An aggressive form of brain cancer called glioblastoma, which is quite difficult to treat might soon be treated with Zika virus vaccine, according to a recent series of experiments.
Zika virus have little in common with glioblastoma. However, they share more likenesses. A team of researchers are currently trying to exploit their common ground in the battle against glioblastoma.
According to the researchers, glioblastoma accounts for about 15,000 deaths in the United States per year.
The brain tumor always returns even if it responds to treatment, making it almost incurable. It can be recurrent because it hides in nearby brain tissue in the form of glioblastoma stem cells (GSCs) after treatment. It was the stem cells that gave researchers the new idea.
The results of the study was published recently in the journal mBio.
Co-lead study author Pei-Yong Shi, Ph.D., of the University of Texas Medical Branch in Galveston says,
“During the Zika epidemic, we learned that the virus preferentially infects neural progenitor cells in the fetus, and causes the devastating microcephaly seen in babies born to infected mothers.”
The other co-authors of the latest study were Jianghong Man, of the National Center of Biomedical Analysis, and Cheng-Feng Qin, of the Chinese Academy of Military Medical Sciences, both in Beijing, China.
GSCs share some properties with cells capable of differentiating into different types of brain cells (neural progenitor cells). This gave the researchers a clue.
According to Man, “We made the connection that perhaps Zika virus could also specifically infect the GSCs.”
Using a mouse model of glioblastoma in previous studies, the researchers proved that the Zika virus can attack GSCs in the laboratory. They also found that the Zika virus was less efficient at attacking brain tissue that had already differentiated into different cell types.
Cheng-Feng Qin said;
“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.”
The team first ensures that they could find a safe way of introducing the Zika virus to patients. For this purpose, Shi’s laboratory developed an attenuated Zika vaccine that they named ZIKV-LAV.
An attenuated virus is still viable, or “live,” but it has been transformed to make it safer. In this case, they deleted a small section of the genome to prevent it from easily replicating.
In tests, ZIKV-LAV was non-virulent and protected both mice and non-human primates against Zika infection. When the vaccine was injected into the brains of mice, there appeared to be no physical or behavioral side effects.
Trying out the vaccine on human tissue
The scientists tested whether the virus could kill GSCs in a mouse model. Half of the mice were injected with human-derived GSCs; the other half received the same GSCs including ZIKV-LAV.
The mice that only received GSCs rapidly developed tumors, but the mice that received GSCs plus the vaccine indicated delayed tumor growth. They also survived considerably longer.
Qin said; The Zika vaccine could be given to patients at the time of surgery in future; that way, the viruses can hunt down the GSCs and destroy them, thereby preventing recurrence of the tumor.
READ ALSO: What is Glioblastoma?
Finally, the researchers wanted to probe a little deeper into the mechanisms that permit the Zika virus to destroy GSCs. They compared the RNA messages of standard GSCs with GSCs that had been treated with ZIKV-LAV.
They concluded that in cells treated with ZIKV-LAV, an antiviral response was sparked, leading to inflammation and eventual cell death.
Though the results are encouraging, but the researchers still want to work with doctors to check the safety of ZIKV-LAV.
Article source: Medicalnewstoday
Image source: vims.ac.in