Subtle changes in PTEN protein levels increase chances of developing cancer

Subtle gene changes may increase cancer susceptibility

A US study has found that even subtle changes in the levels of PTEN, a protein that blocks cancer development, may significantly increase a person's chances of developing cancer.

Scientists already knew that losing one or both copies of the gene which contains the information to make PTEN can increase the chance of developing tumours.

But the latest study from Beth Israel Deaconess Medical Centre (BIDMC) indicates that even tiny changes - which don't mean fully inactivating the genes - may play an important role.

The researchers slightly reduced the level of the PTEN protein in laboratory mice, and found that these mice were more likely to develop breast tumours than those with normal levels of PTEN.

It is hoped that the discovery, which is detailed in Nature Genetics, could help to inform the development of new ways to prevent or treat cancer in future.

Dr Pier Paolo Pandolfi, director of the cancer genetics programme at BIDMC and professor of medicine at Harvard Medical School, said that "even a subtle 20 per cent decrease in gene expression is sufficient to impair its full tumour-suppressive activity"

"This implies that any factor that affects PTEN levels - chemicals, diet, other carcinogens - could increase tumour susceptibility, even in the absence of a full blown genetic mutation."

Jessica Harris, Health Information Officer at Cancer Research UK, said: "Studies like this are important as they help us to understand more about how cancer starts and develops. But future research will be needed to show how this new information can change scientists' approach to preventing and treating cancer."