Study On The Relationship Between Serum Small Molecular Metabolites And Lymph Node Metastasis In Gastric Cancer

Objective:Seeking serum differential metabolites in patients with different lymph node metastasis status;Studying on the differentiation ability of metabolites in different lymph node metastasis status of gastric cancer;A preliminary study on the mechanism of predicting the lymph node metastasis of gastric cancer with small molecular metabolites is performed;Trying to establish a risk scoring model for predicting lymph node metastasis of gastric cancer by using small molecule metabolites and clinical pathological data.Method:1.LC-MS analysis: The serum samples were analyzed by liquid chromatography-mass spectrometry,obtaining metabolic profiling and other data.2.The concentration of serum VEGF-C and VEGF-D were detected by enzyme linked immunosorbent assay(ELISA).3.The density of lymphatic vessels in paracancerous tissues and cancerous tissue VEGF-C ? VEGF-D expression was determined by immunohistochemical staining.4.Data Analysis:principal component analysis,t-test,discriminant analysis and other statistical methods is used to analysis the data,seeking differential metabolite between T1-2N1-3 group and T3N0 group.Clustering analysis is applied to evaluate distinguishing ability of metabolites for a 35 dependent samples,then using t-test and Chi square compare VEGF-C,D level?para-cancerous tissues lymphatic density in group A and group B which is done throuth thermography.Logicalregression choose related independent risk factors for lymph node metastasis.At last,combining clinical pathological parameters and metabolites establish gastric cancer lymph node metastasis risk rating model.Result:1.Study on the serum metabolome,from serum total ion chromatogram which is obtained from the Peakview software,we can clearly observe the differences of samples metabolites of two groups.The PCA score plot results between T1-2N1-3 group and T3N0 group of gastric cancer can be separated very well.The t-test is used to select 31 metabolites between T1-2N1-3 group and T3N0 group.Further applying support vector machine method to discriminant analysis,3 metabolomes are selected which have a stronger ability to identify.The results of cluster analysis show that these differential metabolites had a good ability to distinguish regional lymph node metastasis2.In second part,according to above metabolites,another 35 blood and tissue samples can be effectively divided into two groups:Group A(lymph node metastasis positive gastric cancers)and Group B(lymph node metastasis negative gastric cancers).There was significant difference in serum VEGF-C and VEGF-D concentration(P<0.05).Cancer tissues VEGF-C and VEGF-D expresion?paracancerous tissue lymphatic vessel density of Group A is significantly higher than that of Group B(P<0.05).Furthermore,there is significant difference in survival analysis result.3.In third part:through logical regression,1 clinical pathological parameters and two metabolomes is obtained.We try to use these indicators to establish the risk score model for lymph node metastasis of gastric cancer.The results suggest that the model can effectivelydistinguish different lymph node metastasis status.With the score increasing,percentage of positive lymph node also increased.As a kind of diagnostic experiment,the ROC curve of this model show compared with single independent risk factor,it can better predict lymph node metastasis.Conclusion:1.The differential metabolites between T1-2N1-3 group and T3N0 group can be found.2.The differential metabolites screened by liquid chromatographymass spectrometry(LC-MS)have a strong ability to distinguish different lymph node metastasis status.There is a correlation between metabolomes and lymph node metastasis.3.Based on the differential metabolites and clustering analysis,another 35 cases samples still can be effectively separated.Between groups of serum VEGF-C,D concentration,VEGF-C,D expression of cancer tissue and paracancerous tissue lymph vessel density were significantly different,the difference was statistically significant.4.Metabolites may promote the expression of VEGF-C and D in cancer tissues,mediating the formation of new lymphatic vessels in the paracancerous tissues,and promote lymph node metastasis;It is also possible that the high expression of VEGF-C and D resulted in the difference of serum metabolites;5.The prediction model of gastric cancer lymph node metastasis risk which based on gender and two differential metabolites may be an effective way to predict lymph node metastasis.