S1P2 was responsible for S1P-induced VEGF expression in NB cells. A, SK-N-AS cells were serum starved and stimulated with FTY720-P (10, 100nM) for 2 h or 24 h followed by quantitative real-time PCR (2h) and VEGF ELISA (24h). B, Serum-starved SK-N-AS cells were pretreated with JTE-013 (1μM) or VPC-44116 (1μM) for 0.5 h and stimulated with S1P (1μM) for another 2 h or 24 h followed by quantitative real-time PCR (2h) and VEGF ELISA (24h). C, SK-N-AS cells were infected with adenovirus overexpressing S1P2 or GFP, serum-starved and stimulated with S1P (1μM) for 24 h followed by western blot (left) and VEGF ELISA (right). D, SK-N-AS cells were transfected with 100 nM S1P2 siRNA or non-specific (NS) siRNA, serum-starved and treated with S1P (1μM) for 2 h or 24 h followed by quantitative real-time PCR (left, middle) and VEGF ELISA(right). Results were means ± SE. n=2. *, P < 0.05, **, P < 0.01 versus without S1P treatment or NS siRNA(4D, left); #, P < 0.05, ##, P < 0.01 versus indicated control.