Distinct niche structures and intrinsic programs of fallopian tube and ovarian surface epithelial cells

Epithelial ovarian cancer (EOC) can originate from either fallopian tube epithelial (FTE) or ovarian surface epithelial (OSE) cells, but with different latencies and disease outcomes. To address the basis of these differences, we performed single cell RNA-sequencing of mouse cells isolated from the distal half of fallopian tube (FT) and surface layer of ovary. We find at the molecular level, FTE secretory stem/progenitor cells and OSE cells resemble mammary luminal progenitors and basal cells, respectively. An FT stromal subpopulation, enriched with Pdgfra+ and Esr1+ cells, expresses multiple secreted factor (e.g., IGF1) and Hedgehog pathway genes and may serve as a niche for FTE cells. In contrast, Lgr5+ OSE cells express similar genes largely by themselves, raising a possibility that they serve as their own niche. The differences in intrinsic expression programs and niche organizations of FTE and OSE cells may contribute to their different courses toward the development of EOCs. [Display omitted] •Fallopian tube secretory stem/progenitor cells resemble mammary luminal progenitors•Esr1+ stromal cells serve as a potential niche for fallopian tube epithelial cells•IGF1 is a niche factor supporting fallopian tube epithelial growth/differentiation•Ovarian surface epithelial cells resemble basal cells and may serve as own niche Biological sciences; Molecular biology; Cell biology; Transcriptomics