A combined team of researchers from Washington University School of Medicine in St. Louis and the University Of California San Diego School Of Medicine has shown a way to engineer zika virus to attack and kill brain cancer stem cells.
Zika virus is known to cause microcephaly – abnormally small head and underdeveloped brain – and several other fetal brain defects in the babies of women who were infected while pregnant. And since the virus tends to affect stem cells in the fetus’ brain, researchers say it could be directed to infect glioblastoma cells.
Among many different types of brain cancer, glioblastomas is most aggressive and hard to treat type of brain cancer. Even after surgery and other therapies, it usually recurs and kills people within a year of diagnosis. In the United States alone, about 12,000 people are diagnosed with glioblastomas each year.
“We showed that Zika virus can kill the kind of glioblastoma cells that tend to be resistant to current treatments and lead to death,” says Michael S. Diamond, the study’s co-senior author, in a news release.
Image on the left shows brain cancer stem cells being killed by Zika virus infection. On the right shows cells after Zika treatment.[Image via WUSM]For the study, the researchers injected either Zika virus or a saltwater placebo into the brain tumors of 18 and 15 mice. Two weeks after injection, they found that the mice that were injected Zika virus had smaller tumor, and survived significantly longer than the ones given the placebo.
Additionally, the researchers also injected a mutated form of Zika virus into mice and found that the mutant strain, although weaker than the original strain, still succeeded in killing the cancerous cells.
Human trials are still a way off. But researchers say if the virus were to use in humans, it would have to be injected into the brain, most likely during surgery to remove the primary tumor. Also if the virus were to introduce through another part of the body, the person’s immune system would sweep it away before it could reach the brain.
“We’re going to introduce additional mutations to sensitize the virus even more to the innate immune response and prevent the infection from spreading,” says Diamond. “Once we add a few more changes, I think it’s going to be impossible for the virus to overcome them and cause disease.”
The study, entitled “Zika virus has oncolytic activity against glioblastoma stem cells” has been published in the Journal of Experimental Medicine.