Investigation Of Diagnosis And Follow-up Of Cancer Based On Urinary Nucleosides

Cancer is one of the most dangerous diseases to health. The general survey is an.effective method of finding cancer in early stage. Tumor markers in body fluids will help to find cancer in survey. However, most of tumor markers could not be well applied to survey and follow up cancer patients because of narrow detection scope and low sensitivity. The motivation of this thesis is to determine urinary nucleosides and construct the data processing model, then to test the usefulness of urinary nucleosides as tumor markers.An optimal method for the analysis of 13 urinary nucleosides by micellar electrokinetic chromatography (MEKC) has been developed. The effects of pH, SDS concentration of the running buffer, applied voltage and column temperature on analysis were investigated. Relative mobility was taken as a tool to investigate the peak identification of urinary nucleosides in MEKC for the first time.A method based on high performance liquid chromatography was optimized with regard to gradient elution program, pH and column temperature. A pair of ac4C and m2G was baseline-resolved and m22G was also quantified in this study. Then it was successfully used to measure nucleosides of urine, cultured hepatocellular carcinoma cell and its secretion. Current HPLC analysis of urinary nucleosides involves laborious and time consuming manual sample processing steps due to the complexity of the sample matrix. We set up a liquid chromatographic on-line system that can be used for integrating sample pretreatment and analysis and established the new method for determining urinary nucleosides on this system. Small sample volume, shorten analysis time and improved analytical precision are obtained for the on-line procedure.Factor analysis (FA) and artificial neural network (ANN) combined with the methods developed above were used to study the classification and prediction cancer patients based on urinary nucleoside concentrations.The excretion levels of urinary nucleosides from Chinese healthy volunteers and cancer patients were established by determining urinary nucleosides from 520 cancer patients and 260 healthy persons respectively. Urinary nucleoside concentrations from patients with different cancer types were also compared. It was found the excretion levels of urinary nucleosides in cancer patients are significant increased as compared with those of healthy volunteers. By using FA and ANN data processing methods, 70% and 80% cancer patients were correctly classified from healthy persons, which much better than traditional tumor markers used in clinic. Compared with healthy controls, 90% patients with leukaemia or lymphoma were distinguishable, only 62% patients with gastric cancer could be classified. Furthermore urinary nucleosides are being used as tumor markers for differentiating benign tumor from cancer, monitoring the effect of surgical therapy or chemotherapy on cancer and making prognosis for cancer relapse.In general, urinary nucleosides as universal tumor markers could be applied for cancer survey and prognosis.