Modeling Wilms Tumor Development with Multiple Lineage Human Fetal Kidney Organoids Reveals the Cellular Origin and Specific Drivers of Tumorigenesis

Dysregulation of kidney organogenesis can lead to the development of Wilms tumor (WT), a common pediatric kidney cancer. Although numerous mutations implicated in WT have been identified through genomic studies, the cellular origin and driver mutations in WT remain unclear due to the lack of human models that preserve the complete lineage diversity of the developing kidney. Here, we established an in vitro condition to generate 3D human fetal kidney organoids (FekOs) phenocopying aspects of in vivo renal cellular heterogeneity and complex organization. FekOs faithfully recapitulated the spatial arrangement of ureteric bud (UB) structures and nephron segments. FekOs could be expanded over long time periods. Screening of clinically relevant mutations in WT identified key driver mutations and combinations that result in tumor-like neoplasms. Notably, distinct lineages were isolated from fetal kidney tissues to generate UB organoids and nephron organoids, mapping driver mutations to their specific cellular origins. Together, this model provides insights into how different mutations and their combinations drive Wilms tumorigenesis, providing a scalable platform for advancing human kidney developmental disease research.