Radioactive scorpion venom could be used to fight brain cancer

Scientists have discovered that a non-toxic extract from the venom seeks out and locks onto malignant cells after it is injected into the body.

advertisement
By irradiating it before it goes in the body it can be used to target the cancer cells with killer radiation but at the same time leave the healthy cells unharmed.

The scorpion Leiurus quinquestriatus lives in the Middle East and among the powerful cocktail of neurotoxins packed into its venom is a peptide that is non-toxic to humans but binds to tumour cells.

In laboratory experiments, the peptide has invaded tumours in breast, skin, brain and lung tissue, but left healthy cells untouched.

"It's as if the tumours collect it," Michael Egan of the company TransMolecular in Cambridge, Massachusetts, told the New Scientist.

To see if the peptide could deliver lethal doses of radioactivity to cancer cells, researchers at the company have attached radioactive iodine isotopes to it.

In a trial last year, they injected this agent directly into the tumours of 59 people suffering from inoperable brain cancer.

All the patients have now died, but those receiving a higher dose lived for three months longer, on average.

In recent weeks, researchers at the University of Chicago in Illinois have begun injecting the substance into the bloodstream of people with different types of malignant brain cancer.

This latest trial will allow the company to test whether it can seek out and kill secondary tumours throughout the body, as well as known primary ones.