WTX (Wilms’ tumor gene on the X chromosome) is a developmentally regulated gene with a potentially important role in kidney development (1). Functional studies of WTX suggest that it acts as a tumor suppressor gene in renal cells by promoting β-catenin ubiquitination and degradation, thereby antagonizing WNT/β-catenin signaling (1,2). WTX is found to be inactivated in 30% of Wilms’ tumors, mostly by chromosomal deletion (3). Wilms’ tumor is a pediatric kidney cancer that arises from cells that fail to differentiate during kidney development (4). Inactivation of the WT1 tumor suppressor gene accounts for 10-15% of Wilms’ tumor cases (5). WTX has been shown to enhance WT1-mediated transactivation, suggesting a physiologically significant interaction between WT1 and WTX (6). WTX may be directly involved in the transcriptional regulation of cellular differentiation in the kidney through interactions with WT1 and other transcription factors (6). |