LAUSR

respective parental tumours. Histological analysis showed that three spheroid strains comprised mostly blastemal cells, one was primarily epithelial in origin and the other contained mainly immature stromal cells. Spheroids of each type could be successfully genetically manipulated, but stable transduction was not possible for blastemal-type spheroids. Furthermore, spheroids could be successfully xenografted into mice and, in vitro, spheroid cultures derived from xenografts had similar characteristics to the original tumour. These spheroid cultures can be propagated long term using a simple, low-cost method. They maintain characteristics of the original tumour and can be genetically manipulated and xenografted to enable in vivo study, providing much-needed tools for preclinical investigation of Wilms tumour. Louise Stone