Scorpion Venom May Help Treat Brain Cancer

Aug. 11, 2008— -- The sting of the Giant Yellow Israeli Scorpion packs a painful punch. Its venom contains a potent cocktail of neurotoxins that places an animal or human victim in excruciating agony.

It's not the first place most would think to look for a weapon against cancer. But doctors and researchers report that a particular component within this dangerous mix may be able to seek out brain tumor cells. And one researcher, as reported by ABC affiliate KOMO-TV in Seattle, hope that doctors will one day be able to use this property to "paint" tumors for a surgeons to see.

"Right now it is difficult for a surgeon to be able to distinguish a brain tumor from the normal brain tissue around it," says Dr. James Olson of the Fred Hutchinson Cancer Research Center. He says that this situation often presents today's brain surgeon with an unenviable decision: choose either to cut aggressively, potentially damaging healthy brain tissue, or cut conservatively and run the risk of leaving tumor cells behind.

Enter T-601, the synthetic version of a chemical first found in the scorpion's sting. Neurobiologist Harold Sontheimer of the University of Alabama at Birmingham, who was the first to explore the medical potential of this chemical, found that it was able to pass into the brain unobstructed. That's a feat for most chemicals, as the membrane that separates the brain from the bloodstream (known as the blood-brain barrier) is notoriously impermeable.

For the scorpion, this property if its venom ensures a quick kill of its unfortunate prey. But subtract the poisonous components from the venom, and you have a perfect vehicle for penetrating the brain.

What's more, researchers have found that this chemical seeks out and binds to brain tumor cells.

Olson says these properties make T-601 a perfect candidate for helping doctors distinguish the borders of brain tumors.

"The scorpion has had millions of years to optimize this chemical that crosses into the brain to damage its prey," he says. "It would have cost drug companies hundreds of millions of dollars to develop something like this."

It's not the first time researchers have eyed this compound as a potential cancer fighter. In 2006, Dr. Adam Mamelak, a neurosurgeon at Cedars-Sinai Medical Center in Los Angeles, sought to exploit these properties by using the chemical to carry tiny bits of radioactive material into the brains of patients who had gone through surgery to have brain tumors called gliomas removed.

The idea was that the chemical would seek out the remaining bits of brain cancer, latch onto them, and destroy them. Preliminary trials in humans showed some success.

And Mamelak says Olson's approach may hold promise where other tagging techniques have failed. "This method has been tried with antibodies for man years with less success due to the large size of antibodies," he notes.

But he adds that there could still be a long way to go before such approaches become a fixture in the clinical setting.

"Unfortunately, while this technology is 'sexy' and visually appealing, it is unlikely to have much impact on cancer treatment in the near future," Mamelak says.

Still, other experts in the area of brain research say Olsen's technique represents an exciting step toward better brain tumor removal.