上皮细胞-间充质细胞转换(EMT)在癌症转移、胚胎发育及哺乳动物雌性生殖过程中的作用机制

上皮细胞向间充质细胞转换(epithelial-mesenchymal transition, EMT)，是具有极性的上皮细胞转换为具有运动能力的间充质细胞并获得侵袭和迁移能力的过程，它存在于动物多个生理和病理过程中，并涉及复杂的信号通路调节过程，行使多种生理功能．在早期胚胎发育过程中，EMT和MET(间充质细胞向上皮细胞转换)的相互转换，对于器官的形成及发育起至关重要的作用．另外，EMT还可促进肿瘤的转移．在卵巢、子宫以及胎盘等雌性生殖系统中也都涉及到EMT过程的发生．卵巢中发生的EMT有利于排卵后的修复，子宫中早期蜕膜化过程中发生的MET可使胚胎更好地锚定在子宫中，而胎盘形成过程中发生的EMT则有利于母体和胎儿之间进行营养和气体的交换．这些生殖过程中发生的EMT一旦失败，则可能导致相关的生殖疾病．

Epithelial-mesenchymal Transition During Tumor Metastasis, Embryonic Development and Female Mammalian Reproduction

Epithelial-mesenchymal transition(EMT) is a process that epithelial cells lose polarity, become mesenchymal cells and acquire the ability of migration and invasion. It exists in many physiological and pathological processes. EMT is involved in a number of signal transduction pathways and performs different physiological functions. During the early stages of embryonic development, both EMT and MET(mesenchymal- epithelial transition) contribute to the formation and development of organs. Moreover, EMT can promote tumor metastasis. EMT also occurs in female mammalian reproduction. In the ovary, EMT is beneficial for repairing process following ovulation. During decidualization, MET may be required for successful uterine anchorage of the embryo. Placental development undergoes an EMT in order to facilitate nutrient and gas exchange between mother and fetus. The failure of EMT process may cause related reproductive diseases.