The epithelial splicing regulator ESRP2 is epigenetically repressed by DNA hypermethylation in Wilms tumour and acts as a tumour suppressor

ABSTRACT: Wilms tumour (WT), a childhood kidney cancer with embryonal origins, has been extensively characterised for genetic and epigenetic alterations, but a proportion of WTs still lack identifiable abnormalities. To uncover DNA methylation changes critical for WT pathogenesis, we compared the epigenome of fetal kidney with two WT cell lines, using methyl-CpG immunoprecipitation. We filtered our results to remove common cancer-associated epigenetic changes, and to enrich for genes involved in early kidney development. This identified four candidate genes that were hypermethylated in WT cell lines compared to fetal kidney, of which ESRP2 (epithelial splicing regulatory protein 2), was the most promising gene for further study. ESRP2 was commonly repressed by DNA methylation early in WT development (in nephrogenic rests) and could be reactivated by DNA methyltransferase inhibition in WT cell lines. When ESRP2 was expressed in WT cell lines, it acted as an inhibitor of cellular proliferation in vitro and in vivo it suppressed tumour growth of orthotopic xenografts in nude mice. RNA-seq of the ESRP2-expressing WT cell lines identified several novel splicing targets, in addition to well-characterised targets of ESRP2. One of these targets, LEF1, is a component of the Wnt signalling pathway that is essential for kidney development and commonly disrupted in WT. We propose a model in which the Wnt pathway can be disrupted in early kidney development to generate WT, either by genetic abnormalities such as WT1 mutations, or by epigenetic defects, such as ESRP2 methylation. The microarray data in this deposition identified ESRP2 as a commonly hypermethylated gene in Wilms tumour.

ORGANISM(S): Homo sapiens

PROVIDER: GSE153047 | GEO | 2020/11/02

REPOSITORIES: GEO