A protein that helps fight infection may also act as a trigger for cancer, researchers at Clare Hall Laboratories at Cancer Research UK’s London Research Institute have found.
They report growing evidence that abnormally high levels of the AID protein can mutate genes responsible for cell growth, which may lead to uncontrolled cell division.
The protein is a driver of normal healthy immune systems, and enables the body to make the thousands of different antibodies needed to fight infections.
But when fuelled by the female hormone oestrogen it can cause genes to mutate, which is linked to three quarters of the 45,000 new cases of breast cancer a year in the UK.
Dr Lesley Walker, director of cancer information at Cancer Research UK, said: “Scientists have long wrestled with the task of explaining the link between oestrogen and cancer.
“The link is particularly pertinent to women receiving increased amounts of oestrogen for prolonged periods of time – during hormone replacement therapy (HRT) for instance.
“Knowing how the mutations are fuelled may help us find new ways to stop the oestrogen from activating the AID gene – potentially treating and possibly even preventing cancer.”
The findings are published in the Journal of Experimental Medicine.
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