[EXPRESSION OF PLAKIN FAMILY IN UROTHELIAL CARCINOMA OF THE UPPER URINARY TRACT].

(Objective) To determine whether the plakin family proteins periplakin, desmoplakin, plectin, and envoplakin could be markers of urothelial carcinoma of the upper urinary tract. (Materials and methods) Fifty-seven surgical specimens were obtained from patients with urothelial carcinoma of the upper urinary tract, who were admitted to the Jikei University Hospital between April 2000 and December 2005. The expression of plakin family proteins in cancerous and normal tissues was investigated using immunohistochemistry, and its association with clinicopathological parameters was analyzed. (Results) The expression of periplakin, envoplakin, and desmoplakin was significantly lower in cancerous tissue than in normal urothelium (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). Strong desmoplakin expression in cancerous tissue was significantly associated with poor cancer-specific survival and overall survival (P = 0.023 and P = 0.034, respectively, compared with cancerous tissue with slight or less desmoplakin expression). Furthermore, strong plectin expression was significantly associated with poor metastasis-free survival (P = 0.034, compared with cancerous tissue with slight or less plectin expression). (Conclusion) Plakin family, particularly desmoplakin was suggested to be a prognostic marker of urothelial carcinoma of the upper urinary tract.