A University of Alberta student is looking into novel therapeutic approaches to treating aggressive brain cancer using genetically engineered viruses.
A glioblastoma is a form of rapidly progressing brain cancer currently treated with surgery, radiation, and chemotherapy. Despite these available treatments, the life expectancy for patients after diagnosis is around 15 to 16 months. An emerging field in cancer research is repurposing viruses to specifically target cancer cells, in hopes of finding more effective treatments to brain cancer.
Quinn Storozynsky, a fifth-year PhD student working under supervisor Mary Hitt, is using a mutated virus to infect and kill tumour cells. The research is currently undergoing pre-clinical trials in mice with glioblastomas, but Storozynsky is encouraged by their results so far.
Despite typically being associated with causing disease, Storozynsky assured viruses make for useful vectors in cancer therapy because of their genetic modifications. These mutated viruses — once used to eradicate smallpox — target cancer cells instead of healthy cells.
“If the cancer cells are a better environment for our virus to grow and replicate in, it will grow to the point where it literally produces so much of itself… the cancer cell explodes and releases more of the newly produced virus particles to adjacent cancer cells,” Storozynsky explained.
In this way, he hopes to see the virus — when used in combination with radiotherapy — propagate itself through the tumour and eventually destroy it.
He also explained how oncolytic viruses are unique from currently used cancer therapies. According to Storozynsky, where other cancer therapies may not be as effective in targeting tumour cells, viruses can offer a solution.
“Cancer cells are tricky; they are trying to hide themselves from your immune system so they can grow and that’s not good — we don’t want that,” Storozynsky said. “If you’re using a virus, you can actually induce an anti-tumour immune response and that’s another characteristic other therapies don’t have.”
Viruses are able to bring cancer cells to the attention of the immune system — however, the virus itself is weakened to avoid causing disease in the patient.
“It’s a two-pronged approach: you are both directly killing the cancer cells using a virus but also indirectly you’re activating the host immune system to attack the cancer, which is very interesting to me,” Storozynsky stated.
Despite available treatments, life expectancy remains low and less than five per cent of patients survive more than five years after diagnosis. Storozynsky believes these statistics reflect the importance of innovation in cancer treatment research.
“For glioblastoma, there’s a huge need for novel therapeutic approaches just because the best we have right now isn’t really working,” Storozynsky said.
Although this will be his last year working on the project, he hopes his published work will gain traction in the field and other researchers will improve on their findings for the benefit of cancer patients.
“Oncolytic viruses are a great novel approach and the more I learn about [them] the more excited I am, because there are people [who] are modifying things, combining it with [other therapies] and getting even better results,” Storozynsky said. “I think it’s a promising field for sure.”