The effect of cis-platinum on the repair of radiation damage in plateau phase Chinese hamster (V-79) cells

The interaction of cis-dichlorodiammine platinum (II) (cis-DDP) with irradiation may be important in the clinical settings for which this drug is currently used. We have approached this problem by observing the effect of cis-DDP on repair of sublethal radiation damage (SLD) and potentially lethal radiation damage (PLD).Fed plateau phase Chinese hamster (V-79) cells were pretreated with cis-DDP for 2 hours prior to irradiation and for varying intervals after irradiation in single dose and two dose repair experiments. For drug concentrations of 5 μM and 10 μM (minimally toxic doses), inhibition of repair was observed in a split dose experiment. Repair of PLD was inhibited only minimally in the presence of cis-platinum in single dose experiments. This selective drug radiation interaction suggests that simultaneous combinations of platinum with radiation may result in altered biological effects of radiation.