Biophysical studies of the modification of DNA by antitumour platinum coordination complexes.
Cisplatin (cis-diamminedichloroplatinum(II] is widely used in the treatment of various human tumours. A large body of experimental evidence indicates that the reaction of cisplatin with DNA is responsible for the cytostatic action of this drug. Several platinum-DNA adducts have been identified and their effect on the conformation of DNA has been investigated. Structural studies of platinum-DNA adducts now permit a reasonably good explanation of the biophysical properties of platinated DNA. Antitumouractive platinum compounds induce in DNA, at low levels of binding, local conformational alterations which have the character of non-denaturing distortions. It is likely that these changes occur in DNA due to the formation of intrastrand cross-links between two adjacent purine residues. On the other hand, the modification of DNA by antitumour-inactive complexes results in the formation of more severe local denaturation changes. Conformational alterations induced in DNA by antitumour-active platinum compounds may be reparable with greater difficulty than those induced by the inactive complexes. Alternatively, non-denaturation change induced in DNA by antitumour platinum drugs could represent more significant steric hindrance against DNA replication as compared with inactive complexes.
Brabec
V
V
Institute of Biophysics, Czechoslovak Academy of Sciences, Brno.
Kleinwächter
V
V
Butour
J L
JL
Johnson
N P
NP
D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D006801:Humans; D009944:Organoplatinum Compounds / Q000378:metabolism / Q000494:pharmacology*
D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; D004247:DNA