Irradiation combined with bleomycin treatment of synchronized cells in culture under oxic and hypoxic conditions.

Bleomycin-treated cells are sensitized to radiation delivered under oxic conditions both in the early S and G2 phases of the cycle, irradiated under hypoxic conditions, sensitization occurs only in the early S phase. This difference in the sensitizing effect of the drug is discussed in regard to the possible clinical advantages of a combined treatment ot tumors with irradiation and Bleomycin.