The Zika virus is known for its ability to cause birth defects in pregnant woman. A new study, however, found that the mosquito-borne virus holds potential in fighting the aggressive form of brain cancer that killed Senator John McCain.
In the study published in MBio, researchers used an experimental Zika virus vaccine to target and kill the brain cancer called glioblastoma.
The disease is one of the most lethal brain cancers, killing more than 15,000 Americans per year. US senators John McCain and Ted Kennedy were among those who succumbed to this cancer. The average rate of survival is less than two years despite radiation, chemotherapy, and surgery.
Study researcher Pei-Yong Shi, from the University of Texas Medical Branch in Galveston, and colleagues explained that Zika’s ability to infect brain cells offers a new treatment option for glioblastoma.
Zika has the ability to infect brain cells, which is why it can cause microcephaly, a condition which occurs when the fetal brain does not fully develop, causing abnormal smallness of the head. Pregnant women infected with the virus are at increased risk of bearing a child with this congenital condition.
Shi and colleagues said that the virus can be used to target the brain’s glioblastoma stem cells (GSCs), stem cells believed to be the source of tumor recurrence.
Tumor recurrence in glioblastoma is possibly due to cancerous GSCs that hide in the brain tissue close to the tumor mass even after a surgical operation. Zika-caused microcephaly, on the other hand, develops as a result of the virus targeting stem cells in the fetal brain.
“If we could find a way to specifically target those GSCs that are the source of recurrence, then that might provide an option to prevent recurrence or even a cure,” said study researcher Cheng-Feng Qin, from the Chinese Academy of Military Medical Sciences in Beijing.
To see if Zika could infect and kill GSCs without harming the normal brain cells, the researchers tested their Zika virus vaccine on mice with human glioblastoma tumors.
They found that the vaccine significantly reduced tumor growth and prolonged survival in the animals without causing neurological or behavioral abnormalities.
“Our results showed that ZIKV-LAV retained good efficacy against glioblastoma by selectively killing GSCs within the tumor, Shi and colleagues wrote in their study.
“The good balance between the safety of ZIKV-LAV and its efficacy against human GSCs suggests that it is a potential candidate for combination with the current treatment regimen for GBM therapy.”