Renal Carcinogenesis After Uninephrectomy 1

Nephrectomized rats have widely been used to study chronic renal failure. Interestingly, renal cell carcinoma occurred in the remnant kidney after uninephrectomy (UNX). In this study, we probed insulin-like growth factor (IGF)-1 signaling pathway in UNX-induced renal cancer. Adult male Sprague-Dawley rats were randomized into two groups: UNX rats (n = 22) and sham-operated rats (n = 12). Rats were killed at 3, 7, and 10 months. After 7 months after nephrectomy, the UNX rats developed renal cell carcinoma with increased expression of proliferating cell nuclear antigen, and 68.2% (15/22) of the animals exhibited invasive carcinoma. Western blot demonstrated significant down-regulation of IGF binding protein 3 contrasting with the up-regulation of protein kinase Cζ and Akt/protein kinase B in the renal cancer tissues. These findings indicate a unique rat model of UNX-induced renal cancer associated with enhanced IGF-1 signaling pathway.