US researchers have discovered a gene which they believe plays an important role in whether or not breast cancers spread to other parts of the body, according to a study published in the journal Nature last week. The finding could one day lead to a test for identifying patients with the most lethal forms of cancer - those which might benefit from more aggressive treatment strategies.
Breast cancer affects 44,000 women in the UK each year and causes 12,000 deaths, making it the most common form of cancer in women. The most aggressive tumours are those which splinter off and spread to other parts of the body, and being able to successfully predict this is crucial in deciding on the most appropriate treatment strategy for the patient.
The researchers, based at the University of California in Berkley, examined the genetic makeup of 2,000 lab specimens of human breast tumors and found that a protein - SATB1 - was present at high levels in the most lethal forms of cancer. Moreover mice injected with high level SATB1 human tumors frequently developed tumors prone to spreading, while those with SABT1 switched off developed fewer or even no tumors, helping to confirm scientist's suspicions that this was its role in tumor development.
The gene responsible for SATB1 production regulates up to 1,000 other genes, leading the researchers to believe that its over-activation in turn causes other genes to malfunction in the tumor. 'SATB1 increases the expression of genes that promote tumor growth and reduces the expression of tumor suppressors', explained study leader Dr Terumli Kohwi-Shigematsu. Understanding how this works may help with the development of new drugs which knock out the defective gene, halting the cancer in its tracks, say the researchers.
Scientists have long hoped that they would one day find a 'magic bullet' for cancer, but the complicated nature of the disease leaves many sceptical. "Clearly this gene hasn't evolved just to cause cancer - it's got normal functions as well' Associate Professor Jennifer Byrne, a molecular biologist from Sydney told ABC News, questioning whether it would be possible to interfere with the function of major regulatory genes without causing side effects to normal cells.