7386

UQCRFS1

RIP1|RIS1|RISP|UQCR5;ubiquinol-cytochrome c reductase, Rieske iron-sulfur polypeptide 1;UQCRFS1;ubiquinol-cytochrome c reductase, Rieske iron-sulfur polypeptide 1

Rieske iron-sulfur protein|complex III subunit 5|cytochrome b-c1 complex subunit 5|cytochrome b-c1 complex subunit Rieske, mitochondrial|ubiquinol-cytochrome c reductase iron-sulfur subunit

19q12

protein-coding

The WNT/beta-catenin pathway is involved in numerous human cancers. mutations ofthe CTNNB1 (beta-catenin) gene have also been detected in a subset of pediatric Wilms tumors, but the target genes of the deregulated WNT/beta-catenin pathway in these tumors have yet to be identified. To compare gene expression profiles of Wilms tumors with and without mutations of CTNNB1, we used 11.5-k cDNA microarrays. Most of the tumors (86%) had received preoperative chemotherapy as mandated by the European SIOP protocol. The comparison between Wilms tumors withand without CTNNB1 mutations revealed several target genes specifically deregulated in CTNNB1-mutated Wilms tumors. Among these, PITX2, APCDD1, and two members of the endothelin axis (EDN3 and EDNRA) are directly activated downstream targets of the WNT/beta-catenin pathway that may enhance proliferation of these tumor cells. In addition, several upstream inhibitors of WNT/beta-catenin signaling like WIF1 and PRDC were also strongly up-regulated in the CTNNB1-mutated Wilms tumors. This overexpression may be a negative feedback mechanism in tumors with uncontrolled WNT signaling. Moreover, we identified deregulated genes in both the retinoic acid and the RAS pathways, such as ATX/ENPP2 and RIS1, suggesting an association between these two pathways with that of WNT. In addition, the strong representation of muscle-related genes in the expression profile of CTNNB1-mutated Wilms tumors corresponded to histologically detectable areas of myomatous cells in these tumors that displayed intense and preferential nuclear beta-catenin antibody staining. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.#CI- (c) 2006 Wiley-Liss, Inc.