Dataset: An Animal Model of Myc-driven medulloblastoma

Medulloblastoma (MB) is the most common malignant brain tumor in children. Patients whose tumors exhibit overexpression or amplification of the MYC oncogene (c-MYC) usually have an extremely poor prognosis, but there are no animal models of this subtype of the disease. Here we show that cerebellar stem cells expressing Myc and mutant Trp53 (p53) generate aggressive tumors following orthotopic transplantation. These tumors consist of large, pleiomorphic cells and resemble human MYC-driven MB at a molecular level. Notably, antagonists of PI3K/mTOR signaling, but not Hedgehog signaling, inhibit growth of tumor cells. These findings suggest that cerebellar stem cells can give rise to MYC-driven MB, and identify a novel model that can be used to test therapies for this devastating disease. To gain insight into the pathways that control growth of MYC-driven MB, we compared gene expression profiles of murine Myc/DNp53 (MP) tumor cells to those of freshly isolated cerebellar stem cells (Prom1+Lin- cells) and of tumors from Ptch1 mutant mice (a model for Sonic Hedgehog-associated MB). RNA was isolated from stem cells and tumor cells using the RNAqueous kit (Ambion). RNA was labeled and hybridized to Affymetrix Mouse Genome 430 2.0 arrays. 19 mouse cell samples (stem cells and tumor cells) were analyzed. There are four groups of samples, three with five biological replicates and the last with four (one outlier was removed). To gain insight into the mechanisms of transformation into tumors, we compared the gene expression profiles of MP tumor cells derived from stem cells (Myc/DNp53-infected Prom1+Lin- cells, designated MP-pl) or progenitors (Myc/DNp53-infected Prom1+ cells, designated MP-p) to gene expression profiles of uninfected stem cells (designated NSC) and profiles from a distinct model of medulloblastoma, the patched mutant mouse (designated ptch1).

Species:

mouse

Samples:

19

Source:

E-GEOD-34126

Updated:

Dec.12, 2014

Registered:

Nov.12, 2014