New Nanotechnology Technique Successfully Treats Deadly Brain Cancer in Rats
Brain tumors, or gliomas, are one of the most difficult cancers to treat. Chemotherapy and radiation treatments are often ineffective at prolonging survival, and the tumors are very rarely curable. Now, scientists may have found a new method for treating gliomas: nanotechnology. In a new study, researchers from Johns Hopkins University used nanoparticles to effectively kill brain tumor cells in rats, significantly extending their lives.
Previous studies had already shown that nanoparticles delivering genes could successfully reach brain cancer cells and then turn the genes on. But in this new study, the nanoparticles were carrying genes that, when activated, were able to destroy the cancer cells. The nanoparticles, which were carrying the DNA of an enzyme called herpes simplex virus type 1 thymidine kinase, were used in tandem with an antiviral compound called ganciclovir. Ganciclovir has an insignificant effect on cancer cells on its own, but when combined with the nanoparticles, the therapy was 100% effective at killing cancer cells grown in petri dishes.
"We then evaluated the system in rats with glioma and found that by using a method called intracranial convection-enhanced delivery, our nanoparticles could penetrate completely throughout the tumor following a single injection," said co-author Jordan Green. Intracranial convection-enhanced delivery is simply a delivery of drugs to the brain that uses pressure differentials in order to distribute the drug more efficiently.
"When combined with systemic administration of ganciclovir, rats with malignant glioma lived significantly longer than rats that did not receive this treatment."
This study provides substantial evidence that a similar treatment method could work in human gliomas, and the researchers are already hard at work to modify the treatment for human subjects. But they caution that further study will certainly be necessary before moving forward with an attempt to use this method on human brains.
"To date, this type of system has only been used in humans with viral methods of gene delivery, of which the safety profiles are still heavily in debate," said co-author Betty Tyler. "Additional studies are needed to see if these nanoparticles could also effectively deliver other antitumor genes for the treatment of brain tumors as well as systemic cancers."