An investigation of the cytotoxicity of the morpholino anthracycline MX2 against glioma cells in vitro

MX2 is a novel morpholino anthracycline reported to have lower systemic tox icity than other anthracyclines. It has similar antitumour activity to adri amycin and is cytotoxic towards multi-drug resistant cells and anthracyclin e sensitive sublines of human and murine tumour cells. In this study MX2 sh owed a marked cytocidal effect compared to M2, the most cytotoxically activ e metabolite, and the nitrosourea, BCNU, when 30 ng/ml of each drug was add ed to separate flasks of C6 glioma cells grown in monolayer. The colony for mation of C6 glioma cells was markedly inhibited by MX2 in a dose dependent manner. The LD50 values for MX2, M2 and BCNU were 10.5 ng/ml, 15.8 ng/ml a nd 465 ng/ml respectively. MX2 is likely to be bound to the main plasma pro tein, albumin, and can also interact with the plasma lipoproteins, particul arly high density lipoprotein. The results in this study strongly support t he further investigation of MX2 as a potential chemotherapeutic agent again st brain tumours. (C) 2000 Harcourt Publishers Ltd.