Gold and tea compound may be more effective at treating prostate cancer than chemotherapy
(CBS News) A new study shows gold nanoparticles, in combination with a compound found in tea, may treat prostate cancer better than chemotherapy.
Chemotherapy can treat different kinds of cancer, but typically carries toxic side effects. While it has been known to shrink tumors, chemo also destroys healthy areas as it passes through the body. But, University of Missouri researchers discovered that when small gold particles and a compound found in tea leaves were combined, they targeted prostate cancer tumors more directly.
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"In our study, we found that a special compound in tea was attracted to tumor cells in the prostate," Kattesh Katti, curators' professor of radiology and physics in the School of Medicine and the College of Arts and Science and senior research scientist at the MU Research Reactor, said in the press release. "When we combined the tea compound with radioactive gold nanoparticles, the tea compound helped 'deliver' the nanoparticles to the site of the tumors and the nanoparticles destroyed the tumor cells very efficiently."
The study was published in the July 16 issue of Proceedings of the National Academy of Sciences.
With chemotherapy, hundreds of radioactive "seeds" are injected into the prostate, but their size and their failure to deliver effective doses doesn't make them ideal and renders their ability to treat aggressive forms of prostate cancer rather futile.
But, with the gold and tea combination - called Epigallocatechin gallate (EGCG) - scientists were able to create nanoparticles that were just the right size. Instead of needing hundreds of injections, the compound was injected only once or twice and the nanoparticles were able to stay closer to the tumor sites. The tumors shrunk by 80 percent within 28 days of treatment.
Because radioactive gold nanoparticles have a very short half-life (the time it takes for half of the substance to decay) of 2.7 days, the radioactivity from the gold only lasts for three weeks. This meant the researchers were able to treat the tumor much more effectively and with a dose that was thousands of times less than what is given with chemotherapy.
"Current therapy for this disease is not effective in those patients who have aggressive prostate cancer tumors," Cathy Cutler, research professor at the MU Research Reactor and co-author of the study, said in the press release. "Most of the time, prostate cancers are slow-growing; the disease remains localized and it is easily managed. Aggressive forms of the disease spread to other parts of the body, and it is the second-leading cause of cancer deaths in U.S. men. However, we believe the gold nanoparticles could shrink the tumors, both those that are slow-growing and aggressive, or eliminate them completely."
The experiment took place on mice with human prostate cancer cells, but the researchers hope to test the compound on larger animals like dogs. Human prostate cancer is very similar to the form found in canines. Katti told Fox News she hoped human trails could begin within the next five years.
"We look forward to eliminating pain and suffering through this approach," Katti said to Fox News. "And this is a very simple approach. The chemical we use has already been through the human food chain for thousands of year. Most populations in the world consume tea. It will make patients and non patients alike very comfortable."
