Ksp-cadherin (MRQ-33)

Kidney-specific cadherin (Ksp-cadherin) is a novel, kidney-specific member of the cadherin family of cell adhesion molecules. Within the kidney, Ksp-cadherin is found exclusively in the basolateral membrane of renal tubular epithelial cells and collecting duct cells, and not in glomeruli, renal interstitial cells, or blood vessels. Different cadherins, including E-cadherin, cadherin-6, and N-cadherin, have been investigated in renal cell cancers, demonstrating possible correlations of tumor dedifferentiation and the presence of lymph node metastasis with loss of cadherins. Mazal et al. investigated the utility of using Ksp-cadherin to distinguish chromophobe renal cell carcinoma from oncocytoma. He found a membranous pattern of staining in 96% of 30 chromophobe carcinomas, and in only 6% of 31 oncocytomas leading them to conclude that this is a useful antibody in differentiating these two lesions. Shen et al., on the other hand, found Ksp-cadherin positivity in 100% of 13 chromophobe RCCs, and 95% of 20 oncocytomas.