Zika virus is one of the most dangerous viruses in the world. It can cause babies to be born with severe brain damage. However, we may be able to use the virus to fight brain tumors in adults.
Why is the Zika virus dangerous?
The virus arrived in South America from Polynesia around four years ago. It is most dangerous for pregnant women because it can cause microcephaly – abnormally small heads. What is more, it is associated with neurological problems in the babies of women who were infected while pregnant.
What is more, it promotes a higher rate of miscarriage. The virus does this because Zika can pass from blood into the brain, where it infects and kills stem cells, having severe effects on developing brains.
Zika Virus can fight against brain cancer
The ability to infect brain stem cells may prove useful for fighting deadly brain cancers, many of which are caused by mutated stem cells. Scientists at the University of California, San Diego, have tested the Zika virus on glioblastoma, the most common kind of brain cancer.
Glioblastoma is one of the most difficult cancers to treat – even after surgery and other therapies, it usually kills people within a year of diagnosis. The team found that exposing samples of human glioblastoma tumours grown in a dish to the Zika virus destroyed the cancer stem cells. It is these stem cells that usually kill a person, as they can become resistant to all available treatments.
Zika rarely causes problems in adults. When the team tested the virus on ordinary brain cells from adults without cancer, they found that it didn’t infect the tissue. Furthermore, the team tested the virus on mice implanted with glioblastomas.
Normally such mice would die within a month, but those injected with Zika lived longer. The disease affects mice differently than humans so it is not clear how this would translate to people.
The researchers have no plans to start testing Zika on people with brain cancer as they are concerned that they will cause an outbreak.
The virus could pass to pregnant women and it can be also transmitted sexually. Instead, they plan to see if they can genetically modify the virus and use it as a possible treatment for brain cancer.
However, scientists at the University of Cambridge, have also been investigating this approach and are considering a trial of unaltered Zika in the UK. They says the South American epidemic has shown that Zika infection is usually mild in adults, making it fairly safe for anyone who isn’t pregnant.
It can occasionally cause a form of paralysis called Guillain-Barré syndrome, but this seems rare. What is more, transmission is unlikely in the UK as the mosquitoes that carry Zika can’t survive in the country. Furthermore, most people who get glioblastoma are over 50, so the risks of passing it on to a pregnant woman through sex are low.
While the virus is unlikely to lengthen the lives of people with glioblastoma, there are small chances of benefit.