Nature Reports GM Bacterium Could Help Fight Cancer

Published June 1, 2004

A genetically modified bacterium may offer substantial hope in the battle against cancer, according to a study published in Gene Therapy and reported April 22 in Nature magazine (

Researchers at London’s Hammersmith Hospital genetically modified Escherichia coli (E. coli), a bacterium that often causes food poisoning in humans. After modifying the bacterium, the researchers injected it into mouse tumors and reported startling results. The modified bacterium primed the tumor to accept anti-cancer drugs in a very targeted way, killing the tumor but leaving healthy surrounding cells unaffected.

According to Nature, “The treatment killed cancer cells in the area where the drug had been activated and left surrounding tissue unharmed. Three weeks later the tumours had shrunk by up to two-thirds and most of the remaining cells were dead.”

Added Nature, “Such a targeted effect is an improvement on standard chemotherapy treatments, which can damage healthy as well as cancerous tissue.”

The bacterium appeared most promising in isolating cancer in its early stages and preventing its spread to other parts of the body. The bacterium also could be used to reduce cancerous growths before surgery to remove them, and to prevent cancer recurrences.

Prior to the study, researchers added two foreign genes to the E. coli bacterium. One of the genes, called “inv,” spurs the E. coli bacterium to make a protein that penetrates human cell walls. The other gene, called “hly,” assists E. coli in releasing an enzyme that fights the targeted tumor.

“Genetically engineered bacteria could help fight cancer,” summarized Nature author Helen Pilcher.

James M. Taylor is managing editor of Environment & Climate News. His email address is [email protected].