中文摘要：

上皮间质转化（EMT）是上皮细胞向间充质细胞分化的过程，EMT在恶性肿瘤的侵袭转移中广泛存在。EMT的发生与多种细胞因子、信号转导通路及转录因子有关，受多种影响因素的共同调控。上皮细胞表型的不同程度转化是细胞内外信号传递共同作用的结果。细胞外信号通过与细胞表面特异性受体相结合将信号转入细胞内，再通过胞内的信号转导途径，活化不同的核内转导因子，最终调节转导基因的表达。

英文摘要：

Epithelial-mesenchymal transition （EMT） is a differentiation process of epithelial ceils into mesenchymals, which is widespread in the invasion and metastasis of malignant tumor. Studies show that EMT is influenced by a variety of factors such as cytokines, signaling pathways and transcription factors. Studies also show that intracellular and extracellular signal transmission could induce EMT. Signal transduction is a process which involves ligand-receptor binding in the extracellular, going into the ceil and activating different nuclear transduction factor through intracellular signal transduction pathway.