It may seem strange, but one of the most lethal viruses for humans, Ebola, could prove useful in the treatment of one of the most malignant kind of brain tumors: glioblastoma.
Researchers from Yale University (one of the most prestigious universities in the USA) in fact discovered that when a gene (i.e. a trait of the genetic code) of the Ebola virus, which encodes a protein that plays a key role in the threat posed by the virus, is inserted into another virus (the vesicular stomatitis virus) and then injected into animals with glioblastoma, it is capable of destroying the tumor, leaving the healthy cells intact.
Why does this happen? The mechanisms are not yet clear – explain the researchers in the Journal of Virology – but a key role is attributed to a “fragment” of the protein, called MDL (mucine-line domain), which usually helps Ebola to effectively elude the immune system of the infected organism, and in doing so contributes to its lethality.
When, however, the Ebola gene is inserted into the vesicular stomatitis virus, this virus – which in itself is much weaker than Ebola – is strengthened by the MDL and is able to infect and kill the glioblastoma cells.
The greatest vulnerability of cancer cells (not only of glioblastoma cells) to viruses, compared to healthy cells, is their inability to mount an immune response to infection.
It is for this reason that many international groups of oncologists have been trying to use modified viruses to combat a variety of cancers for years.
These studies are not easy, because the use of viruses poses an obvious risk: the introduction of potentially dangerous diseases.
To avoid this problem, the scientists, including the researchers from Yale, have created so-called chimeric viruses i.e. viruses deriving from the combination of genes “taken” from multiple viruses, selecting the ones that only target cancer cells, without harming the patient.
For now, as we said, the successful results in combatting glioblastoma have been achieved only on laboratory animals, and it will take time before the experiments can also be safely extended to humans.
In any case, according to Anthony van den Pol, professor of neurosurgery at Yale University and co-author of the study, a therapeutic approach involving the combination of viral proteins with neurosurgery could make it possible for glioblastoma to be treated more effectively in the future and to prevent recurrences – if, of course, their ability to fight cancer is confirmed.
The research was funded by the US National Cancer Institute.