Could it be beneficial to harness a potentially devastating virus, such as Zika virus, for use in medical treatment? At first glance, this seems somewhat counterintuitive. Yet a news release from the Washington University School of Medicine in St. Louis suggests otherwise. While Zika virus has caused microcephaly and other neurological defects, new research shows that the same virus was able to destroy glioblastoma in mice. Discover how this virus plays a role in immune cell activation in the study publication in JCI Insight.

The Research

Glioblastoma and Immunotherapy

Typically, glioblastoma, a rare type of astrocytoma, is difficult to treat. This is because the tumor is incredibly aggressive and fast-progressing. In fact, these tumors, which generally begin in the cerebrum, are capable of making their own blood supply. As a result, many doctors find it hard to appropriately intervene and address the root cause of the cancer. But now researchers believe that Zika virus could help enhance immunotherapy for patients with glioblastoma. According to the National Cancer Institute (NCI), immunotherapy is a form of cancer treatment and biological therapy, which uses substances sourced from or created from living organisms, for cancer treatment. The NCI continues that:

As part of its normal function, the immune system detects and destroys abnormal cells and most likely prevents or curbs the growth of many cancers. Immunotherapy helps the immune system to better act against cancer.

Zika Virus as a Glioblastoma Inhibitor

In this study, researchers transplanted brain cancer cells into mouse brains. This idea was first presented in a 2017 study which found that Zika virus was able to destroy these cells, which often do not respond well to normal treatment. After transplantation, glioblastoma tumors began developing in the mice. To determine the effect of Zika virus on these tumors, researchers injected the virus into the tumors. For comparison, they also injected other mice tumors with saltwater. Some findings include:

• Zika virus prompted a high level of immune response, drawing a number of immune and T-cells to the tumor. As a result, mice treated with Zika virus saw significantly greater chances of survival.
• Viral treatment prompted sustained immunological memory in the mice. After 18 months, researchers attempted to reproduce a glioblastoma tumor in a different area of the mice’s brains. However, only one mouse was unable to destroy the tumor after a few weeks. All other mice previously treated with Zika virus were able to prevent metastasis and destroy the glioblastoma.
• Glioblastoma inhibits PD-1, preventing the immune system from suppressing tumor growth. After treating mice with singularly with Zika virus or a PD-1 inhibitor, then in conjunction with each other, researchers determined that this combination treatment greatly improved survival rates.

While these results are both interesting and potentially promising, additional research is needed. As Zika virus has, previously, caused neurological issues and birth defects in fetuses and infants, there is a moral conundrum associated with exploring this type of treatment in humans. However, could it work with a weakened form of Zika virus? In the future, researchers may explore this as an option for patients with brain cancer.

Zika Virus

Primarily spread and transmitted by Aedes mosquitoes, Zika virus is most common in the Pacific Islands, Southeast Asia, and tropical Africa. Additional transmission routes include sexual contact, blood transfusions, and transmission from mother to unborn child. Although many cases are mild, this virus can be dangerous for those who are pregnant and their unborn babies. Zika virus can cause birth defects, neurological defects, stillborn births, and other health issues. Typically, symptoms arise within 3-14 days of infection. In most cases, symptoms last for around 2-7 days. These include:

• Fever
• Muscle and joint pain
• Eye redness
• Headache
• Rash
• General malaise

Because most cases of Zika are mild, and there are no treatments, patients should rest, drink plenty of fluids, and use OTC medications to reduce fever. However, patients can seek out medical attention if their condition worsens.

Learn more about Zika virus.

Glioblastoma

Forming in star-shaped astrocyte cells, glioblastoma is an aggressive brain cancer. Approximately 20% of all brain tumor diagnoses are glioblastomas. Risk factors include prior radiation therapy and genetic disorders, though the underlying cause is unknown. Altogether, males are more likely to develop glioblastoma than females. Unfortunately, because of how aggressive this cancer is, the average survival following diagnosis is only around 14 months (1 year, 2 months). Symptoms include:

• Persistent headaches
• Nausea and vomiting
• Appetite loss
• Loss of balance and coordination
• Difficulty thinking or speaking
• Sleep interruptions
• Double or blurry vision
• Seizures
• Changes in mood, behavior, and personality
• Muscle weakness
• Mental confusion

Learn more about glioblastoma.