Integrated Bioinformatics Analysis of Differentially-Expressed Genes and Immune Cell Infiltration Characteristics in Esophageal Squamous Cell Carcinoma
Abstract Esophageal squamous cell carcinoma (ESCC) is a life-threatening thoracic tumor with a poor prognosis. Identifying the best-targeted therapy, appropriate biomarkers and individual treatment for patients with ESCC remains a significant challenge. The present study aimed to elucidate key candidate genes and immune cell infiltration characteristics in ESCC by integrated bioinformatics analysis. We downloaded nine gene expression datasets from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between ESCC tissues and normal tissues in each dataset were identified by the “limma” R package, and a total of 152 robust DEGs were identified by robust rank aggregation (RRA) algorithm. Functional enrichment analyses of the robust DEGs showed that these genes were significantly associated with extracellular matrix related process. Immune cell infiltration analysis was also conducted by CIBERSORT algorithm. We found that M0 and M1 macrophages were increased dramatically in ESCC while M2 macrophages decreased. Nine hub genes were picked out from a protein-protein interaction (PPI) network used by the CytoHubba plugin in Cytoscape. According to the receiver operating characteristic (ROC) curves and Kaplan-Meier survival analysis, the genes PLAU, SPP1 and VCAN had high diagnostic and prognostic values for ESCC patients. Based on univariate and multivariate regression analyses, seven genes (IL18, PLAU, ANO1, SLCO1B3, CST1, NELL2 and MAGEA11) from the robust DEGs were used to construct a good prognostic model. A nomogram that incorporates seven genes signature was established to develop a quantitative method for ESCC prognosis. Our results might provide aid for exploring potential therapeutic targets and prognosis evaluation in ESCC.