SPHK 1 Inhibitor 5C

SPHK 1 Inhibitor 5C is a selective inhibitor of SphK1, both in vitro (IC₅₀ = 3.3 μM) and in U937 cells overexpressing human SphK1 (70% inhibition at 5 μM). The sphingosine kinases (SphK) phosphorylate sphingosine, producing the important lipid mediator sphingosine-1-phosphate (S1P). The two known kinases, SphK1 and SphK2, have different developmental and tissue expression patterns, suggesting that they have distinct physiological functions. Notably, SphK1 is overexpressed in several forms of cancer and inhibition of SphK1 inhibits tumor growth. It has no inhibitory effect on SphK2 either in vitro or in cells. Similarly, this chemical does not reduce the activity of protein kinase C (PKC) except at very high concentration (>75 μM).