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 prognoses for patients with the same stage of EC can vary substantially. The 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 a basis for personalized treatment. METHODS: The latest gene expression data and clinical follow-up information of single-cell sequencing results of EC samples were downloaded 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 (TME) was performed using bioinformatics analytical 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 cluster of differentiation (CD)8(+) 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 III tumors, which may be 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 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.