[Inhibitors of DNA topoisomerases].

DNA topoisomerases are enzymes regulating the conformational state of DNA in every aspect of genetic processes by catalyzing transient cleavage and religation of DNA strands. The enzymes are targets of some of the important anticancer drugs. Many candidates of anticancer drugs are being screened via inhibition of the enzymes. In the present review, I discuss the role of DNA topoisomerases in genetic processes in mammalian cells, characteristics and mode of action of topoisomerase inhibitors, and resistance of tumor cells to the anticancer drugs.