SKI II

SKI-II is a selective non-lipid inhibitor of sphingosine kinase (IC50 = 0.5 μM) . nhibits acute myelogenous leukemia cell growth in vitro and in vivo. SKI-II was more efficient than two known SphK1 inhibitors SK1-I and FTY720 in inhibiting AML cells. Meanwhile, it induced dramatic apoptosis in above AML cells, and the cytotoxicity by SKI-II was almost reversed by the general caspase inhibitor z-VAD-fmk. SKI-II treatment inhibited SphK1 activation, and concomitantly increased level of sphingosine-1-phosphate (S1P) precursor ceramide in AML cells.