Kinetics of formation and disappearance of a DNA cross-linking effect in mouse leukemia L1210 cells treated with cis- and trans-diamminedichloroplatinum(II).

cis- and trans-diamminedichloroplatinum(II) (PDD) produced a DNA cross-linking effect in mouse leukemia L1210 cells, which was demonstrable after subtoxic treatments with the DNA alkaline elution technique. Cross-linking effects developed following treatments with concentrations as low as 1 micron for cis-PDD and 5 micron for trans-PDD, which permitted over 80% survival of colony-forming ability. The maximum cross-linking effect by cis-PDD required about 12 hr of posttreatment incubation before it was fully developed, whereas the cross-linking effect of trans-PDD was fully developed at the end of the 1-hr drug exposure. The cross-linking effects of both agents were reversed upon further incubation of the cells.