Topoisomerase II function detected as protein-DNA complexes in two sublines of HL-60 cells.
Topoisomerase II forms a cleavable complex with DNA as an intermediate in the topoisomerization reaction. Denaturation produces covalent linkage between the enzyme and DNA, and produces double-stranded DNA breaks at the site of attachment. Thereby topoisomerase function can be detected by measuring the protein-DNA complexes. A whole cell filter binding assay exploiting this mechanism is described. m-AMSA-resistant HL-60 cells have higher protein-DNA complex formation than m-AMSA-sensitive HL-60 cells, suggesting different activities of topoisomerase II in drug-resistant vs. drug-sensitive cells.
Meyer
P
P
Medizinische Poliklinik, Universität Würzburg, Germany.
Boege
F
F
Gieseler
F
F
D000677:Amsacrine / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D004250:DNA Topoisomerases, Type II / Q000187:drug effects / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000187:drug effects; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004351:Drug Resistance; D005047:Etoposide / Q000494:pharmacology; D006801:Humans; D009580:Nitroblue Tetrazolium; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D000677:Amsacrine; D009580:Nitroblue Tetrazolium; D014212:Tretinoin; D005047:Etoposide; D004250:DNA Topoisomerases, Type II; D004121:Dimethyl Sulfoxide