SWITCHING OFF CANCER
PATRICK GUNNING, professor, Department of Chemical & Physical Sciences,
University of Toronto Mississauga
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Cancer is the leading cause of death in Canada and it’s projected to cost $177.5 billion in direct health care costs over the next 30 years. Two proteins, called Stat 3 and Stat 5, are implicated in 70 per cent of all cancers. When working normally, they switch on for a few minutes to help cells grow. In cancer, they don’t switch off, and go on to promote tumour growth. To date, no one has been able to design a drug that effectively targets these proteins in living organisms.
Patrick Gunning’s team has developed new molecules that cure several types of cancer in mice and kill cancer cells in tumours extracted from humans. To be effective in living systems, a drug must be capable of passing through cell membranes, must be the right size to pass through the small intestine, and must not be metabolized by the body. Gunning’s molecules are the first to meet these criteria. They work by binding to Stat 3 and Stat 5 and switching them off. Significantly, healthy cells don’t suffer side effects.
Gunning is working with U of T’s Innovations and Partnerships Office and has filed several patents with their help. A partnership with a major pharmaceutical company means testing is in progress and venture capital firms are evaluating his discoveries.
The molecules will lead to a much less aggressive chemotherapy drug, which can also be used in combination with existing drugs to reduce the harsh side effects associated with cancer treatment. They show promise in treatment of brain cancer, breast cancer, lymphoblastic lymphoma and multiple myeloma.
Clinical trials on patients with brain cancer.
“One of the things I want to do is validate Stat 3 and Stat 5 as proper cancer targets and to really turn industry’s attention toward them and make them realize that this is something they should be going after. If they can put their weight behind
projects to identify Stat 3- and Stat 5-targeting drugs, I think the potential for these molecules would be immense.”