Three 'new' genes implicated in development of breast cancer

In collaboration with Adfero

UK scientists have discovered three new genes involved in the development and growth of breast cancer.

The team, from the Breakthrough Breast Cancer Research Centre at the Institute of Cancer Research (ICR), said this discovery could lead to new ways to treat and prevent the disease, which is diagnosed in 37,000 women in the UK every year.

Publishing their findings in the journal PloS Genetics, they showed that the newly identified genes, were found directly next to the oestrogen receptor (ER) gene, which 'detects' oestrogen, the main driver of hormonal breast cancer – also called ER-positive breast cancer. This form of the disease accounts for approximately 75 per cent of breast tumours.

The ER gene has been closely studied by scientists in recent decades, and is one of the most well-known areas in the human genome.

Study author Dr Anita Dunbier likened the discovery to "finding gold in Trafalgar Square".

"We found these genes in a place we thought we knew a lot about. We now have to look further at how these genes work, but the discovery could lead to possible new therapies that will benefit women with breast cancer in the future," she said.

The starting point for the research was the discovery last year of several genetic 'markers', known as SNPs, some of which are more common amongst women with breast cancer. Cancer Research UK scientists were involved in their identification.

Three of these markers were located right next to the ER gene yet, perplexingly, one of them was associated not just with ER-positive breast cancer but also the less common ER-negative form. This suggested that genes other than ER might be involved.

To investigate further, the team looked at genes that were active in tumour samples from 104 women with ER-positive breast cancer to identify the genes most closely linked to the oestrogen receptor.

They found that three previously identified 'open reading frames' - genes whose function has yet to be assigned or identified - called C6ORF96, C6ORF97 and C6ORF211 - were all switched on at the same time as the oestrogen receptor.

Further experiments revealed that C6ORF211 was involved in tumour growth and was a possible target for new treatments, while levels of C6ORF97 appeared to have a role in whether tumours would grow back.

Commenting on the results, Dr Joanna Owens of Cancer Research UK pointed out that the research built on a decade of genetic research on cancer.

"This paper shows how scientists are beginning to reap the rewards of a decade of research on cancer’s genome. The discovery of these new genes is really intriguing and fills in a significant gap in our understanding," she said.

"In fact, cancer research can be like solving a genetic puzzle – research like this helps us find the pieces, so we can fit them together and learn how to better prevent and treat the disease."

Professor Mitch Dowsett, of the ICR, added: "This research is exciting because it shows that while the oestrogen receptor is the main driver of hormonal breast cancer, there are others next door to it that also appear to influence breast cancer behaviour.

"We now need to better understand how they work together and how we can utilise them to save lives of women with breast cancer."

References

Dunbier, A., Anderson, H., Ghazoui, Z., Lopez-Knowles, E., Pancholi, S., Ribas, R., Drury, S., Sidhu, K., Leary, A., Martin, L., & Dowsett, M. (2011). ESR1 Is Co-Expressed with Closely Adjacent Uncharacterised Genes Spanning a Breast Cancer Susceptibility Locus at 6q25.1 PLoS Genetics, 7 (4) DOI: 10.1371/journal.pgen.1001382