Evidence builds for diabetes drug as potential cancer treatment

In collaboration with the Press Association

A study by US researchers has provided further evidence that a commonly-prescribed diabetes drug is able to kill tumour cells.

Researchers at the University of Pennsylvania School of Medicine have shown that the drug metformin, which is commonly used to treat Type 2 diabetes, can kill tumour cells that lack the key regulatory gene p53.

Senior author Dr Craig Thompson, scientific director of the Abramson Cancer Centre, chair of cancer biology and professor of medicine, said the study shows that the diabetes drug impairs tumour growth.

"It is specific for tumours that lack p53, which is the most common mutation in human cancer," he explained.

p53 has been shown to control a number of processes within cells, including preventing them from developing into cancers. Researchers have found that metformin is also capable of influencing the regulation of these pathways.

The researchers therefore decided to investigate whether the drug could be used to specifically slow the growth of cancers that lack p53.

Writing in the journal Cancer Research, they describe how they implanted human bowel cancer cells with normal p53 function into one side of mice, and bowel cancer cells without p53 into the other side.

p53-deficient tumours treated with daily injections of metformin halved in size over a four-week period, while there was no difference in size when normal p53 tumours were treated with the drug.

The drug is thought to work by activating an enzyme called AMPK, which fools cancer cells into believing they have insufficient resources to grow.

The researchers are now conducting further studies and, if preclinical tests continue to show promise, the drug could be developed relatively quickly as it has already been shown to be safe in humans.