Zika virus could become a weapon against brain cancer

By Dr. Ananya Mandal, MDSep 20 2018

Zika virus infection is a dreaded one that can lead to severe brain damage in the unborn babies of mothers who get it.

In a new research now, scientists from the University of Texas Medical Branch in collaboration with others have found that a modified version of the Zika virus could kill some of the stem cells that let the brain tumour cells live. This was proved to be true in mice and human trials are on the cards say the researchers.

Zika virus is spread by infected mosquito bites and has been causing mental retardation microcephaly (small brain), blindness and other deformities among babies since the 1940s when it was first discovered. It was predominantly seen in Asia, Africa and parts of South and Central America. The last outbreak of this viral flu like illness was noted in 2015 in the Americas. While adults came down with the mild flu like illness, the virus spelled danger to pregnant women, damaging the unborn babies.

Zika virus, a virus which causes Zika fever. Image Credit: Kateryna Kon / Shutterstock

This new study was led by geneticist Pei-Yong Shi of the University of Texas Medical Branch. This team was looking at Zika virus and its genetically similar cousins to understand the effects of the virus on the brains of unborn babies. They noted that despite being similar to the West Nile virus, Zika infected only a specific fetal brain cell called the neural progenitor cell. This hampers the normal growth of the neurons in the brain and alters the brain development of the baby.

This unique property of Zika virus to target the neuro progenitor cells only was a finding wherein researchers wondered if this could help patients with glioblastoma multiforme (GBM). GBM is a form of incurable brain cancer that has less than 5 percent survival among those affected. These tumours are typically resistant to chemotherapy and radiation and tend to return even after they are eradicated. Researchers noted that this tenacity of the tumours to keep returning is dependent on a special type of stem cell that produces the brain cells called the glioma cells. These glioma cells are similar to the neural progenitor cells that the Zika virus prefers. Shi and his team thus hypothesized that the Zika virus could be modified to kill the glioma cells and thus stop the cancer from returning.

The team then started to work with weakened versions of the Zika virus to see if it could affect the cancer and kill the GBM form of brain tumours in the mice. In other words they developed a vaccine strain of the Zika virus which is much weakened. The mice they tested upon had weakened immune system and the vaccine strain of the Zika virus did not cause any harm. In some of the mice, the GBM was grafted. The vaccine Zika strain seemed to kill of these GBM tumours. As obvious, says Shi, this is the first step and much more work is necessary before the virus strain can be used in patients with GBM. “Nothing is guaranteed, but so far the data is very promising, and we would like to move step-by-step to moving into clinics as soon as possible,” he said.

The results of the study were published in the latest issue of the journal mBio.