Fallopian tube epithelial cells (FTEC) were thought to be the origin of high-grade serous ovarian carcinoma (HGSOC). Knowledge of the stemness or initiating characteristics of FTEC is insufficient. Previously, we have characterized the stemness cell marker of FTEC, this study aims to further characterize the clonogenicity and spheroid features of FTEC. We successfully derived FTECs from the epithelial layer of the human fallopian tubes. We examined the morphology, proliferation rate, doubling time, and clonal growth of them. At passage 3, the sphere formations on gelatin-coated culture, suspension culture, and matrigel culture were observed, and the expression of LGR5, SSEA3, SSEA4, and other stemness markers was examined. Furthermore, tissue-reconstituted organoids from coculture of FTEC, fallopian stromal cells (FTMSC) and endothelial cells (HUVEC) were examined. FTEC exhibited cuboidal cell morphology and maintained at a constant proliferation rate for up to nine passages (P9). FTEC could proliferate from a single cell with a clonogenic efficiency of 4%. Flow cytometry revealed expressions of normal stem cell markers (SSEA3, SSEA4, and LGR5) and cancer stem cell markers (CD24, CD44, CD117, ROR1, and CD133). FTEC formed spheres and colonies when cultured on low attach dish. In the presence of Matrigel, the stemness and colony formation activity were much enhanced. In co-culturing with FTMSC and HUVEC, FTEC could form organoids that could be blocked by Wnt inhibitor DKK1. Expressions of LGR5 and FOXJ1 expression were also decreased by adding DKK1. We demonstrated abundantly presence of stem cells in human FTECs which are efficient in forming colonies, spheres and organoids, relying on Wnt signaling. We also reported for the first time the generation of organoid from reconstitutied cell lineages in the tissue. This may provide a new model for studying the regneration and malignant transformation of the tubal epithelium.

中文翻译：

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人输卵管上皮细胞显示出干性特征，自我更新能力以及Wnt相关的类器官形成

输卵管上皮细胞（FTEC）被认为是高级浆液性卵巢癌（HGSOC）的起源。对FTEC的干性或引发特性的了解不足。以前，我们已经表征了FTEC的干细胞标记，这项研究旨在进一步表征FTEC的克隆形成性和球状特征。我们成功地从人类输卵管的上皮层获得了FTEC。我们检查了它们的形态，增殖速率，倍增时间和克隆生长。在第3代，观察明胶包被的培养物，悬浮培养物和基质胶培养物上的球形成，并检查LGR5，SSEA3，SSEA4和其他茎标记的表达。此外，来自FTEC共培养的组织重构类器官，检查了输卵管基质细胞（FTMSC）和内皮细胞（HUVEC）。FTEC表现出长方体细胞形态，并以恒定的增殖速率维持多达9代（P9）。FTEC可以从单个细胞增殖，克隆形成效率为4％。流式细胞仪揭示了正常干细胞标记（SSEA3，SSEA4和LGR5）和癌症干细胞标记（CD24，CD44，CD117，ROR1和CD133）的表达。在低附着培养皿上培养时，FTEC形成球形和菌落。在基质胶存在下，茎和集落形成活性大大增强。通过与FTMSC和HUVEC共同培养，FTEC可以形成类器官，可以被Wnt抑制剂DKK1阻断。通过添加DKK1，LGR5和FOXJ1的表达也降低。我们证明了人类FTEC中干细胞的大量存在，依靠Wnt信号可以有效地形成菌落，球体和类器官。我们还首次报道了组织中重组细胞谱系产生类器官的现象。这可能为研究输卵管上皮的增生和恶变提供新的模型。