U. WASHINGTON (US)—It’s an odd but potent brew. Researchers have found that by adding nanoparticles to a curative compound found in scorpion venom they can create a mixture that could dramatically stop cancer cells from spreading.
Lab tests of the combined therapy show a 98 percent drop in the growth of cancer cells, compared to 45 percent for the scorpion venom alone. The University of Washington study represents the first time nanoparticles have been combined with a therapy that physically stops cancer’s spread.
“People talk about the treatment being more effective with nanoparticles, but they don’t know how much, maybe 5 percent or 10 percent,” says Miqin Zhang, professor of materials science and engineering at University of Washington and lead author of the study. “This was quite a surprise to us.”
For more than a decade scientists have looked at using chlorotoxin, a small peptide isolated from scorpion venom, to target and treat cancer cells. The peptide binds to a surface protein overexpressed by many types of tumors, including brain cancer. Chlorotoxin also disrupts the spread of invasive tumors—specifically, it slows the ability of the cancerous cell to penetrate the protective matrix surrounding the cell and travel to a different area of the body to start a new cancer.
Previous research by Zhang’s group combined chlorotoxin with nanometer-scale particles of iron oxide, which fluoresce at that size, for both magnetic resonance and optical imaging.
Adding nanoparticles often improves a therapy, partly because the combination lasts longer in the body and so has a better chance of reaching the tumor. Combining also boosts the effect because therapeutic molecules clump around each nanoparticle.
So far most cancer research has combined nanoparticles either with chemotherapy that kills cancer cells or therapy seeking to disrupt the genetic activity of a cancerous cell. Zhang’s group investigated chlorotoxin action when it is attached to nanoparticles and found the resultant complex doubles the therapy’s effect compared to chlorotoxin alone.
The research was funded by the National Institutes of Health and fellowships from the National Cancer Institute and Ford Motor Company.
For details about the study, visit http://uwnews.org/article.asp?articleID=48796.
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