Preliminary Application Of Metabolomics Analysis By Liquid Chromatography-mass Spectrometry In Gastric Cancer

Objective:To detect whether gastric cancer(GC)has a unique urinary metabolomic profile compared with benign gastric disease(BN)and healthy(HE)patients based on liquid chromatography-mass spectrometry(LC-MS)metabolomics analysis,and screen the differential metabolites with potential diagnostic value for gastric cancer.Methods:Plasma samples were collected from 66 patients with GC and 44 patients with BN in the First Affiliated Hospital of Soochow University,and 50 healthy subjects served as controls.25 patients with gastric cancer at stage I and II and 25 patients with gastric cancer at stage III and IV were selected from the 66 patients with gastric cancer,and 25 subjects were also selected from 50 healthy controls.The liquid chromatography and mass spectrometry(LC-MS)combined method was used to detect plasma small molecule metabolites of GC patients,BN patients and healthy controls.The liquid chromatography and mass spectrometry(LC-MS)combined method was used to detect plasma small molecule metabolites of GC patients,BN patients and healthy controls.SIMCA-P 13.0 was used to construct principal component analysis(PCA)and partial least squares discriminant analysis(PLS-DA)models to screen and validate differential metabolites,and binary logistic statistical analysis was used to establish optimal diagnostic model.The clinical diagnostic performance of these selected different metabolites was accessed by the ROC curve analysis,and the metabolic pathway analysis of differential metabolites was performed via the KEGG database.Results:(1)According to the research,the PCA and OPLS-DA models from plasma samples were successfully fabricated among GC,BN and HE groups.The PCA model showed a significant distinction in plasma samples between GC and HE patients,and a high overlap between GC and BN samples.Furthermore,PLS-DA models indicated that the separation trend of plasma samples was more pronounced between GC and HE patients.the distinction between BN and either GC or HE was further clear using the PLS-DA model,but with a partial overlap.Meanwhile,PCA model showed that the cancer staging(TNM ?+?and TNM ?+?)of plasma samples of gastric cancer could not be clearly separated from normal controls.However,the PLS-DA model showed a significant difference between different stages(TNM I+? and TNM ?+?)and healthy controls.(2)A total of 19 metabolites were respectively identified between GC(TNM ?+?)vs HE and GC(TNM ?+?)vs HE groups.Among them,13 metabolites were commonly selected in the two models.Compared with plasma samples of healthy controls,plasma levels of eleven metabolites were significantly increased in GC patients:taurine,benzenesulfonamide,iso leucine,cystine,melanin,leucine,benzophenone,sphingosine 1-phosphate,phosphatidyleth anolamine lyso20:4,adenosine and D-galactopyranose.While plasma levels of the remaining eight metabolites were markly decreased:Methionine,3-amino-2-naphthoic acid,tyrosine,arginine,phenylalanine,uridine ribonucleotide,tryptophan,2,3,4-trihydroxybutyrate.(3)According to the ROC curve analysis,nine differential metabolites identified by between GC group and healthy control group were found with above diagnostic value(AUC>0.8):Taurine,isoleucine,leucine,benzophenone,sphingosine-1-phosphate,methionine,tyrosine,arginine,phenylalanine.(4)Logistic regression analysis produced optimal GC vs HE model using just four metabolites:isoleucine,benzophenone,sphingosine-1-phosphate and galactopyranose.The areas under the curve(AUC),95%CI,cut off value,sensitivity,and specificity were 0.963,0.930?0.997,0.871,93.1%and 94.0%.(5)A total of 24 differential metabolites were identified in the patients with stage??+? and stage III+IV of gastric cancer,five of which,including lysine,carnitine,benzenesulfonamide,arginine and docosahexaenoic acid ethyl ester,were changed with the progression of gastric cancer.pipecolic acid and kynurenine may serve as biomarker for early GC diagnosis.(6)Based on the pathway analysis,altered metabolic pathways were principally involved in taurine,sphingolipid,galactose,pyrimidine metabolism and amino acids metabolisms(Leucine,isoleucine,methionine,phenylalanine,tyrosine,arginine,tryptophan)between GC and HE groups.Conclusions:metabolomics based on the platform of liquid chromatography coupled to mass spectrometry can effectively discover the unique changes of serum metabolites in gastric cancer patients.The differential metabolites screened have potential clinical application value for predicting the risk of gastric cancer.