Anandamide and other N-acylethanolamines in human tumors.

Long-chain N-acylethanolamines (NAE), including the endocannabinoid, anandamide, accumulate in mammalian tissues under a variety of pathological conditions. They have also been shown to inhibit the growth of various cancer cell lines in vitro. Here, we report the presence, in widely differing amounts (3.88-254.46 pmol/micromol lipid P), of NAE and their precursor phospholipids in various human tumors and some adjacent unaffected tissues. Anandamide ranged from 1.5 to 48% of total NAE, and incubation of tissue homogenates suggested possible NAE biosynthesis by both the established transacylation-phosphodiesterase pathway via N-acyl PE and by direct N-acylation of ethanolamine.