(A) 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay was employed to evaluate the effect of NOS2-directed shRNA on S-phase transit in CD133+ glioma cells (GSCs). (B) Microarray analysis demonstrated that NOS2-directed shRNA increased transcript expression of the cell cycle inhibitor, CDA1 (2 xenografts in duplicate). NOS2-dependent suppression of CDA1 in GSCs was validated by (C) qRT-PCR and (D) Western analysis. (E) Viability of GSCs and CD133− cells (non-GSCs) was evaluated after treatment with vector or CDA1 expressing lentivirus. F) Neurosphere formation capacity was evaluated 10 d after single vector or CDA1-overexpressing cells were sorted into wells. (G) The decreased EdU incorporation from NOS2-directed shRNAs was partially blocked by concurrent expression of CDA1-directed shRNA. *, p<0.05; **, p < 0.01; ***, p < 0.001, N.S., not significant. See also Figure S4 and Table S1.