It’s been tied to birth defects and brain abnormalities in babies, but could the notorious Zika virus lend a hand in fighting brain cancer?
New U.S. research suggests that Zika, the mosquito-borne virus that hit Brazil and parts of South America, could be used in a combination therapy to kill brain cancer.
It worked in stem cells, at least, according to scientists out of Washington University’s School of Medicine. They injected the virus in stem cells from tumours found in brain cancer patients. They say Zika killed some of the cancer.
“We showed that Zika virus can kill the kind of glioblastoma cells that tend to be resistant to current treatments and lead to death,” Dr. Michael Diamond, the study’s co-author, said in a university statement.
“We see Zika one day being used in combination with current therapies to eradicate the whole tumour,” Dr. Milan Chheda, the study’s co-author, said.
Like dengue, West Nile and yellow fever, Zika virus is a mosquito-borne tropical disease, meaning mosquitoes transmit the disease to humans.
So far, it’s been linked to a 20-fold increase in microcephaly, in which newborns have irregularly small heads and underdeveloped brains.
Zika has also been tied to eye defects, hearing impairment and stunted growth.
It’s relatively harmless in adults, though, presenting with mild, flu-like symptoms in most people. Patients often encounter a headache, followed by a rash, lethargy and runny, red eyes as common symptoms.
But the scientists note it could be a “lethal power” that, when harnessed strategically, could fight malignant cells, specifically in the brain.
For their study, Diamond and Chheda zeroed in on glioblastoma, a brain cancer that’s often fatal within a year of being diagnosed. U.S. Sen. John McCain told the world he was diagnosed with glioblastoma in July.
In conventional treatment, brain cancer patients undergo surgery, followed up with chemotherapy and radiation. It’s an aggressive process but even then tumours typically end up recurring within six months.
The scientists say it’s because of a small population of cells – glioblastoma stem cells – that survive the treatment and continue to produce new tumour cells to replace the ones killed by radiation, chemo and surgery.
This time around, the scientists removed these glioblastoma stem cells from patients at diagnosis.
They infected the tumours with one of two strains of Zika virus. Turns out, both strains seeped into the tumours, infected them and killed the cancer stem cells.
The results are promising, the scientists say, especially if Zika were to be paired with chemo and radiation.
If the trio of surgery, chemo and radiation kills off the majority of cancer cells, Zika could come in to eradicate the rest of the stem cells that are often left behind to regenerate the tumour, they explain.
The scientists followed up their work on mice to see if the therapy would work on living animals. With the rodents, they used Zika virus or a saltwater solution to inject into 33 brain tumours.
In this case, the tumours were “significantly smaller” in Zika-treated mice two weeks post-infection compared to their peers which were given the placebo.
The scientists say that if this therapy were to make its way to humans, brain cancer patients would need to receive their Zika virus injection during surgery and directly to the brain.
If it was introduced through any other part of the body, patients’ immune systems would sweep it away before it made its way into the brain.
The researchers are reassuring the public, too: Zika isn’t destructive in adult brains the same way as it is in developing babies.
The medical community has already warned that Zika appears to be most dangerous when passed on from an expectant mom to her baby in the first trimester.
Health officials in El Salvador, Brazil, Jamaica, Ecuador, Honduras and Colombia told residents to delay pregnancy until doctors better understand if the infection tampers with brain development in infants.
“It is recommended that pregnant women and those considering becoming pregnant discuss their travel plans with their health-care provider to assess their risk and consider postponing travel to areas where the Zika virus is circulating in the Americas,” the PHAC advisory says.
The latest study was published in the Journal of Experimental Medicine.