Mutations were detected in previously described WT "hot spots" (e.g., WT1 and CTNNB1) as well as novel loci that may be unique to the Iraqi population.
At least three different pathways are involved in Wilms tumor; this review represents the outcome of the workshop discussion on the WNT/β-catenin pathway in Wilms tumorigenesis.
The 17.94 cell line contained a TP53 mutation, consistent with the anaplastic histology of the original tumor, but lacked mutations in WT1, WTX, or CTNNB1, which are the other genes involved in WT pathogenesis.
In contrast, FZD7-resistant WT in which no cell death was induced showed a different intra-cellular route of the Ab-FZD7 complex compared with sensitive tumors and accumulation of β-catenin.
Introduction of a stabilizing β-catenin mutation restricted to the kidney is sufficient to induce primitive renal epithelial tumors; however, when compounded with activation of K-RAS, the mice develop large, bilateral, metastatic, multifocal primitive renal epithelial tumors that have the histologic and staining characteristics of the epithelial component of human WT.
Wilms' tumor (WT), the most common pediatric renal malignancy, is associated with mutations in several well-characterized genes, most notably WT1, CTNNB1, WTX, and TP53.
Based on characterization of both genomic and expression status of WT1 and CTNNB1 (beta-catenin) in a series of 60 Wilms tumor samples, combined with genome-wide expression profiling of these tumors, normal mature and fetal kidney controls, we show that WT1/beta-catenin expression was a better classifier than WT1/CTNNB1 mutations.
Clinical relevance of mutations in the Wilms tumor suppressor 1 gene WT1 and the cadherin-associated protein beta1 gene CTNNB1 for patients with Wilms tumors: results of long-term surveillance of 71 patients from International Society of Pediatric Oncology Study 9/Society for Pediatric Oncology.
This overlap in mutation pattern of WT1 and beta-catenin in Wilms' tumor suggests that these 2 genes may collaborate in the genesis of a subset of Wilms' tumors.
In addition, as the beta-catenin mutation is frequently associated with the WT1 mutation, the association of WT1 silencing with the beta-catenin mutation was also investigated. beta-catenin mutated in only one WT without WT1 silencing, suggesting that the beta-catenin mutation was not associated with the reduction of WT1 expression.
To assess the relationship of WT1 mutations vis-à-vis beta-catenin mutations in Wilms tumor, we analyzed 153 primary tumors, and 21 of 153 (14%) carried beta-catenin mutations.