Topoisomerase inhibitors are a class of drugs that interfere with the action of topoisomerases, enzymes that help manage DNA structure during replication and transcription. By disrupting the normal function of these enzymes, these inhibitors prevent DNA from unwinding and rejoining, which is essential for cell division. These inhibitors are commonly used in cancer treatment, as they can effectively target rapidly dividing cells. Examples include doxorubicin and etoposide, which are used to treat various types of cancer by inducing DNA damage, leading to cell death.