Comprehensive Biology and Genetics Compendium of Wilms Tumor Cell Lines with Different WT1 Mutations.

Brigitte Royer-Pokora,Holger Thiele,Mathias Schmidt,Manfred Beier,Andrew D. Woods,Jaume Mora,Maike Anna Busch,Sarah Tenbusch

doi:10.3390/cancers13010060

Abstract

Simple SummaryWilms tumor is a childhood kidney tumor arising from embryonal cells. Wilms tumors are heterogeneous with several distinct subgroups that differ in their response to treatment. The genetic basis for these diverse forms of Wilms tumor is not fully understood. One subgroup of Wilms tumors is associated with mutations in the WT1 gene, encoding a transcription factor with a role in early kidney differentiation. Patients with WT1 mutant Wilms tumor may harbor germline mutations in this gene. Cell lines from Wilms tumors are notoriously difficult to establish and only few exist. We developed a method to cultivate cells from the WT1 mutant subtype of Wilms tumors and have established 11 cell lines with different mutations in WT1 to date. These cells will be instrumental to study the biology and genetics ultimately to develop precision treatmentsPurpose: WT1 mutant Wilms tumors represent a distinct subgroup, frequently associated with CTNNB1 mutations. The genetic basis for the development of this subtype is currently not fully understood. Methods: Live WT1 mutant Wilms tumors were collected during surgery of patients and cell cultures established in mesenchymal stem cell medium. They were studied for mutations in WT1 and CTNNB1, their differentiation capacity and protein activation status. Four cell lines were immortalized with a triple mutant ts SV40 largeT antigen and Telomerase. Results: 11 cell lines were established from Wilms tumors of nine patients, including a left and right tumor from the same patient and a primary and second tumor from another patient. Six patients had germ line and three were tumor specific mutations. All cell lines harbored only mutant or deleted WT1 genes. CTNNB1 was wild type in three, all others carried mutations affecting amino acid S45. They had variable and limited capacities for mesenchymal differentiation, a high migratory capacity and a low invasive potential. All cells showed an activation of multiple receptor tyrosine kinases and downstream signaling pathways. Conclusions: These cell lines represent an important new tool to study WT1 mutant Wilms tumors, potentially leading to new treatment approaches.

Highlights

WT1 mutant Wilms tumors represent a distinct subgroup, frequently associated with CTNNB1 mutations
We describe in detail the genetics, biological properties and molecular features of 11 WT1 mutant Wilms tumor cell lines that we have established to date
Cell cultures from 11 Wilms tumor samples were established in MSC medium from nine patients

Summary

Introduction

WT1 mutant Wilms tumors represent a distinct subgroup, frequently associated with CTNNB1 mutations. Methods: Live WT1 mutant Wilms tumors were collected during surgery of patients and cell cultures established in mesenchymal stem cell medium. They were studied for mutations in WT1 and CTNNB1, their differentiation capacity and protein activation status. Wegert et al, established short term cultures for 23 different types of Wilms tumors with known genetic alterations; only half of these had the same alterations as the tumor [9] Two of these had mutations in WT1 and in one case the WT1 mutation was heterozygous, suggesting that the cells were not pure tumor cells [9]. We developed a new method to reproducibly establish long-term cultures of Wilms tumors with WT1 mutations These cell cultures can be transfected and transduced with lentiviral vectors. We describe in detail the genetics, biological properties and molecular features of 11 WT1 mutant Wilms tumor cell lines that we have established to date

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