Single cell sequencing reveals heterogeneity within ovarian cancer epithelium and cancer associated stromal cells.
Boris J Winterhoff, Makayla Maile, Amit Kumar Mitra, Attila Sebe, Martina Bazzaro, Melissa A Geller, Juan E Abrahante, Molly Klein, Raffaele Hellweg, Sally A Mullany, Kenneth Beckman, Jerry Daniel, Timothy K Starr
Author Information
Boris J Winterhoff: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
Makayla Maile: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
Amit Kumar Mitra: Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN, USA.
Attila Sebe: Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany.
Martina Bazzaro: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
Melissa A Geller: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
Juan E Abrahante: University of Minnesota Informatics Institute, University of Minnesota, Minneapolis, MN, USA.
Molly Klein: Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA.
Raffaele Hellweg: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA.
Sally A Mullany: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA.
Kenneth Beckman: Genomics Center, University of Minnesota, Minneapolis, MN, USA.
Jerry Daniel: Genomics Center, University of Minnesota, Minneapolis, MN, USA.
Timothy K Starr: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA. Electronic address: star0044@umn.edu.
OBJECTIVES: The purpose of this study was to determine the level of heterogeneity in high grade serous ovarian cancer (HGSOC) by analyzing RNA expression in single epithelial and cancer associated stromal cells. In addition, we explored the possibility of identifying subgroups based on pathway activation and pre-defined signatures from cancer stem cells and chemo-resistant cells. METHODS: A fresh, HGSOC tumor specimen derived from ovary was enzymatically digested and depleted of immune infiltrating cells. RNA sequencing was performed on 92 single cells and 66 of these single cell datasets passed quality control checks. Sequences were analyzed using multiple bioinformatics tools, including clustering, principle components analysis, and geneset enrichment analysis to identify subgroups and activated pathways. Immunohistochemistry for ovarian cancer, stem cell and stromal markers was performed on adjacent tumor sections. RESULTS: Analysis of the gene expression patterns identified two major subsets of cells characterized by epithelial and stromal gene expression patterns. The epithelial group was characterized by proliferative genes including genes associated with oxidative phosphorylation and MYC activity, while the stromal group was characterized by increased expression of extracellular matrix (ECM) genes and genes associated with epithelial-to-mesenchymal transition (EMT). Neither group expressed a signature correlating with published chemo-resistant gene signatures, but many cells, predominantly in the stromal subgroup, expressed markers associated with cancer stem cells. CONCLUSIONS: Single cell sequencing provides a means of identifying subpopulations of cancer cells within a single patient. Single cell sequence analysis may prove to be critical for understanding the etiology, progression and drug resistance in ovarian cancer.
