WASHINGTON: Researchers have modified a toxin found in the deadly anthrax bacteria and used it to fight cancerous tumours in mice, according to a study published on Monday.

The modified anthrax toxin seeks out a particular type of human cancer cell, marked by a high level of the urokinase enzyme.

In trials on mice with the equivalent of a human cancer, the modified toxin destroyed several types of cancer cells without any apparent effects on healthy cells, according to the study published in the Proceedings of the National Academy of Sciences in the United States.

After one treatment, the mice’s tumours shrank 65 to 92 percent. A second treatment eliminated 88 percent of fibrosarcoma tumours and 17 percent of melanoma tumours.

The cancerous cells began to die 12 hours after the first treatment, US National Institute of Health researcher Stephen Leppla found.

The toxin did not damage cells near the tumours, prompting the researchers to conclude that the modified toxin was very selective in choosing its targets and could have fewer side-effects than some current cancer treatments.

Additional research is needed to determine whether the modified anthrax toxin will effectively fight cancer in humans.—AFP