Open up and say 'aah'

A miracle treatment for cancer discovered in the mouth of the North American shrew

David Hosking/CORBIS

A miracle treatment for cancer may have been discovered in a very bizarre place—the mouth of the North American shrew. With its saliva, “we were able to reduce the growth of ovarian, breast and prostate cancer tumours at least as well as standard chemo,” says Dr. Jack Stewart, who discovered the cancer-fighting properties of the furry mammal’s paralytic venom—which it uses to stun prey—when he was working as a biochemist at Mount Allison University. Now he’s the scientific adviser for Soricimed Biopharma, a small New Brunswick pharmaceutical company he founded to get the drug onto the market.

The venom contains soricidin, a peptide, that bonds to a calcium channel that’s activated in the human body when cells turn cancerous. It then clogs up the channel, causing the diseased cells to self-destruct. The peptide only targets one chemical, produced by very few cells in the body, so it has almost no side effects, and is also very effective at locating tumours and detecting cancer early. “We attached a fluorescent tag to our drug and injected it into mice. Within two hours the tumours were lighting up.”

The drug still has a long way to go before it reaches pharmacies. Stewart says it should go into phase one of human trials within a year, and hopes a larger pharmaceutical company will front the hundreds of millions of dollars needed to get it through two more phases and onto the market. Dr. Rodney Ouellette, president of the Atlantic Cancer Research Institute, which helped Stewart in the early testing of soricidin, says only two to three per cent of drugs make it to human testing, but the ones that do usually wind up in pharmacies. “We have to remain cautiously optimistic,” he says. “But I’m excited.”

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