PAX-2, KIDNEY DEVELOPMENT, AND ONCOGENESIS

The development of a complex tissue from a few simple precursor cells requires the precise activation and repression of tissue-specific gene s that determine cell lineages, tissue patterning, and cellular prolif eration. In the kidney, a number of recently identified genes are crit ical for normal development. Among these, the Pax-2 gene encodes a tra nscription factor that is expressed in the ureter bud, in the induced kidney mesenchyme, and in the progenitor cells of the glomerular and t ubular epithelium. Although the differentiation of the renal epitheliu m requires Pax-2 function, failure to suppress the gene in mature epit helium is detrimental to normal renal function. Recent, data suggest t hat the Wilms' tumor-suppressor gene WT1 can down-regulate Pax-2 expre ssion, consistent with high levels of Pax-2 in Wilms' tumors. Addition al studies suggest that reactivation of this developmental regulator c an contribute to a variety of other renal diseases. (C) 1996 Wiley-Lis s, Inc.