Human glioblastoma-initiating cells invade specifically the subventricular zones and olfactory bulbs of mice after striatal injection.

This study reports the subsequent isolation of human glioblatoma cells able to initiate experimental brain tumors, specifically and repeatedly found in the subventricular zones and olfactory bulbs following xenograft in the caudate putamen of immunodeficient mice.In patients with glioblastoma multiforme, recurrence is the rule despite continuous advances in surgery, radiotherapy and chemotherapy. Within these malignant gliomas, glioblastoma stem cells or initiating cells have been recently described and they were shown to be specifically involved in experimental tumorigenesis. In this study, we show that some human glioblastoma cells injected into the striatum of immunodeficient nude mice exhibit a tropism for the subventricular zones. There and similarily to neurogenic stem cells, these subventricular glioblastoma cells were then able to migrate towards the olfactory bulbs. Finally, the glioblastoma cells isolated from the adult mouse subventricular zones and olfactory bulbs display high tumorigenicity when secondary injected in a new mouse brain. Together, these data suggest that neurogenic zones could be a reservoir for particular cancer-initiating cells.