KINETICS OF FORMATION AND DISAPPEARANCE OF A DNA CROSS-LINKING EFFECT IN MOUSE LEUKEMIA-L1210 CELLS TREATED WITH CIS-DIAMMINEDICHLOROPLATINUM .2. AND TRANS-DIAMMINEDICHLOROPLATINUM(II)

Abstract

Cis- and trans-Diamminedichloroplatinum(II) (PDD) produced DNA cross-linking 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 .mu.M for cis-PPD and 5 .mu.M for trans-PDD, which permitted over 80% survival of colony-forming ability. The maximum cross-linking effect by cis-PDD required about 12 h 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-h drug exposure. The cross-linking effects of both agents were reversed on further incubation of the cells.