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 co nstitutes a unique animal model in which to study genes involved in th e initiation and progression of the human Wilms' tumor. Along this lin e, we have identified a new cellular gene (nov, for nephroblastoma ove rexpressed) 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 to the extracellular matrix and likely to be involved in cell growth regulation. The recent data that are di scussed in this review strongly suggest that the nov protein might pla y a critical role in normal and pathological nephrogenesis.