imWilms1 Cells

The Wilms1 cell line was originally derived from a primary Wilms tumor, obtained from a patient diagnosed with large bilateral kidney tumors, a characteristic presentation of Wilms tumor (nephroblastoma). This cell line harbors a homozygous nonsense mutation in the WT1 gene (c.149 C>A, p.S50X), leading to the production of a truncated, non-functional WT1 protein. WT1 is a critical gene in kidney development, and its mutation is closely associated with the pathogenesis of Wilms tumor, particularly in tumors exhibiting stromal differentiation. Wilms1 cells display a stable karyotype without significant chromosomal abnormalities, and they are characterized by a mesenchymal phenotype, expressing vimentin while lacking epithelial markers like cytokeratin. The line shows a limited but significant capacity for mesenchymal differentiation, including the potential to differentiate into muscle-like cells under specific conditions, making it a crucial model for studying the molecular consequences of WT1 mutations.

To overcome the limited lifespan of the primary Wilms1 cells, the imWilms1 cell line was established by introducing a triple mutant SV40 large T antigen (U19dl89-97tsA58) into the original tumor cells, facilitating their immortalization. This modification allows imWilms1 cells to proliferate indefinitely while maintaining chromosomal stability, thereby offering a reliable model for long-term studies. The immortalized imWilms1 cells continue to exhibit the same WT1 mutation and retain the mesenchymal characteristics of the parent Wilms1 line.

In addition to its genetic and phenotypic features, the imWilms1 cell line has been extensively analyzed for its signaling pathway activity. Proteomic studies have revealed the phosphorylation and activation of several receptor tyrosine kinases (RTKs), including EGFR, PDGFRβ, and AXL, with downstream activation of the MAPK signaling pathways. The consistent activation of these pathways in imWilms1 cells underscores their relevance for exploring targeted therapeutic strategies in Wilms tumor. Overall, imWilms1 serves as a robust and long-term model for investigating the molecular mechanisms underlying Wilms tumor development and progression, particularly those driven by WT1 mutations and aberrant signaling pathways.