Subtle genetic changes make bowel more vulnerable to cancer

In collaboration with the Press Association

UK scientists have detected subtle changes in certain genes that appear to make the bowel more vulnerable to cancer.

Researchers at the Institute of Food Research in Norwich measured the number of chemical tags attached to DNA in cells taken from the lining of the large intestine in bowel cancer patients.

The chemical tags attached to a DNA molecule make up its 'epigenetic code' and determine whether individual genes will be switched on or off over the course of a cell's life cycle.

Mistakes in this epigenetic code have been implicated in some forms of cancer, as genes for growth may be erroneously switched on while genes involved in cell death may be switched off.

Professor Ian Johnson, a researcher at the Institute of Food Research, revealed that the team looked at changes in 18 genes that play a role in the initial onset of bowel cancer.

"We detected clear chemical differences in these genes in otherwise normal tissue in cancer patients," he revealed. "This represents a new way to identify defects that could eventually lead to cancer."

The scientists, whose findings are published in the British Journal of Cancer, believe that mistakes in the epigenetic code may occur in apparently normal tissue long before a tumour begins to develop.

Cancer Research UK welcomed the results but pointed out that further clarification was needed.

Henry Scowcroft, science information manager at the charity, said: "This study represents a small but intriguing piece in a larger jigsaw puzzle, and there are still some important bits missing. For example, it finds that 'normal' gut cells from people with bowel cancer contain 'abnormal' DNA regulation patterns, which the authors suggest may be used to detect cancer early.

"But these changes could also be a response to already having cancer, or to cancer treatment, and more studies will be needed to confirm this. This approach has a lot of potential, but there's a long way to go before doctors could use it as a predictive or diagnostic test," he added.