Drug features that contribute to the activity of quinolones against mammalian topoisomerase II and cultured cells: correlation between enhancement of enzyme-mediated DNA cleavage in vitro and cytotoxic potential

Elsea, Sarah H.; McGuirk, Paul R.; Gootz, Thomas D.; Moynihan, Melinda S.; Osheroff, Neil

doi:10.1128/aac.37.10.2179

Cited by 66 publications

(72 citation statements)

References 36 publications

(45 reference statements)

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“…Quinolones, such as CP-115,953, are the only drugs that show high activity against eukaryotic and prokaryotic type II enzymes [101,[122][123][124][125]. While this last drug class has not yet been exploited to treat cancer, quinolones such as ciprofloxacin and levofloxacin that target bacterial type II topoisomerases are the most active and broad-spectrum oral antibacterials in clinical use [124,126,127].…”

Section: Non-covalent Topoisomerase II Poisonsmentioning

confidence: 99%

DNA topoisomerase II, genotoxicity, and cancer

McClendon

Osheroff

2007

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

359

466

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Type II topoisomerases are ubiquitous enzymes that play essential roles in a number of fundamental DNA processes. They regulate DNA under-and overwinding, and resolve knots and tangles in the genetic material by passing an intact double helix through a transient double-stranded break that they generate in a separate segment of DNA. Because type II topoisomerases generate DNA strand breaks as a requisite intermediate in their catalytic cycle, they have the potential to fragment the genome every time they function. Thus, while these enzymes are essential to the survival of proliferating cells, they also have significant genotoxic effects. This latter aspect of type II topoisomerase has been exploited for the development of several classes of anticancer drugs that are widely employed for the clinical treatment of human malignancies. However, considerable evidence indicates that these enzymes also trigger specific leukemic chromosomal translocations. In light of the impact, both positive and negative, of type II topoisomerases on human cells, it is important to understand how these enzymes function and how their actions can destablize the genome. This article discusses both aspects of human type II topoisomerases.

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Section: Non-covalent Topoisomerase II Poisonsmentioning

confidence: 99%

DNA topoisomerase II, genotoxicity, and cancer

McClendon

Osheroff

2007

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

359

466

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“…Furthermore, in both cases, the 4′-OH groups are essential for drug action (91,92). Thus, this group may play equivalent roles across a spectrum of topoisomerase II poisons.…”

Section: Role Of the 5-oh And 4′-oh Groups In Mediating Isoflavonementioning

confidence: 99%

Bioflavonoids as Poisons of Human Topoisomerase IIα and IIβ

2007

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Bioflavonoids are human dietary components that have been linked to the prevention of cancer in adults and the generation of specific types of leukemia in infants. While these compounds have a broad range of cellular activities, many of their genotoxic effects have been attributed to their actions as topoisomerase II poisons. However, the activities of bioflavonoids against the individual isoforms of human topoisomerase II have not been analyzed. Therefore, we characterized the activity and mechanism of action of three major classes of bioflavonoids, flavones, flavonols, and isoflavones, against human topoisomerase IIR and II . Genistein was the most active bioflavonoid tested and stimulated enzymemediated DNA cleavage ∼10-fold. Generally, compounds were more active against topoisomerase II . DNA cleavage with both enzyme isoforms required a 5-OH and a 4′-OH and was enhanced by the presence of additional hydroxyl groups on the pendant ring. Competition DNA cleavage and topoisomerase II binding studies indicate that the 5-OH group plays an important role in mediating genistein binding, while the 4′-OH moiety contributes primarily to bioflavonoid function. Bioflavonoids do not require redox cycling for activity and function primarily by inhibiting enzyme-mediated DNA ligation. Mutagenesis studies suggest that the TOPRIM region of topoisomerase II plays a role in genistein binding. Finally, flavones, flavonols, and isoflavones with activity against purified topoisomerase IIR and II enhanced DNA cleavage by both isoforms in human CEM leukemia cells. These data support the hypothesis that bioflavonoids function as topoisomerase II poisons in humans and provide a framework for further analysis of these important dietary components.

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“…Recently, it has been shown that 6,8-difluoro-7-(4Ј-hydroxyphenyl)-1-cyclopropyl-4-quinolone-3-carboxylic acid (CP-115, 953), a fluoroquinolone closely related to ciprofloxacin, is highly toxic to mammalian cells in culture (11,12). Studies in yeast demonstrated that top2 is the primary physiological target for this quinolone (13).…”

Section: A Sermentioning

confidence: 99%

Mutation of a Conserved Serine Residue in a Quinolone-resistant Type II Topoisomerase Alters the Enzyme-DNA and Drug Interactions

Strumberg

Nitiss²,

Rose³

et al. 1999

Journal of Biological Chemistry

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A Ser740 3 Trp mutation in yeast topoisomerase II (top2) and of the equivalent Ser 83 in gyrase results in resistance to quinolones and confers hypersensitivity to etoposide (VP-16). We characterized the cleavage complexes induced by the top2 S740W in the human c-myc gene. In addition to resistance to the fluoroquinolone CP-115,953, top2 S740W induced novel DNA cleavage sites in the presence of VP-16, azatoxin, amsacrine, and mitoxantrone. Analysis of the VP-16 sites indicated that the changes in the cleavage pattern were reflected by alterations in base preference. C at position ؊2 and G at position ؉6 were observed for the top2 S740W in addition to the previously reported C؊1 and G؉5 for the wildtype top2. The VP-16-induced top2 S740W cleavage complexes were also more stable. The most stable sites had strong preference for C؊1, whereas the most reversible sites showed no base preference at positions ؊1 or ؊2. Different patterns of DNA cleavage were also observed in the absence of drug and in the presence of calcium. These results indicate that the Ser 740 3 Trp mutation alters the DNA recognition of top2, enhances its DNA binding, and markedly affects its interactions with inhibitors. Thus, residue 740 of top2 appears critical for both DNA and drug interactions.DNA topoisomerases are enzymes that catalyze changes in the topology of DNA via a mechanism involving the transient breakage and rejoining of phosphodiester bonds in the DNA backbone (1). Studies in both prokaryotic and eukaryotic cells have demonstrated the importance of topoisomerases in transcription, DNA replication, and chromosome segregation. The type II topoisomerases, which make transient double-strand breaks and change the linking number of DNA in steps of two, play key roles in chromosome structure. In eukaryotic cells, these enzymes are essential for chromosome condensation/decondensation and decatenation of chromosome loops during mitosis (2, 3).Topoisomerase II (top2) 1 has also been identified as a major target of chemotherapeutic agents that are specifically active against prokaryotic (4) or cancer cells (5-8). Fluoroquinolones are antibacterial agents that target DNA gyrase (the prokaryotic type II topoisomerase) (9), whereas a variety of DNAintercalating agents such as anthracyclines, amsacrine, and mitoxantrone and nonintercalating agents such as the epipodophyllotoxin etoposide (VP-16) are active against eukaryotic top2 and are clinically important anti-cancer agents (5-8).Azatoxin is also a nonintercalative top2 poison (10).Recently, it has been shown that 6,8-difluoro-7-(4Ј-hydroxyphenyl)-1-cyclopropyl-4-quinolone-3-carboxylic acid (CP-115, 953), a fluoroquinolone closely related to ciprofloxacin, is highly toxic to mammalian cells in culture (11,12). Studies in yeast demonstrated that top2 is the primary physiological target for this quinolone (13). Unlike etoposide, which stabilizes top2-mediated DNA cleavage primarily by inhibiting the religation reaction of top2, CP-115,953 stabilizes DNA cleavage by enhancing the forward rate o...

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Drug features that contribute to the activity of quinolones against mammalian topoisomerase II and cultured cells: correlation between enhancement of enzyme-mediated DNA cleavage in vitro and cytotoxic potential

Cited by 66 publications

References 36 publications

DNA topoisomerase II, genotoxicity, and cancer

DNA topoisomerase II, genotoxicity, and cancer

Bioflavonoids as Poisons of Human Topoisomerase IIα and IIβ

Mutation of a Conserved Serine Residue in a Quinolone-resistant Type II Topoisomerase Alters the Enzyme-DNA and Drug Interactions

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