University of Virginia researchers report that MRI-guided ultrasound can open the blood-brain barrier to deliver microRNAs that slowed glioblastoma growth and extended survival in animals; human trials are still to come.
Researchers at the University of Virginia Comprehensive Cancer Center, led by Roger Abounader, have described an experimental strategy against glioblastoma, the most common and aggressive malignant brain tumor in adults. The team identified microRNAs, tiny genetic molecules that can suppress several genes driving tumor growth at the same time, and combined them with nanoparticles, microbubbles and MRI-guided focused ultrasound. The work was published in the Journal of Clinical Investigation, and the study is open access.
The delivery method addresses one of the main obstacles in treating brain tumors. The blood-brain barrier shields the brain from harmful substances but also blocks many drugs. In the UVA approach, focused ultrasound works with microbubbles to open that barrier temporarily, giving nanoparticles carrying the microRNAs a brief window to enter the brain. In laboratory experiments and animal models of glioblastoma, the researchers report that the treatment slowed tumor growth and helped the animals live longer.
The strategy remains experimental and has not been tested in patients. Glioblastoma claims more than 13,000 lives in the United States each year, and current care typically combines surgery with radiation and chemotherapy, because cancer cells spread into surrounding healthy tissue and the tumor is difficult to remove completely. Abounader said the team hopes to translate the findings into future clinical trials, noting that targeting several cancer-promoting molecules at once could reach targets for which no drugs currently exist. Results in animals do not guarantee the same effect in people, and further research will be needed first.
