Generation of a Mouse Model of Von Hippel-Lindau Kidney Disease Leading to Renal Cancers by Expression of a Constitutively Active Mutant of HIF1α

Renal cancers are highly aggressive and clinically challenging, but a transgenic mouse model to promote pathologic studies and therapeutic advances has yet to be established. Here, we report the generation of a transgenic mouse model of von Hippel-Lindau (VHL) renal cancer termed the TRACK model (transgenic model of cancer of the kidney). TRACK mice specifically express a mutated, constitutively active HIF1 alpha in kidney proximal tubule (PT) cells. Kidney histologies displayed by TRACK mice are highly similar to histologies seen in patients with VHL disease, including areas of distorted tubular structure, cells with clear cytoplasm and increased glycogen and lipid deposition, multiple renal cysts, and early onset of clear cell renal cell carcinoma (ccRCC). Distorted tubules in TRACK mice exhibit higher levels of CA-IX, Glut1, and VEGF than tubules in nontransgenic control mice. Furthermore, these tubules exhibit increased numbers of endothelial cells, increased cell proliferation, and increased expression of the human ccRCC marker CD70 (TNFSF7). Moreover, PT cells in kidney tubules from TRACK mice exhibit increased genomic instability, as monitored by elevated levels of gamma H2AX. Our findings establish that activated HIF1 alpha in murine kidney PT cells is sufficient to promote cell proliferation, angiogenesis, genomic instability, and other phenotypic alterations characteristic of human VHL kidney disease, establishing the TRACK mouse as a valid preclinical model of human renal cell carcinoma. Cancer Res; 71(21); 6848-56. (C) 2011 AACR.