[E-cadherin expression and histopathological features in renal cell carcinomas].

E-cadherin, a member of the cadherin family, plays a major role in cell-cell adhesion of normal epithelium. Recent studies have demonstrated that heterogeneous expression, reduction or loss of E-cadherin is involved in invasion and metastasis of cancer cells. In this study, the localization of E-cadherin in the normal human kidney and the relationship between E-cadherin expression and histopathological features in renal cell carcinomas was examined immunohistochemically. Renal cell carcinoma tissues and normal kidney counterparts were obtained from 20 patients. E-cadherin in the normal kidney was detected in the cell-cell border of the distal tubules, collecting duct and Bowman's capsule but not in the proximal tubules. E-cadherin expression was reduced in all the clear cell type renal cell carcinomas with compact or cystic configuration (n = 15), while it was well preserved in all the papillary type (n = 3) and chromophobe cell type (n = 1) renal cell carcinomas. Different expression patterns between primary site and metastasis, i.e., homogeneously weak in primary tumor and heterogeneously positive in metastatis, was observed in a case of clear cell type renal cell carcinoma. Different patterns of expression between clear and non-clear cell type, or between papillary and non-papillary type, together with strong expression in chromophobe type might reflect the origin of each type of renal cell carcinoma. Further studies will clarify whether the change in expression of E-cadherin is associated with the prognosis of renal cell carcinoma.