WASHINGTON — The Zika virus outbreak in 2017 unleashed a new level of fear among many who live and vacation in warmer climates, but its vaccine may have inadvertently unlocked hope for cancer patients. A new study found that a live form of the Zika virus could one day be the foundation of a new treatment for a type of deadly brain cancer, glioblastoma.
Glioblastoma is responsible for the deaths of about 15,000 adults in the United States every year. The disease is considered incurable because of the high recurrence rate after the standard battery of treatments (chemotherapy, surgery, and radiation). Cancer experts think the high recurrence rate is due to the glioblastoma stem cells (GSCs) hiding out in the brain tissue during treatment.
During the Zika outbreak, researchers determined that the virus attacked certain brain cells in fetuses, which caused deformities from microcephaly in babies born to infected mothers. The international team of scientists behind this latest study predicted that the virus may also kill GSCs because of their similarity to the infected cells seen in infants.
Pei-Yong Shi, a virologist at University of Texas Medical Branch in Galveston, and other researchers had previously proven that the Zika virus killed GSCs grown in a lab dish and in mice with glioblastoma. But they hadn’t figured out how to target the cells behind the recurrence of the cancer, which could perhaps lead to a cure for the aggressive disease.
For the study, Shi and the research team developed a potential vaccine, known as ZIKV-LAV, using a live, attenuated form of the virus. The scientists injected human-derived GSCs into the brains of mice, then treated them with the Zika vaccine. They discovered that mice treated with the vaccine showed a significant delay in tumor development, compared to mice that were only injected with the GSCs. Mice treated with the vaccine also lived about 20 days longer on average compared to those that weren’t.
The authors hope to begin testing ZIKV-LAV in human glioblastoma patients and are considering ways to modify the vaccine so that it’s even more effective in killing cancer cells.
“As a virologist, I see that we should take advantage of the ‘bad’ side of viruses,” Shi says in a release by the American Society for Microbiology. “They should have a role to play in cancer treatment.”
The study was published September 18, 2018 in the open-source journal mBio.