In vitro DNA crosslinking by Ledakrin, an antitumor derivative of 1-nitro-9-aminoacridine

• Published in: Chemico-Biological Interactions 1997-02, Vol.103 (2), p.141-151
• Main Authors: Bartoszek, Agnieszka, Dackiewicz, Paweł, Składanowski, Andrzej, Konopa, Jerzy
• Format: Article
• Language: English
• Subjects: 1-nitroacridines; 32P-post-labelling assay; Animals; Antineoplastic Agents - metabolism; Antineoplastic Agents - pharmacology; Cattle; Cross-Linking Reagents - metabolism; Cross-Linking Reagents - pharmacology; Dithiothreitol - pharmacology; DNA - drug effects; DNA - metabolism; DNA adducts; DNA Adducts - biosynthesis; DNA crosslinking; DNA, Single-Stranded - drug effects; DNA, Single-Stranded - metabolism; Intercalating Agents - metabolism; Intercalating Agents - pharmacology; Ledakrin; Nitracrine - metabolism; Nitracrine - pharmacology; Poly C - metabolism; Poly G - metabolism; Sulfhydryl Reagents - metabolism
• ISSN: 0009-2797; 1872-7786
• DOI: 10.1016/S0009-2797(96)03754-4

Using agarose gel electrophoresis we confirmed that Ledakrin is capable of incurring covalent crosslinking in pBR322 plasmid DNA and also in poly(dGdC) in the presence of a simple activating system containing DTT. The identification of adducts resulting from DNA crosslinking was carried out by 32P-post-labelling assay. We assumed that such adduct(s) should be brought about more readily with double-stranded than with single-stranded polynucleotides or nucleotides. Since our earlier experiments had shown that guanine is a major site of covalent binding of 1-nitroacridines, we compared DNA adduct formation by Ledakrin for ctDNA, dG-containing synthetic homopolymers and 3′-pdG. 32P-Post-labelling assay revealed two adduct spots that were enhanced in samples containing double-stranded substrates in which interstrand crosslinking between guanines was possible, namely ctDNA and poly(dGdC).