The gene, called SLIRP, was discovered by a team at the Western Australian Institute for Medical Research's (WAIMR) Laboratory for Cancer Medicine, led by Professor Peter Leedman, in collaboration with Professor Bert O'Malley's team at Baylor College of Medicine in Texas.
"When we baited our hook and went fishing in the breast cancer gene library we came up with SLIRP, much to our surprise, as this gene had not been characterised during the mapping of the human genome," said Professor Leedman.
"What's exciting is that SLIRP has the potential to shut down oestrogen in breast cancer cells and testosterone in prostate cancer cells.
"Most of those cancers depend on the hormones to stay alive, so if we can use SLIRP to block the hormones we may be able to help stop those diseases in their tracks."
Professor Leedman said the discovery could open the door to targeted new treatments for the cancers.
"If we can unravel the mystery of how SLIRP works to turn down the hormone action in cancer cells we could potentially develop so-called 'smart' drugs that zoom in on the gene," he said.
"The benefit is that 'smart' drugs can mean fewer nasty side effects for patients as they target specific genes, not entire areas of the body."
The find could also help researchers create blood tests to diagnose breast and prostate cancer.
"A breakthrough in the techniques available to diagnose breast and prostate cancer would hopefully allow for earlier detection and, importantly, lead to better survival rates," said Professor Leedman.
SLIRP has also been shown to turn down genes involved in energy metabolism.
"With its ability to turn off one of the key regulators of energy metabolism, SLIRP could well lead to progress in tackling diabetes and weight problems," Professor Leedman said.
The findings are to be published in the international journal, Molecular Cell, today, Friday, June 9.
Professor Leedman and his team have now applied for a patent on the gene.
Professor Leedman, who is also deputy director of WAIMR, is recognized internationally for his work on hormones. Several funding bodies have contributed to this work, including the National Health and Medical Research Council, the National Breast Cancer Foundation, the Cancer Council of WA and the Royal Perth Hospital Medical Research Foundation.
Breast cancer is the most common cancer in Australian women, and about 2500 women and men die each year from breast and prostate cancer.