Analysis of modified nucleosides in the urine of patients with malignant cancer by liquid chromatography/electrospray ionization mass spectrometry

Abstract

As modified nucleosides reflect altered tRNA turnover which seems to be impaired in the body of cancer patients, they have been evaluated as potential tumor markers. High-performance liquid chromatography/electrosprary ionization quadrupole time-of-flight mass spectrometry (HPLC/ESI-Q-TOFMS) was used to identify nucleosides purified from urine in positive ionization mode. Potential nucleosides were assessed by their evident UV absorbance in HPLC and then further examined by mass spectrometric techniques. In this manner, 21 nucleosides were detected in the urine of a patient with lymphoid cancer including three modified nucleosides 5'-dehydro-2-deoxyinosine, N1,N2,N7-trimethylguanosine and N1-methyl-N2-ethylguanosine, which had never been reported previously.

5-methylcytosine in RNA: detection, enzymatic formation and biological functions

“…In addition to the retention times, determination of the nucleosides’ molecular mass, and/or their fragmentation pattern is used to confirm the chemical identity of a given modification. Applications of current LC/MS/MS techniques allow the detection of modified nucleosides even in the sub-picomolar range (13). Modifications can also be detected by LC-MS in oligonucleotides obtained, e.g.…”

A novel method of liquid chromatography–tandem mass spectrometry combined with chemical derivatization for the determination of ribonucleosides in urine

“…For example, on-line extraction was performed by connecting a precolumn and an analytical column via a six-way switching valve [16]. For off-line extraction, solid phase extraction (SPE) is the most common pretreatment approach for ribonucleosides [17,18]. The SPE methods can pre-concentrate ribonucleosides but their specificity is poor.…”

RNA 5-Methylcytosine Analysis by Bisulfite Sequencing

“…Recent developments, especially the application of sensitive mass spectrometry tools to nucleic acid chemistry (i.e., liquid chromatography combined with mass spectrometry, LC-MS) has considerably increased analytical sensitivity, opening up possibilities for quantifying also the modifications status of low-abundance RNAs (Kellner et al, 2014;Li et al, 2008;Russell & Limbach, 2013). Using LC-MS has provided unprecedented insights into the dynamic landscape of RNA modifications (including m 5 C) in abundant RNAs, especially during stress conditions (Chan et al, 2010(Chan et al, , 2012.…”