The intravenous antimicrobial tigecycline targets and destroys leukemia stem cells by cutting off the cell’s energy production, Canadian researchers discovered (Cancer Cell. 2011;20:674-688). The drug, which was approved in the United States in 1995, is indicated for the treatment of complicated skin and skin structure infections, complicated intra-abdominal infections, and community-acquired pneumonia.
In a search for FDA-approved agents that target leukemic cells, the Canadian researchers identified tigecycline as the most potent of only a handful of drugs to have any impact in a chemical screen on two human leukemic cell lines. (A total of 500 approved agents were tested.)
The activity of tigecycline against the cells revealed new information regarding the biology of leukemia. Tigecycline could block protein synthesis in the mitochondria, shutting down required energy production in leukemia cells. The antibacterial selectively killed leukemia stem and progenitor cells compared to their normal counterparts and also showed antileukemic activity in mouse models of human leukemia.
The beneficial effects of tigecycline were enhanced in acute myelogenous leukemia (AML) vs normal hematopoietic cells, leading the investigators to conclude that the drug is a potential therapeutic agent for AML therapy.