Fig. 3

Pristimerin inhibits SPHK-1, and SPHK-1 mediates the activation of HIF-1α under hypoxia. PC-3 cells were treated with pristimerin (1 μM) and or SPHK-1 inhibitor (SKI) (10 μM) for 4 h under hypoxia. a Effect of pristimerin on the expression of SPHK-1, HIF-1α, p-AKT and pGSK-3β in hypoxic PC-3 cells. Western blotting was performed to determine the expression of SPHK-1, HIF-1α, p-AKT, AKT, pGSK-3β, GSK-3β, and β-actin in hypoxic PC-3 cells. b The activity of SPHK-1 in pristimerin treated PC-3 cells. SPHK-1 activity was measured by using SPHK-1 activity kit. Data are presented as means ± SD. * p <0.05 and ** p <0.01 compared with hypoxia control. c PC-3 prostate cancer cells were transfected with control vector or SPHK-1 siRNA for 48 h to decrease the expression of SPHK-1. Then PC-3 cells were treated with 1 μM of pristimerin for 4 h. Western blotting was performed to determine the expression of SPHK-1, HIF-1α, p-AKT, AKT, pGSK-3β, GSK-3β, and β-actin in hypoxic PC-3 cells. d The activity of SPHK-1 in pristimerin treated PC-3 cells. SPHK-1 activity was measured by using SPHK-1 activity kit. Data are presented as means ± SD. * p <0.05 and ** p <0.01 compared with hypoxia control