There’s a small but growing body of research — much of it conducted in India and Brazil where stinging critters abound — suggesting that bee, scorpion, and snake venoms can kill cancer cells. The findings had been consigned to the dusty shelf of fascinating but more or less useless science because the toxins also damage healthy tissue and because most critters make too little of their poisons to supply pharmaceutical companies.
But a new study led by Dipanjan Pan, a chemist educated in India who is now a bioengineer at the University of Illinois at Urbana-Champaign, gives those findings new relevance. Pan and his colleagues made venom in the lab and delivered it directly into cancer cells using nanoparticles. The synthesized bee venom delivered this way was effective against various types of cancer in the lab, including melanoma skin cancer and estrogen-negative breast cancers.
The method killed as many as half of the cancerous cells in lab experiments, according to findings published in the Royal Society of Chemistry and presented this week at the annual meeting of the American Chemical Society in San Francisco.
High Tech Poison Dart Takes Aim at Cancer
The approach resembles a 21st-century poison dart fired right at a tumor.
The researchers simulated bee venom’s active ingredient, melittin, which kills cells by allowing too much water in and causing them to explode. Then they made a very high-tech, and very, very small dart.
Nanoparticles, named for their tiny size, can sneak medicine past the immune system’s watchdogs the same way a flea can sneak by a dog waiting to pounce on a cat. The immune system does recognize the larger molecules of the venom when it’s not hidden in the nanoparticle “dart.” The surface of the dart can be designed to target characteristics specific to cancer cells.
Nanoparticles make a great delivery system that could potentially work for other anti-cancer drugs as well.
“If we think about conventional therapeutics, the problem is that those [drugs] are not specific — they hit the cancer cells and the healthy cells. That’s why we want to package everything as part of the nanoparticle,” Pan said in a press conference on Tuesday.
But many drugs used today aren’t effective in the tiny volumes that a nano-dart can accommodate. Venom is.
The researchers have already started testing bee and scorpion venom delivered by nano-darts in mice with cancer, and the early findings are promising.
Lingering Questions About Nanotech
But there’s a lot still to learn about nanotechnology. Perhaps most importantly, it has yet to be definitively proven safe for use in animals.
Because their size is so different from those of natural materials, scientists don't know how the body will flush out the nanoparticles once they’ve delivered their poison payload.
“We need to do a lot more studies to understand how they metabolize in the body," Pan said. "We just don’t know at this point."