Single-cell sequencing reveals the heterogeneity and intratumoral crosstalk in human endometrial cancer.

Background: Endometrial cancer (EC) is one of the most common gynecologic malignancies with increasing morbidity. Cell-cell and cell-matrix interactions within the tumour microenvironment (TME) exert a powerful influence over the progression of EC. Therefore, a comprehensive exploration of heterogeneity and intratumoral crosstalk is essential to elucidate the mechanisms driving EC progression and develop novel therapeutic approaches.

Methods: 4 EC and 2 normal endometrium samples were applied for single-cell RNA sequencing (scRNA-seq) analysis. In addition, we also included the public database to explore the clinical benefits of the single cell analysis.

Results: 9 types of cells were identified with specific expression of maker genes. Both the malignant epithelial cells and cells comprising the immune microenvironment displayed a high degree of intertumoral heterogeneity. Notably, the proliferation T cells also showed an exhausted feature. Moreover, the malignant cells may induce an immunosuppressive microenvironment through TNF-ICOS pair. Cancer-associated fibroblasts (CAFs) were divided into four subsets with distinct characteristics and they maintained frequent communications with malignant cells which facilitating the progression of EC. We also found that the existence of vascular CAF (vCAF) may indicate a worse prognosis for EC patients through integrating TCGA database.

Conclusion: The TME of human EC remains highly heterogeneous. Out finding that malignant cells interact closely with immune cells and vCAFs identifies potential therapeutic targets.