A few years ago, news reports were full of stories about the Zika virus epidemic sweeping across South and Central America. The Zika virus, which is mostly transmitted through mosquito bites, increased the risk of serious birth defects when pregnant women became infected.
With increased attention on the virus and a better understanding of its severity, scientists set to work studying the virus and developing vaccines, some of which are now entering early clinical trials.
Researchers have found that the Zika virus attacks cells in the brain that are critical for healthy development. But the virus can also attack brain cancer stem cells, which develop into and regenerate tumours after treatment.
This raises an intriguing possibility – is there a way to use a safe version of the virus, such as a vaccine, to treat brain cancer?
Specialized viruses can treat cancer
Researchers have been studying how to use viruses to fight cancer for a number of years, and this approach is starting to be tested in clinical trials. These oncolytic viruses can be engineered to be highly specific to cancer cells, resulting in fewer side effects than traditional cancer treatments.
The viruses can attack cancer cells directly, while also prompting the immune system to attack cancer cells. Researchers are testing different types of viruses for their effectiveness in treating different tumours, and they are also ensuring that these viruses are safe to use in people with cancer.
Zika vaccine targeted brain cancer stem cells
A team of researchers based in China recently published a study testing the use of a Zika virus vaccine to treat the brain cancer glioblastoma.
They created a vaccine by specifically engineering a Zika virus to remove certain parts of its genetic code, with the goal that it would still target brain cancer stem cells but not have any of its harmful effects. They then gave the vaccine to brain cancer cells in the lab and in animal models.
The researchers found that the vaccine still targeted brain cancer stem cells and could delay tumour growth and improve survival in animal models. Importantly, they also found that the vaccine was safe – it was highly specific to brain cancer stem cells, and mice who received the treatment did not show any of the harmful effects associated with Zika virus.
Their results suggested that this Zika vaccine triggered a strong anti-viral immune response and turned on genes that block cell growth, both of which may work together to fight cancer cells.
Vaccine may be effective treatment for brain cancer
Cancer-fighting viruses are an exciting possible form of treatment, especially for glioblastoma, which is resistant to many traditional therapies. But they also come with risks, especially when the virus in question, such as the Zika virus, is known to cause significant health issues. But this research suggests that it is possible to create a Zika virus vaccine that is both safe and effective in eliminating brain cancer stem cells, which are responsible for tumours coming back. A vaccine like this could be used in combination with current treatments to boost treatment success and improve survival.
It’s always exciting when research in one field can be applied to another, since it helps to move the research along more quickly. In this case, a Zika virus vaccine may be a shared solution to two health problems, Zika infection and brain cancer, that seem to have little in common.
Eileen Hoftyzer, BSc