Tag Archives: colon tumours

Bacterial link to bowel cancer

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A type of bacterium known to cause dental decay and skin ulcers may also be linked to bowel cancer, scientists suspect.

Two independent research teams have now found the bug Fusobacterium in colon tumours.

It’s not yet clear if the pathogen might cause cancerous changes or whether it is an incidental finding, they told Genome Research journal.

If it is to blame, antibiotics might be able to treat it and prevent cancer.

Bowel cancer is the third most common cancer in the UK after after breast and lung.

Although the exact cause of bowel cancer is unknown, there are certain factors that increase risk, such as a strong family history of the disease and older age.

It may be that Fusobacterium infection can be added to that list, according to the experts, but they say much more work is needed to establish this.

Bowel cancer

Bowel cancer

The infection has already been linked with a gut condition called ulcerative colitis which is itself a risk factor for bowel cancer.

And other cancers are known to be linked with certain bacteria and viruses – for example, HPV and cervical cancer.

The first study, led by Dr Robert Holt from Simon Fraser University in Canada, identified Fusobacterium’s hallmark in RNA present in bowel cancer tumours. RNA is genetic material similar to DNA which is involved in transmitting and translating the genetic code.

The other team, led by Dr Matthew Meyerson from the Dana-Farber Cancer Institute in Boston, US, found microbial sequences of DNA indicative of Fusobacterium.


Together, they looked at more than 100 samples of healthy and cancerous bowel tissue.

Sarah Williams, of Cancer Research UK, said the research gave a clue about the environment in which bowel cancer grows, but added: “It’s early days and we look forward to the results of more specific, in-depth studies.

“In the meantime, people can reduce their risk of bowel cancer by not smoking, cutting down on alcohol, keeping a healthy weight, being active, reducing the amount of red and processed meat in their diet and eating plenty of fibre.”

Anthocyanins and Colon cancer

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New research shows that antioxidant compounds called anthocyanins, which give foods like blueberries and aubergines their intense colour, could be the key to cutting colon cancer cell growth

“These foods contain many compounds, and we’re just starting to figure out what they are and which ones provide the best health benefits,” said the study author, Monica Giusti, who is an assistant professor of food science at Ohio State University.

In the university’s studies on human colon cancer cells grown in lab dishes, the researchers tested the anti-cancer effects of anthocyanin-rich extracts from a variety of fruits and vegetable including grapes, radishes, purple corn, chokeberries, bilberries, purple carrots and elderberries – all chosen for their extremely deep colours and high anthocyanin content.

The researchers found that the amount of anthocyanin extract needed to reduce cancer cell growth by 50 per cent varied among the plants. Purple corn extract was the most potent, in that it took the least amount of this extract to cut cell numbers in half, but radish extract proved the least potent, taking nine times as much of this compound to halve cell growth.

Blueberries

Blueberries

In additional laboratory studies, she and her colleagues found that anthocyanin pigments from radish and black carrots slowed the growth of cancer cells anywhere from 50 to 80 per cent. But pigments from purple corn and chokeberries not only completely stopped the growth of cancer cells, but also killed roughly 20 per cent of the cancer cells while having little effect on healthy cells.

In tests on rats that had colon cancer, those that were fed a daily diet of anthocyanin extracts either from bilberries or chokeberries, reduced signs of colon tumours by 70 and 60 per cent, respectively, compared to rats that did not receive this dietary addition.


Giusti says the results suggest that anthocyanins may protect against certain gastrointestinal cancers.

“Very little anthocyanin is absorbed by the bloodstream,” she said. “But a large proportion travels through the gastrointestinal tract, where those tissues absorb the compound.”

“All fruits and vegetables that are rich in anthocyanins have compounds that can slow down the growth of colon cancer cells, whether in experiments in laboratory dishes or inside the body.”

“It is possible to use natural, anthocyanin-based food colourants instead of synthetic dyes,” she added, “doing so still maintains the wonderful colours of foods while enhancing their health-promoting properties.”

The research was presented yesterday at the annual meeting of the American Chemical Society in Boston.