排卵启动的卵巢上皮干细胞EMT及其异常调控的机制研究

Ovarian epithelium experiences repeated damage and regeneration during ovulation and post-ovulation, which results in increasing possibility of cellular mutation. However, role of ovarian epithelial stem cells during ovulation and its regulating mechanism remains largely unknown. The epithelium on ovarian surface, with the view of embryonic development, is developped from Müllerian duct which exhibits both epithelial and mesenchymal phenotypes. The cellular epithelial or mesenchymal features of ovarian epithelium are subjected to diversify during menstrual cycle and cellular mutation. This diversity indicates the complexity of the whole process which initiate from ovarian epithelial stem cells. We hypothesize that celluar epithelial-mesenchymal transition or abnormal phenotypes occurred on ovarian epithelial stem cells would determine the way to physiological or pathological process. We have sorted normal or malignant ovarian tissue stem cells by using Hoechst 33342 or ALDH staining. We found that, under abnormal epithelial-mesenchymal transition (EMT), ovarian cancer stemlike cells showed decreased epithelial and increased mesenchymal expressions during their differentiation. Expression of related transcript factors were upregulated as well. Moreover, we showed that with the differention, EMT process can support ovarian cancer stemlike cells engraftment and thus exert function on tumor mestastasis. In this study, we will investigate the variation tendency of ovarian epithelial stem cell phenotype during menstrual cycle, sex hormone stimulation and mutating process. By comparison with ovarian epithelial stem cell function of various phenotypes, the mechanism of EMT-regulating cellular transformation in ovarian functional storage, regeneration and malignant mutation will be clarified.

排卵使卵巢上皮细胞经历反复的损伤和修复，突变机率增加，但卵巢上皮干细胞在其中的作用及相关分子调节机制尚未完全明了。被覆于卵巢表面的上皮细胞兼有上皮和间质表型，卵巢上皮细胞在月经周期不同时相及恶性转化后可出现表型多样化，提示了这一过程的复杂性。我们推测，卵巢上皮干细胞经历的上皮-间质转化（EMT）及表型转化的异常调控决定卵巢生理或病理进程。我们以Hoechst33342拒染法和ALDH标记法证实正常和恶变的卵巢组织中均有干细胞存在。在异常EMT情况下，恶性卵巢组织干细胞分化过程中表现为上皮表型减弱，间质表型增强，EMT转录因子表达水平增高，有助于恶性卵巢组织干细胞在局部的浸润和转移。本课题将进一步研究月经周期不同时相、性激素刺激以及细胞恶性转化过程中卵巢上皮干细胞的上皮-间质特性和变化趋势，比较不同组织表型对卵巢上皮干细胞功能的影响，阐明EMT在卵巢生理储备、损伤修复和恶性转化中的作用机制。

排卵使卵巢上皮细胞经历反复的损伤和修复，突变机率增加。被覆于卵巢表面的上皮细胞兼有上皮和间质表型，卵巢上皮细胞在月经周期不同时相及恶性转化后可出现表型多样化，提示了这一过程的复杂性。卵巢上皮干细胞经历的上皮-间质转化（EMT）及表型转化的异常调控决定卵巢生理或病理进程。我们以Hoechst33342拒染法和ALDH标记法证实正常和恶变的卵巢组织中均有干细胞存在。在异常EMT情况下，恶性卵巢组织干细胞分化过程中表现为上皮表型减弱，间质表型增强，EMT转录因子表达水平增高，有助于恶性卵巢组织干细胞在局部的浸润和转移。此外，我们还发现Zeb2是卵巢上皮干细胞生物学功能的重要转录因子，在EMT表型、侵袭能力、抗凋亡能力方面均有调控作用；在miRNA水平，miR-628-5p通过对FGF-R2的作用调控卵巢癌上皮干细胞的成瘤性。项目执行期间，课题组邀请美国麻省总院妇产科的Dr. Goodman 来访；课题组共发表标注的SCI 论文6篇，其它中文论文3篇，获授权专利 1项；毕业硕士研究生 4名，博士研究生 1名。因此，本项目研究成果对探究正常卵巢生理功能的储备和修复机制、上皮性卵巢癌的发生、临床激素替代与促排卵治疗的风险因素评估等具有重要意义。