Coexisting cancer stem cells with heterogeneus gene amplifications, transcriptional profiles and malignancy can be isolated from single glioblastomas. Identification of stem-like cells recapitulating GBM subclonal components with subtle genetic evolution and sharp phenotypic differences

In glioblastoma (GBM), therapeutic efficacy is limited by coexistence of heterogeneous tumor subclones, each supported by a distinct glioblastoma stem cell (GSC). The relative contribution of GSC genetic and transcriptional heterogeneity to tumor subclonal properties is debated. In this study we systematically characterized multiple distinct GSCs (neurospheres) from single, treatment-naïve GBMs. The tumorigenic potential of each GSC better correlated with its transcriptional profile rather than genetic make-up, with classical GSCs being invariably more aggressive than mesenchymal across multiple GBMs. In a paradigmatic tumor with histopathologically distinct components, including a conventional GBM and a more aggressive primitive neuronal component, we isolated GSCs with homogeneous genetic, but distinct transcriptional and biological features, each reproducing one or the other tumor histopathological aspect and aggressiveness. Overall, these findings indicate that GSCs with different and stable transcriptional profiles coexist in single GBMs and can support escalation to a hypermalignant phenotype regardless of genetic alterations.