CHARACTERIZATION OF CHEMOTHERAPY-INDUCED MORPHONUCLEAR MODIFICATIONS IN THE P388 LEUKEMIA AND THE MXT MAMMARY-TUMOR MODELS OF THE MOUSE

Chemotherapy-induced morphonuclear modifications were monitored in viv o by means of the digital cell image analysis of Feulgen-stained nucle i. Two experimental models were used, i.e. the P388 mouse leukaemia an d the MXT mouse mammary carcinoma. The drugs used were doxorubicin, et oposide and cyclophosphamide. The results indicate that the chemothera py induced a significant decrease in the MXT tumour growth and a signi ficant increase in the survival of the P388 leukaemic mice. These effe cts were accompanied at the morphonuclear level by an increase in the nuclear area, by modifications in the DNA content in accordance with t he effects of the drugs on the cell cycle and by several modifications in the chromatin texture in accordance with the model or the drugs st udied. While there were neither homogeneous morphonuclear changes in a ll treatment groups nor clearcut correlations between the morphonuclea r changes: and tumour growth or the survival of the animals, the prese nt: study nevertheless shows that it is possible, at least partly, to monitor in vivo certain chemotherapy-induced effects occurring at the morphonuclear level, and subsequently to obtain information on the mod e of action of the drugs.