Molecular biology of renal-cell carcinoma

Renal-cell cancer (RCC) is an heterogeneous disease consisting of different subtypes that show peculiar histological features and genetic alterations. Although inherited or familial predisposition occurs in less than 4% of renal cancers, most of the available information on the genetic alterations involved in the pathogenesis of RCC derives from the study of the inherited forms of kidney cancer: von Hippel-Lindau (VHL gene), hereditary papillary renal carcinoma (MET proto-oncogene), hereditary leiomyomatosis and renal-cell cancer (fumarate hydratase gene), and Birt-Hogg-Dube (BHD gene) syndromes. Such genetic alterations have also been detected in sporadic RCCs. In particular, inactivation of VHL gene by mutation or hypermethylation has been found in up to 70% of sporadic clear-cell RCC, and it has been associated with increased hypoxia-inducible factor (HIF) activity. The knowledge of these deregulated genes and their downstream pathways provides the rationale for the development of target-based approaches for RCC.