Ozdemir, D. D. | bioRxiv Science

bioRxiv2025

Genotype-phenotype correlations in Wilms tumor initiation.

Wilms tumor, the most common pediatric kidney cancer, arises from abnormal embryonic kidney development. Therapy resistance and tumor recurrence remain major challenges, likely driven by the presence of Cancer Stem Cells (CSCs). Here, we elucidate the earliest pathogenic events in genetically engineered mouse models exhibiting loss of Wt1 or LIN28B overexpression, two Wilms tumor driver genes. Loss of Wt1 leads to a disturbance of lineage identity of the mutant cells, whereas LIN28B leads to a disturbed transition between uninduced and induced NPC (nephron progenitor cell) state. In both cases the appearance of cells positive for all four Wilms tumor cancer stem cell markers is the result of the tumor initiating mutation. The existence of genotype-phenotype correlations in primary developmental phenotypes and cancer stem cell expression patterns has important implications for therapeutic opportunities and requirements.

developmental biology↗

bioRxiv2023

Mutational scanning reveals oncogenic CTNNB1 mutations have diverse effects on signalling and clinical traits

CTNNB1, the gene encoding {beta}-catenin, is a frequent target for oncogenic mutations activating the canonical Wnt signalling pathway, typically via missense mutations within a degron hotspot motif in exon 3. Here, we combine saturation genome editing with a fluorescent reporter assay to quantify signalling phenotypes for all 342 missense mutations in the mutation hotspot, including 74 recurrent mutations reported in over 6000 tumours. Our data define the genetic requirements for {beta}-catenin degron function and reveal diverse levels of signal activation among known driver mutations. Tumorigenesis in different human tissues involves selection for CTNNB1 mutations spanning distinct ranges of effect size. In hepatocellular carcinoma, mutations that activate {beta}-catenin relatively weakly are associated with worse prognosis compared to stronger activating mutations, despite greater immune cell infiltration in the tumour microenvironment. Our work therefore provides a resource to understand mutational diversity within a pan-cancer mutation hotspot, with potential implications for targeted therapy.

cancer biology↗