Inhibition of Phytohemagglutinine-Induced T Lymphocyte Proliferation by 6-(octadecyldithio)purine, a Novel Liposomal Prodrug of 6-mercaptopurine

Abstract

6-mercaptopurine (6-MP) is used in a variety of immune and neoplastic disorders. The antiproliferative effect on neoplastic and immune competent cells is based on the competitive inhibition of hypoxanthine-guanine-phosphoribosylpy-rophosphate-transferase resulting in impaired activation of purine bases for RNA- and DNA-synthesis. Furthermore, metabolites of 6-MP are incorporated as ‘false bases’ into RNA and DNA leading together with the inhibition of other enzymes to the so called ‘purine-less’ cell death. The main target of 6-MP are rapidly proliferating and metabolically active cells.