Researchers in Hamilton, Ontario, are working on what could become an inexpensive, simple, accurate and non-invasive test for colorectal cancer. They are developing fluorescent DNAzymes that will detect cancer markers in stool samples. If cancer is present, the molecules will glow, leading to early treatment and better outcomes for patients.
Dr Yingfu Li, a biochemist, and Dr Bruno Salena, a gastroenterologist – both at McMaster University – thought of this novel idea while on the golf course. The doctors work in entirely different fields of science but discovered that they share an interest in early detection of disease. Dr Li has been studying fluorescent DNAzymes for many years, while Dr Salena has been treating patients with colorectal cancer and other bowel diseases.
“We got talking about the fluorescent enzymes and the possibilities for early detection of cancer and I got quite excited,” says Dr Salena. “I looked at Dr Li’s data and I loved it. I thought this is something new we can try.” The 2 men put their heads together and applied for a Canadian Cancer Society Innovation Grant, which they were awarded in July.
“The Innovation Grants program is perfect for this type of research,” says Dr Li. “There are no other grant programs in Canada that support unconventional approaches like this.”
The researchers will first create a DNA pool that contains as many as a quadrillion (1015) different DNA sequences. With this massive DNA pool they will conduct a Darwinian-like evolution experiment in a test tube. The purpose of this experiment is to search for a few “magical” DNAzymes that will light up in the presence of stool samples from people who have already been diagnosed with colorectal cancer but will remain muted in samples from healthy participants. If the researchers are successful, the detection tool could one day be used in the doctor’s office as a simple, inexpensive test for colorectal and other cancers.
“This serendipitous collaboration between Drs Li and Salena allows them to tackle an old problem in a completely new way. It’s a great example of the importance of supporting innovation in cancer research,” says Dr Siân Bevan, Director of Research for the Canadian Cancer Society. “In fact, in part because of the strength of the applications, this is the largest number of Innovation Grants we’ve funded since we launched the program. Congratulations to all the researchers who have received 51 grants totalling almost $10 million.”
Colorectal cancer is the second leading cause of cancer deaths in Canada. There is a need for better, more accurate methods of early detection. When the disease is caught early, it is 90% treatable. Current colorectal cancer screening programs use fecal occult blood tests to find tiny amounts of blood in stool samples. These tests have the possibility of false positive (detecting cancer even though cancer is not present) or false negative (not detecting cancer even when it is present) results. A colonoscopy is a more accurate test but it is invasive and expensive and is not recommended for screening in the general population.