The growth of cancer cells relies more on increased proliferation and autonomy compared to non-malignant cells. The rate of de novo nucleotide biosynthesis correlates with cell proliferation rates. In part, glutamine is needed to sustain high rates of cellular proliferation as a key nitrogen donor in purine and pyrimidine nucleotide biosynthesis. In addition, glutamine serves as an essential substrate for key enzymes involved in the de novo synthesis of purine and pyrimidine nucleotides. Here, we developed a novel liquid chromatography (LC-MS) to quantify glutamine-derived [15N] nitrogen flux into nucleosides and nucleobases (purines and pyrimidines). For this, DNA from 5637 bladder cancer cell line cultured in 15N labelled glutamine and then enzymatically hydrolyzed by sequential digestion. Subsequently, DNA hydrolysates were separated by LC-MS and Selected Reaction Monitoring (SRM) was employed to identify the nucleobases and nucleosides. Thus, high sensitivity and reproducibility of the method make it a valuable tool to identify the nitrogen flux primarily derived from glutamine and can be further adaptable for high throughput analysis of large set of DNA in a clinical setting.
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http://dx.doi.org/10.4172/2155-9872.1000267 | DOI Listing |
Se Pu
January 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China;3. University of Chinese Academy of Sciences, Beijing 100049, China.
Post-transcriptional ribonucleic acid (RNA) modifications play crucial roles in regulating gene expression, with both eukaryotic and prokaryotic RNA exhibiting more than 170 distinct and ubiquitous modifications. RNA turnover generates numerous free nucleosides, including unmodified nucleosides and a variety of modified ones. Unlike unmodified nucleosides, modified nucleosides are not further degraded or used in the salvage-synthesis pathway owing to a lack of specific enzymes, which leads to the cytosolic accumulation or cellular efflux of modified nucleosides.
View Article and Find Full Text PDFChem Sci
December 2024
Department of Pure & Applied Chemistry, University of Strathclyde 295 Cathedral Street Glasgow G1 1XL UK
Ribonucleosides are essential building blocks used extensively in antiviral and oligonucleotide therapeutics. A major challenge in the further development of nucleoside analogues for therapeutic applications is access to scalable and environmentally sustainable synthetic strategies. This study uses the type II nucleoside 2'-deoxyribosyltransferase from (NDT-2) to prepare a suite of ribonucleoside analogues using naturally-occurring uridine and cytidine sugar donors.
View Article and Find Full Text PDFJ Bacteriol
December 2024
Department of Molecular Enzymology, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Brandenburg, Germany.
Modifications of transfer RNA (tRNA) have been shown to play critical roles in the biogenesis, metabolism, structural stability, and function of RNA molecules, and the specific modifications of nucleobases with sulfur atoms in tRNA are present in prokaryotes and eukaryotes. The s group of sU34 stabilizes anticodon structure, confers ribosome-binding ability to tRNA, and improves reading frame maintenance. In particular, specific enzymes catalyze the biosynthesis of sulfur-containing nucleosides of sU34, such as the L-cysteine desulfurase IscS and the tRNA thiouridylase MnmA in .
View Article and Find Full Text PDFNucleosides Nucleotides Nucleic Acids
December 2024
Department of Chemistry, Stanford University, Stanford, CA, USA.
Hydrolytic and oxidative damage to pyrimidine nucleobases in DNA represents a significant source of mutations in the human genome. To better understand how these lesions are incorporated and repaired in human cells, it is desirable to have ready access to isotopically enriched nucleosides for use in isotope tracing and mass spectrometry-based quantification experiments. Here we report on improved syntheses of deoxyuridine, deoxycytidine, 5-hydroxydeoxyuridine, and 5-hydroxydeoxycytidine nucleosides labeled with C and N.
View Article and Find Full Text PDFChem Res Toxicol
December 2024
Department of Medical Imaging and Radiation Sciences, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12e Avenue Nord, Sherbrooke, Québec J1H 5N4, Canada.
Radical oxidation of DNA gives rise to potentially deleterious lesions such as strand breaks and various nucleobase modifications including 5-formyl-2'-deoxyuridine (5-fo-dU), a prevalent product derived from the oxidation of the C5-methyl group of thymidine. The present study investigates the unusual transformation of 5-fo-dU into 5-hydroxy-2'-deoxyuridine (5-oh-dU) and 5,6-dihydroxy-5,6-dihydro-2'-deoxuridine (gly-dU), two products typically associated with the oxidation of 2'-deoxycytidine. Detailed mechanistic analyses reveal that hydrogen peroxide, either generated as a byproduct of ascorbate autoxidation or added exogenously, mediates the formation of these oxidatively induced C5-dealkylated products.
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