Contribution of MAV-1-induced nephroblastoma to the study of genes involved in human Wilms' tumor development.

The avian nephroblastoma induced by myeloblastosis-associated virus constitutes a unique animal model in which to study genes involved in the initiation and progression of the human Wilms' tumor. Along this line, we have identified a new cellular gene (nov, for nephroblastoma overexpressed) whose expression is regulated in vitro by the WT1 proteins and is stimulated in all avian nephroblastomas. The nov gene is also conserved in human and its expression is altered in Wilms' tumors. In both species, the nov gene encodes a potential insulin growth factor (IGF)-binding protein associated tot he extracellular matrix and likely to be involved in cell growth regulation. The recent data that are discussed in this review strongly suggest that the nov protein might play a critical role in normal and pathological nephrogenesis.