Methionine synthase supports tumor tetrahydrofolate pools

Mammalian cells require activated folates to generate nucleotides for growth and division. The most abundant circulating folate species is 5-methyl tetrahydrofolate (5-methyl-THF), which is used to synthesize methionine from homocysteine via the cobalamin-dependent enzyme methionine synthase (MTR). Cobalamin deficiency traps folates as 5-methyl-THF. Here, we show using isotope tracing that methionine synthase is only a minor source of methionine in cell culture, tissues, or xenografted tumors. Instead, methionine synthase is required for cells to avoid folate trapping and assimilate 5-methyl-THF into other folate species. Under conditions of physiological extracellular folates, genetic MTR knockout in tumor cells leads to folate trapping, purine synthesis stalling, nucleotide depletion, and impaired growth in cell culture and as xenografts. These defects are rescued by free folate but not one-carbon unit supplementation. Thus, MTR plays a crucial role in liberating tetrahydrofolate for use in one-carbon metabolism.

[1]  M. V. Vander Heiden,et al.  Methionine synthase is essential for cancer cell proliferation in physiological folate environments , 2021, Nature Metabolism.

[2]  J. Rabinowitz,et al.  SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia , 2020, Leukemia.

[3]  E. White,et al.  Serine Catabolism Feeds NADH when Respiration Is Impaired. , 2020, Cell metabolism.

[4]  Jared L. Johnson,et al.  Regulation of folate and methionine metabolism by multisite phosphorylation of human methylenetetrahydrofolate reductase , 2019, Scientific Reports.

[5]  Gabriela Kalna,et al.  Improving the metabolic fidelity of cancer models with a physiological cell culture medium , 2019, Science Advances.

[6]  Herschel Rabitz,et al.  Peak Annotation and Verification Engine for Untargeted LC-MS Metabolomics. , 2018, Analytical chemistry.

[7]  Joshua M. Korn,et al.  Next-generation characterization of the Cancer Cell Line Encyclopedia , 2019, Nature.

[8]  E. White,et al.  Autophagy maintains tumor growth through circulating arginine , 2018, Nature.

[9]  C. Lindskog,et al.  A pathology atlas of the human cancer transcriptome , 2017, Science.

[10]  J. Rabinowitz,et al.  An LC-MS chemical derivatization method for the measurement of five different one-carbon states of cellular tetrahydrofolate , 2017, Analytical and Bioanalytical Chemistry.

[11]  Joshua D. Rabinowitz,et al.  Metabolite Spectral Accuracy on Orbitraps. , 2017, Analytical chemistry.

[12]  P. Stover,et al.  Folate rescues vitamin B12 depletion-induced inhibition of nuclear thymidylate biosynthesis and genome instability , 2017, Proceedings of the National Academy of Sciences.

[13]  Xin Gao,et al.  Physiologic Medium Rewires Cellular Metabolism and Reveals Uric Acid as an Endogenous Inhibitor of UMP Synthase , 2017, Cell.

[14]  Joshua D Rabinowitz,et al.  One-Carbon Metabolism in Health and Disease. , 2017, Cell metabolism.

[15]  C. Dann,et al.  Tumor Targeting with Novel 6-Substituted Pyrrolo [2,3-d] Pyrimidine Antifolates with Heteroatom Bridge Substitutions via Cellular Uptake by Folate Receptor α and the Proton-Coupled Folate Transporter and Inhibition of de Novo Purine Nucleotide Biosynthesis. , 2016, Journal of medicinal chemistry.

[16]  J. Rabinowitz,et al.  Reversal of Cytosolic One-Carbon Flux Compensates for Loss of the Mitochondrial Folate Pathway. , 2016, Cell metabolism.

[17]  K. Vousden,et al.  Serine Metabolism Supports the Methionine Cycle and DNA/RNA Methylation through De Novo ATP Synthesis in Cancer Cells , 2016, Molecular cell.

[18]  G. von Heijne,et al.  Tissue-based map of the human proteome , 2015, Science.

[19]  P. Finglas,et al.  Folic acid handling by the human gut: implications for food fortification and supplementation123 , 2014, The American journal of clinical nutrition.

[20]  K. Vousden,et al.  Serine, but not glycine, supports one-carbon metabolism and proliferation of cancer cells. , 2014, Cell reports.

[21]  C. Pfeiffer,et al.  A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product , 2013, Analytical and Bioanalytical Chemistry.

[22]  M. Mann,et al.  Initial Quantitative Proteomic Map of 28 Mouse Tissues Using the SILAC Mouse* , 2013, Molecular & Cellular Proteomics.

[23]  B. Golding,et al.  Mechanism-based design, synthesis and biological studies of N⁵-substituted tetrahydrofolate analogs as inhibitors of cobalamin-dependent methionine synthase and potential anticancer agents. , 2012, European journal of medicinal chemistry.

[24]  Yehuda G Assaraf,et al.  Antifolates in cancer therapy: structure, activity and mechanisms of drug resistance. , 2012, Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy.

[25]  A. Ayav,et al.  A splicing variant leads to complete loss of function of betaine-homocysteine methyltransferase (BHMT) gene in hepatocellular carcinoma. , 2012, The international journal of biochemistry & cell biology.

[26]  D. Watkins,et al.  Inborn errors of cobalamin absorption and metabolism , 2011, American journal of medical genetics. Part C, Seminars in medical genetics.

[27]  M. Cragg,et al.  Contents lists available at ScienceDirect The International Journal of Biochemistry & Cell Biology , 2011 .

[28]  G. Shaw,et al.  Folic acid in early pregnancy: a public health success story , 2010, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[29]  D. Appling,et al.  Compartmentalization of Mammalian folate-mediated one-carbon metabolism. , 2010, Annual review of nutrition.

[30]  Daniel Amador-Noguez,et al.  Metabolomic analysis via reversed-phase ion-pairing liquid chromatography coupled to a stand alone orbitrap mass spectrometer. , 2010, Analytical chemistry.

[31]  J. Rabinowitz,et al.  A domino effect in antifolate drug action in Escherichia coli. , 2008, Nature chemical biology.

[32]  Cai Tang,et al.  Two newly synthesized 5-methyltetrahydrofolate-like compounds inhibit methionine synthase activity accompanied by cell cycle arrest in G1/S phase and apoptosis in vitro , 2008, Anti-cancer drugs.

[33]  P. Stover,et al.  Folate-mediated one-carbon metabolism. , 2008, Vitamins and hormones.

[34]  J. Finkelstein,et al.  Metabolic regulatory properties of S-adenosylmethionine and S-adenosylhomocysteine , 2007, Clinical chemistry and laboratory medicine.

[35]  C. Pfeiffer,et al.  Comparison of serum folate species analyzed by LC-MS/MS with total folate measured by microbiologic assay and Bio-Rad radioassay. , 2007, Clinical chemistry.

[36]  Anna Nicolaou,et al.  Inhibition of cobalamin‐dependent methionine synthase by substituted benzo‐fused heterocycles , 2007, The FEBS journal.

[37]  M. Pajares,et al.  Betaine homocysteine S-methyltransferase: just a regulator of homocysteine metabolism? , 2006, Cellular and Molecular Life Sciences CMLS.

[38]  E. Araki,et al.  AMPK and cell proliferation – AMPK as a therapeutic target for atherosclerosis and cancer , 2006, The Journal of physiology.

[39]  J. Walling From methotrexate to pemetrexed and beyond. A review of the pharmacodynamic and clinical properties of antifolates , 2006, Investigational new drugs.

[40]  P. Finglas,et al.  Differential kinetic behavior and distribution for pteroylglutamic acid and reduced folates: a revised hypothesis of the primary site of PteGlu metabolism in humans. , 2005, The Journal of nutrition.

[41]  R. Banerjee,et al.  Expression profiling of homocysteine junction enzymes in the NCI60 panel of human cancer cell lines. , 2005, Cancer research.

[42]  E.,et al.  THE AMINO ACID REQUIREMENTS OF MAN , 2003 .

[43]  T. Hudson,et al.  Hyperhomocysteinemia due to methionine synthase deficiency, cblG: structure of the MTR gene, genotype diversity, and recognition of a common mutation, P1173L. , 2002, American journal of human genetics.

[44]  M. Stitzel,et al.  Targeted Disruption of the Methionine Synthase Gene in Mice , 2001, Molecular and Cellular Biology.

[45]  S. Lu,et al.  S-Adenosylmethionine. , 2020, The international journal of biochemistry & cell biology.

[46]  R. Matthews,et al.  Cobalamin-dependent methionine synthase and serine hydroxymethyltransferase: targets for chemotherapeutic intervention? , 1998, Advances in enzyme regulation.

[47]  S. Sunden,et al.  Betaine-homocysteine methyltransferase expression in porcine and human tissues and chromosomal localization of the human gene. , 1997, Archives of biochemistry and biophysics.

[48]  R. Matthews,et al.  Cobalamin-dependent methionine synthase: a modular protein and a zinc metalloenzyme , 1997 .

[49]  P. Stover,et al.  5-Formyltetrahydrofolate polyglutamates are slow tight binding inhibitors of serine hydroxymethyltransferase. , 1991, The Journal of biological chemistry.

[50]  R. Matthews,et al.  Providing One-Carbon Units for Biological Methylations: Mechanistic Studies on Serine Hydroxymethyltransferase, Methylenetetrahydrofolate Reductase, and Methyltetrahydrofolate-Homocysteine Methyltransferase , 1990 .

[51]  J. Finkelstein,et al.  Methionine metabolism in mammals. , 1990, The Journal of nutritional biochemistry.

[52]  R. Matthews,et al.  Cobalamin‐dependent methionine synthase , 1990, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[53]  C. Allegra,et al.  Evidence for direct inhibition of de novo purine synthesis in human MCF-7 breast cells as a principal mode of metabolic inhibition by methotrexate. , 1987, The Journal of biological chemistry.

[54]  D. Baker,et al.  Transmethylation of homocysteine to methionine: efficiency in the rat and chick. , 1985, The Journal of nutrition.

[55]  C. Allegra,et al.  Inhibition of phosphoribosylaminoimidazolecarboxamide transformylase by methotrexate and dihydrofolic acid polyglutamates. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[56]  E. Stokstad,et al.  Vitamin B12-folate interrelationships. , 1985, Annual review of nutrition.

[57]  M. Tattersall,et al.  Methotrexate rescue by 5-methyltetrahydrofolate or 5-formyltetrahydrofolate in lymphoblast cell lines. , 1982, Cancer research.

[58]  Elaine,et al.  Nitrous oxide has multiple deleterious effects on cobalamin metabolism and causes decreases in activities of both mammalian cobalamin-dependent enzymes in rats. , 1981, The Journal of clinical investigation.

[59]  D. Horne,et al.  Effect of dietary and nitrous oxide-induced vitamin B-12 deficiency on uptake of 5-methyltetrahydrofolate by isolated rat hepatocytes. , 1980, The Journal of nutrition.

[60]  R. J. Meade,et al.  L-methionine and L-cystine requirements of the growing rat. , 1972, Journal of animal science.

[61]  A. Hoffbrand,et al.  Observations on the Biochemical Basis of Megaloblastic Anaemia , 1972, British journal of haematology.

[62]  V. Herbert,et al.  Interrelations of vitamin B12 and folic acid metabolism: folic acid clearance studies. , 1962, The Journal of clinical investigation.

[63]  M. A. Bennett Utilization of homocystine for growth in presence of vitamin B12 and folic acid. , 1950, The Journal of biological chemistry.

[64]  J. R. Rachele,et al.  The Biological Synthesis of "Labile Methyl Groups" , 1950 .

[65]  W. Rose,et al.  The amino acid requirements of man. 1. The role of valine and methionine. , 1950 .