Single-cell RNA sequencing reveals tissue architecture during human high-grade serous ovarian cancer progression

As the most fatal type of gynecological cancers, high-grade serous ovarian cancer (HGSOC) exhibits heterogeneity that obstacles therapeutics. Up to date, the pathogenesis of HGSOC remains poorly understood. Here, we performed the deep single-cell RNA sequencing (scRNA-seq) using 59,324 cells isolated from seven treatment-naïve HGSOC patients at early or late tumor stages and five age-matched non-malignant ovarian samples. Our sequencing data showed a highly complex ecosystem of tumor, immune and stromal cells based on their marker genes and functional properties. We showed that normal ovary-specific fibroblasts were carried with the properties of mesenchymal stem cells (MSCs), which could be reprogrammed to cancer-associated fibroblasts. During tumor progression, matrix CAFs (mCAFs) could induce the EMT properties of the tumor cells. Furthermore, the analysis of the early stage tumors illuminated enrichments of IDO-expressing macrophages, CD8+ TRM cells, and the activated CD8+ TEX cells (TRM-CXCL13), whereas those tumors at the late stages loss these features and expressed signatures related to epithelial-to-mesenchymal transition (EMT) program. Also, we characterized a specific chemokine-receptor communication in HGSOC tumor microenvironment, which may contribute to shape the HGSOC features. Our compendia of scRNA-seq results provide valuable insights for understanding the landscape of HGSOC ecosystem, which will be helpful in advancing HGSOC cancer diagnosis and therapy and enabling personalized approaches to the treatment. landscape of HGSOC ecosystem