MTHFD2 is a metabolic checkpoint controlling effector and regulatory T cell fate and function.

Antigenic stimulation promotes T cell metabolic reprogramming to meet increased biosynthetic, bioenergetic, and signaling demands. We show that the one-carbon (1C) metabolism enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) regulates de novo purine synthesis and signaling in activated T cells to promote proliferation and inflammatory cytokine production. In pathogenic T helper-17 (Th17) cells, MTHFD2 prevented aberrant upregulation of the transcription factor FoxP3 along with inappropriate gain of suppressive capacity. MTHFD2 deficiency also promoted regulatory T (Treg) cell differentiation. Mechanistically, MTHFD2 inhibition led to depletion of purine pools, accumulation of purine biosynthetic intermediates, and decreased nutrient sensor mTORC1 signaling. MTHFD2 was also critical to regulate DNA and histone methylation in Th17 cells. Importantly, MTHFD2 deficiency reduced disease severity in multiple in vivo inflammatory disease models. MTHFD2 is thus a metabolic checkpoint to integrate purine metabolism with pathogenic effector cell signaling and is a potential therapeutic target within 1C metabolism pathways.

Optical coherence tomography-guided Brillouin microscopy highlights regional tissue stiffness differences during anterior neural tube closure in the Mthfd1l murine mutant.

Neurulation is a highly synchronized biomechanical process leading to the formation of the brain and spinal cord, and its failure leads to neural tube defects (NTDs). Although we are rapidly learning the genetic mechanisms underlying NTDs, the biomechanical aspects are largely unknown. To understand the correlation between NTDs and tissue stiffness during neural tube closure (NTC), we imaged an NTD murine model using optical coherence tomography (OCT), Brillouin microscopy and confocal fluorescence microscopy. Here, we associate structural information from OCT with local stiffness from the Brillouin signal of embryos undergoing neurulation. The stiffness of neuroepithelial tissues in Mthfd1l null embryos was significantly lower than that of wild-type embryos. Additionally, exogenous formate supplementation improved tissue stiffness and gross embryonic morphology in nullizygous and heterozygous embryos. Our results demonstrate the significance of proper tissue stiffness in normal NTC and pave the way for future studies on the mechanobiology of normal and abnormal embryonic development.

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

BACKGROUND: 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. RESULTS: 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. CONCLUSIONS: 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.

Newcastle Disease Virus Manipulates Mitochondrial MTHFD2-Mediated Nucleotide Metabolism for Virus Replication.

Viruses require host cell metabolic reprogramming to satisfy their replication demands; however, the mechanism by which the Newcastle disease virus (NDV) remodels nucleotide metabolism to support self-replication remains unknown. In this study, we demonstrate that NDV relies on the oxidative pentose phosphate pathway (oxPPP) and the folate-mediated one-carbon metabolic pathway to support replication. In concert with [1,2-13C2] glucose metabolic flow, NDV used oxPPP to promote pentose phosphate synthesis and to increase antioxidant NADPH production. Metabolic flux experiments using [2,3,3-2H] serine revealed that NDV increased one-carbon (1C) unit synthesis flux through the mitochondrial 1C pathway. Interestingly, methylenetetrahydrofolate dehydrogenase (MTHFD2) was upregulated as a compensatory mechanism for insufficient serine availability. Unexpectedly, direct knockdown of enzymes in the one-carbon metabolic pathway, except for cytosolic MTHFD1, significantly inhibited NDV replication. Specific complementation rescue experiments on small interfering RNA (siRNA)-mediated knockdown further revealed that only a knockdown of MTHFD2 strongly restrained NDV replication and was rescued by formate and extracellular nucleotides. These findings indicated that NDV replication relies on MTHFD2 to maintain nucleotide availability. Notably, nuclear MTHFD2 expression was increased during NDV infection and could represent a pathway by which NDV steals nucleotides from the nucleus. Collectively, these data reveal that NDV replication is regulated by the c-Myc-mediated 1C metabolic pathway and that the mechanism of nucleotide synthesis for viral replication is regulated by MTHFD2. IMPORTANCE Newcastle disease virus (NDV) is a dominant vector for vaccine and gene therapy that accommodates foreign genes well but can only infect mammalian cells that have undergone cancerous transformation. Understanding the remodeling of nucleotide metabolic pathways in host cells by NDV proliferation provides a new perspective for the precise use of NDV as a vector or in antiviral research. In this study, we demonstrated that NDV replication is strictly dependent on pathways involved in redox homeostasis in the nucleotide synthesis pathway, including the oxPPP and the mitochondrial one-carbon pathway. Further investigation revealed the potential involvement of NDV replication-dependent nucleotide availability in promoting MTHFD2 nuclear localization. Our findings highlight the differential dependence of NDV on enzymes for one-carbon metabolism, and the unique mechanism of action of MTHFD2 in viral replication, thereby providing a novel target for antiviral or oncolytic virus therapy.

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.

Mitochondrial translation requires folate-dependent tRNA methylation.

Folates enable the activation and transfer of one-carbon units for the biosynthesis of purines, thymidine and methionine. Antifolates are important immunosuppressive and anticancer agents. In proliferating lymphocytes and human cancers, mitochondrial folate enzymes are particularly strongly upregulated. This in part reflects the need for mitochondria to generate one-carbon units and export them to the cytosol for anabolic metabolism. The full range of uses of folate-bound one-carbon units in the mitochondrial compartment itself, however, has not been thoroughly explored. Here we show that loss of the catalytic activity of the mitochondrial folate enzyme serine hydroxymethyltransferase 2 (SHMT2), but not of other folate enzymes, leads to defective oxidative phosphorylation in human cells due to impaired mitochondrial translation. We find that SHMT2, presumably by generating mitochondrial 5,10-methylenetetrahydrofolate, provides methyl donors to produce the taurinomethyluridine base at the wobble position of select mitochondrial tRNAs. Mitochondrial ribosome profiling in SHMT2-knockout human cells reveals that the lack of this modified base causes defective translation, with preferential mitochondrial ribosome stalling at certain lysine (AAG) and leucine (UUG) codons. This results in the impaired expression of respiratory chain enzymes. Stalling at these specific codons also occurs in certain inborn errors of mitochondrial metabolism. Disruption of whole-cell folate metabolism, by either folate deficiency or antifolate treatment, also impairs the respiratory chain. In summary, mammalian mitochondria use folate-bound one-carbon units to methylate tRNA, and this modification is required for mitochondrial translation and thus oxidative phosphorylation.

p53 deficiency induces MTHFD2 transcription to promote cell proliferation and restrain DNA damage.

Cancer cells acquire metabolic reprogramming to satisfy their high biogenetic demands, but little is known about how metabolic remodeling enables cancer cells to survive stress associated with genomic instability. Here, we show that the mitochondrial methylenetetrahydrofolate dehydrogenase (MTHFD2) is transcriptionally suppressed by p53, and its up-regulation by p53 inactivation leads to increased folate metabolism, de novo purine synthesis, and tumor growth in vivo and in vitro. Moreover, MTHFD2 unexpectedly promotes nonhomologous end joining in response to DNA damage by forming a complex with PARP3 to enhance its ribosylation, and the introduction of a PARP3-binding but enzymatically inactive MTHFD2 mutant (e.g., D155A) sufficiently prevents DNA damage. Notably, MTHFD2 depletion strongly restrains p53-deficient cell proliferation and sensitizes cells to chemotherapeutic agents, indicating a potential role for MTHFD2 depletion in the treatment of p53-deficient tumors.

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.

Mitochondrial one-carbon metabolic enzyme MTHFD2 facilitates mammary gland development during pregnancy.

Mitochondrial one-carbon metabolism is crucial for embryonic development and tumorigenesis, as it supplies one-carbon units necessary for nucleotide synthesis and rapid cell proliferation. However, its contribution to adult tissue homeostasis remains largely unknown. To examine its role in adult tissue homeostasis, we specifically investigated mammary gland development during pregnancy, as it involves heightened cell proliferation. We discovered that MTHFD2, a mitochondrial one-carbon metabolic enzyme, is expressed in both luminal and basal/myoepithelial cell layers, with upregulated expression during pregnancy. Using the mouse mammary tumor virus (MMTV)-Cre recombinase system, we generated mice with a specific mutation of Mthfd2 in mammary epithelial cells. While the mutant mice were capable of properly nurturing their offspring, the pregnancy-induced expansion of mammary glands was significantly delayed. This indicates that MTHFD2 contributes to the rapid development of mammary glands during pregnancy. Our findings shed light on the role of mitochondrial one-carbon metabolism in facilitating rapid cell proliferation, even in the context of the adult tissue homeostasis.

The catalytic mechanism of the mitochondrial methylenetetrahydrofolate dehydrogenase/cyclohydrolase (MTHFD2).

Methylenetetrahydrofolate dehydrogenase/cyclohydrolase (MTHFD2) is a new drug target that is expressed in cancer cells but not in normal adult cells, which provides an Achilles heel to selectively kill cancer cells. Despite the availability of crystal structures of MTHFD2 in the inhibitor- and cofactor-bound forms, key information is missing due to technical limitations, including (a) the location of absolutely required Mg2+ ion, and (b) the substrate-bound form of MTHFD2. Using computational modeling and simulations, we propose that two magnesium ions are present at the active site whereby (i) Arg233, Asp225, and two water molecules coordinate [Formula: see text], while [Formula: see text] together with Arg233 stabilize the inorganic phosphate (Pi); (ii) Asp168 and three water molecules coordinate [Formula: see text], and [Formula: see text] further stabilizes Pi by forming a hydrogen bond with two oxygens of Pi; (iii) Arg201 directly coordinates the Pi; and (iv) through three water-mediated interactions, Asp168 contributes to the positioning and stabilization of [Formula: see text], [Formula: see text] and Pi. Our computational study at the empirical valence bond level allowed us also to elucidate the detailed reaction mechanisms. We found that the dehydrogenase activity features a proton-coupled electron transfer with charge redistribution connected to the reorganization of the surrounding water molecules which further facilitates the subsequent cyclohydrolase activity. The cyclohydrolase activity then drives the hydration of the imidazoline ring and the ring opening in a concerted way. Furthermore, we have uncovered that two key residues, Ser197/Arg233, are important factors in determining the cofactor (NADP+/NAD+) preference of the dehydrogenase activity. Our work sheds new light on the structural and kinetic framework of MTHFD2, which will be helpful to design small molecule inhibitors that can be used for cancer treatment.

Performance of Paracoccus pantotrophus MA3 in heterotrophic nitrification-anaerobic denitrification using formic acid as a carbon source.

Excess amount of nitrogen in wastewater has caused serious concerns, such as water eutrophication. Paracoccus pantotrophus MA3, a novel isolated strain of heterotrophic nitrification-anaerobic denitrification bacteria, was evaluated for nitrogen removal using formic acid as the sole carbon source. The results showed that the maximum ammonium removal efficiency was observed under the optimum conditions of 26.25 carbon to nitrogen ratio, 3.39% (v/v) inoculation amount, 34.64 °C temperature, and at 180 rpm shaking speed, respectively. In addition, quantitative real-time PCR technique analysis assured that the gene expression level of formate dehydrogenase, formate tetrahydrofolate ligase, 5,10-methylenetetrahydrofolate dehydrogenase, serine hydroxymethyltransferase, respiratory nitrate reductase beta subunit, L-glutamine synthetase, glutamate dehydrogenase, and glutamate synthase were up-regulated compared to the control group, and combined with nitrogen mass balance analysis to conclude that most of the ammonium was removed by assimilation. A small amount of nitrate and nearly no nitrite were accumulated during heterotrophic nitrification. MA3 exhibited significant denitrification potential under anaerobic conditions with a maximum nitrate removal rate of 4.39 mg/L/h, and the only gas produced was N2. Additionally, 11.50 ± 0.06 mg/L/h of NH4+-N removal rate from biogas slurry was achieved.

MTHFD2 promotes tumorigenesis and metastasis in lung adenocarcinoma by regulating AKT/GSK-3ß/ß-catenin signalling.

Recent studies have demonstrated that one-carbon metabolism plays a significant role in cancer development. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), a mitochondrial enzyme of one-carbon metabolism, has been reported to be dysregulated in many cancers. However, the specific role and mechanism of MTHFD2 in lung adenocarcinoma (LUAD) still remains unclear. In this study, we evaluated the clinicopathological and prognostic values of MTHFD2 in LUAD patients. We conducted a series of functional experiments in vivo and in vitro to explore novel mechanism of MTHFD2 in LUAD. The results showed that MTHFD2 was significantly up-regulated in LUAD tissues and predicted poor prognosis of LUAD patients. Knockdown of MTHFD2 dramatically inhibited cell proliferation and migration by blocking the cell cycle and inducing the epithelial-mesenchymal transition (EMT). In addition, MTHFD2 knockdown suppressed LUAD growth and metastasis in cell-derived xenografts. Mechanically, we found that MTHFD2 promoted LUAD cell growth and metastasis via AKT/GSK-3ß/ß-catenin signalling. Finally, we identified miR-30a-3p as a novel regulator of MTHFD2 in LUAD. Collectively, MTHFD2 plays an oncogenic role in LUAD progression and is a promising target for LUAD diagnosis and therapy.

Non-metabolic function of MTHFD2 activates CDK2 in bladder cancer.

Bladder cancer is a common tumor with a high recurrence rate and high fatality rate, and its mechanism of occurrence and development remains unclear. Many proteins and metabolites reprogram at different stages of tumor development to support tumor cell growth. The moonlighting effect happens when a protein performs multiple functions simultaneously in a cell. In this study, we identified a metabolic protein, MTHFD2, which participates in the cell cycle by binding to CDK2 in bladder cancer. MTHFD2 has been shown to affect bladder cancer cell growth, which is independent of its metabolic function. We found that MTHFD2 was involved in cell cycle regulation and could encourage cell cycle progression by activating CDK2 and sequentially affecting E2F1 activation. In addition, moonlighting MTHFD2 might be regulated by the dynamics of the mitochondria. In conclusion, MTHFD2 localizes in the nucleus to perform a distinct function of catalyzing metabolic reactions. Moreover, the nuclear MTHFD2 activates CDK2 and promotes bladder cancer cell growth by modulating the cell cycle.

A novel oral inhibitor for one-carbon metabolism and checkpoint kinase 1 inhibitor as a rational combination treatment for breast cancer.

Patients with triple-negative breast cancer have a poor prognosis as only a few efficient targeted therapies are available. Cancer cells are characterized by their unregulated proliferation and require large amounts of nucleotides to replicate their DNA. One-carbon metabolism contributes to purine and pyrimidine nucleotide synthesis by supplying one carbon atom. Although mitochondrial one-carbon metabolism has recently been focused on as an important target for cancer treatment, few specific inhibitors have been reported. In this study, we aimed to examine the effects of DS18561882 (DS18), a novel, orally active, specific inhibitor of methylenetetrahydrofolate dehydrogenase (MTHFD2), a mitochondrial enzyme involved in one-carbon metabolism. Treatment with DS18 led to a marked reduction in cancer-cell proliferation; however, it did not induce cell death. Combinatorial treatment with DS18 and inhibitors of checkpoint kinase 1 (Chk1), an activator of the S phase checkpoint pathway, efficiently induced apoptotic cell death in breast cancer cells and suppressed tumorigenesis in a triple-negative breast cancer patient-derived xenograft model. Mechanistically, MTHFD2 inhibition led to cell cycle arrest and slowed nucleotide synthesis. This finding suggests that DNA replication stress occurs due to nucleotide shortage and that the S-phase checkpoint pathway is activated, leading to cell-cycle arrest. Combinatorial treatment with both inhibitors released cell-cycle arrest, but induced accumulation of DNA double-strand breaks, leading to apoptotic cell death. Collectively, a combination of MTHFD2 and Chk1 inhibitors would be a rational treatment option for patients with triple-negative breast cancer.

Oncogenic Ras expression increases cellular formate production.

One-carbon units, critical intermediates for cell growth, may be produced by a variety of means, one of which is via the production of formate. Excessive formate accumulation, known as formate overflow and a characteristic of oxidative cancer, has been observed in cancer cells. However, the basis for this high rate of formate production is unknown. We examined the effect of elevated expression of oncogenic Ras (RasV12), on formate production in NIH-3T3 cells (mouse fibroblasts) cultured with either labelled 13C-serine or 13C-glycine. Formate accumulation by the fibroblasts transformed by RasV12 was increased two-threefold over those by vector control (Babe) cells. The production of formate exceeded the rate of utilization in both cell types. 13C-formate was produced almost exclusively from the #3 carbon of 13C-serine. Virtually no labelled formate was produced from either the #2 carbon of serine or the #2 carbon of glycine. The increased formate production by RasV12 cells was associated with increased mRNA abundances for enzymes of formate production in both the mitochondria and the cytosol. Thus, we find the oncogenic RasV12 significantly increases formate overflow and may be one way for tumor cells to produce one-carbon units required for enhanced proliferation of these cells and/or for other processes which have not been identified.

Melatonin modulates metabolic remodeling in HNSCC by suppressing MTHFD1L-formate axis.

Metabolic remodeling is now widely recognized as a hallmark of cancer, yet its role in head and neck squamous cell carcinoma (HNSCC) remains largely unknown. In this study, metabolomic analysis of melatonin-treated HNSCC cell lines revealed that exogenous melatonin inhibited many important metabolic pathways including folate cycle in HNSCC cells. Methylenetetrahydrofolate dehydrogenase 1 like (MTHFD1L), a metabolic enzyme of the folate cycle regulating the production of formate, was identified as a downstream target of melatonin. MTHFD1L was found to be markedly upregulated in HNSCC, and MTHFD1L overexpression was significantly associated with unfavorable clinical outcome of HNSCC patients. In addition, MTHFD1L promoted HNSCC progression in vitro and in vivo and reversed the oncostatic effects of exogenous melatonin. More importantly, the malignant phenotypes suppressed by knockdown of MTHFD1L or exogenous melatonin could be partially rescued by formate. Furthermore, we found that melatonin inhibited the expression of MTHFD1L in HNSCC cells through the downregulation of cyclic AMP-responsive element-binding protein 1 (CREB1) phosphorylation. Lastly, this novel regulatory axis of melatonin-p-CREB1-MTHFD1L-formate was also verified in HNSCC tissues. Collectively, our findings have demonstrated that MTHFD1L-formate axis promotes HNSCC progression and melatonin inhibits HNSCC progression through CREB1-mediated downregulation of MTHFD1L and formate. These findings have revealed new metabolic mechanisms in HNSCC and may provide novel insights on the therapeutic intervention of HNSCC.

Oxidative stress inhibits distant metastasis by human melanoma cells.

Solid cancer cells commonly enter the blood and disseminate systemically, but are highly inefficient at forming distant metastases for poorly understood reasons. Here we studied human melanomas that differed in their metastasis histories in patients and in their capacity to metastasize in NOD-SCID-Il2rg(-/-) (NSG) mice. We show that melanomas had high frequencies of cells that formed subcutaneous tumours, but much lower percentages of cells that formed tumours after intravenous or intrasplenic transplantation, particularly among inefficiently metastasizing melanomas. Melanoma cells in the blood and visceral organs experienced oxidative stress not observed in established subcutaneous tumours. Successfully metastasizing melanomas underwent reversible metabolic changes during metastasis that increased their capacity to withstand oxidative stress, including increased dependence on NADPH-generating enzymes in the folate pathway. Antioxidants promoted distant metastasis in NSG mice. Folate pathway inhibition using low-dose methotrexate, ALDH1L2 knockdown, or MTHFD1 knockdown inhibited distant metastasis without significantly affecting the growth of subcutaneous tumours in the same mice. Oxidative stress thus limits distant metastasis by melanoma cells in vivo.

hnRNPC regulates cancer-specific alternative cleavage and polyadenylation profiles.

Alternative cleavage and polyadenylation (APA) can occur at more than half of all human genes, greatly enhancing the cellular repertoire of mRNA isoforms. As these isoforms can have altered stability, localisation and coding potential, deregulation of APA can disrupt gene expression and this has been linked to many diseases including cancer progression. How APA generates cancer-specific isoform profiles and what their physiological consequences are, however, is largely unclear. Here we use a subcellular fractionation approach to determine the nuclear and cytoplasmic APA profiles of successive stages of colon cancer using a cell line-based model. Using this approach, we show that during cancer progression specific APA profiles are established. We identify that overexpression of hnRNPC has a critical role in the establishment of APA profiles characteristic for metastatic colon cancer cells, by regulating poly(A) site selection in a subset of genes that have been implicated in cancer progression including MTHFD1L.

A comprehensive association analysis between homocysteine metabolic pathway gene methylation and ischemic stroke in a Chinese hypertensive population.

BACKGROUND: Ischemic stroke (IS) is a serious global health burden. In order to improve our understanding of the risk factors associated with IS, we investigated the combined effect of the methylation of five genes related to the metabolism of homocysteine on developing IS. METHODS: Quantitative methylation-specific PCR was used to measure the levels of promoter methylation in hypertensive and stroke patients. The cutoff value calculated by the maximum Youden index was used to classify the levels of gene methylation as hypomethylation and hypermethylation. Logistic regression was used to explore the relationship between gene methylation and IS. RESULTS: The methylation levels of the genes encoding methylenetetrahydrofolate dehydrogenase 1 [MTHFD1], cystathionine ß-synthase [CBS], and dihydrofolate reductase [DHFR] in hypertensive patients were higher than those in stroke patients (all p < 0.01). MTHFD1 hypermethylation, CBS hypermethylation, and DHFR hypermethylation were protective factors for stroke after adjustment for confounding factors. Compared with individuals carrying none of the biomarkers, the ORs [95% CIs] for stroke of those with 1 and 2 elevated biomarkers were 4.068 [1.670-9.913] and 15.345 [6.198-37.994] after adjustment for confounding factors. The participants with a larger number of biomarkers had an increased risk of stroke (p for trend <0.001). For the combination biomarkers, the area under the curve of the receiver operating characteristic was 0.716. CONCLUSION: A significant linear relationship between the number of elevated biomarkers and the risk of stroke has been observed, suggesting that elevations of these biomarkers could be used for potentially predicting the disease.

Down-regulation of MTHFD2 inhibits NSCLC progression by suppressing cycle-related genes.

Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a bifunctional enzyme located in the mitochondria. It has been reported to be overexpressed in several malignancies. However, the relationship between the expression of MTHFD2 and non-small cell lung cancer (NSCLC) remains largely unknown. In this study, we found that MTHFD2 was significantly overexpressed in NSCLC tissues and cell lines. Knockdown of MTHFD2 resulted in reduced cell growth and tumorigenicity in vitro and in vivo. Besides, the mRNA and protein expression level of cell cycle genes, such as CCNA2, MCM7 and SKP2, was decreased in MTHFD2 knockdown H1299 cells. Our results indicate that the inhibitory effect of MTHFD2 knockdown on NSCLC may be mediated via suppressing cell cycle-related genes. These findings delineate the role of MTHFD2 in the development of NSCLC and may have potential applications in the treatment of NSCLC.