Expression of plakoglobin in renal cell carcinoma.

Little is known about the role of molecules involved in cell-cell interactions during the progression of renal cell carcinoma (RCC). We investigated the expression of plakoglobin (a component of the cadherin-catenin adhesion system) in 94 samples of normal kidney tissue from patients with RCC, in 109 primary renal cell carcinomas and in 16 metastases by immunohistochemistry. Expression of plakoglobin was significantly diminished in tumor tissue, particularly in metastatic lesions, as compared to normal kidney tissue (p < 0.001). Follow-up data were available from 87 patients. Patients with a diffuse plakoglobin expression (91-100% positive cells) in primary tumor tissue had a significant better survival rate than patients with a disturbed plakoglobin expression (p < 0.05) as determined by the log rank test. These results indicate that loss of plakoglobin may play an important role in malignant transformation of renal cells. Plakoglobin expression status could give additional information about the individual prognosis.