Dr. Roy Duncan
Inflammation, Infection & Immunity, Cancer, Molly Appeal
From lizard virus to cancer treatment:
Dr. Roy Duncan discovers a viral superpower to harness against cancer
Dr. Roy Duncan did not set out to find a cure for cancer. As a virologist, he simply wanted to understand why the version of reovirus that infects lizards and chickens causes disease, while its cousin, the human reovirus, does not.
"We found that the reovirus that affects reptiles and birds triggers an extraordinary phenomenon called cell-to-cell fusion," says Dr. Duncan, professor in theDepartment of Microbiology & Immunology and Killam Chair in Virology at Dalhousie Medical School. "The virus literally causes the cells it has infected to fuse with thecells next to them, which then fuse with the cells next to them, and so on, allowing the virus to spread much faster and further."
This is not a good thing if you're an iguana infected with reovirus, but Dr. Duncan, his team and their collaborators are learning how to exploit this mechanism as a treatment for human cancer.
"We took the lizard virus gene that controls cell-to-cell fusion and added it to another virus that preferentially infects and kills human cancer cells," Dr. Duncan says. "Also known as oncolytic viruses, these viruses are able to selectively target and kill cancer cells without harming healthy cells. Imagine how quickly they could destroy a tumour if they could also cause the cancer cells to fuse. We showed that this was, in fact, the case -- the cell fusion gene significantly improved the cancer killing activity of the virus!"
Not only do the oncolytic viruses kill cancer, they also alert the immune system to clean up the virus-infected cancer cells. "On top of this, they educate the immune system to recognize and attack cancer cells of the ssame type that arise in the future," notes Dr. Duncan. "They even destroy cancer stem cells, which are the real driving force behind the proliferation of cancer."
Dr. Duncan and his team will use a sophisticated piece of equipment called the ImageStreamX Mark II, funded through Dalhousie Medical Research Foundation's 2018-19 Fall Molly Appeal, to learn more about how viruses can fuse cells together and how they can combine this viral superpower with oncolytic viruses (such as the human reovirus and the measles virus) to provide new cancer treatments.