Epigenetic regulation of MYC modulates glioblastoma tumorigenicity

One aspect of intra-tumoral heterogeneity in glioblastoma involves subpopulations of cells capable of self-renewal and indefinite propagation. Conceptually, this capacity is frequently treated as a static property. Here we provide data suggesting that tumorigenicity in glioblastomais a dynamic property that can be acquired or lost. Integrated expression analyses suggest that tumorigenicity is determined by the level of MYC expression relative to a threshold. Transitions between tumorigenic and non-tumorigenic cell states are associated with changes in histone modifications at the MYC locus, suggesting tumorigenicity is epigenetically regulated. To verify genomic stability at the nucleotide level, we tested whether subclones derived from single cells shared common Single-Nucleotide Polymorphisms (SNPs). Ten single cell-derived subclones of U87MG underwent SNP profiling by Affymetrix Human Mapping 250K Nsp arrays.