Endocrine Abstracts

Worldwide, breast cancer is the most common cancer to develop in women. Steroid receptors play a key role in the progression of the majority of breast cancer subtypes. Estrogen Receptor-α (ERα), for example drives the growth of approximately 70% of tumours and is therefore a useful therapeutic target for this disease. However, the Androgen Receptor (AR) is the highest expressed receptor in normal breast and appears to also play an important role in breast cancer. In contrast, in ERα positive disease the crosstalk between ERα and AR is inhibitory to tumour growth. The mechanisms underlying this cross-talk occurs are not completely understood and warrant further investigation. In growth assays and reporter assays, AR and ERα were demonstrated to inhibit each others activity. To characterise this further, ERα mutants that are unable to translocate to the nucleus or bind DNA were co-transfected with the AR. The data suggest that competition for coactivators could explain the inhibitory cross-talk. It is hoped that this work will further our understanding of AR/ERα signaling in breast cancer and could identify strategies to utilise this cross-talk for therapeutic gain.

Presenting Author: Mohammad A M Alkheilewi, School of Biological Sciences, University of Essex Wivenhoe Park Colchester, CO4 3Q20, UK. Email: [email protected]