Cell death and cell survival in HNK-1 knockdown NSCs. a, cell death of NSCs transfected with HNK-1ST or TNC siRNA was evaluated by TUNEL assay. Tunicamycin was used as a control inducer of cell death (1 μg/ml for 10 h). There is no difference in the numbers of TUNEL+ cells between control siRNA, HNK-1ST siRNA, and TNC siRNA-transfected cells. Scale bar, 25 μm. b, activation of cell survival signaling and cell death signaling pathways (phosphoinositide 3-kinase-Akt pathway and caspase pathway, respectively) in NSCs transfected with HNK-1ST siRNA was evaluated by Western blotting with antibodies to Akt, phospho-Akt, caspase 3, and β-actin. The cell survival signaling and cell death signaling pathways in NSCs were not inhibited or activated by transfection with HNK-1ST siRNA.