Antineoplastic and apoptotic effects of cannabinoids. N-acylethanolamines: protectors or killers?

The proapoptotic and antineoplastic properties of cannabinoids with emphasis on effects of N-acylethanolamines were analyzed. Cannabinoids enhanced apoptotic and necrotic processes in many types of tumour cells and tissues. Involvement of different types of receptors and signaling pathways in mediating the proapoptotic effects of cannabinoids are discussed. The evidences in favour of both proapoptotic, pronecrotic and protective, antiapoptotic effects of cannabinoids and, especially N-acylethanolamines, are evaluated. The hypothesis is suggested that N-acylethanolamines, formed in some tissues under strong stress conditions, can be not a consequence of tissue damage but cause such damage. The conclusion is made on promising of cannabinoids as potential anticancer agents.