title: Sleeping Beauty mutagenesis in a mouse medulloblastoma model defines networks that discriminate between human molecular subgroups.
abstract: The Sleeping Beauty (SB) transposon mutagenesis screen is a powerful tool to facilitate the discovery of cancer genes that drive tumorigenesis in mouse models. In this study, we sought to identify genes that functionally cooperate with sonic hedgehog signaling to initiate medulloblastoma (MB), a tumor of the cerebellum. By combining SB mutagenesis with Patched1 heterozygous mice (Ptch1(lacZ/+)), we observed an increased frequency of MB and decreased tumor-free survival compared with Ptch1(lacZ/+) controls. From an analysis of 85 tumors, we identified 77 common insertion sites that map to 56 genes potentially driving increased tumorigenesis. The common insertion site genes identified in the mutagenesis screen were mapped to human orthologs, which were used to select probes and corresponding expression data from an independent set of previously described human MB samples, and surprisingly were capable of accurately clustering known molecular subgroups of MB, thereby defining common regulatory networks underlying all forms of MB irrespective of subgroup. We performed a network analysis to discover the likely mechanisms of action of subnetworks and used an in vivo model to confirm a role for a highly ranked candidate gene, Nfia, in promoting MB formation. Our analysis implicates candidate cancer genes in the deregulation of apoptosis and translational elongation, and reveals a strong signature of transcriptional regulation that will have broad impact on expression programs in MB. These networks provide functional insights into the complex biology of human MB and identify potential avenues for intervention common to all clinical subgroups.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Genovesi
authors.forename: Ching Ging
authors.initials: CG
authors.lastname: Ng
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Davis
authors.forename: Marc
authors.initials: M
authors.lastname: Remke
authors.forename: Michael D
authors.initials: MD
authors.lastname: Taylor
authors.forename: David J
authors.initials: DJ
authors.lastname: Adams
authors.forename: Alistair G
authors.initials: AG
authors.lastname: Rust
authors.forename: Jerrold M
authors.initials: JM
authors.lastname: Ward
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Ban
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Jenkins
authors.forename: Neal G
authors.initials: NG
authors.lastname: Copeland
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Wainwright
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002874:Chromosome Mapping; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics; D053263:Gene Regulatory Networks / Q000235:genetics*; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008527:Medulloblastoma / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D016254:Mutagenesis, Insertional / Q000379:methods; D051839:NFI Transcription Factors / Q000235:genetics*; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D016133:Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000235:genetics; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000235:genetics*; D019895:Transposases / Q000235:genetics
chemical_list: D017931:DNA Primers; D004251:DNA Transposable Elements; D053823:Hedgehog Proteins; D051839:NFI Transcription Factors; C497592:NFIA protein, human; C000606236:PTCH1 protein, human; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; C000606240:Ptch1 protein, mouse; D011956:Receptors, Cell Surface; D019895:Transposases; C494471:sleeping beauty transposase, human