Ceramides Mixture, an endogenous ceramide, consists of hydroxy and non-hydroxy fatty acid-containing ceramides. It is involved in the regulation of cell cycle arrest, growth inhibition, and modulation of telomerase activity.

Endogenous Ceramides inhibits mRNA synthesis of telomerase reverse transcriptase and telomerase activity via inactivation of the c-Myc transcription factor in the A549 human lung adenocarcinoma cell line. The sustained generation of long-chain endogenous ceramide requires the biochemical recycling of the sphingosine backbone of C6-ceramide, which involves deacylation and reacylation of ceramide for the generation of endogenous long-chain ceramide, most likely by CoA-dependent ceramide synthase, which is inhibited by fumonisin B1. In A549 cells the generation of long-chain endogenous ceramide mediates the effects of exogenous C6-ceramide on growth inhibition, cell cycle arrest, and the modulation of telomerase activity [1].