Von Hippel-Lindau (VHL) disease is associated with various missense germline mutations in the VHL tumor suppressor gene. Some are associated with type 1 VHL disease,
renal cell carcinoma (RCC) without
pheochromocytoma, while others are associated with type 2A or 2B VHL disease,
pheochromocytoma without and with RCC, respectively. These mutations may cause substitutions of specific
amino acid residue and functional change of VHL
protein (pVHL), which leads to the
oncogenesis of the particular
tumor types that characterize the different VHL disease types. To investigate, we transfected a pVHL-null RCC cell line with plasmids expressing wild-type pVHL (WT) or pVHL bearing 1 of 3 point mutations. These occur in the pVHL regions that bind
hypoxia-inducible factor alpha (HIF-alpha ) or
Elongin C. Microarray analysis showed that the clones bearing a mutation in the
elongin-binding region (mutant 167) were unique, as many more genes were suppressed than up-regulated. The other two mutant groups, which bear a mutation in the HIF-alpha -binding region (mutants 98 and 111), showed the opposite pattern. The 167 mutation is associated with type 2B VHL disease. Real-time PCR analysis confirmed the altered expression of selected genes in the clones. Relative to WT, stratifin (14-3-3 sigma) and
lysyl oxidase-like 1 were down-regulated in the 167 mutants, while the
transforming growth factor beta-induced protein (beta ig-h3) was up-regulated in the 111 mutants. Thus, the location of pVHL mutations results in distinct gene expression patterns. Moreover, a mutation in the
elongin-binding domain may induce type 2B
tumors through different molecular pathways compared to those induced by type 1- or 2A-associated mutations in the HIF-alpha -binding region.