Methylenetetrahydrofolate Dehydrogenase Research Articles

EP300-mediated H3 acetylation elevates MTHFD2 expression to reduce mitochondrial dysfunction in lipopolysaccharide-induced tubular epithelial cells.

Sepsis represents an organ dysfunction resulting from the host's maladjusted response to infection, and can give rise to acute kidney injury (AKI), which significantly increase the morbidity and mortality of septic patients. This study strived for identifying a novel therapeutic strategy for patients with sepsis-induced AKI (SI-AKI). Rat tubular epithelial NRK-52E cells were subjected to lipopolysaccharide (LPS) exposure for induction of in-vitro SI-AKI. The expressions of E1A binding protein p300 (EP300) and methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) in NRK-52E cells were assessed by western blot and qRT-PCR, and their interaction was explored by chromatin immunoprecipitation performed with antibody for H3K27 acetylation (H3K27ac). The effect of them on SI-AKI-associated mitochondrial dysfunction of tubular epithelial cells was investigated using transfection, MTT assay, TUNEL staining, 2',7'-Dichlorodihydrofluorescein diacetate probe assay, Mitosox assay, and JC-1 staining. MTHFD2 and EP300 were upregulated by LPS exposure in NRK-52E cells. LPS increased the acetylation of H3 histone in the MTHFD2 promoter region, and EP300 suppressed the effect of LPS. EP300 ablation inhibited the expression of MTHFD2. MTHFD2 overexpression antagonized LPS-induced viability reduction, apoptosis promotion, reactive oxygen species overproduction, and mitochondrial membrane potential collapse of NRK-52E cells. By contrast, MTHFD2 knockdown and EP300 ablation brought about opposite consequences. Furthermore, MTHFD2 overexpress and EP300 ablation counteracted each other's effect in LPS-exposed NRK-52E cells. EP300-mediated H3 acetylation elevates MTHFD2 expression to reduce mitochondrial dysfunction of tubular epithelial cells in SI-AKI.

Nuclear localization of MTHFD2 is required for correct mitosis progression.

Subcellular compartmentalization of metabolic enzymes establishes a unique metabolic environment that elicits specific cellular functions. Indeed, the nuclear translocation of certain metabolic enzymes is required for epigenetic regulation and gene expression control. Here, we show that the nuclear localization of the mitochondrial enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) ensures mitosis progression. Nuclear MTHFD2 interacts with proteins involved in mitosis regulation and centromere stability, including the methyltransferases KMT5A and DNMT3B. Loss of MTHFD2 induces severe methylation defects and impedes correct mitosis completion. MTHFD2 deficient cells display chromosome congression and segregation defects and accumulate chromosomal aberrations. Blocking the catalytic nuclear function of MTHFD2 recapitulates the phenotype observed in MTHFD2 deficient cells, whereas restricting MTHFD2 to the nucleus is sufficient to ensure correct mitotic progression. Our discovery uncovers a nuclear role for MTHFD2, supporting the notion that translocation of metabolic enzymes to the nucleus is required to meet precise chromatin needs.

LC-Orbitrap HRMS-Based Proteomics Reveals Novel Mitochondrial Dynamics Regulatory Proteins Associated with RasV12-Induced Glioblastoma (GBM) of Drosophila.

Glioblastoma multiforme (GBM) is the most prevalent and aggressive brain tumor found in adult humans with a poor prognosis and average survival of 14-15 months. In order to have a comprehensive understanding of proteome and identify novel therapeutic targets, this study focused mainly on the differentially abundant proteins (DAPs) of RasV12-induced GBM. RasV12 is a constitutively active Ras mutant form essential for tumor progression by continuously activating signaling pathways leading to uncontrolled tumor growth. This study used a transgenic Drosophila model with RasV12 overexpression using the repo-GAL4 driver line, specifically in glial cells, to study GBM. The high-resolution mass spectrometry (HRMS)-based proteomic analysis of the GBM larval central nervous system identified three novel DAPs specific to mitochondria. These DAPs, probable maleylacetoacetate isomerase 2 (Q9VHD2), bifunctional methylene tetrahydrofolate dehydrogenase (Q04448), and glutamine synthetase1 (P20477), identified through HRMS were further validated by qRT-PCR. The protein-protein interaction analysis revealed interactions between RasV12 and DAPs, with functional links to mitochondrial dynamics regulators such as Drp1, Marf, Parkin, and HtrA2. Notably, altered expressions of Q9VHD2, P20477, and Q04448 were observed during GBM progression, which offers new insights into the involvement of mitochondrial dynamic regulators in RasV12-induced GBM pathophysiology.

Betaine and B12 Intake, Glutathione Concentration, and MTHFR, PEMT, and MTHFD1 Genotypes Are Associated with Diabetes-Related Parameters in Polish Adults

BackgroundThere is a growing body of evidence on associations between one-carbon metabolism (OCM) and diabetes-related parameters. For this reason, we aimed to examine the associations of plasma choline, betaine, trimethylamine N-oxide (TMAO), glutathione (GSH), serum folate, vitamin B12, dihydrofolate reductase (rs70991108) genotype, methylenetetrahydrofolate reductase (MTHFR) (rs180113) genotype, methylenetetrahydrofolate dehydrogenase (MTHFD1) (rs2236225) genotype, and phosphatidylethanolamine N-methyltransferase (rs7946 and rs12325817) genotype with fasting glucose level, insulin level, and diabetes-related indices. MethodsThe study group consisted of 421 Polish adults aged 20–40 y. Food intake was assessed using a 3-d food diary. Plasma concentrations of choline, betaine, and TMAO were determined by ultra-high-performance liquid chromatography-electrospray ionization mass spectrometry. The total plasma GSH level was measured by high-performance liquid chromatography. Insulin, folate, and vitamin B12 concentrations were estimated by enzyme-linked immunosorbent assay method. Genotyping was performed with TaqMan probes. ResultsGSH level was negatively associated with insulin (β = −0.11, P < 0.05) and gamma-glutamyl transferase (GGTP) (β = −0.12, P < 0.05), and positively associated with fasting glucose (β = 0.11, P < 0.05). Betaine intake was negatively associated with serum insulin concentration (β = −0.13, P < 0.05) and HOMA-IR (β = −0.12, P < 0.05). Choline intake was negatively associated with insulin (β = −0.17, P < 0.01). Serum folate level was negatively associated with GGTP (β = −0.11; P < 0.05). The methylenetetrahydrofolate reductase (MTHFR) CC genotype was associated with higher serum insulin levels (β = 0.15; P < 0.01) and higher HOMA-IR (β = 0.15, P < 0.01), whereas the MTHFD1 AA genotype was negatively associated with Quantitative Insulin Sensitivity Check Index (β = −0.11, P < 0.05). ConclusionsOur findings suggest that higher GSHL and higher intake of betaine, B12, and choline, as well as the TT genotype of MTHFR and the AA genotype of MTHFD1, are associated with lower diabetes-related parameters among adults.

Selectivity analysis of diaminopyrimidine-based inhibitors of MTHFD1, MTHFD2 and MTHFD2L

The mitochondrial enzyme methylenetetrahydrofolate dehydrogenase (MTHFD2) is involved in purine and thymidine synthesis via 1C metabolism. MTHFD2 is exclusively overexpressed in cancer cells but absent in most healthy adult human tissues. However, the two close homologs of MTHFD2 known as MTHFD1 and MTHFD2L are expressed in healthy adult human tissues and share a great structural resemblance to MTHFD2 with 54% and 89% sequence similarity, respectively. It is therefore notably challenging to find selective inhibitors of MTHFD2 due to the structural similarity, in particular protein binding site similarity with MTHFD1 and MTHFD2L. Tricyclic coumarin-based compounds (substrate site binders) and xanthine derivatives (allosteric site binders) are the only selective inhibitors of MTHFD2 reported till date. Nanomolar potent diaminopyrimidine-based inhibitors of MTHFD2 have been reported recently, however, they also demonstrate significant inhibitory activities against MTHFD1 and MTHFD2L. In this study, we have employed extensive computational modeling involving molecular docking and molecular dynamics simulations in order to investigate the binding modes and key interactions of diaminopyrimidine-based inhibitors at the substrate binding sites of MTHFD1, MTHFD2 and MTHFD2L, and compare with the tricyclic coumarin-based selective MTHFD2 inhibitor. The outcomes of our study provide significant insights into desirable and undesirable structural elements for rational structure-based design of new and selective inhibitors of MTHFD2 against cancer.

Mitochondrial serine catabolism safeguards maintenance of the hematopoietic stem cell pool in homeostasis and injury

Hematopoietic stem cells (HSCs) employ a very unique metabolic pattern to maintain themselves, while the spectrum of their metabolic adaptations remains incompletely understood. Here, we uncover a distinct and heterogeneous serine metabolism within HSCs and identify mouse HSCs as a serine auxotroph whose maintenance relies on exogenous serine and the ensuing mitochondrial serine catabolism driven by the hydroxymethyltransferase 2 (SHMT2)-methylene-tetrahydrofolate dehydrogenase 2 (MTHFD2) axis. Mitochondrial serine catabolism primarily feeds NAD(P)H generation to maintain redox balance and thereby diminishes ferroptosis susceptibility of HSCs. Dietary serine deficiency, or genetic or pharmacological inhibition of the SHMT2-MTHFD2 axis, increases ferroptosis susceptibility of HSCs, leading to impaired maintenance of the HSC pool. Moreover, exogenous serine protects HSCs from irradiation-induced myelosuppressive injury by fueling mitochondrial serine catabolism to mitigate ferroptosis. These findings reframe the canonical view of serine from a nonessential amino acid to an essential niche metabolite for HSC pool maintenance.

Exploring the Anticancer Potential of Furanpydone A: A Computational Study on its Inhibition of MTHFD2 Across Diverse Cancer Cell Lines.

Cancer poses a significant global health challenge due to its high mortality rate and complex treatment strategies. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), which is notably overexpressed in various malignancies, represents a promising target for anticancer drug development. Furanpydone A, a new 4-hydroxy-2-pyridone alkaloid isolated from the endophytic fungus Arthrinium sp. GZWMJZ-606, has shown potent inhibitory activity against several cancer cell lines. This study provides the first computational evaluation of furanpydone A, focusing on its potential inhibition of MTHFD2 through molecular docking and 200 ns molecular dynamics (MD) simulations. Molecular docking revealed a binding free energy of -8.08 kcal/mol for furanpydone A, comparable to the control compound DS44960156 (-8.13 kcal/mol), indicating stable interactions with the MTHFD2 active site. MD simulations confirmed the structural stability of the furanpydone A-MTHFD2 complex, with RMSD values ranging from 1.5 to 2.9 Å, RMSF values below 4 Å, and a radius of gyration (Rg) of 26.7 Å. Furanpydone A maintained approximately four consistent hydrogen bonds throughout the simulation. Analysis of furanpydone A binding pose orientations and interactions with the MTHFD2 enzyme at 0 ns, 40 ns, 80 ns, 120 ns, 160 ns, and 200 ns revealed consistent and stable binding. MM-PBSA analysis showed a binding free energy (ΔGbind) of -23.57 ± 0.13 kcal/mol, with electrostatic and van der Waals interactions contributing significantly, suggesting competitive binding affinity to the control compound (-25.32 ± 0.11 kcal/mol). The contribution of individual amino acid residues, including key residues such as ARG43, TYR84, ASN87, LYS88, GLN132, and PRO314, indicated strong interactions that support the stability of the furanpydone A-MTHFD2 complex. ADMET predictions indicated that furanpydone A met key drug-likeness criteria and demonstrated good oral bioavailability, suitable distribution profile, minimal risk of drug-drug interactions, efficient elimination, and low toxicity potential. These findings suggest that furanpydone A is a promising candidate for cancer treatment, warranting further in vitro and in vivo validation, and highlighting its potential impact on the development of new anticancer therapies.

Compound Bacillus improves eggshell quality and egg metabolites of hens by promoting the metabolism balance of calcium and phosphorus and uterine cell proliferation

Probiotics have beneficial effects on improving egg quality, but there is little research about the effect of probiotics on metabolite composition, and the mechanisms are not yet fully understood. The aim of this study was to investigate the potential mechanisms by which compound Bacillus improves egg quality and metabolite composition. A total of 20,000 Jingfen No. 6 laying hens at 381 d old were randomly divided into two treatments: control group with a basal diet, and the basal diet with compound Bacillus supplementation (Ba) group. The trial lasted eight weeks. The results showed that compound Bacillus improved the gloss and strength of eggshells and reduced the ratio of sand-shell eggs by 23.8%. Specifically, the effective layer of eggshell was thicker and its calcite column was closely connected. Compound Bacillus increased the contents of beneficial fatty acids in the egg yolk, and lipids and lipid-like molecules in the albumen (P < 0.01), while decreased the contents of total cholesterol, triglycerides, and benzene ring compounds in the egg yolk and organic oxygen compounds in the albumen (P < 0.01). In addition, the compound Bacillus increased the calcium absorption in the duodenum by up-regulating the expression of transporters and serum hormone synergism (P < 0.05), and promoted metabolic balance of calcium and phosphorus. Simultaneously, uterine transcriptome showed that the expression of ChaC glutathione specific gamma-glutamylcyclotransferase 1 (CHAC1), glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1), phosphatidylinositol-4-phosphate 5-kinase type 1 beta (PIP5K1B), methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), brain enriched myelin associated protein 1 (BCAS1), and squalene epoxidase (SQLE) genes were increased (P < 0.01), indicating that nutrient metabolism activity was enhanced. The expression of the BCAS1, C1GALT1, KLF transcription factor 13 (KLF13), and leucine rich repeat neuronal 1 (LRRN1) was increased (P < 0.01), indicating that the cell proliferation was enhanced, which slowed uterus aging. In conclusion, compound Bacillus improved the eggshell strength and metabolite composition in the egg by promoting metabolic balance of calcium and phosphorus, cell proliferation, and nutrient metabolism in the uterus.

Metabolic determinants of germinal center B cell formation and responses.

Germinal center (GC) B cells are crucial for the generation of GCs and long-lived humoral immunity. Here we report that one-carbon metabolism determines the formation and responses of GC B cells. Upon CD40 stimulation, GC B cells selectively upregulate methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) expression to generate purines and the antioxidant glutathione. MTHFD2 depletion reduces GC B cell frequency and antigen-specific antibody production. Moreover, supplementation with nucleotides and antioxidants suffices to promote GC B cell formation and function in vitro and in vivo through activation of the mammalian target of rapamycin complex 1 signaling pathway. Moreover, we found that antigen stimulation enhances YY1 binding to the Mthfd2 promoter and promotes MTHFD2 transcription. Interestingly, these findings can be generalized to the pentose phosphate pathway, which is another major source of reducing power and nucleotides. Therefore, these results suggest that an increased capacity for nucleotide synthesis and redox balance is required for GC B cell formation and responses, revealing a key aspect of GC B cell fate determination.

Radiological and Molecular Analysis of Radioiodinated Anastrozole and Epirubicin as Innovative Radiopharmaceuticals Targeting Methylenetetrahydrofolate Dehydrogenase 2 in Solid Tumors.

In the dynamic field of radiopharmaceuticals, innovating targeted agents for cancer diagnosis and therapy is crucial. Our study enriches this evolving landscape by evaluating the potential of radioiodinated anastrozole ([125I]anastrozole) and radioiodinated epirubicin ([125I]epirubicin) as targeting agents against MTHFD2-driven tumors. MTHFD2, which is pivotal in one-carbon metabolism, is notably upregulated in various cancers, presenting a novel target for radiopharmaceutical application. Through molecular docking and 200 ns molecular dynamics (MD) simulations, we assess the binding efficiency and stability of [125I]anastrozole and [125I]epirubicin with MTHFD2. Molecular docking illustrates that [125I]epirubicin has a superior binding free energy (∆Gbind) of -41.25 kJ/mol compared to -39.07 kJ/mol for [125I]anastrozole and -38.53 kJ/mol for the control ligand, suggesting that it has a higher affinity for MTHFD2. MD simulations reinforce this, showing stable binding, as evidenced by root mean square deviation (RMSD) values within a narrow range, underscoring the structural integrity of the enzyme-ligand complexes. The root mean square fluctuation (RMSF) analysis indicates consistent dynamic behavior of the MTHFD2 complex upon binding with [125I]anastrozole and [125I]epirubicin akin to the control. The radius of gyration (RG) measurements of 16.90 Å for MTHFD2-[125I]anastrozole and 16.84 Å for MTHFD2-[125I]epirubicin confirm minimal structural disruption upon binding. The hydrogen bond analysis reveals averages of two and three stable hydrogen bonds for [125I]anastrozole and [125I]epirubicin complexes, respectively, highlighting crucial stabilizing interactions. The MM-PBSA calculations further endorse the thermodynamic favorability of these interactions, with binding free energies of -48.49 ± 0.11 kJ/mol for [125I]anastrozole and -43.8 kJ/mol for MTHFD2-. The significant contribution of Van der Waals and electrostatic interactions to the binding affinities of [125I]anastrozole and [125I]epirubicin, respectively, underscores their potential efficacy for targeted tumor imaging and therapy. These computational findings lay the groundwork for the future experimental validation of [125I]anastrozole and [125I]epirubicin as MTHFD2 inhibitors, heralding a notable advancement in precision oncology tools. The data necessitate subsequent in vitro and in vivo assays to corroborate these results.

Dynamic evolution of the mTHF gene family associated with primary metabolism across life.

The folate cycle of one-carbon (C1) metabolism, which plays a central role in the biosynthesis of nucleotides and amino acids, demonstrates the significance of metabolic adaptation. We investigated the evolutionary history of the methylenetetrahydrofolate dehydrogenase (mTHF) gene family, one of the main drivers of the folate cycle, across life. Through comparative genomic and phylogenetic analyses, we found that several lineages of Archaea lacked domains vital for folate cycle function such as the mTHF catalytic and NAD(P)-binding domains of FolD. Within eukaryotes, the mTHF gene family diversified rapidly. For example, several duplications have been observed in lineages including the Amoebozoa, Opisthokonta, and Viridiplantae. In a common ancestor of Opisthokonta, FolD and FTHFS underwent fusion giving rise to the gene MTHFD1, possessing the domains of both genes. Our evolutionary reconstruction of the mTHF gene family associated with a primary metabolic pathway reveals dynamic evolution, including gene birth-and-death, gene fusion, and potential horizontal gene transfer events and/or amino acid convergence.

Serine Metabolism Regulates the Replicative Senescence of Human Dental Pulp Cells through Histone Methylation.

Tissue regeneration therapy based on human dental pulp cells (hDPCs) faces the distinct challenge of cellular senescence during massive expansion in vitro. To further explore the regulatory mechanism of cellular senescence in hDPCs, we conduct experiments on young cells (Passage 5, P5) and replicative senescent (Passage 12, P12) hDPCs. The results confirm that hDPCs undergo replicative senescence with passaging, during which their ability to proliferate and osteogenic differentiation decreases. Notably, during replicative senescence, phosphoglycerate dehydrogenase (PHGDH), the key enzyme of the serine synthesis pathway (SSP), is significantly downregulated, as well as S-adenosylmethionine (SAM) levels, resulting in reduced H3K36me3 modification on Sirtuin 1 (SIRT1)and Runt-related transcription factor 2 (RUNX2) promoters. Inhibition of PHGDH leads to the same phenotype as replicative senescence. Serine supplementation fails to rescue the senescence phenotype caused by replicative senescence and inhibitors, in which folate metabolism-related genes, including serine hydroxymethyl transferase 2 (SHMT2), methylenetetrahydrofolate dehydrogenase 1(MTHFD1), methylenetetrahydrofolate dehydrogenase 2(MTHFD2), are notably decreased. Our research raised a possibility that PHGDH may be involved in cellular senescence by affecting folate metabolism and histone methylation in addition to serine biosynthesis, providing potential targets to prevent senescence.

Serine synthesis and catabolism in starved lung cancer and primary bronchial epithelial cells

Serine and glycine give rise to important building blocks in proliferating cells. Both amino acids are either synthesized de novo or taken up from the extracellular space. In lung cancer, serine synthesis gene expression is variable, yet, expression of the initial enzyme, phosphoglycerate dehydrogenase (PHGDH), was found to be associated with poor prognosis. While the contribution of de novo synthesis to serine pools has been shown to be enhanced by serine starvation, the impact of glucose deprivation, a commonly found condition in solid cancers is poorly understood. Here, we utilized a stable isotopic tracing approach to assess serine and glycine de novo synthesis and uptake in different lung cancer cell lines and normal bronchial epithelial cells in variable serine, glycine, and glucose conditions. Under low glucose supplementation (0.2 mM, 3–5% of normal plasma levels), serine de novo synthesis was maintained or even activated. As previously reported, also gluconeogenesis supplied carbons from glutamine to serine and glycine under these conditions. Unexpectedly, low glucose treatment consistently enhanced serine to glycine conversion, along with an up-regulation of the mitochondrial one-carbon metabolism enzymes, serine hydroxymethyltransferase (SHMT2) and methylenetetrahydrofolate dehydrogenase (MTHFD2). The relative contribution of de novo synthesis greatly increased in low serine/glycine conditions. In bronchial epithelial cells, adaptations occurred in a similar fashion as in cancer cells, but serine synthesis and serine to glycine conversion, as assessed by label enrichments and gene expression levels, were generally lower than in (PHGDH positive) cancer cells. In summary, we found a variable contribution of glucose or non-glucose carbon sources to serine and glycine and a high adaptability of the downstream one-carbon metabolism pathway to variable glucose supply.

Interference with MTHFD2 induces ferroptosis in ovarian cancer cells through ERK signaling to suppress tumor malignant progression.

Ovarian cancer (OC) is a deadliest gynecological cancer with the highest mortality rate. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), a crucial tumor-promoting factor, is over-expressed in several malignancies including OC. The present study aimed to explore the role and mechanisms of MTHFD2 in OC malignant progression. Thus, cell proliferation, cycling, apoptosis, migration, and invasion were evaluated by CCK-8 assay, EdU assay, flow cytometry, wound healing, transwell assay and western blotting. Additionally, glycolysis was assessed by measuring the level of glucose and lactate production, as well as the expressions of GLUT1, HK2 and PKM2. Then the expression of ferroptosis-related proteins and ERK signaling was detected using western blotting. Ferroptosis was detected through the measurement of iron level, GSH, MDA and ROS activities. The results revealed that MTHFD2 was highly expressed in OC cells. Besides, interference with MTHFD2 induced ferroptosis, promoted ROS accumulation, destroyed mitochondrial function, reduced ATP content and inhibited glycolysis in OC cells. Subsequently, we further found that interference with MTHFD2 affected mitochondrial function and glycolysis in OC cells through ERK signaling. Moreover, interference with MTHFD2 affected ferroptosis to inhibit the malignant progression of OC cells. Collectively, our present study disclosed that interference with MTHFD2 induced ferroptosis in OC to inhibit tumor malignant progression through regulating ERK signaling.

Implications of MTHFD2 expression in renal cell carcinoma aggressiveness.

Renal cell carcinoma (RCC) is the most common type of cancer in kidney and is often diagnosed in advanced stages. Until now, there is no reliable biomarker to assess tumor prognosis during histopathological diagnosis. The Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) overexpression has been suggested as prognostic indicator for RCC, however, its protein profile needs to be clarified. This study investigated the MTHFD2 expression in different RCC cohorts, associating it with tumor characteristics and prognostic factors. Gene expression comparisons between non-neoplastic (NN) and tumor samples, as well as patients' survival analysis, were assessed using KM-Plotter tool. MTHFD2 protein pattern was evaluated in 117 RCC by immunohistochemistry and associations with prognosis, clinical and pathological data were investigated. The tumors exhibited higher MTHFD2 transcript levels than NN, being even higher in the metastatic group. Opposite gene expression patterns were found among clear cell renal cell carcinoma (ccRCC) and pappilary renal cell carcinoma (pRCC) subtypes, showing higher and lower expressions compared to NN samples respectively. Overexpression was associated with shorter overall survival for ccRCC and pRCC subtypes, and shorter recurrence-free survival for pRCC. The immunolabeling profile varied according to tumor subtypes, with lower intensity and expression scores in ccRCC compared to pRCC and to chromophobe renal cell carcinoma (chRCC). MTHFD2 protein expression was associated with larger tumors and higher Fuhrman grades. Although prognostic value of protein immunostaining was not confirmed, patients with higher MTHFD2 tended to have lower survival rates in the pRCC group. The results highlight MTHFD2 different patterns according to RCC histological subtypes, revealing marked variations at both the genetic and protein levels. The mRNA indicated tumor prognosis, and greater expression in the tumor samples. Although MTHFD2 immunolabeling suggests tumor aggressiveness, it needs to be validated in other cohorts as potential prognostic factor.

CircUBE3A(2,3,4,5) promotes adenylate-uridylate-rich binding factor 1 nuclear translocation to suppress prostate cancer metastasis

Metastatic progression is the primary cause of mortality in prostate cancer (PCa) patients. Although circular RNAs (circRNAs) have been implicated in cancer progression and metastasis, our current understanding of their role in PCa metastasis remains limited. In this study, we identified that circUBE3A(2,3,4,5), which originated from exons 2, 3, 4 and 5 of the human ubiquitin-protein ligase E3A (UBE3A) gene, was specifically downregulated in PCa tissues and correlated with the Gleason score, bone metastasis, and D'Amico risk classification. Through the in vitro and in vivo experiments, we demonstrated that overexpression of circUBE3A(2,3,4,5) inhibited PCa cell migration, invasion, metastasis, and proliferation. Mechanistically, circUBE3A(2,3,4,5) was found to bind to adenylate-uridylate-rich binding factor 1 (AUF1), promoting the translocation of AUF1 into the nucleus. This led to decreased AUF1 in the cytoplasm, resulting in methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) mRNA instability and a subsequent reduction at the protein level. The downregulation of MTHFD2 further inhibited vimentin expression, thereby suppressing PCa cell epithelial-mesenchymal transition. Additionally, two pairs of the short-inverted repeats (TSIRs) in flanking introns were identified to synergistically facilitate the generation of circUBE3A(2,3,4,5) and other circRNAs. In summary, TSIRs-induced circUBE3A(2,3,4,5) acts as a suppressor of PCa metastasis by enhancing AUF1 nuclear translocation, reducing MTHFD2, and subsequently inhibiting vimentin expression. This study characterizes circUBE3A(2,3,4,5) as a functional circRNA and proposes it as a highly promising target for preventing PCa metastasis.

Induction of MTHFD2 in Macrophages Inhibits Reactive Oxygen Species-mediated NF-κB Activation and Protects against Inflammatory Responses.

The one-carbon metabolism enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is critical for cancer cell proliferation and immune cell phenotypes, but whether it can contribute to macrophage inflammatory responses remains unclear. In this study, we show that MTHFD2 was upregulated by LPS in murine macrophages upon activation of the TLR4-MyD88-IKKα/β-NF-κB signaling pathway. MTHFD2 significantly attenuated LPS-induced macrophage proinflammatory cytokine production through its enzymatic activity. Notably, ablation of myeloid MTHFD2 rendered mice more sensitive to septic shock and CCl4-induced acute hepatitis. Mechanistically, MTHFD2 restrained IKKα/β-NF-κB activation and macrophage inflammatory phenotype by scavenging reactive oxygen species through the generation of NADPH. Our study reveals MTHFD2 as a "self-control" mechanism in macrophage-mediated inflammatory responses.

Targeting SHMTs and MTHFDs in cancer: attractive opportunity for anti-tumor strategy.

One-carbon metabolism is a universal metabolic process that mediates the transfer of one-carbon units for purine and thymidine synthesis. One-carbon metabolism has been found to be dysregulated in various cancer types due to its role in production of purine and pyrimidine nucleotides, epigenetic program, and redox homeostasis. One-carbon metabolism is composed a network of one-carbon metabolic enzymes. Disturbing the expression and enzymatic activity of these one-carbon metabolic enzymes could lead to fluctuations of metabolites in the tumor microenvironment. Serine hydroxymethyltransferases (SHMTs) and methylenetetrahydrofolate dehydrogenases (MTHFDs) are gradually recognized as important one-carbon metabolic enzymes for regulating tumor initiation and development, representing potential therapeutic targets for anti-tumor strategies. In the review, we primarily focused on the role of SHMTs and MTHFDs in cancer. Several inhibitors targeting MTHFDs and SHMTs have exert its potential to decrease tumor burden and inhibit tumor proliferation, highlighting the potential of targeting one-carbon metabolic enzymes for anti-cancer strategies.

MTHFD1 regulates the NADPH redox homeostasis in MYCN-amplified neuroblastoma.

MYCN amplification is an independent poor prognostic factor in patients with high-risk neuroblastoma (NB). Further exploring the molecular regulatory mechanisms in MYCN-amplified NB will help to develop novel therapy targets. In this study, methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) was identified as the differentially expressed gene (DEG) highly expressed in MYCN-amplified NB, and it showed a positive correlation with MYCN and was associated with a poor prognosis of NB patients. Knockdown of MTHFD1 inhibited proliferation and migration, and induced apoptosis of NB cells in vitro. Mouse model experiments validated the tumorigenic effect of MTHFD1 in NB in vivo. In terms of the mechanism, ChIP-qPCR and dual-luciferase reporter assays demonstrated that MTHFD1 was directly activated by MYCN at the transcriptional level. As an important enzyme in the folic acid metabolism pathway, MTHFD1 maintained the NADPH redox homeostasis in MYCN-amplified NB. Knockdown of MTHFD1 reduced cellular NADPH/NADP+ and GSH/GSSG ratios, increased cellular reactive oxygen species (ROS) and triggered the apoptosis of NB cells. Moreover, genetic knockdown of MTHFD1 or application of the anti-folic acid metabolism drug methotrexate (MTX) potentiated the anti-tumor effect of JQ1 both in vitro and in vivo. Taken together, MTHFD1 as an oncogene is a potential therapeutic target for MYCN-amplified NB. The combination of MTX with JQ1 is of important clinical translational significance for the treatment of patients with MYCN-amplified NB.

Unraveling the role of the mitochondrial one-carbon pathway in undifferentiated thyroid cancer by multi-omics analyses

The role of the serine/glycine metabolic pathway (SGP) has recently been demonstrated in tumors; however, the pathological relevance of the SGP in thyroid cancer remains unexplored. Here, we perform metabolomic profiling of 17 tumor-normal pairs; bulk transcriptomics of 263 normal thyroid, 348 papillary, and 21 undifferentiated thyroid cancer samples; and single-cell transcriptomes from 15 cases, showing the impact of mitochondrial one-carbon metabolism in thyroid tumors. High expression of serine hydroxymethyltransferase-2 (SHMT2) and methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is associated with low thyroid differentiation scores and poor clinical features. A subpopulation of tumor cells with high mitochondrial one-carbon pathway activity is observed in the single-cell dataset. SHMT2 inhibition significantly compromises mitochondrial respiration and decreases cell proliferation and tumor size in vitro and in vivo. Collectively, our results highlight the importance of the mitochondrial one-carbon pathway in undifferentiated thyroid cancer and suggest that SHMT2 is a potent therapeutic target.