Characterizing the tumor microenvironment of metastatic ovarian cancer by single-cell transcriptomics
Susan Olalekan, Bingqing Xie, Rebecca Back, Heather Eckart, Anindita Basu
Abstract
Understanding the cellular composition of the tumor microenvironment and the interactions of the cells is essential to the development of successful immunotherapies in cancer. We perform single-cell RNA sequencing (scRNA-seq) of 9,885 cells isolated from the omentum in 6 patients with ovarian cancer and identify 9 major cell types, including cancer, stromal, and immune cells. Transcriptional analysis of immune cells stratifies our patient samples into 2 groups: (1) high T cell infiltration (high T inf ) and (2) low T cell infiltration (low T inf ). TOX -expressing resident memory CD8 + T (CD8 + Trm) and granulysin-expressing CD4 + T cell clusters are enriched in the high T inf group. Concurrently, we find unique plasmablast and plasma B cell clusters, and finally, NR1H2 + IRF8 + and CD274 + macrophage clusters, suggesting an anti-tumor response in the high T inf group. Our scRNA-seq study of metastatic tumor samples provides important insights in elucidating the immune response within ovarian tumors.