Expression of cadherin-8 in renal cell carcinoma and fetal kidney.

Cadherins represent a family of calcium-dependent cell adhesion molecules with an important regulatory function for maintenance of tissue architecture. Alterations of cadherin expression have been demonstrated in the development and progression of different epithelial tumors. In renal cell carcinoma (RCC), the majority of tumors express N-cadherin and cadherin-6. Screening a series of 16 RCC cell lines for the expression of different novel type II cadherins by RT-PCR revealed a complex pattern of cadherin expression: cadherins 6 and 14 were expressed in most of the RCC cell lines, whereas cadherins 11, 12 and 13 could not be detected at all. Interestingly, cadherin-8, previously shown in mice to be restricted to the CNS and thymus during development, was detected by RT-PCR, immunofluorescence and in situ hybridization in 4 of 16 RCC cell lines as well as in paraffin sections of the corresponding human RCC biopsies. In normal renal tissue, however, cadherin-8 could be detected only during the early stages of kidney development. These results suggest that alterations of type II cadherin expression may play a role in RCC development. In particular, cadherin-8 may be involved in both kidney morphogenesis as well as tumorigenesis in some types of RCC.