Quantification of modified nucleotides and nucleosides by isotope dilution mass spectrometry

• Published in: Mass spectrometry reviews 2024-09, Vol.43 (5), p.998-1018
• Main Authors: Marchante‐Gayón, Juan M., Nicolás Carcelén, Jesús, Potes Rodríguez, Helí, Pineda‐Cevallos, Daniela, Rodas Sánchez, Laura, González‐Gago, Adriana, Rodríguez‐González, Pablo, García Alonso, Jose I.
• Format: Article
• Language: English
• Subjects: Animals; Chromatography; Chromatography, Liquid - methods; DNA Methylation; Epigenetics; gas and liquid chromatography; Gas chromatography; Gas Chromatography-Mass Spectrometry - methods; Humans; Indicator Dilution Techniques; Ionization; isotope dilution; Isotope Labeling - methods; Liquid chromatography; Mass spectrometry; Mass Spectrometry - methods; Mass spectroscopy; methylated and modified nucleotides and nucleosides; Nucleoside analogs; Nucleosides - analysis; Nucleosides - chemistry; Nucleotide analogs; Nucleotides - analysis; Nucleotides - chemistry; Scientific imaging; Tandem Mass Spectrometry - methods
• ISSN: 0277-7037; 1098-2787; 1098-2787
• DOI: 10.1002/mas.21865

Epigenetic modifications are closely related to certain disorders of the organism, including the development of tumors. One of the main epigenetic modifications is the methylation of DNA cytosines, 5‐methyl‐2′‐deoxycycytidine. Furthermore, 5‐mdC can be oxidized to form three new modifications, 5‐(hydroxymethyl)‐2′‐deoxycytidine, 5‐formyl‐2′‐deoxycytidine, and 5‐carboxy‐2′‐deoxycytidine. The coupling of liquid chromatography with tandem mass spectrometry has been widely used for the total determination of methylated DNA cytosines in samples of biological and clinical interest. These methods are based on the measurement of the free compounds (e.g., urine) or after complete hydrolysis of the DNA (e.g., tissues) followed by a preconcentration, derivatization, and/or clean‐up step. This review highlights the main advances in the quantification of modified nucleotides and nucleosides by isotope dilution using isotopically labeled analogs combined with liquid or gas chromatography coupled to mass spectrometry reported in the last 20 years. The different possible sources of labeled compounds are indicated. Special emphasis has been placed on the different types of chromatography commonly used (reverse phase and hydrophilic interaction liquid chromatography) and the derivatization methods developed to enhance chromatographic resolution and ionization efficiency. We have also revised the application of bidimensional chromatography and indicated significant biological and clinical applications of these determinations.