A nurse assists a patient undergoing a mammogram. Picture: Supplied
A nurse assists a patient undergoing a mammogram. Picture: Supplied

12 new genes identify breast cancer risk

AN international study led by Queensland researchers has identified a dozen new genes that influence a person's risk of developing breast cancer, using an exciting new scientific method they hope will lead to more drugs to treat or prevent disease.

The scientists say the new method of researching disease risk, known as a transcriptome-wide association study, is expected to speed up the discovery of more genes associated with cancer and other diseases.

The study, led by QIMR Berghofer Medical Research Institute scientists Professor Georgia Chenevix-Trench and Dr Wei Shi, is published today in the prestigious journal, Nature Genetics.

Previous genetic research has resulted in the discovery of about 170 DNA markers linked to breast cancer, but the studies involved were unable to determine whether particular genes were "turned up or down".

Professor Chenevix-Trench said that using the Transcriptome-wide association study method, international scientists analysed 8500 genes in breast tissue to see if they were linked to cancer risk and whether they were "turned up high like a very bright light, or turned down low like a dim light".

Professor Georgia Chenevix-Trench.
Professor Georgia Chenevix-Trench.

She said they then looked at a much smaller group of the genes to further study the effect of being turned up or down, on the risk of developing breast cancer.

In laboratory experiments, they found that when 12 of the genes were turned down, breast cancer cells failed to grow as well.

"This is an important finding because these genes were not previously known to influence the risk of developing breast cancer," Professor Chenevix-Trench said.

She said the next step was to understand the biology of the 12 genes better to uncover how they affected breast-cancer risk and to determine whether that information could be used to develop a drug to treat, or prevent, the disease.

Researchers also hope to use the transcriptome-wide association study method to pinpoint genes that act through the immune system to affect the body's ability to identify rogue cancer cells and eliminate them.

Professor Chenevix-Trench said the new scientific method had already identified genes associated with a person's risk of developing schizophrenia, bowel cancer, asthma and other diseases.

The QIMR Berghofer-led study is the largest project using the method to discover new breast-cancer genes.