Advances in research on regulation of apoptosis by sphingosine kinase

The sphingolipid metabolites ceramide(Cer), sphingosine(Sp), and sphingosine 1-phosphate(S1P) play important roles in the regulation of cell proliferation, survival, and apoptosis. Sphingosine kinase (SPK) is a key enzyme catalyzing the formation of sphingosine 1 phosphate (S1P), which is a lipid messenger regulating cell proliferation and apoptosis through intracellular as well as extracellular mechanisms. SPK is believed to be involved in the transmission of several cytokine signals. Overexpression of SPK in cells results in inhibition of caspase cleavage and upregulation of Bcl-2 expression. The construction and activation of SPK and its regulatory roles in the apoptosis are reviewed in this paper.