Functions of sphingosine in cell proliferation and death.

Interest in the biological functions of sphingosine, the metabolic product of sphingolipids, increased dramatically during the last few years. Sphingosine was found to be an exogenous inhibitor of protein kinase C and of many cell functions which depend on this enzyme including cell proliferation, differentiation, and programmed death. Sphingosine also activates some other protein kinases and regulates a variety of enzymes which are involved in the transmission of cell signals. Sphingosine mobilizes Ca2+ from intracellular stores and controls the specific Ca2(+)-channel. Sphingosine influences the synthesis of DNA and interacts with DNA in competition for the binding sites with histones, some enzymes, and transcriptional factors. Sphingosine is suggested to be a second messenger in the transmission of cell proliferation and apoptosis signals. The possible use of sphingosine in combined treatment of various diseases as a synergist of many drugs is considered.