Identification of ZEB2 as an Immune-Associated Gene in Endometrial Carcinoma and Associated with Macrophage Infiltration by Bioinformatic Analysis

Endometrial cancer (EC) is the most common gynecological tumor arising from the endometrium. In this study, we use a published single-cell transcriptome profile of endometrial carcinoma (EC) to reveal the composition of immune cells and found an immunosuppressive environment since the presence of macrophage subtype M2 and exhausted CD8(+) T cell markers. We focused on ZEB2 (Zinc finger E-box binding homeobox 2), a well-known player in epithelial to mesenchymal transition process, and we showed that ZEB2 is exclusively expressed in immune cells in single-cell transcriptome and, at the same time, downregulated in TCGA-UCEC (The Cancer Genome Atlas-Uterine Corpus Endometrial Carcinoma) bulk RNA-seq data and negatively associated with tumor purity. Loss of ZEB2 protein in EC in normal endometrium and EC samples was validated in samples using immunohistochemistry (IHC) from HPA (Human Protein Atlas) database. Furthermore, we found ZEB2 was associated with immune infiltrations especially for macrophage using TIMER 2.0. Interestingly, ZEB2 prognostic significance differed under various macrophage and Th2 helper cell content using Kaplan-Meier Plotter analysis. More importantly, we showed that over 11% EC patients have somatic mutations of ZEB2 in EC samples collected from cBioportal and they have a lower body weight, earlier diagnosis age, and better overall survival and disease-free survival status compared with the unaltered group. Analysis in TIMER2.0 suggested that ZEB2 mutation would possibly change the composition of tumor-infiltrating lymphocytes. Taken together, by combining the results from single-cell data, bulk TCGA RNA-seq, and other online bioinformatic tools, we provided evidence that ZEB2 might have a unique role in the immune environment of EC. These results would provide a better insight into the pathogenetic process and ZEB2 might further be used an immunotherapeutic target of EC.