`Genetic switch` behind breast cancer identified

Last Updated: Jan 02, 2013, 15:11 PM IST

Melbourne: Australian researchers have discovered a "genetic switch" that can make breast cancer cells more responsive to different kinds of treatments.

The switch allows scientists to change breast cancer cells and make them more responsive to treatments, such as anti-oestrogen therapies.

Researchers from the Garvan Institute of Medical Research in Sydney found that the molecule known as ELF5 can turn genes on or off.

By manipulating the molecule, the breast cancer cell`s sensitivity to anti-oestrogen drugs used to treat breast cancer can be increased.

"We`ve made a discovery that concerns the basic biology of breast cancer. ELF5 determines whether cells will respond to oestrogen therapy or not," said Professor Chris Ormandy.

Oestrogen plays a key role in breast cancers. Women who don`t experience much hormone in their lives either because they start menstruating later in life or begin menopause early have a lower risk of breast cancer.

The finding establishes for the first time that there is a link between the molecule and breast cancer, the report said.

Found in all breast cells, the molecule was discovered by Ormandy`s team in 1999.

In 2008 his group showed that it triggered milk production in women.

The latest discovery raises the potential for developing a new class of drugs designed to reduce the amount of the molecule in cancer cells dependent on ELF5 for their proliferation.

"This molecule could have some prognostic or predictive value to guide treatment decisions ... Particularly if we can identify them early, then we can pick a treatment that is going to be most suitable," he said.

Breast cancer is the second most common cancer, after lung cancer, to cause death in women.

There are five types of breast cancer, distinguished by the pattern of genes expressed, the prognosis and the different sensitivities to drugs.

The main way different breast cancers are determined is by establishing the number of oestrogen receptors inside each tumour.

The study was published in the journal PLoS Biology.