title: Single cell sequencing reveals heterogeneity within ovarian cancer epithelium and cancer associated stromal cells.
abstract: 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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Boris J
authors.initials: BJ
authors.lastname: Winterhoff
authors.affiliation: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Makayla
authors.initials: M
authors.lastname: Maile
authors.affiliation: Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Amit Kumar
authors.initials: AK
authors.lastname: Mitra
authors.affiliation: Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany.
authors.forename: Attila
authors.initials: A
authors.lastname: Sebe
authors.affiliation: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Martina
authors.initials: M
authors.lastname: Bazzaro
authors.affiliation: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Geller
authors.affiliation: University of Minnesota Informatics Institute, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Juan E
authors.initials: JE
authors.lastname: Abrahante
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Molly
authors.initials: M
authors.lastname: Klein
authors.affiliation: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Hellweg
authors.affiliation: Department of Obstetrics, Gynecology & Women's Health, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Sally A
authors.initials: SA
authors.lastname: Mullany
authors.affiliation: Genomics Center, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Beckman
authors.affiliation: Genomics Center, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Jerry
authors.initials: J
authors.lastname: Daniel
authors.affiliation: 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.
authors.forename: Timothy K
authors.initials: TK
authors.lastname: Starr
mesh_terms: D000077216:Carcinoma, Ovarian Epithelial; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D009375:Neoplasms, Glandular and Epithelial / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D059010:Single-Cell Analysis / Q000379:methods; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology*
chemical_list: D012333:RNA, Messenger; D012334:RNA, Neoplasm
keywords: Molecular subtypes; Ovarian cancer; Single cell sequencing and cancer stem cells