March 22nd, 2010
11:54 AM ET
By Elizabeth Landau
Nanotechnology has been generating a lot of excitement in the cancer research community. Scientists at institutions worldwide have gotten involved in looking at how tiny particles, specially designed to target cancer in the body and treat it, might work better than taking a regular drug. That's because targeted therapies would not harm healthy cells, reducing the toxic side effects seen in chemotherapy drugs.
After decades of work in animal models, there is now evidence that the approach works in humans. A paper published Sunday in the journal Nature shows that nanoparticles can successfully home to proteins associated with cancer progression, deliver medication, and turn off those proteins.
This is the first study to show that this particular method, using a mechanism called RNA interference, works in humans, said Gayle Woloschak, professor of radiology, and cell and molecular biology, at Northwestern University, who was not involved in the study.
But the study, led by Mark Davis at California Institute of Technology, is preliminary. It looked at three patients with melanoma, a form of skin cancer. Because only one of the patients consented to the biopsies due to all of the analysis, the researchers have conclusive evidence that the therapy – and not any previous treatment the patient may have had – was responsible for reducing the cancer-related protein in that patient, Davis said.
But the study showed targeting – that the nanoparticles got inside the tumor cells – in all three patients, Davis said. The more nanoparticles sent into the body, the more of these tiny structures get into the tumor cells, he said.
Although this is a small sample of participants, the study is still very important to show how the new technology works in humans, Woloschak said.
Particles used in this study were about 70 nanometers across, smaller than most viruses, Woloschak said. The therapy was injected directly into the patients' bloodstreams.
Researchers also demonstrated that a large number of different materials can be put together by using nanoparticles as scaffolds. This study used a tumor targeting agent and an anti-cancer therapy, but future possibilities include an imaging agent "so that a tumor can be observed as it is progressing through therapy," she said.
Results from the clinical trial associated with Davis' study will be presented at the meeting of the American Society of Clinical Oncology in June.
Largely, the idea of targeted nanoparticles as cancer treatments has been shown to work in animals, but not humans. Last year CNNHealth reported on the buzz on "nanobees," which use this method, as well as other concepts in the works. Read more about that here.
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