National Toxicology Program

National Toxicology Program

Nomination Summary for Topoisomerase II inhibitors (N95003)

Topoisomerase II inhibitors

Specific Substances: No Specific Substances or Agents are Selected for this Nomination

Nomination Date: 11/22/1994

Nominator: Private Individual

Rationale: When Topoisomerase II (TOPO II) enzymes were initially recognized as targets for chemicals it appeared that these were isolated examples restricted to anticancer drugs. However, it is increasingly becoming recognized that other types of chemicals have TOPO II targets -- including drugs used to treat urinary infections, environmental agents & food components, as well as some pesticides that may have TOPO II effects. Recent data make it clear that they are potent carcinogens causing cancers with characteristic cytogenetic modifications and short latent periods. Extensive study needed.

NTP Principles: not specified

Status: In Review/Pending

NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.