Human glioblastoma stem-like cell line (0316-GSC) [39] was maintained in neurobasal medium (Life Technologies) containing N2, B27 (Life Technologies), and human recombinant FGF2 (10 ng/ml; 233-FB-025) and EGF (20 ng/ml; 236-EG-200) (R&D Systems). The U87 cell line (ATCC HTB-14) was obtained from the American Type Culture Collection, and maintained in Eagle’s minimum essential medium (MEM) supplemented with 10% fetal bovine serum (FBS), 100 units/ml penicillin, and 10 μg/ml streptomycin.