Immune characteristics and genetic markers of esophageal cancer by single-cell analysis: Implications for immunotherapy

Background: Esophageal cancer (EC) is one of the most common cancers worldwide. The prognosis for patients with the same stage of EC can vary substantially. Progress of single-cell analysis technology has furthered the understanding of tumor heterogeneity. This paper aimed to apply single-cell analysis to explore the characteristics of the tumor environment of EC and provide inspiration for personalized treatment. Methods: The latest gene expression data and clinical follow-up information of single-cell sequencing results of EC samples were downloaded using from The Cancer Genome Atlas (TCGA) Genomic Data Commons (GDC) Application Programming Interface (API). A differential gene function analysis of the immune infiltration signature agents in the tumor microenvironment was undertaken using bioinformatics analytic methods, and potential molecular targets were sought. Results: We identified specific cell subsets in the EC and paracancerous samples, including panel cells, natural killer (NK) cells, exhausted CD8+ T cells, CD8+ memory T (Tcm) cells, and effector memory T (Tem) cells, including B cell enrichment in the cancer samples. Differences were detected between B cells and monocytes in Stage II and Stage III tumors, and these differences may have related to RNA transcription and degradation. The CXCL8 protein was identified as a valid potential prognostic marker. Conclusions: Cell groups with homogenous cell surface markers exhibit intercellular variations that exert a considerable effect on cell function. Our study will contribute to the understanding of the tumor immune microenvironment (TME) and cellular heterogeneity in EC patients and serve as a valuable resource for in-depth exploration of the pathogenesis of EC and the identification of potential therapeutic targets in the future.