Effects of the enediyne C-1027 on intracellular DNA targets.
We examined DNA damage induced by the enediyne-containing antitumor antibiotic C-1027 in intracellular nuclear and mitochondrial DNA targets using the episome-containing cell line 935.1. Strand-scission activity of the C-1027 holoantibiotic was measured by the topological forms conversion assay in episomal and mitochondrial DNA, as well as in cell-free plasmid DNA. Genomic DNA damage was quantitated by filter elution analysis. Comparisons were made to the well-characterized enediyne neocarzinostatin. From these studies, mixed single- and double-strand breaks were observed not only in cell-free, plasmid DNA but also in intracellular episomal, mitochondrial, and genomic DNA at low nanomolar concentrations. C-1027 cleaved DNA 285-fold more efficiently in cells than in a cell-free environment, and displayed preference for intracellular DNA species in the following rank order: episome > mitochondrial DNA >> genomic. NCS also damaged the non-histone-associated mitochondrial DNA, but not the episome. Cleavage of the 935.1 cell episome by C-1027 occurred at specific sites including the BPV origin of replication and E6/E7 open reading frame regions, as well as the MMTV LTR promoter region.
Cobuzzi
R J
RJ
Department of Experimental Therapeutics, Grace Cancer Drug Center, Roswell Park Cancer Institute, Buffalo, New York 14263.
Kotsopoulos
S K
SK
Otani
T
T
Beerman
T A
TA
D000617:Aminoglycosides; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D001483:Base Sequence; D002460:Cell Line; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D004272:DNA, Mitochondrial / Q000187:drug effects; D053281:Enediynes; D016678:Genome; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010455:Peptides; D010957:Plasmids / Q000187:drug effects
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D000903:Antibiotics, Antineoplastic; D004272:DNA, Mitochondrial; D053281:Enediynes; D010455:Peptides; C058024:C 1027; D004247:DNA