Abstract 3373: Identification of the stem cells in the epithelium of human Fallopian tube
Authors: Kessler Mirjana , Fotopoulou Christina , Winsauer Caroline , Thieck Oliver , Meyer Thomas F. 
Published: August 2012

Abstract
Fallopian tubes, are one of the critical components of the female genital tract, providing environment for transport of gametes, the fertilization process and passage of the zygote to the uterus. Recent clinical studies reinforced a focus on the Fallopian tube and its potential contribution to the etiology of serous ovarian carcinoma (Dietl et al. 2011). Previously, we have shown that the Wnt signaling pathway plays a role in regulation of epithelial homeostasis within a tubal mucosa and the tissue response during the infection processes (Kessler et al. 2011). We were interested in identifying epithelial progenitors which could mediate cell renewal and turnover in the epithelium. Primary epithelial cells were isolated, from the clinical fragments of human fallopian tube. In addition to expression of epithelial markers (EpCAM and Cdh1) we could confirm presence of cells with robust expression of pluripotency markers OCT4, NANOG, SOX2 and CD133. This suggests existence of not only differentiated epithelial cells within the culture but also of epithelial progenitor cells and actively proliferating cells, which might explain detected rapid growth of the culture. Cells were seeded in 3D within a Matrigel matrix, to ensure an in vitro environment which closely resembles the in vivo situation. Knowing about the importance of the Wnt pathway for epithelial homeostasis in the tube, as it is as well the case for well characterized ex vivo models of gastrointestinal tract cells (Sato et al 2009), we have provided a cocktail of growth factors stimulating Wnt (R-spondin1, Wnt3) in addition to the Noggin and epidermal growth factor (EGF). Only in the presence of EGF, cells aggregated in a ball-like compact mass. Stimulation of Wnt pathway on the other hand resulted in formation of “organoid” like hollow structures resembling the epithelium of mucosal folds. Indeed, confocal imaging of paraffin sections revealed an epithelial monolayer of apico-basal polarized cells within the organoid like structures as assessed by polarity markers like Muc1. Interestingly, individual cells within organoid like structuress were positive for SOX2 while OCT4 was detected in broader domains. Activity of Wnt signaling in the organoid like structures was confirmed using live cell imaging of a lentiviral GFP-TCF reporter. Organoid like structures could be grown and maintained in vitro by serial passage. Furthermore, testing of the effects of growth factors on polarization and growth of cells in 2D culture revealed a positive effect of Noggin on proliferation of epithelial progenitors, while the complete “organoid” cocktail promoted cell adhesion and differentiation. Taken together, we find evidence for existence of pluripotent progenitor cells within the Fallopian epithelium. Identification of a stem cell niche in vivo and investigation of its stemness potential would be of great importance for the understanding of pathological sequels in the female genital tract.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3373. doi:1538-7445.AM2012-3373