Screening And Validation Of Molecular Metabolic Markers In Urine Of Bladder Cancer

Objective Using liquid chromatography-mass spectrometry coupled with metabolomics,we analyzed the differences in endogenous metabolite levels in the urine of bladder cancer patients and normal subjects to find potential diagnostic tumor markers related to bladder cancer.It was also compared with other urological diseases to provide new ideas for early diagnosis and disease surveillance of bladder cancer.Methods This study was divided into two phases.In the first part,an experimental approach of non-targeted metabolomics was used to screen out the differential metabolites between the bladder cancer group and the control group by including 30 bladder cancer patients as the experimental group and 30 healthy individuals as the normal control group,collecting early morning mid-morning urine from both groups and applying the metabolomics technique of liquid chromatography-mass spectrometry,followed by qualitative and quantitative analysis of the screened metabolites.Principal component analysis,partial least squares analysis and orthogonal partial least variance discriminant analysis were used to analyze and test the data of the two groups,and the ROC curves of the screened differential metabolites were plotted and the area under the curve was calculated to assess their diagnostic efficacy.The screened differential metabolites were subjected to metabolic pathway analysis and matched to five metabolic pathways that may be involved in the metabolic network of bladder cancer.In the second part,the sample size of the experimental group was expanded and other related diseases of the urinary system were collected for comparison.85 patients with bladder cancer,30 patients with prostate hyperplasia,15 patients with renal cysts,6patients with ureteral cancer,15 patients with renal cancer,and 10 patients with benign adrenal tumors were included in the targeted metabolomics study.Results In the first part,22 cases of highly significant differential tumor markers were identified,among which 5 cases were highly expressed in bladder cancer as3,4-dihydroxyphenyl propionate,L-Aspartic acid,L-Asparagine,guanidinoacetic acid,and hydroxyindole,respectively,and 18 cases were lowly expressed.L-Aspartic acid,L-Asparagine,and guanidineacetic acid were selected for the second part of the study,and the ROC curves were constructed by comparing bladder cancer with other urological-related diseases,respectively,in a two-by-two comparison.The results revealed that separate tumor markers were able to distinguish bladder cancer from benign urinary tract diseases,while L-Aspartic acid,L-Asparagine and guanidinoacetic acid did not have high diagnostic value for comparing bladder cancer with urological malignancies.The construction of a combined diagnostic model analysis was found to improve the diagnostic efficacy of bladder cancer,and the sensitivity and specificity were also significantly improved.Conclusion Urine metabolomics can discriminate between bladder cancer patients and normal population,providing new ideas for early diagnosis of bladder cancer.The analysis of metabolic pathways will reveal metabolic abnormalities in the development of bladder cancer,which in turn will be the starting point for finding new drug targets.