Scientists at Yale School of Medicine design a virus to treat ovarian cancer

Marisa Peryer, Senior Photographer
A new Yale study showed that certain genetically modified viruses can cure ovarian cancer in mice. It may be of use in the treatment of ovarian cancer in humans.
Researchers at the Yale School of Medicine have tested a chimeric virus — containing genes from two different viruses — that can selectively infect and kill ovarian cancer cells in mice. Their findings represent a potential breakthrough in the long-term treatment of ovarian cancer in humans. The study was published in the journal Virology on Nov. 12, two weeks after the death of the paper’s lead author Anthony Van den Pol, former professor of neurosurgery and psychiatry at Yale.
“Every year, around 20,000 women are diagnosed with ovarian cancer, which is a smaller number compared to cancer types such as breast cancer,” said Gil Mor, the scientific director of the C.S. Mott Center for Human Growth and Development at Wayne State University and a co-author of the paper. “However, unfortunately only around 4,000 of those women can survive the disease.”
The main reason behind the lethality of ovarian cancer is the lack of treatments preventing the recurrence of the disease. In 80 percent of cases, patients who respond positively to chemotherapy still experience a return of the disease, according to Mor. He explained that once the cancer comes back and begins to spread, there is little that doctors can do.
The inspiration for the study was born out of a collaboration between Van den Pol and Mor many years ago, when they worked in adjacent labs at the Yale School of Medicine. Van den Pol, a research scientist in the Neurosurgery Department, had concentrated his research on the long-term treatment of brain tumors. Mor, on the other hand, had been working on treatments for ovarian cancer. The two scientists decided to collaborate to find an alternative treatment for ovarian cancer through oncolytic viruses, which selectively infect and kill cancer cells.
In the experiment’s in vitro phase, in which the research takes place in laboratory tubes or petri dishes without a living component, researchers made a virus called Lassa-VSV in the laboratory. Lassa-VSV consists of three parts: the Lassa virus, the vesicular stomatitis virus, or VSV, and a fluorescent label to facilitate tracing, according to Nazli Albayrak, a scientist who was involved in the in vitro phase. During this phase, the team infected different ovarian cancer cell lines, eventually choosing the ones that were infected most frequently to proceed with the research.
Then, after deciding on the cell line, the team injected tumor cells into the bodies of the mice, the paper explains. As the tumor cells began to replicate, the team then injected the Lassa-VSV virus into the tumor clusters. They observed that the virus infected the tumor cells very effectively yet did not harm the healthy cells