Glioblastoma Tumor Sampling and Stem Cell Culture

Before any therapy, glioblastoma samples were obtained after informed consent from patients admitted to the neurosurgery department at Toulouse University Hospital. Tumors were histologically diagnosed as glioblastoma according to WHO criteria. For patients 1 and 2, two tumor samples were removed from the cortical area (CT1, CT2) and from the periventricular zone (PVZ1 and PVZ2) by utilizing stereotactic image-guided sampling. These patients had a large tumor that was in contact with both CT and PVZ. After mechanical dissociation of tumor tissues, cells were seeded at 37° C in a humid atmosphere of 5% CO₂ in glioblastoma stem cell medium (GSM) composed of DMEM-F12 (Lonza) supplemented with B27 and N2 additives (Invitrogen), EGF (20 ng/mL) and basic FGF (20 ng/mL) (Peprotech). When neurospheres were formed, they were isolated, dissociated with trypsin and cultured as previously described [23 (link)]. The percentage of GSCs into the neurosphere was evaluated by flow cytometry [23 (link)] (Supplementary Table 10). For other patients (A1, G, I, K, SC1, SC3), only one tumor sample was removed from different brain zones.