Exploring the tumor micro-environment of ovarian cancer histotypes and tumor sites

Ovarian cancer is a common, malignant cancer in the female reproductive system. Despite the commonly affected tissue ovary, ovarian cancer is a heterogeneous disease consisting of at least five different histological subtypes and varying clinical features, cells of origin, molecular composition, risk factors, and treatments. With cumulative studies on the tumor microenvironment, a comprehensive landscape of the constituent cell types, and their interactions are yet to be established in ovarian cancer and its histotypes. Further characterization of tumor progression, metastasis, and various histotypes is needed to connect molecular signatures to pathological grading for tailored diagnosis and treatment. In this study, we leveraged high-resolution single-cell RNA sequencing technology to elucidate the cellular compositions on 21 solid tumor samples collected from 12 patients with six ovarian cancer histotypes and both primary (ovaries) and metastatic (omentum, rectum) sites. The diverse collection allows us to zoom in on histotype and tumor site-specific expression patterns of cells in the tumor and identify key marker genes and ligand-receptor pairs that are active in the ovarian tumor microenvironment. Our findings can be used in improving disease stratification and design of customized treatment. Overall design: scRNA-seq of ovarian cancer cells from 8 ovarian cancer patients with different cancer histotypes, where tumor samples were dissected from both primary and metastatic sites.