It seems like a paradox, but the Zika virus (ZIKV), which causes serious damage to the brains of fetuses, could be used to fight brain tumors in adults . This virus, which is transmitted by the bite of vector mosquitoes of the Aedes genus, arrived in South America from Polynesia about four years ago and is especially dangerous for pregnant women and, above all, for their unborn children .
Among other things, it causes microcephaly, a neurological disorder that causes underdevelopment of the skull and causes the circumference of the head to be smaller than that corresponding to the age and sex of the child, in addition to other neurological problems associated with babies. whose mothers are infected with Zika during pregnancy. It also results in a high rate of aborted pregnancies.
This virus has this ability because, unlike other microbes, it can pass from the blood to the brain, where it infects and kills stem cells , with serious consequences for brain development. But unexpectedly, this same ability to attack stem cells can be effective in fighting brain tumors, many of which are caused by stem cell mutations .
Jeremy Rich and his team at the University of California, San Diego have tested the Zika virus to treat glioblastoma, which is the most common brain cancer .
So far, it is also one of the most difficult tumors to treat, even after surgery and other therapies, and typically kills patients within a year of diagnosis . Well, these scientists discovered that if they exposed samples of human glioblastoma tumors grown in the laboratory to the action of the Zika virus, they destroyed cancer stem cells, which in addition to killing those affected have so far been resistant to all treatments.
Glioblastoma is one of the most prevalent and deadly cancers of the brain. To the difficulty of removing it due to its location is added its enormous resistance to chemotherapy and radiotherapy . As we have said, at present, the average survival of patients does not exceed one year or at most 15 months due to the enormous capacity of these stem cells to survive and proliferate.
That is why this experiment with the Zika virus, responsible for the increase in cases of microcephaly in fetuses and babies registered last year in South America, especially in Brazil, may be very promising for medicine . The feasibility of using Zika viruses that act on cancer stem cells and destroy them is based on the fact that, although they interrupt fetal brain development by acting preferentially on neural progenitor cells, their effects on adult brains are much milder , since with age the amount of active stem cells in the thinking organ decreases. The paradox is that Zika, which is very dangerous for the fetus during pregnancy, is practically harmless in adults.
To solidify their theory, the scientists induced the development of an aggressive glioblastoma in mice, which were then inoculated with a rodent-adapted strain of Zika virus. And indeed they found that the virus had a tendency to infect glioblastoma stem cells and not neurons or already differentiated tumor cells, thereby drastically slowing tumor growth .
So there is hope that the modified Zika virus will become the tool to deal with this deadly type of cancer. It is a first step towards developing safe and effective virus strains for use in Neuro-Oncology.
References:
Zhe Zhu, Matthew, J. Gorman, Lisa D. McKenzie, Jiani N. Chai, Christopher G. Hubert, Briana C. Prager, Estefania Fernandez, Justin M. Richner, Rong Zhang, Chao Shan, Xiuxing Wang, Pei-Yong Shi, Michael S. Diamond, Jeremy N. Rich, Milan G. Chheda. Zika virus has oncolytic activity against glioblastoma stem cells. The Journal of Experimental Medicine. (2017). DOI: 10.1084/jem.20171093
