Most breast cancer patients have tumours that require the female sex hormone oestrogen to grow and develop. Blocking this action of oestrogen (using drugs like tamoxifen) is a commonly used and effective therapy. However, many patients develop resistance to these drugs, leading to disease recurrence with poor prognosis. Understanding how therapeutic resistance occurs is therefore critical for the development of more effective therapies.
We have identified a novel protein (of unknown function) that becomes activated in breast cancers that have developed resistance to tamoxifen. We have shown that this protein amplifies the effects of oestrogen – making breast cancer cells more responsive to the hormone, and increasing their ability to divide and spread. This effect may make cells less responsive to tamoxifen, thereby contributing to the development of resistance.
We are currently working to:
– Understand how this protein modulates oestrogen action at the molecular level
– Determine its potential as a marker to identify patients who may not respond well to tamoxifen
This research has received funding from the International Association for Cancer Research.