Abstract 1439: Loss of expression of SWI/SNF subunits in high risk Wilms tumor is accompanied by global gene expression changes

Introduction: The TARGET initiative seeks to identify therapeutic targets through genomic sequencing supported by copy number and gene expression analysis. The High Risk Wilms Tumor TARGET project, currently in progress, includes the analysis of favorable histology (FH) tumors that relapsed and tumors with anaplasia (unfavorable histology). We report the identification of a group of Wilms tumors (WT) identified by a unique gene expression pattern. Methods and Results: 102 high risk WT (43 anaplastic, 59 relapsed FH) were analyzed using Affymetrix U133+2 chips. Unsupervised hierarchical analysis consistently selected 9 tumors (5 anaplastic, 4 FH) that shared a striking gene expression pattern. These patients presented at 15-96 months (median 51); 7 had a triphasic histology and 2 were blastemal predominate; 4 died of their disease. When the top differentially expressed genes (P