Study On Metabonomics Of Colorectal Cancer By~1H-NMR Spectrometry

ObjectiveBy using a proton nuclear magnetic resonance (1H-NMR) techniques to researchmetabolites changes of serum and feces samples from patients with colorectal cancer,and to explore changes in metabolic profiling, and find out the characteristicmetabolites associated intimately with colorectal cancer，as the early diagnostic toolfor detecting colorectal cancer.MethodThe serum and feces samples from colorectal cancer (CRC) patients, colorectalpolyp patients and healthy controls were investigated by1H-NMR technique. Themetabolic profiling of serum samples were analyzed by principal component analysis(PCA)、partial least squares discriminant analysis (PLS-DA) and orthogonal partialleast squares discriminant analysis (OPLS-DA) methods. According to the literatureand network databases to identify the characteristic spectral peaks, and to identify thecharacteristic metabolites. Univariate statistical analysis was used for detectingsignificantly change of metabolites in fecal samples.Results1. The metabolites of serum samples were changed between healthy controls,colorectal polyp patients and CRC patients. PCA、PLS-DA and OPLS-DA modelsshowed robust discrimination from healthy controls, colorectal polyps patients andCRC patients. A total of23characteristic metabolites including carbohydrates, someamino acids, fatty acids and other intermediate metabolites were identified byOPLS-DA loading plot. Compared with healthy controls, levels of lactate, glycine,serine, choline and3-Hydroxybutyrate were increased significantly（P<0.05，P<0.0l）,but levels of succinate, citrate, valine, alanine, glutamine, aspartate, lipid, glycerol andNAc were decreased significantly (P<0.05，P<0.0l）in the colorectal polyp patients and CRC patients. Compared with colorectal polyps patients, levels of thesemetabolites were changed significantly in CRC patients（P<0.05，P<0.0l）.2. A total of23metabolites were identified in one-dimensional1H-NMR spectraof fecal water extracts from healthy controls, colorectal polyp patients and CRCpatients. Compared with healthy controls, levels of short-chain fatty acids (SCFAs)including butyrate, isobutyrate, and propionate were elevated, but acetate. Levels ofamino acids were also elevated. But levels of dimethylamine (DMA) andtrimethylamine (TMA) were decreased. However, changes of these metabolites werenot statistically significant（P>0.05）.Conclusion1. Metabolic profiling of serum from patients with colorectal cancer was changedsignificantly. Glucose metabolism, amino acid metabolism and lipid metabolismpathways were disordered.2. Although concentration of metabolites were changed in stool samples fromCRC patients, more studies is needed to confirm the value of early screening anddiagnosis of CRC3. The application of1H-NMR metabolomics ananlysis to serum has interestingpotential as a new detection and diagnostic tool for early diagnosis of CRC.