A Strategy for Identifying Novel Inhibitors of DNA Topoisomerase I

DNA topoisomerases alter DNA topology by transiently breaking either one (topoisomerase I) or both (topoisomerase II) strands of DNA (1). The essential role that these enzymes play in cellular processes such as DNA replication, transcription and recombination (2) suggests that they may constitute logical targets in the design of antineoplastic agents. In fact, several useful antitumor agents have now been shown to function, at least in part, via inhibition of DNA topoisomerase II (3,4).