The etiology of central nervous system (CNS)
tumor heterogeneity is unclear. To clarify this issue, a novel animal model was developed of
glioma and atypical teratoid/rhabdoid-like
tumor (ATRT) produced in rats by nonviral cellular transgenesis initiated in utero. This model system affords the opportunity for directed oncogene expression, clonal labeling, and addition of
tumor-modifying transgenes. By directing HRasV12 and AKT transgene expression in different cell populations with promoters that are active ubiquitously (CAG promoter), astrocyte-selective (
glial fibrillary acidic protein promoter), or oligodendrocyte-selective (
myelin basic protein promoter) we generated
glioblastoma multiforme and anaplastic oligoastrocytoma, respectively. Importantly, the
glioblastoma multiforme and anaplastic oligoastrocytoma
tumors were distinguishable at both the cellular and molecular level. Furthermore, proneural basic helix-loop-helix (
bHLH) transcription factors, Ngn2 (NEUROG2) or NeuroD1, were expressed along with HRasV12 and AKT in neocortical radial glia, leading to the formation of highly lethal ATRT like
tumors. This study establishes a unique model in which determinants of CNS
tumor diversity can be parsed out and reveals that both mutation and expression of neurogenic
bHLH transcription factors contribute to CNS
tumor diversity.
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