Cytotoxic effects of cis-diamminedichloroplatinum-(II) (cis-DDP) are thought to be mediated by binding to DNA. Studies on binding of cis-DDP to cellular DNA rely heavily on the availability of specific antibodies. We therefore raised and characterized four rabbit antisera: one against cis-DDP-modified DNA (antiserum NKI-A59) and three others against the cis-DDP-modified (di)nucleotides cis-Pt(NH3)2d(pApG) (NKI-A68), cis-Pt(NH3)2d(GMP)2 (NKI-A10), and Pt(NH3)3dGMP (NKI-A39). Reactivities to platinum compounds were determined in an enzyme-linked immunosorbent assay (ELISA) and in a quantitative immunocytochemical assay. In the ELISA, NKI-A59 showed a high affinity for DNA heavily substituted with either cis-DDP or CBDCA [cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II)]; amounts of platinum per well giving 50% inhibition (IA50) were as low as 15 and 76 fmol, respectively. NKI-A59 also showed affinity to cis-DDP-modified poly[d(G-C)].poly[d(G-C)], poly(dC), and poly(dG). No affinity was found for trans-DDP [trans-diamminedichloro-platinum(II)]-modified DNA, enzymatically digested cis-DDP-DNA, or cis-DDP-DNA, or cis-DDP-modified poly(dA).poly(dT), oligo(dA)15.oligo(dT)15, oligo(dG)21, oligo(dG)42, or oligo(dAAAG)10. The efficiency of binding to cis-DDP-DNA decreased with decreasing DNA modification levels. Although other cis-DDP-DNA- and cis-DDP-(di)nucleotide-specific antisera have been identified, NKI-A59 is the first antiserum described that is suitable for the in situ detection of cis-DDP-DNA adducts at clinically relevant platinum levels. Adduct-specific immunostaining signals in cultured RIF-1 cells or rat liver paralleled platinum-DNA binding as measured by atomic absorption spectroscopy. The antisera NKI-A68, NKI-A10, and NKI-A39 showed high affinity for their corresponding haptens and varying affinity for non-hapten cis-DDP-DNA adducts. Their affinity for digested cis-DDP-modified DNA was up to 30 times that for intact cis-DDP-DNA. Neither NKI-A68 nor NKI-A10 resulted in specific immunocytochemical staining of cis-DDP-DNA adducts. We conclude that NKI-A68, NKI-A10, and NKI-A39 are suitable for platinum-DNA adduct analysis of digested DNA in ELISA and that NKI-A59 is suitable for platinum-DNA adduct detection at the single-cell level using immunocytochemical methods.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/BF00685507 | DOI Listing |
Chem Pharm Bull (Tokyo)
September 2001
Department of Analytical Chemistry of Medicines, Showa Pharmaceutical University, Machida, Tokyo, Japan.
We show that the topological significance of the gel mobility of cis-diamminedichloroplatinum(II) (DDP)-closed circular DNA (ccDNA) adducts decreases with reaction time, until a point at which it joins relaxed DNA, and that the mobility of the adducts increases again. There is no relationship between the relative length of the adducts and the gel mobility. Although the significance of the decrease of gel mobility is due to the unwinding of cis-DDP-DNA (or trans-DDP-DNA) adducts, the conformational significance of the subsequent increase in mobility is unclear.
View Article and Find Full Text PDFChem Pharm Bull (Tokyo)
June 1999
Department of Drug Analysis, Showa College of Pharmaceutical Sciences, Tokyo, Japan.
The reaction of cis-Pt(NH3)2Cl2(cis-DDP)-closed circular DNA adducts with DNA topoisomerse I(topo I) were studied by electron microscopy. We identified unique topoisomers such as a singly-linked catenane (2(1)2), trefoil (3(1), and dimetric catenane (2(1)2), etc., by analysis with electron micrographs.
View Article and Find Full Text PDFThe bioluminescence method of assessing SOS response in Escherichia coli cells was applied to test the genotoxicity of five complex platinum compounds: cis-diamminedichloroplatinum, cycloplatam, trans-diamminedichloroplatinum, and two trans-binuclear complexes. Strains AB1157 (pPLS-1) and JC9239 (pPLS-1), a variant of AB1157 carrying the recF143 mutation, were used in the test procedure. SOS response in JC9239 cells was shown to be induced by significantly lower concentrations of cis-DDP and cycloplatam than in AB1157 cells.
View Article and Find Full Text PDFJ Inorg Biochem
July 1996
Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Spain.
In the present paper, we show that the reaction of the antipyranosomatid berenil drug with K2PtCl4 resulted in the synthesis of a covalent (Pt(II)-berenil compound of formula [Pt2Cl4(berenil)2]Cl4.4H2O as shown by IR, 1H, 13C, and 195Pt-NMR. The Pt-berenil compound was tested for in vitro antitumor activity against HL-60 and U-937 human leukemic cells.
View Article and Find Full Text PDFBiochemistry
January 1993
Department of Biochemistry, School of Medicine and Dentistry, University of Rochester, New York 14642.
DNA polymerase (pol) epsilon is essential for DNA replication and is thought to be a component of DNA repair systems in eukaryotic cells. The activities of pol epsilon have been examined using a series of synthetic oligonucleotides designed with cis-diamminedichloroplatinum(II) (cis-DDP)-modified specific guanine residues. Pol epsilon was incapable of synthesis over cis-DDP-modified single guanine or adjacent guanine residues present in the template strand.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!