HNSCC progression and suggests that simultaneously targeting PFKP and c-Myc may be a novel and effective therapeutic strategy for HNSCC.

Glycolytic enzyme PFKL governs lipolysis by promoting lipid droplet-mitochondria tethering to enhance β-oxidation and tumor cell proliferation

Lipid droplet tethering with mitochondria for fatty acid oxidation is critical for tumor cells to counteract energy stress. However, the underlying mechanism remains unclear. Here, we demonstrate that glucose deprivation induces phosphorylation of the glycolytic enzyme phosphofructokinase, liver type (PFKL), reducing its activity and favoring its interaction with perilipin 2 (PLIN2). On lipid droplets, PFKL acts as a protein kinase and phosphorylates PLIN2 to promote the binding of PLIN2 to carnitine palmitoyltransferase 1A (CPT1A). This results in the tethering of lipid droplets and mitochondria and the recruitment of adipose triglyceride lipase to the lipid droplet-mitochondria tethering regions to engage lipid mobilization. Interfering with this cascade inhibits tumor cell proliferation, promotes apoptosis and blunts liver tumor growth in male mice. These results reveal that energy stress confers a moonlight function to PFKL as a protein kinase to tether lipid droplets with mitochondria and highlight the crucial role of PFKL in the integrated regulation of glycolysis, lipid metabolism and mitochondrial oxidation.

[TRIM21 Inhibits the Proliferation and Migration of Lung Adenocarcinoma Cells by Interacting with ZSWIM1]

BACKGROUND

Lung adenocarcinoma (LUAD) is a highly morbid and fatal cancer. Despite advancements in modern medical treatment, the 5-year survival rate of patients remains suboptimal. Our previous study revealed that zinc finger SWIM-type containing 1 (ZSWIM1), a novel protein, promotes the proliferation, migration, and invasion of LUAD cells. The aim of this study is to investigate the impact of E3 ubiquitin ligase tripartite motif protein 21 (TRIM21) on ZSWIM1-mediated cell proliferation and migration.

METHODS

The interaction and co-localization between TRIM21 and ZSWIM1 were verified using co-immunoprecipitation (Co-IP) and immunofluorescence (IF). The effects of TRIM21 and ZSWIM1 on the proliferation and migration of LUAD cells were assessed through MTT and Transwell assays, respectively. Western blot (WB) analysis was conducted to evaluate the impact of TRIM21 and ZSWIM1 on the expression of epithelial-mesenchymal transition (EMT) markers in LUAD cells. The influence of TRIM21 on the ubiquitination of ZSWIM1 was examined using Co-IP combined with WB.

RESULTS

TRIM21 was found to interact and co-localize with ZSWIM1. Overexpression of TRIM21 inhibited the proliferation and migration of LUAD cells. Overexpression of TRIM21 reduced the promoting effect of ZSWIM1 on the proliferation, migration, and invasion of lung adenocarcinoma cells, and reversed the impact of ZSWIM1 on the expression of E-cadherin and Vimentin. Conversely, knockdown of TRIM21 further enhanced the promoting effect of ZSWIM1 on the proliferation and migration of LUAD cells. Mechanistically, we observed that overexpression of TRIM21 significantly enhanced the ubiquitination level of ZSWIM1, leading to a decrease in ZSWIM1 protein expression.

CONCLUSIONS

TRIM21 binds to and promotes the ubiquitination of ZSWIM1, resulting in reduced protein expression of ZSWIM1, which leads to the inhibition of ZSWIM1-mediated promotion of proliferation, migration, and invasion in LUAD cells.

Advancing glioblastoma treatment by targeting metabolism

Alterations in cellular metabolism are important hallmarks of glioblastoma(GBM). Metabolic reprogramming is a critical feature as it meets the higher nutritional demand of tumor cells, including proliferation, growth, and survival. Many genes, proteins, and metabolites associated with GBM metabolism reprogramming have been found to be aberrantly expressed, which may provide potential targets for cancer treatment. Therefore, it is becoming increasingly important to explore the role of internal and external factors in metabolic regulation in order to identify more precise therapeutic targets and diagnostic markers for GBM. In this review, we define the metabolic characteristics of GBM, investigate metabolic specificities such as targetable vulnerabilities and therapeutic resistance, as well as present current efforts to target GBM metabolism to improve the standard of care.

Metabolic Roles of HIF1, c-Myc, and p53 in Glioma Cells

The metabolic reprogramming that promotes tumorigenesis in glioblastoma is induced by dynamic alterations in the hypoxic tumor microenvironment, as well as in transcriptional and signaling networks, which result in changes in global genetic expression. The signaling pathways PI3K/AKT/mTOR and RAS/RAF/MEK/ERK stimulate cell metabolism, either directly or indirectly, by modulating the transcriptional factors p53, HIF1, and c-Myc. The overexpression of HIF1 and c-Myc, master regulators of cellular metabolism, is a key contributor to the synthesis of bioenergetic molecules that mediate glioma cell transformation, proliferation, survival, migration, and invasion by modifying the transcription levels of key gene groups involved in metabolism. Meanwhile, the tumor-suppressing protein p53, which negatively regulates HIF1 and c-Myc, is often lost in glioblastoma. Alterations in this triad of transcriptional factors induce a metabolic shift in glioma cells that allows them to adapt and survive changes such as mutations, hypoxia, acidosis, the presence of reactive oxygen species, and nutrient deprivation, by modulating the activity and expression of signaling molecules, enzymes, metabolites, transporters, and regulators involved in glycolysis and glutamine metabolism, the pentose phosphate cycle, the tricarboxylic acid cycle, and oxidative phosphorylation, as well as the synthesis and degradation of fatty acids and nucleic acids. This review summarizes our current knowledge on the role of HIF1, c-Myc, and p53 in the genic regulatory network for metabolism in glioma cells, as well as potential therapeutic inhibitors of these factors.

Viral infection and spread are inhibited by the polyubiquitination and downregulation of TRPV2 channel by the interferon-stimulated gene TRIM21

Interferon (IFN) contributes to the host's antiviral response by inducing IFN-stimulated genes (ISGs). However, their functional targets and the mechanism of action remain elusive. Here, we report that one such ISG, TRIM21, interacts with and degrades the TRPV2 channel in myeloid cells, reducing its expression and providing host protection against viral infections. Moreover, viral infection upregulates TRIM21 in paracrine and autocrine manners, downregulating TRPV2 in neighboring cells to prevent viral spread to uninfected cells. Consistently, the Trim21-/- mice are more susceptible to HSV-1 and VSV infection than the Trim21+/+ littermates, in which viral susceptibility is rescued by inhibition or deletion of TRPV2. Mechanistically, TRIM21 catalyzes the K48-linked ubiquitination of TRPV2 at Lys295. TRPV2K295R is resistant to viral-infection-induced TRIM21-dependent ubiquitination and degradation, promoting viral infection more profoundly than wild-type TRPV2 when reconstituted into Lyz2-Cre;Trpv2fl/fl myeloid cells. These findings characterize targeting the TRIM21-TRPV2 axis as a conducive strategy to control viral spread to bystander cells.

Extracellular Vesicles Derived from Glioma Stem Cells Affect Glycometabolic Reprogramming of Glioma Cells Through the miR-10b-5p/PTEN/PI3K/Akt Pathway

OBJECTIVE

Glioma is one of the most prevalently diagnosed types of primary malignant brain tumors. Glioma stem cells (GSCs) are crucial in glioma recurrence. This study aims to elucidate the mechanism by which extracellular vehicles (EVs) derived from GSCs modulate glycometabolic reprogramming in glioma.

METHODS

Xenograft mouse models and cell models of glioma were established and treated with GSC-EVs. Additionally, levels and activities of PFK1, LDHA, and FASN were assessed to evaluate the effect of GSC-EVs on glycometabolic reprogramming in glioma. Glioma cell proliferation, invasion, and migration were evaluated using MTT, EdU, Colony formation, and Transwell assays. miR-10b-5p expression was determined, with its target gene PTEN and downstream pathway PI3K/Akt evaluated. The involvement of miR-10b-5p and the PI3K/Akt pathway in the effect of GSC-EVs on glycometabolic reprogramming was tested through joint experiments.

RESULTS

GSC-EVs facilitated glycometabolic reprogramming in glioma mice, along with enhancing glucose uptake, lactate level, and adenosine monophosphate-to-adenosine triphosphate ratio. Moreover, GSC-EV treatment potentiated glioma cell proliferation, invasion, and migration, reinforced cell resistance to temozolomide, and raised levels and activities of PFK1, LDHA, and FASN. miR-10b-5p was highly-expressed in GSC-EV-treated glioma cells while being carried into glioma cells by GSC-EVs. miR-10b-5p targeted PTEN and activated the PI3K/Akt pathway, hence stimulating glycometabolic reprogramming.

CONCLUSION

GSC-EVs target PTEN and activate the PI3K/Akt pathway through carrying miR-10b-5p, subsequently accelerating glycometabolic reprogramming in glioma, which might provide new insights into glioma treatment.

Structural basis for allosteric regulation of human phosphofructokinase-1

Phosphofructokinase-1 (PFK1) catalyzes the rate-limiting step of glycolysis, committing glucose to conversion into cellular energy. PFK1 is highly regulated to respond to the changing energy needs of the cell. In bacteria, the structural basis of PFK1 regulation is a textbook example of allostery; molecular signals of low and high cellular energy promote transition between an active R-state and inactive T-state conformation, respectively Little is known, however, about the structural basis for regulation of eukaryotic PFK1. Here, we determine structures of the human liver isoform of PFK1 (PFKL) in the R- and T-state by cryoEM, providing insight into eukaryotic PFK1 allosteric regulatory mechanisms. The T-state structure reveals conformational differences between the bacterial and eukaryotic enzyme, the mechanisms of allosteric inhibition by ATP binding at multiple sites, and an autoinhibitory role of the C-terminus in stabilizing the T-state. We also determine structures of PFKL filaments that define the mechanism of higher-order assembly and demonstrate that these structures are necessary for higher-order assembly of PFKL in cells.

Blockade of C5aR1 resets M1 via gut microbiota-mediated PFKM stabilization in a TLR5-dependent manner

Targeting C5aR1 modulates the function of infiltrated immune cells including tumor-associated macrophages (TAMs). The gut microbiome plays a pivotal role in colorectal cancer (CRC) tumorigenesis and development through TAM education. However, whether and how the gut flora is involved in C5aR1 inhibition-mediated TAMs remains unclear. Therefore, in this study, genetic deletion of C5ar1 or pharmacological inhibition of C5aR1 with anti-C5aR1 Ab or PMX-53 in the presence or absence of deletion Abs were utilized to verify if and how C5aR1 inhibition regulated TAMs polarization via affecting gut microbiota composition. We found that the therapeutic effects of C5aR1 inhibition on CRC benefited from programming of TAMs toward M1 polarization via driving AKT2-mediated 6-phosphofructokinase muscle type (PFKM) stabilization in a TLR5-dependent manner. Of note, in the further study, we found that C5aR1 inhibition elevated the concentration of serum IL-22 and the mRNA levels of its downstream target genes encoded antimicrobial peptides (AMPs), leading to gut microbiota modulation and flagellin releasement, which contributed to M1 polarization. Our data revealed that high levels of C5aR1 in TAMs predicted poor prognosis. In summary, our study suggested that C5aR1 inhibition reduced CRC growth via resetting M1 by AKT2 activation-mediated PFKM stabilization in a TLR5-dependent manner, which relied on IL-22-regulated gut flora.

Molecular Determinants of Neurocognitive Deficits in Glioma: Based on 2021 WHO Classification

Cognitive impairment is a common feature among patients with diffuse glioma. The objective of the study is to investigate the relationship between preoperative cognitive function and clinical as well as molecular factors, firstly based on the new 2021 World Health Organization's updated classification of central nervous system tumors. A total of 110 diffuse glioma patients enrolled underwent preoperative cognitive assessments using the Mini-Mental State Examination and Montreal Cognitive Assessment. Clinical information was collected from medical records, and gene sequencing was performed to analyze the 18 most influenced genes. The differences in cognitive function between patients with and without glioblastoma were compared under both the 2016 and 2021 WHO classification of tumors of the central nervous system to assess their effect of differentiation on cognition. The study found that age, tumor location, and glioblastoma had significant differences in cognitive function. Several genetic alterations were significantly correlated with cognition. Especially, IDH, CIC, and ATRX are positively correlated with several cognitive domains, while most other genes are negatively correlated. For most focused genes, patients with a low number of genetic alterations tended to have better cognitive function. Our study suggested that, in addition to clinical characteristics such as age, histological type, and tumor location, molecular characteristics play a crucial role in cognitive function. Further research into the mechanisms by which tumors affect brain function is expected to enhance the quality of life for glioma patients. This study highlights the importance of considering both clinical and molecular factors in the management of glioma patients to improve cognitive outcomes.

Diallyl disulfide induces DNA damage and growth inhibition in colorectal cancer cells by promoting POU2F1 ubiquitination

Previous studies have demonstrated that diallyl disulfide (DADS) exhibits potent anti-tumor activity. However, the pharmacological actions of DADS in inhibiting the growth of colorectal cancer (CRC) cells have not been clarified. Herein, we show that DADS treatment impairs the activation of the pentose phosphate pathway (PPP) to decrease PRPP (5-phosphate ribose-1-pyrophosphate) production, enhancing DNA damage and cell apoptosis, and inhibiting the growth of CRC cells. Mechanistically, DADS treatment promoted POU2F1 K48-linked ubiquitination and degradation by attenuating the PI3K/AKT signaling to up-regulate TRIM21 expression in CRC cells. Evidently, TRIM21 interacted with POU2F1, and induced the K272 ubiquitination of POU2F1. The effects of DADS on the enhanced K272 ubiquitination of POU2F1, the PPP flux, PRPP production, DNA damage and cell apoptosis as well as the growth of CRC tumors in vivo were significantly mitigated by TRIM21 silencing or activating the PI3K signaling in CRC cells. Conversely, the effects of DADS were enhanced by TRIM21 over-expression or inhibiting the PI3K/AKT signaling in CRC cells. Collectively, our findings reveal a novel mechanism by which DADS suppresses the growth of CRC by promoting POU2F1 ubiquitination, and may aid in design of novel therapeutic intervention of CRC.

PFKP deubiquitination and stabilization by USP5 activate aerobic glycolysis to promote triple-negative breast cancer progression

BACKGROUND

Triple-negative breast cancer (TNBC) remains the most challenging subtype of breast cancer and lacks definite treatment targets. Aerobic glycolysis is a hallmark of metabolic reprogramming that contributes to cancer progression. PFKP is a rate-limiting enzyme involved in aerobic glycolysis, which is overexpressed in various types of cancers. However, the underlying mechanisms and roles of the posttranslational modification of PFKP in TNBC remain unknown.

METHODS

To explore whether PFKP protein has a potential role in the progression of TNBC, protein levels of PFKP in TNBC and normal breast tissues were examined by CPTAC database analysis, immunohistochemistry staining (IHC), and western blotting assay. Further CCK-8 assay, colony formation assay, EDU incorporation assay, and tumor xenograft experiments were used to detect the effect of PFKP on TNBC progression. To clarify the role of the USP5-PFKP pathway in TNBC progression, ubiquitin assay, co-immunoprecipitation (Co-IP), mass spectrometry-based protein identification, western blotting assay, immunofluorescence microscopy, in vitro binding assay, and glycolysis assay were conducted.

RESULTS

Herein, we showed that PFKP protein was highly expressed in TNBC, which was associated with TNBC progression and poor prognosis of patients. In addition, we demonstrated that PFKP depletion significantly inhibited the TNBC progression in vitro and in vivo. Importantly, we identified that PFKP was a bona fide target of deubiquitinase USP5, and the USP5-mediated deubiquitination and stabilization of PFKP were essential for cancer cell aerobic glycolysis and TNBC progression. Moreover, we found a strong positive correlation between the expression of USP5 and PFKP in TNBC samples. Notably, the high expression of USP5 and PFKP was significantly correlated with poor clinical outcomes.

CONCLUSIONS

Our study established the USP5-PFKP axis as an important regulatory mechanism of TNBC progression and provided a rationale for future therapeutic interventions in the treatment of TNBC.

Revving the engine: PKB/AKT as a key regulator of cellular glucose metabolism

Glucose metabolism is of critical importance for cell growth and proliferation, the disorders of which have been widely implicated in cancer progression. Glucose uptake is achieved differently by normal cells and cancer cells. Even in an aerobic environment, cancer cells tend to undergo metabolism through glycolysis rather than the oxidative phosphorylation pathway. Disordered metabolic syndrome is characterized by elevated levels of metabolites that can cause changes in the tumor microenvironment, thereby promoting tumor recurrence and metastasis. The activation of glycolysis-related proteins and transcription factors is involved in the regulation of cellular glucose metabolism. Changes in glucose metabolism activity are closely related to activation of protein kinase B (PKB/AKT). This review discusses recent findings on the regulation of glucose metabolism by AKT in tumors. Furthermore, the review summarizes the potential importance of AKT in the regulation of each process throughout glucose metabolism to provide a theoretical basis for AKT as a target for cancers.

Cellular signaling in the hypoxic cancer microenvironment: Implications for drug resistance and therapeutic targeting

The rewiring of cellular metabolism is a defining characteristic of cancer, as tumor cells adapt to acquire essential nutrients from a nutrient-poor environment to sustain their viability and biomass. While hypoxia has been identified as a major factor depriving cancer cells of nutrients, recent studies have revealed that cancer cells distant from supporting blood vessels also face nutrient limitations. To overcome this challenge, hypoxic cancer cells, which heavily rely on glucose as an energy source, employ alternative pathways such as glycogen metabolism and reductive carboxylation of glutamine to meet their energy requirements for survival. Our preliminary studies, alongside others in the field, have shown that under glucose-deficient conditions, hypoxic cells can utilize mannose and maltose as alternative energy sources. This review aims to comprehensively examine the hypoxic cancer microenvironment, its association with drug resistance, and potential therapeutic strategies for targeting this unique niche. Furthermore, we will critically evaluate the current literature on hypoxic cancer microenvironments and explore state-of-the-art techniques used to analyze alternate carbohydrates, specifically mannose and maltose, in complex biological fluids. We will also propose the most effective analytical methods for quantifying mannose and maltose in such biological samples. By gaining a deeper understanding of the hypoxic cancer cell microenvironment and its role in drug resistance, novel therapeutic approaches can be developed to exploit this knowledge.

Hitting the Sweet Spot: How Glucose Metabolism Is Orchestrated in Space and Time by Phosphofructokinase-1

Glycolysis is the central metabolic pathway across all kingdoms of life. Intensive research efforts have been devoted to understanding the tightly orchestrated processes of converting glucose into energy in health and disease. Our review highlights the advances in knowledge of how metabolic and gene networks are integrated through the precise spatiotemporal compartmentalization of rate-limiting enzymes. We provide an overview of technically innovative approaches that have been applied to study phosphofructokinase-1 (PFK1), which represents the fate-determining step of oxidative glucose metabolism. Specifically, we discuss fast-acting chemical biology and optogenetic tools that have delineated new links between metabolite fluxes and transcriptional reprogramming, which operate together to enact tissue-specific processes. Finally, we discuss how recent paradigm-shifting insights into the fundamental basis of glycolytic regulatory control have shed light on the mechanisms of tumorigenesis and could provide insight into new therapeutic vulnerabilities in cancer.

Potential therapies targeting nuclear metabolic regulation in cancer

The interplay between genetic alterations and metabolic dysregulation is increasingly recognized as a pivotal axis in cancer pathogenesis. Both elements are mutually reinforcing, thereby expediting the ontogeny and progression of malignant neoplasms. Intriguingly, recent findings have highlighted the translocation of metabolites and metabolic enzymes from the cytoplasm into the nuclear compartment, where they appear to be intimately associated with tumor cell proliferation. Despite these advancements, significant gaps persist in our understanding of their specific roles within the nuclear milieu, their modulatory effects on gene transcription and cellular proliferation, and the intricacies of their coordination with the genomic landscape. In this comprehensive review, we endeavor to elucidate the regulatory landscape of metabolic signaling within the nuclear domain, namely nuclear metabolic signaling involving metabolites and metabolic enzymes. We explore the roles and molecular mechanisms through which metabolic flux and enzymatic activity impact critical nuclear processes, including epigenetic modulation, DNA damage repair, and gene expression regulation. In conclusion, we underscore the paramount significance of nuclear metabolic signaling in cancer biology and enumerate potential therapeutic targets, associated pharmacological interventions, and implications for clinical applications. Importantly, these emergent findings not only augment our conceptual understanding of tumoral metabolism but also herald the potential for innovative therapeutic paradigms targeting the metabolism-genome transcriptional axis.

Targeting glycolytic pathway in fibroblast-like synoviocytes for rheumatoid arthritis therapy: challenges and opportunities

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by hyperplastic synovium, pannus formation, immune cell infiltration, and potential articular cartilage damage. Notably, fibroblast-like synoviocytes (FLS), especially rheumatoid arthritis fibroblast-like synoviocytes (RAFLS), exhibit specific overexpression of glycolytic enzymes, resulting in heightened glycolysis. This elevated glycolysis serves to generate ATP and plays a pivotal role in immune regulation, angiogenesis, and adaptation to hypoxia. Key glycolytic enzymes, such as hexokinase 2 (HK2), phosphofructose-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), and pyruvate kinase M2 (PKM2), significantly contribute to the pathogenic behavior of RAFLS. This increased glycolysis activity is regulated by various signaling pathways.

MATERIALS AND METHODS

A comprehensive literature search was conducted to retrieve relevant studies published from January 1, 2010, to the present, focusing on RAFLS glycolysis, RA pathogenesis, glycolytic regulation pathways, and small-molecule drugs targeting glycolysis.

CONCLUSION

This review provides a thorough exploration of the pathological and physiological characteristics of three crucial glycolytic enzymes in RA. It delves into their putative regulatory mechanisms, shedding light on their significance in RAFLS. Furthermore, the review offers an up-to-date overview of emerging small-molecule candidate drugs designed to target these glycolytic enzymes and the upstream signaling pathways that regulate them. By enhancing our understanding of the pathogenic mechanisms of RA and highlighting the pivotal role of glycolytic enzymes, this study contributes to the development of innovative anti-rheumatic therapies.