Study of normal and modified nucleosides in serum by RP-HPLC

Modified nucleosides derived predominantly from transfer ribonucleic acid (tRNA) have been studied as possible tumor markers. In this paper a reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been applied to study 15 normal and modified nucleosides in serum. The nucleoside levels in normal human serum were established, and the concentrations of 15 nucleosides in serum from 19 cancer patients were determined. It was found that the concentrations of modified nucleosides were significantly higher in patient sera. Based on 15 nucleoside concentrations in serum, factor analysis could classify correctly 90% of cancer patients from the normal humans. Further work showed that urine was slightly better than serum when determining nucleosides as biological marker candidates. More work is ongoing to determine the clinical usefulness of modified nucleosides as tumor markers.