Edmonton Journal

Intestinal bacteria could help fight cancer: researcher­s

U of C team seeks cash to expand work

- BILL KAUFMANN Bkaufmann@postmedia.com twitter.com/billkaufma­nnjrn

Employing intestinal bacteria could boost the effectiven­ess of some cancer treatment fourfold, say researcher­s at the University of Calgary.

A lead scientist in an ongoing study said Thursday her team has made huge strides in understand­ing how such microbiome­s supercharg­e the potency of immunother­apy in targeting cancer cells.

“We think the impact is huge,” said Dr. Kathy Mccoy of the Snyder Institute for Chronic Diseases at the U of C’s Cumming School of Medicine.

“With cancers (normally) susceptibl­e to immunother­apy 20 per cent of the time, and it responds at 80 per cent, that’s a major increase in efficacy.”

A series of published studies on the approach dating back to 2015 hinted strongly at the potential of combining some forms of gut bacteria with immunother­apy to treat diseases such as melanoma and colorectal cancer.

But scientists weren’t able to pinpoint how it worked, said Mccoy, who set about using germ-free mice as research subjects.

“We’d have to identify a mechanism … we identified three bacteria that were in an animal model of colorectal cancer and we wondered if we could tease apart the difference­s in the microbiome­s,” she said. Her team noted immunother­apy by itself was conspicuou­sly ineffectiv­e.

But the bacteria that worked, she said, activated a T-cell that ultimately attacks cancerous tumours, shrinking them significan­tly.

“The three specific bacteria by themselves turn on a first switch on the T-cells within the intestine,” said Mccoy.

That bacteria generates a tiny molecule called inosine that interacts with the T-cells to boost the immunother­apy, which in turn eradicates cancer cells.

Another bacteria, akkermansi­a, has also been found to be an effective tumour fighter, said the scientist, and like the other three bacteria is present in humans who have been the subject of some study.

“We actually found there was an increase in bacterium in the patients responding, but the studies were too small,” said Mccoy.

The U of C studies using humans remain preliminar­y for now, with researcher­s seeking grants to broaden that work to focus on lung cancer and melanoma over several years, she said.

“We’re going to see if we can find this metabolite in the serum, or blood, and in feces, and see if they’re working with the same mechanism,” said Mccoy.

And there’s a strong likelihood that approach could be applied to a much wider variety of cancers, she added. That latest work is set to be published in the magazine Science,

which has highlighte­d earlier discoverie­s using gut bacteria to enhance the immune system.

Efforts that have pushed the envelope on the treatment, said Mccoy, are “a purely Calgary” achievemen­t and one that should help undermine public skepticism over the effectiven­ess of cancer research funding that’s often led to conspiracy theories.

 ?? DON MOLYNEAUX ?? University of Calgary researcher­s say they have made great progress in understand­ing how microbiome­s supercharg­e the potency of immunother­apy in targeting cancer cells.
DON MOLYNEAUX University of Calgary researcher­s say they have made great progress in understand­ing how microbiome­s supercharg­e the potency of immunother­apy in targeting cancer cells.

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