| Cancer is one of the serious threats to human beings, however, because of most of patients with cancer have reached advanced stage while diagnose owing to lack of an effective method in finding it in early stage, so it's very important to seek right tumor marker. Numerous studies suggested that urinary nucleosides are potential biomarkers for cancers. The aim of present study is qualitative and quantitative analysis of urinary modified nucleosides by mass spectrometry (MS) method in combination with high performance liquid chromatography (HPLC) by optimized conditions, and then to test the usefulness of urinary modified nucleosides as tumor markers.With the optimal method by Oasis(?) HLB SPE cartridges, HPLC/ESI-Q-TOF-MS, we detected 22 modified nucleosides from cancer patients, included O6-methylguanosine and N7-methyl-N2-ethylguanosine which had never been reported before, and quantitatived analysis these modified nucleosides. It was found that the excretion levels of urinary modified nucleosides in bladder cancer were higher than that of healthy adults. The mean level of modified nucleosides N1-methyladenosine, O6-methylguanosine, N1-methylinosine, Nl-methylguanosine, N3-methylcytidine, N3-methyl guanine, PCNR,5'-dehydro-2'-deoxyinosine, N2,N2-dimethylguanosine, N6-threonylcarbamoyladenosine, N3-methyladenosine were higher in bladder cancer than that in healthy volunteers.Using aforementioned method, the possibility of urinary modified nucleosides in other disease diagnosis is searched after urinary excretion of modified nucleosides of rheumatoid arthritis and lupus erythematodes were analyzed. The mean level of adenosine,5'-deoxy-5'-methylthioadenosine, N1-methylinosine, Nl-methylguanosine, N3-methylcytidine, Xanthine,5'or 2'-O-methylcytidine,3-methylguanine, PCNR, 5'-deoxy-2'-deoxyinosine, N2-methylguanosine, N3-methyl adenosine, N7-methyl-N2-ethylguanosine in urine from rheumatoid arthritis of nonmobile phase were significantly different compared. In patients with lupus erythematodes of nonmobile phase, the level of N6-threonylcarbamoyladenosine, N3-methyladenosine, 06-ethylguanosine were significantly different compared. It shows that the method is significant to diagnose other diseases.In conclusion, the excretion of modified nucleosides with bladder cancer, rheumatoid arthritis and lupus erythematodes are analyzedfound. Some modified nucleosides are found can be studied as potential tumor marker. It is important for clinical diagnosis and disease detection. |
