THE EFFECT OF CYCLOSPORINE-A ON THE GROWTH OF HUMAN GLIOMA CELL-LINES

Cyclosporin A, an potent immunosuppressant, has been known to be one o f the modulators of drug resistance as well as a cytostatic drug. Desp ite many attempts to basic or clinical application of cyclosporin A, t here are few reports on the inhibition of brain tumor cells. In the pr esent experiment, the possibility of cyclosporin A as synergic adjuvan t was investigated by MTT assay, [H-3] thymidine uptake and through fl owcytometric anaysis. Sole treatment of cyclosporin A on the CRT and C H235-MG glioma cell line revealed dose dependent cytotoxicity within a range of tested dose. Combined treatment of cyclosporin A with ACNU, BCNU and hydroxyurea on various glioma cancer cell line led to a signi ficant synergistic cytotoxicity as well as inhibition of DNA synthesis with dose-dependency. In addition, cyclosporin A alone or combined tr eatment caused discernible changes of cell cycle in the tested cells. These data provide that cyclosporin A could potentiate the effect of n itrosourea compounds in vitro on human glioma cells.