Diagnosis For Gastric Carcinoma Using Urinary Modified Nucleosides

Objective: Analyze whether modified nucleosides can be used as a tumor biomarker by determining the urinary modified nucleosides concentration to diagnose gastric carcinoma.Methods: The concentration of 15 urinary normal and modified nucleosides from 50 healthy persons and 48 patients with gastric carcinoma was determined by high-performance liquid chromatography combined pattern recognition system. These 15 nucleosides were pseudouridine (Pseu),adenosone (A), uridine (U),cytidine (C),5-methyluridine (m5U). inosioe (I). 1-methylinisine (mII). N₄-acetylcytidine (ac4C), guanosine (G), xanthosine (X), 2-methylguanosine (m2G), N₆-methyladenosine (m6A),1-methyladenosine (mlA), N_2.2-methylguanosine (m22G) and 1-methylguanosine (mlG). The serum carcino-embryonic antigen (CEA) level of 25 patients with gastric carcinoma was detected by Radioimmunoassay (RIA)method, and compared it with urinary nucleosides were determined.Results: The individual urinary nucleoside concentration of the healthy persons is very low. Except m5U, the concentrations of 14 kinds of urinary nucleosides from patients with gastric ca(?)inoma were higher than those of health persons. (Pseu, mIA, X, m'I, m1G, m2G, m22G P<0.001; I, G, A,ac4C,m6A P<0.01; C,U,m5U P<0.05) . The level of nucleosides C, I and G were significant positive correlation with the tumor size. The urinary levels of nucleosides X, I and G were significant positive correlation with tumor lymph node metastasis (P<0.05). When compared with the levels of urinary nucleosides from healthy persons, 50% patients with gastric carcinoma were correctly found by the pattern recognition system.Conclusion: The urinary nucleosides excretion is elevated in stomach cancer patients. About 50% stomach cancer patients can be classified by the pattern recognition system. Urinary modified nucleosides level reflects the proliferation of gastric carcinoma cells. Urinary modified nucleoside will be a valuable tumor biomarker for gastric carcinoma. which has high efficiency and sensitivity.