MITOTIC INDEX AND CELL-PROLIFERATION KINETICS FOR IDENTIFICATION OF ANTINEOPLASTIC ACTIVITY

The mitotic index (MI) and cell proliferation kinetics (CPK) of human blood lymphocyte cultures were determined to evaluate the effects of s ix antineoplastic drugs with well known cytostatic activity: cisplatin , melphalan, bleomycin, methotrexate, 5-fluorouracil and 6-mercaptopur ine. All six drugs showed a clear effect on the inhibition of MI. The first three drugs interact directly with DNA showing a dose-related re tardation of CPK. Methotrexate, 5-fluorouracil and 6-mercaptopurine, w hich act on ribonucleotide biosynthesis, showed no significant effects on CPK. The results suggest that CPK and MI measurements are useful f or the prescreening of drugs with potential cytostatic activity.