Mechanism of 1-ß-D-Arabinofuranosylcytosine-induced Cell Lethality

1-ß-D-Arabinofuranosylcytosine-induced cell lethality as measured by survival fraction in a plating efficiency assay with the use of cultures of hamster fibroblasts correlates with the production of five or more chromatid breaks per metaphase. By contrast neither the degree of inhibition of DNA synthesis nor the magnitude of unbalanced growth as determined by cell sizing produced by a variety of 1-ß-D-arabinofuranosylcytosine dosages correlated with cell death. Chromatid breakage can therefore be used as a sensitive means of assessing cell cytotoxicity.