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Cited by 57Folate and B Vitamins ResearchCancer, Hypoxia, and MetabolismBiochemical and Molecular Research

A review of small-molecule inhibitors of one-carbon enzymes: SHMT2 and MTHFD2 in the spotlight

Open access
Cuthbertson, Christine R., Arabzada, Zahra, Bankhead, Armand, Kyani, Armita, Neamati, Nouri·2021·ACS Pharmacology & Translational Science
DOI 10.1021/acsptsci.0c00223PMC PMC8033767
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Abstract

Metabolic reprogramming is a key hallmark of cancer and shifts cellular metabolism to meet the demands of biomass production necessary for abnormal cell reproduction. One-carbon metabolism (1CM) contributes to many biosynthetic pathways that fuel growth and is comprised of a complex network of enzymes. Methotrexate and 5-fluorouracil were pioneering drugs in this field and are still widely used today as anticancer agents as well as for other diseases such as arthritis. Besides dihydrofolate reductase and thymidylate synthase, two other enzymes of the folate cycle arm of 1CM have not been targeted clinically: serine hydroxymethyltransferase (SHMT) and methylenetetrahydrofolate dehydrogenase (MTHFD). An increasing body of literature suggests that the mitochondrial isoforms of these enzymes (SHMT2 and MTHFD2) are clinically relevant in the context of cancer. In this review, we focused on the 1CM pathway as a target for cancer therapy and, in particular, SHMT2 and MTHFD2. The function, regulation, and clinical relevance of SHMT2 and MTHFD2 are all discussed. We expand on previous clinical studies and evaluate the prognostic significance of these critical enzymes by performing a pan-cancer analysis of patient data from the The Cancer Genome Atlas and a transcriptional coexpression network enrichment analysis. We also provide an overview of preclinical and clinical inhibitors targeting the folate pathway, the methionine cycle, and folate-dependent purine biosynthesis enzymes.

AI snapshot

Written from the paper’s full text.

TL;DR

This review synthesizes one-carbon metabolism as an anticancer target, focusing on SHMT2 and MTHFD2 function, regulation, clinical relevance, and small-molecule inhibitors. It adds an independent TCGA pan-cancer survival and coexpression analysis, finding significant survival associations for SHMT2 in ACC and MTHFD2 in BLCA/UCEC, among others.

Key findings

  • The review catalogs 1CM inhibitors, including only experimentally validated compounds with activity ≤50 μM and excluding likely PAINS. Notable examples: BI-4924 inhibits PHGDH with an IC50 of 2 nM; AGF347 is the first in vivo active SHMT inhibitor; (+)SHIN2 showed in vivo SHMT2 target engagement and anticancer activity in T-ALL models; DS18561882 is a potent MTHFD2 inhibitor efficacious in vivo.
  • A high-throughput screen of >200k compounds identified two sub-micromolar SHMT hits: “hit 1” is ∼20-fold selective for SHMT1, while “hit 2” is the first reported SHMT2-selective inhibitor (∼5-fold).
  • TCGA survival analysis found higher SHMT2 expression significantly associated with reduced survival in adrenocortical carcinoma (ACC); SHMT1 was marginally associated but not significant after multiple testing. Higher MTHFD2 was significantly associated with reduced survival in bladder urothelial carcinoma (BLCA) and uterine corpus endometrial carcinoma (UCEC), corroborating PAAD, KIRC, and KIRP; lower MTHFD2 was significantly associated with reduced survival in GBM and LGG.
  • GSEA identified 34 gene sets commonly enriched for SHMT1-correlated genes in ACC and LGG, and nine gene sets enriched for MTHFD2-correlated genes in BLCA, KIRC, KIRP, PAAD, and UCEC, related to cell cycle, MYC signaling, and unfolded protein response.

Methods

  • Design: narrative review plus original pan-cancer analysis of TCGA patient data and transcriptional coexpression network enrichment analysis; inhibitor overview covers preclinical and clinical compounds.
  • TCGA analysis: patients stratified by median SHMT1/SHMT2 expression; log-rank statistic used; p-values FDR-adjusted across 33 cancer types with FDR-adjusted p < 0.05 considered significant; RNA-Seq RSEM-normalized expression and survival metadata from TCGA GDAC Firehose; Kaplan–Meier plots generated in R.
  • GSEA: PreRanked V2.2.3 used to score Hallmark and KEGG gene sets from MSigDBv7; SHMT1 analyzed in ACC and LGG; MTHFD2 analyzed in BLCA, KIRC, KIRP, PAAD, and UCEC.

Limitations

  • Stated: no cocrystal structures of SHMT1 with any published inhibitors; no inhibitors specific to SHMT2; MTHFD2L activity of MTHFD2 inhibitors has not been evaluated; no crystal structures are available for MTHFD1L or MTHFD2L; AGF347 polyglutamylation remains to be determined experimentally.
  • Stated: the mechanism of MTHFD2’s nonenzymatic proliferation function is not well understood; the kinases and purposes of MTHFD2 phosphorylation sites are unknown; BHMT1/2 physiological roles remain incompletely understood.
  • Evident: the TCGA/GSEA findings are correlative and rely on public datasets without functional validation; some survival associations were not significant after multiple testing; the summary lists MTHFD2-associated cancers (ESCA, HNSC, LUAD, MESO) that are not detailed in the results section.

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Integrity signals

Registry

Crossref · 10.1021/acsptsci.0c00223

Cites

219 of 219 references verified0 citation errors · 0 not checkable

Statistics

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Claims the paper makes

0 of 91 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Thirty-four enriched gene sets were commonly enriched in ACC and LGG networks.

    “Interestingly 34 enriched gene sets were commonly enriched in ACC and LGG networks (Figure 4D, GSEA Supporting Information Table)”
    Quote in the paperNot a substantial claim
  • Findingown data

    Higher expression of SHMT2 in adrenocortical carcinoma was significantly associated with reduced survival.

    “We observed higher expression of SHMT2 in adrenocortical carcinoma (ACC), which was significantly associated with reduced survival”
    Quote in the paperSubstantial claim
  • Findingown data

    In three TCGA diseases, higher levels of SHMT1 were associated with improved survival.

    “We identified three TCGA diseases for which higher levels of SHMT1 was associated with improved survival”
    Quote in the paperSubstantial claim
  • Findingown data

    In brain lower grade glioma, patients with higher expression of SHMT1 were significantly associated with reduced survival.

    “Interestingly, in brain lower grade glioma (LGG), patients with a higher expression of SHMT1 were significantly associated with reduced survival”
    Quote in the paperNot a substantial claim
  • Findingown data

    Nine gene sets are statistically enriched for genes correlated with MTHFD2 in BLCA, KIRC, KIRP, PAAD, and UCEC patient cohorts.

    “Our transcriptional coexpression network enrichment analysis identified nine gene sets statistically enriched for genes correlated with MTHFD2 in BLCA, KIRC, KIRP, PAAD, and UCEC patient cohorts. (Figure 5C, GSEA Supporting Information Table).”
    Quote in the paperNot a substantial claim
  • May combine two claims. 25
  • Classified as probably not a substantial claim. 3

  • May combine two claims.

    Findingown data

    SHMT1 was marginally associated with reduced survival in adrenocortical carcinoma, but the p-value was not significant after multiple testing.

    “SHMT1 was also marginally associated with reduced survival (p-value not significant after multiple testing).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In brain lower grade glioma, patients with higher expression of SHMT2 were moderately associated with improved survival, but the p-value was not significant after FDR correction.

    “and patients with a higher expression of SHMT2 were moderately associated with improved survival (p-value not significant after FDR correction).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Higher expression of MTHFD2 is associated with significant reduction in survival in bladder urothelial carcinoma (BLCA) and uterine corpus endometrial carcinoma (UCEC).

    “We identified significant reduction in survival with a higher expression of MTHFD2 in bladder urothelial carcinoma (BLCA) and uterine corpus endometrial carcinoma (UCEC) (Figure 5B).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Compound 2.12 has selective activity against SHMT1 and displays anticancer activity in the mid-micromolar range.

    “In addition to having selective activity against SHMT1, compound 2.12 (Table 7) also displayed anticancer activity in the mid-micromolar range.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [148] Marani, 2016, A pyrazolopyran derivative preferentially inhibits the activity of human cytosolic serine hydroxymethyltransferase and induces cell death in lung cancer cells, Oncotarget source

      Not checked in the free run.

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    Premisecitation

    Only a handful of SHMT2 inhibitors have been published, and none are specific to SHMT2.

    “Despite encouraging evidence that SHMT2 is a viable anticancer target, only a handful of inhibitors have been published to date (discussed below).143−146 However, none are specific to SHMT2.”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [143] Ducker, 2017, Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma, Proc. Natl. Acad. Sci. U. S. A. source

      Not checked in the free run.

    • cites [144] Dekhne, 2019, Novel pyrrolo­[3,2-d]­pyrimidine compounds target mitochondrial and cytosolic one-carbon metabolism with broad-spectrum antitumor efficacy, Mol. Cancer Ther. source

      Not checked in the free run.

    • cites [145] Garcia-Canaveras, 2021, SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia, Leukemia source

      Not checked in the free run.

    • cites [146] Han, 2021, Identification of three new compounds that directly target human serine hydroxymethyltransferase SHMT2, Chem. Biol. Drug Des. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Nonaka et al. identified two hits with sub-micromolar activity; hit 1 is about 20-fold selective for SHMT1, and hit 2 is the first-reported SHMT2 selective inhibitor, about 5-fold selective.

    “They identified two hits with sub-micromolar activity (Table 7). “Hit 1” is ∼20-fold selective for SHMT1, while “hit 2” is the first-reported SHMT2 selective inhibitor (∼5-fold).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [156] Nonaka, 2019, Design strategy for serine hydroxymethyltransferase probes based on retro-aldol-type reaction, Nat. Commun. source

      Not checked in the free run.

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    Premisecitation

    AGF347 is the first in vivo active SHMT inhibitor and showed in vivo activity in pancreatic adenocarcinoma models.

    “The first in vivo active SHMT inhibitor, AGF347, is a folate mimetic.144 Despite being much less potent than the pyrazolopyran compounds against recombinant protein, AGF347 showed in vivo activity in pancreatic adenocarcinoma models”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [144] Dekhne, 2019, Novel pyrrolo­[3,2-d]­pyrimidine compounds target mitochondrial and cytosolic one-carbon metabolism with broad-spectrum antitumor efficacy, Mol. Cancer Ther. source

      Not checked in the free run.

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    Premisecitation

    In vivo studies of dual SHMT1/2 inhibitors show that coinhibition is efficacious with minimal systemic toxicities.

    “In vivo studies of the dual SHMT1/2 inhibitors show that coinhibition is efficacious with minimal systemic toxicities,144,145 suggesting that selectivity may not be required.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [144] Dekhne, 2019, Novel pyrrolo­[3,2-d]­pyrimidine compounds target mitochondrial and cytosolic one-carbon metabolism with broad-spectrum antitumor efficacy, Mol. Cancer Ther. source

      Not checked in the free run.

    • cites [145] Garcia-Canaveras, 2021, SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia, Leukemia source

      Not checked in the free run.

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    Premisecitation

    FDA-approved antifolates inhibit SHMTs, but higher concentrations of at least 100 μM are required.

    “FDA-approved antifolates do inhibit SHMTs, but higher concentrations are required (≥100 μM).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [152] Scaletti, 2019, Structural basis of inhibition of the human serine hydroxymethyltransferase SHMT2 by antifolate drugs, FEBS Lett. source

      Not checked in the free run.

    • cites [153] Paiardini, 2015, Screening and in vitro testing of antifolate inhibitors of human cytosolic serine hydroxymethyltransferase, ChemMedChem source

      Not checked in the free run.

    • cites [154] Daidone, 2011, In silico and in vitro validation of serine hydroxymethyltransferase as a chemotherapeutic target of the antifolate drug pemetrexed, Eur. J. Med. Chem. source

      Not checked in the free run.

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    Premisecitation

    SHMT2 knockout causes mitochondrial translation to stall at specific methylated tRNAs, and this effect depends on SHMT2 enzymatic activity.

    “Outside of nutrient contributions, SHMT2 knockout caused mitochondrial translation to stall at specific methylated tRNAs, and this was dependent on its enzymatic activity.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [123] Morscher, 2018, Mitochondrial translation requires folate-dependent tRNA methylation, Nature source

      Not checked in the free run.

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    Premisecitation

    (+)SHIN2 showed in vivo target engagement of SHMT2 and anticancer activity in models of T-ALL.

    “A breakthrough came this past year with the disclosure of (+)SHIN2 which showed in vivo target engagement of SHMT2 in addition to anticancer activity in models of T-ALL.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [145] Garcia-Canaveras, 2021, SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia, Leukemia source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The mitochondrial isoform of SHMT is selectively overexpressed compared to its cytosolic counterpart and is associated with poor patient prognosis, staging, and metastasis in several cancers.

    “The mitochondrial isoform of SHMT is selectively overexpressed compared to its cytosolic counterpart and is associated with poor patient prognosis, staging, and metastasis in several cancers including kidney, gastric, liver, breast, lung, colorectal, esophageal and intrahepatic cholangiocarcinoma, oral squamous carcinoma, and glioma.”
    Quote in the paperSubstantial claim0 of 10 sources checked
    • cites [162] Shi, 2019, High expression of serine hydroxymethyltransferase 2 indicates poor prognosis of gastric cancer patients, Med. Sci. Monit. source

      Not checked in the free run.

    • cites [163] Liu, 2019, High expression of SHMT2 is correlated with tumor progression and predicts poor prognosis in gastrointestinal tumors, Eur. Rev. Med. Pharmacol Sci. source

      Not checked in the free run.

    • cites [164] Ji, 2019, Increased expression of serine hydroxymethyltransferase 2 (SHMT2) is a negative prognostic marker in patients with hepatocellular carcinoma and is associated with proliferation of HepG2 cells, Med. Sci. Monit. source

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    • cites [165] Bernhardt, 2017, Proteomic profiling of breast cancer metabolism identifies SHMT2 and ASCT2 as prognostic factors, Breast Cancer Res. source

      Not checked in the free run.

    • cites [166] Zhang, 2016, Prognostic and therapeutic value of mitochondrial serine hydroxyl-methyltransferase 2 as a breast cancer biomarker, Oncol. Rep. source

      Not checked in the free run.

    • cites [167] Lee, 2014, Comparative oncogenomics identifies PSMB4 and SHMT2 as potential cancer driver genes, Cancer Res. source

      Not checked in the free run.

    • cites [168] Ning, 2018, SHMT2 overexpression predicts poor prognosis in intrahepatic cholangiocarcinoma, Gastroenterol Res. Pract source

      Not checked in the free run.

    • cites [169] Wu, 2017, Overexpression of mitochondrial serine hydroxyl-methyltransferase 2 is associated with poor prognosis and promotes cell proliferation and invasion in gliomas, OncoTargets Ther. source

      Not checked in the free run.

    • cites [170] Wang, 2017, Mitochondrial serine hydroxymethyltransferase 2 is a potential diagnostic and prognostic biomarker for human glioma, Clin Neurol Neurosurg source

      Not checked in the free run.

    • cites [171] Wang, 2020, Evaluating the clinical significance of SHMT2 and its co-expressed gene in human kidney cancer, Biol. Res. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Hypoxia induces SHMT2 expression, and SHMT2 is necessary for redox homeostasis and cell survival under hypoxic conditions.

    “Hypoxia induces SHMT2 expression and was found to be necessary for redox homeostasis and cell survival under hypoxic conditions.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [125] Engel, 2020, Serine-dependent redox homeostasis regulates glioblastoma cell survival, Br. J. Cancer source

      Not checked in the free run.

    • cites [126] Ye, 2014, Serine catabolism regulates mitochondrial redox control during hypoxia, Cancer Discovery source

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  • May combine two claims.

    Premisecitation

    When the mitochondrial folate pathway is inhibited, the cytosolic pathway reverses flux to compensate; therefore, inhibition of both SHMT isoforms is essential for antitumor activity.

    “Additionally, when the mitochondrial folate pathway is inhibited, the cytosolic pathway reverses flux to compensate; therefore, inhibition of both isoforms is essential for antitumor activity.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [158] Ducker, 2016, Reversal of cytosolic one-carbon flux compensates for loss of the mitochondrial folate pathway, Cell Metab. source

      Not checked in the free run.

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    Premisecitation

    DS18561882 is an optimized inhibitor that is potent in vitro and efficacious in vivo.

    “Later that year, the same group followed up with an optimized inhibitor, DS18561882, that was not only potent in vitro but also efficacious in vivo.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [186] Kawai, 2019, Discovery of a potent, selective, and orally available MTHFD2 inhibitor (DS18561882) with in vivo antitumor activity, J. Med. Chem. source

      Not checked in the free run.

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    Premisecitation

    DS44960156 was the first truly MTHFD2-selective inhibitor, although its potency was lacking.

    “The first truly MTHFD2-selective inhibitor was reported in 2019, DS44960156, although potency was lacking.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [210] Kawai, 2019, Structure-based design and synthesis of an isozyme-selective MTHFD2 inhibitor with a tricyclic coumarin scaffold, ACS Med. Chem. Lett. source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Five sites of phosphorylation on MTHFD2 have been identified through phosphoproteomics.

    “Five sites of phosphorylation on MTHFD2 have been identified through phosphoproteomics (S149, T187, T191, T306, and T324).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [206] Hornbeck, 2012, PhosphoSitePlus: a comprehensive resource for investigating the structure and function of experimentally determined post-translational modifications in man and mouse, Nucleic Acids Res. source

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    Premisecitation

    MTHFD2 is the only MTHFD isoform not expressed in adult human tissues and is primarily expressed during embryonic development or in cancerous cells.

    “Of the four MTHFD isoforms, MTHFD2 is the only one that is not expressed in adult human tissues and is primarily expressed during embryonic development or in cancerous cells, making it an attractive anticancer target.9”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [9] Nilsson, 2014, Metabolic enzyme expression highlights a key role for MTHFD2 and the mitochondrial folate pathway in cancer, Nat. Commun. source

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    Premisecitation

    Carolacton is selective for MTHFD2 with the dehydrogenase function, but for MTHFD1 with the cyclohydrolase function.

    “Interestingly, carolacton was selective for MTHFD2 with the dehydrogenase function, but for MTHFD1 with the cyclohydrolase function.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [185] Fu, 2017, The natural product carolacton inhibits folate-dependent C1 metabolism by targeting FolD/MTHFD, Nat. Commun. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Noncoding RNAs reported to regulate MTHFD2 expression include miR-9, miR-92a, miR-940, miR-33a-5p, miR-22, and LIN28B.

    “Noncoding RNAs reported to regulate MTHFD2 expression include miR-9 (along with lncRNA TUG1), miR-92a, miR-940, miR-33a-5p, miR-22, and LIN28B.”
    Quote in the paperNot a substantial claim0 of 7 sources checked
    • cites [195] Selcuklu, 2012, MicroRNA-9 inhibition of cell proliferation and identification of novel miR-9 targets by transcriptome profiling in breast cancer cells, J. Biol. Chem. source

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    • cites [196] Gu, 2017, miR-92a inhibits proliferation and induces apoptosis by regulating methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) expression in acute myeloid leukemia, Oncol. Res. source

      Not checked in the free run.

    • cites [197] Xu, 2019, MicroRNA-940 inhibits glioma progression by blocking mitochondrial folate metabolism through targeting of MTHFD2, Am. J. Cancer Res.

      Not checked in the free run.

    • cites [198] Yan, 2019, MicroRNA-33a-5p suppresses colorectal cancer cell growth by inhibiting MTHFD2, Clin. Exp. Pharmacol. Physiol. source

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    • cites [199] Zhou, 2017, Inhibition of LIN28B impairs leukemia cell growth and metabolism in acute myeloid leukemia, J. Hematol. Oncol. source

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    • cites [200] Zhao, 2016, LncRNA taurine-upregulated gene 1 promotes cell proliferation by inhibiting microRNA-9 in MCF-7 cells, J. Breast Cancer source

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    • cites [201] Tong, 2020, MiR-22, regulated by MeCP2, suppresses gastric cancer cell proliferation by inducing a deficiency in endogenous S-adenosylmethionine, Oncogenesis source

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  • May combine two claims.

    Premisecitation

    Carolacton was originally discovered as an inhibitor of the E. coli isoform FolD but also possesses potent activity against MTHFD1 and MTHFD2.

    “Around the same time, the natural product carolacton was originally discovered as an inhibitor of the E. coli isoform, FolD, but it also possessed potent activity against MTHFD1 and MTHFD2.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [185] Fu, 2017, The natural product carolacton inhibits folate-dependent C1 metabolism by targeting FolD/MTHFD, Nat. Commun. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    MTHFD2's relation to MYC has previously been established.

    “MTHFD2’s relation to MYC has previously been established.189,216,217”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [189] Ju, 2019, Modulation of redox homeostasis by inhibition of MTHFD2 in colorectal cancer: mechanisms and therapeutic implications, J. Natl. Cancer Inst source

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    • cites [216] Pikman, 2016, Targeting MTHFD2 in acute myeloid leukemia, J. Exp. Med. source

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    • cites [217] Moran, 2014, KRAS mutation status is associated with enhanced dependency on folate metabolism pathways in non-small cell lung cancer cells, Mol. Cancer Ther. source

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    Premisecitation

    LY345899 is the first described MTHFD2 inhibitor, is a folate analog, has high nanomolar activity, and is about 7-fold selective for MTHFD1.

    “The first described MTHFD2 inhibitor, LY345899, is a folate analog. While it had activity in the high nanomolar range, it was still ∼7-fold selective for MTHFD1.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [209] Gustafsson, 2017, Crystal structure of the emerging cancer target MTHFD2 in complex with a substrate-based inhibitor, Cancer Res. source

      Not checked in the free run.

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    Premisecitation

    MTHFD2 has secondary functions including nonenzymatic driven proliferation, potential physical interaction with nuclear-RNA-related proteins, and localization to DNA replication sites.

    “Other secondary functions of MTHFD2 have also been discovered such as nonenzymatic driven proliferation, potential physical interaction with nuclear-RNA-related proteins, and localization to DNA replication sites.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [193] Gustafsson Sheppard, 2015, The folate-coupled enzyme MTHFD2 is a nuclear protein and promotes cell proliferation, Sci. Rep. source

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    • cites [194] Koufaris, 2018, Protein interaction and functional data indicate MTHFD2 involvement in RNA processing and translation, Cancer Metab source

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  • May combine two claims.

    Premisecitation

    MTHFD2 regulation extends beyond canonical metabolism-related transcription factors; several microRNAs and transcription factors such as EWS-FLI1 impact MTHFD2 expression.

    “Similar to SHMT2, regulation of MTHFD2 expression extends beyond canonical metabolism-related transcription factors such as c-MYC, mTOR, ATF4, HIF-1α, AMPK, and NRF2.1 For example, several microRNAs and transcription factors like the chimeric oncogene EWS-FLI1 have been shown to impact MTHFD2 expression.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [7] Zhu, 2020, More than a metabolic enzyme: MTHFD2 as a novel target for anticancer therapy?, Front. Oncol. source

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    • cites [137] Sen, 2018, EWS-FLI1 reprograms the metabolism of Ewing sarcoma cells via positive regulation of glutamine import and serine-glycine biosynthesis, Mol. Carcinog. source

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    Premisecitation
    § 5. Summary

    Both SHMT2's and MTHFD2's enzymatic activity is regulated by SIRT3.

    “Interestingly, both SHMT2’s and MTHFD2’s enzymatic activity is regulated by SIRT3.133,205”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [133] Wei, 2018, Deacetylation of serine hydroxymethyl-transferase 2 by SIRT3 promotes colorectal carcinogenesis, Nat. Commun. source

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    • cites [205] Wan, 2020, Cisplatin inhibits SIRT3-deacetylation MTHFD2 to disturb cellular redox balance in colorectal cancer cell, Cell Death Dis. source

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  • May combine two claims.

    Premisecitation

    Inhibition of MTHFD2 reduces proliferation, migration, invasion, tumor growth, and stem-cell-like properties, and promotes cell death, differentiation, and chemosensitivity in several cancer types.

    “Both through genetic and small molecule approaches, inhibition of MTHFD2 reduces proliferation, migration, invasion, tumor growth, stem-cell-like properties, and promotes cell death, differentiation, and chemosensitivity in several cancer types.”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [7] Zhu, 2020, More than a metabolic enzyme: MTHFD2 as a novel target for anticancer therapy?, Front. Oncol. source

      Not checked in the free run.

    • cites [185] Fu, 2017, The natural product carolacton inhibits folate-dependent C1 metabolism by targeting FolD/MTHFD, Nat. Commun. source

      Not checked in the free run.

    • cites [186] Kawai, 2019, Discovery of a potent, selective, and orally available MTHFD2 inhibitor (DS18561882) with in vivo antitumor activity, J. Med. Chem. source

      Not checked in the free run.

    • cites [187] Yu, 2020, Down-regulation of MTHFD2 inhibits NSCLC progression by suppressing cycle-related genes, J. Cell. Mol. Med. source

      Not checked in the free run.

    • cites [188] Chan, 2020, Modulating redox homeostasis and cellular reprogramming through inhibited methylenetatrahydrofolate dehydrogenase 2 enzymatic activities in lung cancer, Aging source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    MTHFD2 plays a role in redox homeostasis through its cofactor NAD+ and through involvement with expression of hypoxia-related proteins such as HIF-2α.

    “In addition to its involvement in nutrient regulation, MTHFD2 plays a role in redox homeostasis through the use of its cofactor NAD+, as well as involvement with expression of hypoxia-related proteins such as HIF-2α.”
    Quote in the paperNot a substantial claim0 of 5 sources checked
    • cites [158] Ducker, 2016, Reversal of cytosolic one-carbon flux compensates for loss of the mitochondrial folate pathway, Cell Metab. source

      Not checked in the free run.

    • cites [189] Ju, 2019, Modulation of redox homeostasis by inhibition of MTHFD2 in colorectal cancer: mechanisms and therapeutic implications, J. Natl. Cancer Inst source

      Not checked in the free run.

    • cites [190] Green, 2019, MTHFD2 links RNA methylation to metabolic reprogramming in renal cell carcinoma, Oncogene source

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    • cites [191] Yang, 2020, Serine catabolism feeds NADH when respiration is impaired, Cell Metab. source

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    • cites [192] Fan, 2014, Quantitative flux analysis reveals folate-dependent NADPH production, Nature source

      Not checked in the free run.

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  • The authors state this as an assumption.

    SHMT and MTHFD have not been targeted clinically.

    “Two other enzymes complete the folate cycle arm of 1CM but have not been targeted clinically at this point: serine hydroxymethyltransferase (SHMT) and methylenetetrahydrofolate dehydrogenase (MTHFD).”

  • The paper relies on this without support.

    MTHFD2L takes the place of MTHFD2's function in normal adult tissues.

    “MTHFD2L takes the place of MTHFD2’s function in normal adult tissues, so an important next step would be to evaluate the activity of these molecules against this mitochondrial isoform.”
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  • Plasmodium and Marani studies were published in different years

    Minor

    The text says Marani and colleagues published their study in the same year as the Plasmodium SHMT study. The cited references date those studies to 2016 and 2015, respectively.

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  1. 2016, Broad Institute TCGA Genome Data Analysis Center

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Authors
Cuthbertson, C. R., Arabzada, Z., Bankhead, A., Kyani, A., & Neamati, N.
Affiliations
University of Michigan (US)
Corresponding author
Neamati, Nouri
ORCID
Venue
ACS Pharmacology & Translational Science
Publisher
American Chemical Society (ACS)
Published
2021-03-01
Volume
4
Issue
2
Pages
624-646
ISSN
2575-9108 (ISSN-L)
DOI
10.1021/acsptsci.0c00223
PMC
PMC8033767
OpenAlex
W3133846151
Cited by
57
References
219
Citations by year
2026: 12 · 2025: 12 · 2024: 9 · 2023: 9 · 2022: 8 · 2021: 7
FWCI
1.35
Type
journal article
Language
en
Open access
Licence
Locations
  • ACS Pharmacology & Translational Science (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
National Institutes of Health (R01 CA188252, T32-GM007767)
Topics
  • Health Sciences › Medicine › Rheumatology › Folate and B Vitamins Research
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Cancer, Hypoxia, and Metabolism
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Biochemical and Molecular Research
Keywords
one-carbon metabolism, SHMT2, MTHFD2, serine hydroxymethyltransferase, methylenetetrahydrofolate dehydrogenase, folate cycle, small molecule inhibitors, tumor metabolic reprogramming, methionine cycle, purine biosynthesis, prognostic factors, pan-cancer analysis, anticancer drug targets

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