Cancer metastasis is an important stage in its development, and the majority of patients died of metastasis. So the transfer has been a hot area of cancer research. Studies suggest that epithelial-mesenchymal transformation（EMT） plays a key role in malignant tumor invasion and metastasis. Studys of the origin factor in EMT and its downstream pathway in tumor growth, invasion and metastasis, and how to block this mechanism have great significance, in the early diagnosis and early treatment of the malignant tumors. Here we will give you a review about the role of epithelial-mesenchymal transformation in the embryonic tissue development, the relevant signaling pathways involved, tumor invasion and metastasis and the role in invasion and metastasis of oral cancer.
