New clues to aggressive breast cancer

12 Nov 2013

Queensland scientists have identified a genetic “switch” which indicates whether a woman’s breast cancer will spread. 

Teams from QIMR Berghofer Medical Research Institute and the Institute for Molecular Bioscience have found that a particular ribonucleic acid (RNA) molecule goes missing in aggressive cancers. 

QIMR Berghofer’s Dr Nicole Cloonan said the finding could provide a clearer prognosis for breast cancer patients, and ultimately open the door for new treatments. 

“Essentially, this particular gene fragment, or microRNA, normally acts like an emergency brake in our genetic program, ensuring our cells continue to reproduce normally,” Dr Cloonan said. 

“But we’ve identified that this “emergency brake” fails in invasive, aggressive tumours. Its sudden absence in cancer tests would be a clear marker that a tumour is likely to spread. 

“And we know that primary breast cancer rarely kills; it is those aggressive tumours that spread, or metastasise, which result in poor outcomes,” Dr Cloonan said. 

Breast cancer is the most common cancer in women. Survival can depend on when the cancer is diagnosed; once it has metastasised there is a five-year survival rate of only 21 per cent. 

“But this research has wider implications too," Dr Cloonan said.

"Although we focused on breast cancer, it’s clear this microRNA is also missing in aggressive liver, stomach, brain and skin cancers, and potentially others too.

"What we’ve uncovered seems to be a common cellular process which could be a new drug target.

“These microRNAs were once thought the “junk” of our genetic programs, something that finetuned pathways but that was all. 

“But in recent years, we’ve come to appreciate the driving role they play in cancer, and as this work shows, a key role in preventing breast cancer cells from migrating throughout a person’s body.” 

This research is published online in the advance issue of RNA and can be viewed at

This research was funded by the Australian Research Council, and used breast cancer samples provided by the Brisbane Breast Bank. 

About IMB

The Institute for Molecular Bioscience was established in 2000 as The University of Queensland's first research institute. Today, it is home to around 500 scientists, students and support staff from more than 40 countries working with colleagues around the world to translate research into benefits for the community. IMB is a multidisciplinary research institute committed to improving quality of life by pursuing discoveries through research in medical genomics, drug discovery and biotechnology. IMB's research impact areas include cancer, pain, infection and inflammation, obesity and diabetes, childhood diseases, clean energy and agriculture.

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