Readership Survey
Team hopes new mouse model will point the way to treatments for ovarian cancer
BY ANDREW VOWLES
“We can't let any more women go through this.” Those words from one listener at a recent talk given by Prof. Jim Petrik, Biomedical Sciences, reflect the conviction he himself feels about his studies aimed at ovarian cancer, the fifth-highest cause of cancer deaths among Canadian women.
Now Petrik hopes a new development in his Ontario Veterinary College laboratory will ultimately improve diagnosis and treatment of this killer disease, including leading the way to new drugs to effectively choke tumour growth.
“It's a treatable disease if we can get to it early enough,” he says.
Working with colleague Prof. Roger Moorehead and PhD student Jim Greenaway, Petrik has developed a mouse model for in vivo testing of the disease. They've been collaborating with researchers at the University of Western Ontario and Harvard University. Last fall, Petrik received a $500,000 grant from the newly formed Ontario Cancer Research Network to support this work.
Until now, researchers have relied on artificially cultured clumps of cells and immuno- compromised mice that poorly mimic disease progression in normal animals. Over the past 18 months, the U of G researchers have perfected a technique for injecting cancer cells directly into mouse ovaries. (The tumour cells come from a reproductive biologist at Kansas State University who first isolated them.)
Ovarian cancer spontaneously occurs in about two months, allowing the researchers to follow tumour progression, including characteristic development of secondary lesions and fluid buildup. Petrik hopes to hunt down particular genes and proteins involved in that progression as candidate targets for early diagnosis and treatment.
Conceding that the disease and particular genes may not work exactly the same in mice and humans, he says researchers know enough about cancer genetics to suspect that certain biochemical pathways and early “biomarkers” may be common.
Petrik is now working with an American pharmaceutical company making anti-angiogenic drugs, or compounds that curtail blood vessel growth and effectively cut off the tumour's supply of oxygen and nutrients. In addition, he and Moorehead are discussing collaborations with an ovarian cancer research group at the University of Toronto.
Clinicians and other researchers are offering positive reviews of the new development, says Petrik, who presented his work at a recent conference. It generated particular interest among clinical oncologists who see the disease every day in their clinics, he says.
About 1,500 Canadian women die of ovarian cancer each year, and about 2,500 new cases occur annually, according to the National Ovarian Cancer Association in Toronto. It's usually diagnosed only in later stages, earning it the nickname of the “silent disease.” Its vague symptoms include abdominal pain or swelling, nausea and bloating, all of which may be ascribed to other problems.
Outside his OVC lab, Petrik has spoken about his work occasionally to cancer survivor groups and supporters.
“Women are so concerned about other women having to go through this,” he says. “I really try to stay grounded with my research, and I appreciate the opportunity to interact with people who make what I'm doing relevant.”
Along with Moorehead, he took part in a Canadian Cancer Society Relay for Life fundraiser last weekend in Fergus, including speaking during a candlelight ceremony.
