Uroplakin II

Uroplakin Ⅱ (UPK2) is a highly conserved urinary tract epithelial cell specific glycoprotein, and it is a crucial component in maintaining normal structure and function of the bladder. Some research has found that UPK2 can form plaque structures together with other UPK subtypes, which will cover the transitional epithelial cells on the surface of mucosa. When the bladder dilates, plaques can fuse with intracellular vesicles to expand the cell surface area and prevent damage. When it contracts, plaques are stored in the form of vesicles inside the cell. In clinical practice, UPK2 is mainly used for the diagnosis of primary and metastatic urothelium derived tumors. Especially, it has become a highly specific and sensitive biomarker for bladder transitional cell carcinoma (BTCC). Some scholars pointed out that UPK2, as a necessary factor for the terminal differentiation of urinary tract epithelium, has a positive correlation between its expression level and the differentiation degree of cancer cells, which has important reference value for the grade diagnosis of tumors.