Microenvironment-related prognostic genes in esophageal cancer

Background: Esophageal cancer is one of the most common malignant tumors. The role of tumor microenvironment in esophageal cancer is unclear. Methods: The gene expression profiles and clinical data of 158 patients with esophageal cancer were extracted from The Cancer Genome Atlas database. Immune scores and stromal scores were calculated based on ESTIMATE algorithm. According to different immune/stromal scores, differentially expressed genes (DEGs) were identified. The function enrichment, protein interactions of shared DEGs and their associations with overall survival were analyzed. Results: In regard to the association of the immune/stromal scores and disease stage, pathological type and overall survival, only the stromal scores among the different stages were significantly different (P=0.015). In the high immune and stromal score groups, 603 shared up-regulated genes were found. The related function and pathways included regulation of lymphocyte activation, cytokine binding and chemokine signaling pathway. Protein-protein interaction analysis showed that ITGAM had the most connections, followed by CXCL10 and CCR2. High expression of 11 genes, including MS4A7, TMIGD3, MS4A4A, EVI2A, MS4A6A, FCER1G, AIF1, GNGT2, LCP2, DNAJC5B and RNASE6, were found to be associated with shorter overall survival. Conclusions: Microenvironment-associated functions and pathways were analyzed in esophageal cancer, and 11 microenvironment-associated genes were correlated to poor prognoses. Further studies on these genes may be helpful to understand the tumor microenvironment and provide new therapies for esophageal cancer.