Effect of the antitumor drug cis-diamminedichloroplatinum(II) and related platinum complexes on eukaryotic DNA replication

Journal Article · Tue Sep 11 04:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00488a037· OSTI ID:5868173

Heiger-Bernays, W J; Essigmann, J M; Lippard, S J ^[1]

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1. Massachusetts Institue of Technology, Cambridge (USA)

An SV40-based in vitro replication system has been used to examine the effects of platinum compounds on eukaryotic DNA replication. Plasmid templates containing the SV40 origin of replication were modified with the anticancer drug cis-diamminedichloroplatinum(II) (cis-DDP, cisplatin) or the inactive analogues (Pt(dien)Cl){sup +} and trans-DDP. The platinated plasmids were used as templates for DNA synthesis by the DNA polymerases present in cytosolic extracts prepared from human cell lines HeLa and 293. Bifunctional adducts formed by cis- and trans-DDP inhibited DNA replication by 95% at a bound drug to nucleotide ratio ((D/N){sub b}) of <9 x 10{sup {minus}4}, in contrast to the monofunctional (Pt(dien)Cl){sup +} analogues, which required a (D/N){sub b} of 3.4 x 10{sup {minus}3} for 62% inhibition of DNA replication. An average of two platinum adducts per genome was sufficient for inhibition of DNA replication by cisplatin. When trans-DDP-modified, but not cis-DDP-modified, SV40 origin containing plasmids were allowed to incubate in the 293 cytosolic extracts for 1 h prior to addition of T-antigen to initiate replication, DNA synthesis was restored to 30% of control. This result suggested the presence of an activity in the extracts that reactivates trans-DDP-modified DNA templates for replication. This hypothesis was confirmed by an in vitro nucleotide excision repair assay that revealed activity in 293 and HeLa cell extracts selective for trans-DDP-modified plasmid DNAs. Such selective repair of tans-DDP-damaged DNA in human cells would contribute to its lack of antitumor activity.

• OSTI ID: 5868173
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:36; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism &amp; Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADDUCTS
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
DNA ADDUCTS
DNA REPAIR
DNA REPLICATION
HELA CELLS
MOLECULAR BIOLOGY
NUCLEIC ACID REPLICATION
PLASMIDS
PLATINUM COMPOUNDS
RECOVERY
REPAIR
TRANSITION ELEMENT COMPOUNDS