Most of us view Zika as a serious health threat. However, the virus could come in handy in the treatment of aggressive brain tumors. A new study has found that Zika can kill glioblastoma cells, the most common type of brain tumor. It affects 12,000 Americans every year and is usually lethal in less than two years. It is also notoriously hard to treat.
Zika naturally targets stem cells called neuroprogenitor cells in the brain. Adult brains don't have many of these cells, so Zika usually isn't very harmful. In contrast, infants have larger numbers of these cells, so Zika is much more serious for them. In unborn babies, it can lead to microcephaly, which causes abnormally small heads and undeveloped brains.
However, researchers from the Washington University School of Medicine in St. Louis and the University of California San Diego School of Medicine have shown that the disease could actually benefit our health. Their results were published in The Journal of Experimental Medicine
"It looks like there's a silver lining to Zika. This virus that targets cells that are very important for brain growth in babies, we could use that now to target growing tumors," Dr Michael Diamond, the study's co-senior author, told BBC News.
The virus kills the stem cells of glioblastoma tumors, which radiotherapy, chemotherapy, and surgery often fail to target. After treatment, these cells can keep on growing and dividing, forming new cancers and allowing tumors to regrow.
This is where Zika comes in. Because Zika targets stem cells, it can be used to specifically attack these cancer-causing stem cells in the brain.
The researchers infected human brain tumor tissue with Zika in the lab and found that it successfully killed tumor stem cells. When the same experiment was done using healthy brain tissue, Zika did not infect normal brain cells. It seems the virus targets tumor stem cells over both non-stem cancer cells and healthy cells.
Live mice with tumors were also injected with either Zika or a placebo. Those with Zika developed smaller tumors and lived considerably longer than their placebo counterparts.
In combination with chemotherapy, Zika could be used to create a unique treatment for glioblastoma sufferers. Chemotherapy radiation is good at targeting already formed tumor cells but not so good at killing stem cells, but Zika's affinity for stem cells solves this problem.
But isn't Zika still dangerous? The researchers are already modifying the virus to make it safe to use. They have weakened its ability to tackle the body's immune defenses meaning that it shouldn't grow in healthy cells. Cancer cells already have weak defenses so Zika could still attack them.
"Once we add a few more changes, I think it's going to be impossible for the virus to overcome them and cause disease," said Diamond.
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