title: Effects of acronycine, bleomycin and cytosine arabinoside on the cell cycle. Some aspects of their interaction with radiation determined by pulse cytophotometry.
abstract: The influence of three chemotherapeutic agents, acronycine, bleomycin and cytosine arabinoside, alone and combined with radiation, on cell cycle progression and viability of L-cells was examined. The percentages of cells in G1, S and (G2 + M)-phases as derived from pulse cytophotometric DNA distribution patterns were recorded as a function of exposure time. After 24-h treatment with 10 microgram/ml acronycine, 46.4% of cells were accumulated in (G2 + M)-phase compared to 12.1% in the controls. This accumulation was significantly enhanced by an irradiation with 150 rads of X-rays resulting in arresting 63.1% of cells in this phase. Similar findings were obtained after a 24-h treatment with 100 microgram/ml bleomycin. 54.4% of cells were arrested in (G2 + M)-phase by the chemical treatment alone, while the combined treatment, bleomycin and radiation, yielded an accumulation of 66.3% of cells in G2 + M. A 24-h exposure to 0.2 microgram/ml cytosine arabinoside (Ara-C) produced a reversible block of 72.8% of cells in S phase compared to 27.4% in the control cultures. This S block was less pronounced after the combined treatment (51.1%). Some implications of the results for combined therapy are discussed.
mesh_terms: D000175:Acronine / Q000494:pharmacology*; D000470:Alkaloids / Q000494:pharmacology*; D001761:Bleomycin / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects* / Q000528:radiation effects; D003561:Cytarabine / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D007739:L Cells / Q000187:drug effects; D011675:Pulse Radiolysis / Q000379:methods; D013997:Time Factors
chemical_list: D000470:Alkaloids; D003561:Cytarabine; D001761:Bleomycin; D000175:Acronine