A research team from Northwestern University has demonstrated this week that nanotechnology can be used to increase survival rates in mice with brain tumours. Researchers coated gold nanoparticles with small interfering RNA, and injected them into mice with glioblastoma multiforme. Dubbed ‘spherical nucleic acids’ or SNAs, the new treatment showed around a 20% increase in survival rate and over threefold reductions in tumour size.
Glioblastoma multiforme (GBM), the most common type of brain tumour in adults, is also one of the most aggressive, resulting in a life expectancy of less than a year. It is considered incurable, and fewer than six in 100 patients remain alive after five years.
The aim of the treatment being developed in this study was to switch off a gene that is overexpressed in GBM. This discovery is the first in the nanomedical field to show that a gene-regulating drug can increase survival rates significantly in mice with brain tumours. The team also showed that SNAs are small enough to cross the blood-brain barrier, a protective barrier that often causes problems in drug delivery to the brain.
Although scientists are yet to test the drug, currently known as siL12-SNA, in clinical trials, its lack of toxicity in mice is attractive. The hope is that doctors can use siL12-SNA in conjunction with other treatments, decreasing the need for aggressive chemotherapy with many side effects, whilst increasing patients’ survival rates.
Chad Mirkin, one of the authors of the study, said that the study is “a beautiful marriage of a new technology with the genes of a terrible disease.” The study follows the FDA approval earlier this year of a cholesterol-busting drug that also uses a form of RNA to regulate genes. Studies like these add proof to the concept of gene regulation as a means of treating disease, and may lead to the treatment of other types of cancer, as well as some genetic diseases.
Paper can be found at: http://stm.sciencemag.org/content/5/209/209ra152