snake or scorpion venom could form the basis of a new generation of
cancer-fighting drugs, scientists find. They have developed a method for
targeting venom proteins specifically to malignant cells while sparing healthy
ones, which reduces or eliminates side effects that the toxins would otherwise cause.
Dipanjan Pan from the University of Illinois, who led the study, said that they had successfully used venom toxins in tiny nanometer-sized particles to cure breast cancer and melanoma cells in the laboratory.
"These particles, which are camouflaged from the immune system, take the toxin directly to the cancer cells, sparing normal tissue," Pan said.
The research team says that some of substances found in any of these venoms could be effective anti-tumor agents. However, just injecting venoms into a patient would have side effects. These effects include heart muscle or nerve cells, unwanted clotting or, alternately, bleeding under the skin.
The team set out to solve this problem. In the honeybee study, the team discovered a substance in the venom called melittin that keeps the cancer cells from multiplying.
Bees make so little venom that it's not possible to extract and separate out the substance time after time for lab testing or for later clinical use. That's why they synthesized melittin in the lab.
They carried out computational studies to figure out how melittin would work inside a nanoparticle. They did the test and injected their synthetic toxin into nanoparticles. They explain, "The peptide toxins we made are so tightly packed within the nanoparticle that they don't leach out when exposed to the bloodstream and cause side effects."
What they do is go directly to the tumor, where they bind to cancer stem cells, blocking their growth and spread. According to the team, the next step is to examine the new treatment approach in rats and pigs. Eventually, they hope to begin a study involving patients. He estimates that this should be in the next three to five years.