Background: Increased levels of modified nucleosides have been observed in urine from patients suffering from
several cancers. In this study, we evaluated whether urinary nucleosides can serve as potential tumor markers
for colorectal cancer by high performance liquid chromatography–electrospray/tandem mass spectrometry
(HPLC/ESI-MS/MS).
Methods: A simple and specific method based on HPLC/ESI-MS/MS was developed to determine the urinary
nucleosides from patients with colorectal cancer. We studied the excretion patterns of nucleosides in urine
from 26 patients with colorectal cancer and 18 healthy controls.
Results: The LC/MS/MS approach with selective reaction monitoring (SRM) allowed for the sensitive
determination of nucleosides in human urine samples with colorectal cancer. The mean levels of 5 urinary
nucleosides (adenosine, cytidine, N2,N2-dimethylguanine, 8-hydroxy-2′-deoxyguanosine and uridine) were
significantly higher in the patients with colorectal cancer than in the healthy adults.
Conclusions: The results indicate that urinary nucleosides determined by LC/MS/MS may be useful as biological
markers for colorectal cancer. Our findings suggest that LC/MS/MS is a highly specific and sensitivemethod for
rapidly screening a large number of nucleoside that may be useful as markers for cancer in humans.
