AB137. Decreased expression of receptor tyrosine kinase of EphB1 protein in renal cell carcinomas

OBJECTIVE: Receptors tyrosine kinase of Eph superfamily plays an important role in human cancers. METHODS: In the present study, using specific anit-EphB1 polyclonal antibody and immunohistochemistry, we evaluated EphB1 protein expression levels in renal cell carcinoma (RCC) specimens surgically resected from 82 patients (including 62 conventional clear-cell RCC, 10 papillary, and 10 chromophobic RCC cases). RESULTS: We found EphB1 protein is positively expressed in the epithelium of renal tubules. Decreased expression of EphB1 was found in all RCC carcinomas compared with expression in the normal epithelium of renal tubules. EphB1 protein moderately expressed in chromophobic RCC, weakly expressed in clear-cell RCC and negatively expressed in papillary RCC. CONCLUSIONS: Our results indicate that EphB1 may be involved in carcinogenesis of RCC, the molecular mechanisms of down-regulation of EphB1 including genetic and epigenetic alterations and the dedicated roles of EphB1 in occurrence and progress of RCC need to be explicated in next step.