The in vitro more efficiently repaired cisplatin adduct cis-Pt.GG is in vivo a more mutagenic lesion than the relative slowly repaired cis-Pt.GCG adduct.
The toxic effect and the mutagenicity of two differentially repaired site-specific cis-diamminedichloroplatinum(II) (cis-DDP) lesions were investigated. Detailed analysis of the UvrABC-dependent repair of the two lesions in vitro showed a more efficient repair of the cis-Pt.GG adduct compared to that of the cis-Pt.GCG adduct (Visse et al., 1994). Furthermore, previously, a dependency of cis-DDP mutagenesis on UvrA and UvrB, but not on UvrC was found (Brouwer et al., 1988). To possibly relate survival and mutagenesis to repair, plasmids containing the same site-specific cis-DDP lesions as those that were used in the detailed repair studies were transformed into Escherichia coli. The results indicate that both lesions are very efficiently bypassed in vivo. Mutation analysis was performed using a denaturing gradient gel electrophoresis technique, which allows identification of mutations without previous selection. Although the cis-Pt.GG adduct is in vitro more efficiently repaired than the cis-Pt.GCG adduct, it appeared to be more mutagenic. We present a model in which this result is related to the previously observed dependency of the mutagenicity of cis-DDP lesions on the Uvr A and B proteins.
Laboratory of Molecular Genetics, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Netherlands.
J A
JA
Brandsma
M
M
de Ruijter
R
R
Visse
D
D
van Meerten
M
M
van der Kaaden
J G
JG
Moggs
P
P
van de Putte
D000970:Antineoplastic Agents / Q000494:pharmacology*; D001483:Base Sequence; D002945:Cisplatin / Q000494:pharmacology*; D003596:Cytosine / Q000378:metabolism; D018736:DNA Adducts / Q000494:pharmacology*; D004252:DNA Mutational Analysis / Q000379:methods; D017931:DNA Primers; D004260:DNA Repair; D004269:DNA, Bacterial / Q000032:analysis / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D006147:Guanine / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009153:Mutagens / Q000494:pharmacology*; D009691:Nucleic Acid Denaturation; D009692:Nucleic Acid Heteroduplexes / Q000032:analysis; D010957:Plasmids; D017354:Point Mutation
D000970:Antineoplastic Agents; D018736:DNA Adducts; D017931:DNA Primers; D004269:DNA, Bacterial; D009153:Mutagens; D009692:Nucleic Acid Heteroduplexes; C057270:cisplatin-DNA adduct; D006147:Guanine; D003596:Cytosine; D002945:Cisplatin