Microscopic carbon tubes appear to boost a drug’s ability to stamp out brain tumors, according to City of Hope researchers. The finding, which appeared in the Feb. 15 issue of Clinical Cancer Research, is the latest step in applying technology from space exploration to treat one of the deadliest forms of cancer.
|Behnam Badie explores the use of nanotechnology for brain cancer. (Photo by Walter Urie)|
Glioblastoma — glioma, for short — is one of the most aggressive and difficult cancers to treat.
City of Hope researchers, hoping to gain an advantage, are harnessing the body’s natural defenses to attack tumors, but gliomas can suppress the immune system and protect themselves from cancer-killing white blood cells.
They are testing new ways of delivering a drug called CpG, which can reinvigorate the body’s defenses to attack brain cancer cells.
In previous laboratory studies, the researchers showed that CpG can stimulate an immune response to brain tumors; however, the doses needed showed significant toxic side effects when injected into brain tumors.
The team, led by Behnam Badie, M.D., chief of the Division of Neurosurgery and director of the Brain Tumor Program, enlisted the help of the National Aeronautics and Space Administration’s Jet Propulsion Laboratory (JPL). JPL provided microscopic carbon nanotubes designed to carry CpG directly to their target cells, minimizing exposure to the rest of the body and lowering toxic side effects.
Carbon nanotubes consist of graphite carefully shaped into tiny tubes about 1/10,000th the width of a human hair. The nanotubes carry CpG directly to immune system cells, where the drug stimulates the immune system to recognize and attack gliomas.
Testing the nanotube delivery system in mice with glioma, the researchers found that nanotube-delivered CpG eliminated tumors in more than half the rodents. None of the mice that received injections of free CpG, without the nanotube delivery system, were cured.
“The results show a clear advantage to using carbon nanotubes to deliver CpG,” said Badie. “Not only did tumor rejection increase, but also mice that were cured by the nanoparticle therapy developed immunity and were protected against subsequent tumor exposure.”
Badie cautioned that laboratory results do not always translate to humans. He and the team continue the research to eventually begin a clinical trial to test carbon nanotube CpG delivery for glioma patients.
Additional City of Hope authors on the study include Dongchang Zhao, M.D., Ph.D., Darya Alizadeh, Leying Zhang, Ph.D., Omar Farrukh, Edwin Manuel, Ph.D., and Don J. Diamond, Ph.D. The study was supported by the National Institutes of Health, the James S. McDonnell Foundation and ThinkCure.