Cytotoxic and cytokinetic effects of 1-beta-D-arabinofuranosylcytosine, daunorubicin, and 6-thioguanine on HeLa cells in culture.
Exponentially growing HeLa cells were exposed to 1-beta-D-arabinofuranosylcytosine, daunorubicin, and 6-thioguanine singly and in combination for 21 hr. Survivals were determined by a colony-counting assay, and cytokinetic effects of the drugs were evaluated by flow cytometry. When used in two-drug combinations (concurrent exposures). 1-beta-D-arabinofuranosylcytosine was found to protect cells against both 6-thioguanine- and daunorubicin-induced lethality, the former to a greater extent than the latter. Protection against 6-thioguanine appeared to be related to the degree of inhibition of DNA synthesis by 1-beta-D-arabinofuranosylcytosine, but this was not the case with daunorubicin. When cells were exposed to the three drugs simultaneously, survivals were in agreement with those predicted from the various two-drug combinations. This implies that no additional drug interactions occurred when a third drug was added to the two-drug combinations.
D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003561:Cytarabine / Q000633:toxicity*; D003630:Daunorubicin / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D006367:HeLa Cells / Q000187:drug effects*; D006801:Humans; D013866:Thioguanine / Q000633:toxicity*
D003561:Cytarabine; D013866:Thioguanine; D003630:Daunorubicin