极性蛋白与上皮肿瘤恶性转变

细胞极性是指细胞形态、蛋白分布以及细胞功能的不对称性，它是细胞发育、维持项一底极性、损伤修复及组织完整性等生理过程所必需的，主要是由极性蛋白调控。一旦极性蛋白之间的平衡失调，则会破坏细胞极性，诱导肿瘤发生、增殖及迁移。研究表明，极性蛋白的异常表达及错误定位均与肿瘤紧密相关。上皮细胞肿瘤发生及恶性转变过程通常伴有细胞极性丢失以及组织结构紊乱的现象，尤其是经历上皮间充质转变的上皮肿瘤细胞更易侵袭周围基质，最终引发转移。作者就目前有关极性蛋白在肿瘤方面的研究作一综述，重点阐述极性蛋白在肿瘤转移中的功能，并对相关问题进行讨论。

Relationships Between Polarity Proteins and Epithelial Tumor Transformation

Cell polarity is the asymmetry of cell morphology, protein distribution and cell function. It is essential in many physiological processes, including cell development, wound healing, as well as maintenance of apical-basal cell polarity and tissue integrity, which is regulated by polarity proteins. Loss of the cell polarity will lead to tumorigenesis and metastasis. Studies have shown that aberrant expression and localization of polarity proteins are closely related with human tumors, particularly in epithelial tumors. Loss of cell polarity and the tissue disorganization are commonly observed in epithelial tumor transformation. After epithelial-mesenchymal transition, epithelial tumor cells are more easily to invade the surrounding matrix, and eventually form metastases. In this study, the current data that the role of polarity proteins in cancer are reviewed, focusing on the function of polarity proteins in tumor metastasis.