Glioblastomas (GBM) may contain a variable proportion of active cancer stem cells (CSCs) capable of self-renewal, of aggregating into CD133(+) neurospheres, and to develop intracranial tumors that phenocopy the original ones.
Replicative senescence in HNGC-1 led to a high level of genomic instability and emergence of a spontaneously immortalized clone that developed into cell line HNGC-2 with features of cancer stem cells (CSCs), which include the ability for self-renewal and the capacity to form CD133-positive neurospheres and develop intracranial tumors.