Wilms11 Cells

The Wilms11 cell line was derived from a primary Wilms tumor (nephroblastoma) in a pediatric patient. Unlike many other Wilms tumor cell lines, Wilms11 is characterized by the presence of wild-type WT1, meaning it does not harbor mutations in the WT1 gene, which is typically associated with Wilms tumors exhibiting more aggressive or stromal phenotypes. However, the Wilms11 tumor exhibited significant stromal differentiation, with large areas of rhabdomyomatous differentiation, indicative of mesenchymal elements within the tumor. The presence of wild-type WT1, coupled with the tumor’s stromal differentiation, provides a unique model for understanding Wilms tumor biology in cases where WT1 mutations are absent.

Genetic studies of Wilms11 have shown that this cell line carries a tumor-specific mutation in CTNNB1, the gene encoding β-Catenin, which plays a crucial role in the Wnt signaling pathway. In Wilms11, this mutation affects serine 45, a key phosphorylation site involved in β-Catenin degradation. The CTNNB1 mutation results in the stabilization of β-Catenin, leading to its accumulation and constitutive activation of the Wnt signaling pathway, a driver of cell proliferation and tumorigenesis. This makes Wilms11 an important model for studying the interplay between Wnt signaling and Wilms tumor development, particularly in cases where WT1 remains intact.

Proteomic analyses of Wilms11 have revealed activation of several receptor tyrosine kinases (RTKs), including PDGFRβ and AXL, which are involved in driving tumor cell growth and survival. Downstream signaling pathways, such as the MAPK and PI3K/AKT pathways, are also activated in Wilms11 cells, contributing to their tumorigenic behavior. The ability of Wilms11 cells to undergo mesenchymal differentiation, particularly rhabdomyomatous differentiation, highlights their potential as a model for studying the mesenchymal components of Wilms tumor. Overall, Wilms11 serves as a valuable tool for investigating the molecular mechanisms that drive Wilms tumorigenesis in the absence of WT1 mutations but in the context of Wnt pathway activation.