High-throughput Sequencing Proves Poor Prognosis In Patients With Gastric Cancer With High Expression Of PENK And GNGT1

Objective: Through the analysis of the high-throughput sequencing data of gastric cancer in TCGA database,to explore the differentially expressed gene(DEGs)and its related biological significance,and to screen the genes related to the prognosis of gastric cancer,which provides the basis for follow-up research.Methods: The RNA-seq expression matrix data of 343 gastric cancer tissues and 30 normal tissues were downloaded from TCGA database.Perl5.28.1software and R language were used for data collation and unified standardized analysis.The differentially expressed genes were analyzed by edge R and Deseq software packages respectively,and the differential genes screened by the two methods were intersected,and then the differentially expressed genes(DEGs)were analyzed by DAVID online database(https://david.ncifcrf.gov/)and KOBAS database(http://kobas.cbi.pku.edu.cn/)and Jingdu Encyclopedia of Gene and Genome(KEGG).Then the Protein-Protein Interaction(PPI)network was established by using the search tool of interaction gene(STRING)database(http://STRING-db.org/),and the visualization was carried out by Cytoscape software.Using MCC and Degree algorithms,the first TOP10 differentially expressed genes were screened,and then the intersection was selected as the key gene,and then verified by module analysis.The differential genes were screened by KM survival analysis and Log-rank test,and the differential genes related to the prognosis of gastric cancer were screened.Results : 1560 differentially expressed genes(DEGs)were obtained by edge R and DEseq analysis.Then GO analysis and KEGG analysis showed that these genes mainly enriched the classical pathway of complement activation,receptor-mediated endocytosis,proteolysis,Fc-γ receptor signal pathway involved in phagocytosis,regulation of immune response,Fcepsilon receptor signal pathway,immune response,phagocytosis.Recognition,positive regulation of B cell activation,digestion,B cell receptor signal pathway,ion transmembrane transport,collagen catabolism,epidermal cell development,keratinocyte differentiation,(BP);response to drugs.Extracellular region,extracellular space,blood particles,plasma membrane,extracellular body,protein extracellular matrix,immunoglobulin complex,circulation,plasma membrane components,apical plasma membrane,Z disk(CC);antigen binding,serine endopeptidase activity,immunoglobulin receptor binding,metallopeptidase activity(MF)and so on.KEGG pathway analysis showed that the differentially expressed genes were mainly concentrated in cytochrome P450 metabolism,chemical carcinogenesis,neuroactive ligandreceptor interaction,metabolic pathway,drug metabolism-cytochrome P450,protein digestion and absorption,retinol metabolism c AMP signal pathway,fat digestion and absorption and so on.The protein-protein interaction(PPI)network was established by using STRING database retrieval tool.In Cytoscape,five significant differential genes were screened by MCODE plugin and Cytohubba plug-in as candidate center nodes,namely GNGT1,GNG7,ANXA1,PENK and CHRM2.Then the five candidate central nodes selected by the online survival analysis website Kaplan-Meier Plotter,were used for survival analysis.Log-rank test showed that there was statistical significance.Conclusion: In this study,we obtained the differentially expressed genes and related pathways in gastric cancer,and confirmed that PENK and GNGT1 may be the indicators of prognosis of gastric cancer,PENK and GNGT1 are poor prognostic factors,and high expression is significantly related to the shortening of survival time of patients.