CHAPERONES IN BREAST CANCER AND ESTROGEN RECEPTOR FUNCTION
Funder
National Health and Medical Research Council
Funding Amount
$256,573.00
Summary
Resistance to hormone therapy in breast cancer is due to adaptations of estrogen signalling mechanisms that result in ERa activation causing growth. So, in the search for new treatments, we are looking for ways to remove ERa from the breast cancer cell. Our study addresses this major issue by focussing on Hsp90 molecular chaperone machinery that is essential for ERa function and in particular immunophilin 'helper' cochaperones that form part of receptor-Hsp90 complexes and fine-tune receptor res ....Resistance to hormone therapy in breast cancer is due to adaptations of estrogen signalling mechanisms that result in ERa activation causing growth. So, in the search for new treatments, we are looking for ways to remove ERa from the breast cancer cell. Our study addresses this major issue by focussing on Hsp90 molecular chaperone machinery that is essential for ERa function and in particular immunophilin 'helper' cochaperones that form part of receptor-Hsp90 complexes and fine-tune receptor responses to hormone. Through a novel mode of action, coumarin-based Hsp90 inhibitors disrupt Hsp90 dimerization causing receptor release and subsequent depletion. We will confirm this novel mechanism for new, high affinity Hsp90 inhibitors and determine which can best interfere with estrogen signalling, either alone or in combination with antiestrogen therapies in the treatment of hormone-dependent cancers. Our study has the potential to pin point the site of action of the immunophilins in ERa to a proline in a region critical for ligand-induced receptoractivation. We will determine the role of the immunophilins and this active-site proline residue in modulating receptor stability and function. Aberrant expression of receptor-associated immunophilins appears linked to endocrine resistance and metastasis in breast cancer. Our study will profile the expression of these chaperones in well defined breast cancer tissue microarrays, and has the potential to identify them as informative biomarkers in the treatment of the disease.Read moreRead less
Factors Regulating The Temporal And Spatial Assembly Of G-protein Coupled Receptor-mediated Arrestin Complexes
Funder
National Health and Medical Research Council
Funding Amount
$472,770.00
Summary
G-protein coupled receptors are proteins that are present at the surface of most cells in the human body. They recognise and bind to specific molecules, such as hormones, the act of which results in a specific signal being transmitted into the cell. This signal alters the function of the cell and so it is critical that it is appropriate, both in type and duration. G-protein coupled receptors and the molecules that activate them provide an essential function within the human body for communicatin ....G-protein coupled receptors are proteins that are present at the surface of most cells in the human body. They recognise and bind to specific molecules, such as hormones, the act of which results in a specific signal being transmitted into the cell. This signal alters the function of the cell and so it is critical that it is appropriate, both in type and duration. G-protein coupled receptors and the molecules that activate them provide an essential function within the human body for communicating between cells, and consequently between organs. They are a major mechanism by which nerve signals are transmitted and hormones regulate bodily functions. They are therefore an important target for pharmaceuticals, with up to 50% of ethical drugs and many drugs of abuse acting upon them. It is critical to understand how these receptors alter cellular function once they receive an appropriate signal, but it is also essential to know how such responses are switched off. Arrestins are proteins within cells that interact with G-protein coupled receptors to 'arrest' their signalling. They desensitise the cell to continuous stimulation, but also act to resensitise the cell to respond to future, separate signals. Recently, they have also been shown to provide alternative mechanisms of altering cellular activity by interacting with other cellular proteins. These interactions greatly increase the potential ways in which a cell can respond once a G-protein coupled receptor is activated. Understanding the resulting complexity is essential if we are to fully exploit the vast therapeutic potential of this important receptor family.Read moreRead less
Discovery Early Career Researcher Award - Grant ID: DE120100434
Funder
Australian Research Council
Funding Amount
$375,000.00
Summary
Estrogen-mediated regulation of gene expression via transcriptional and translational control: complementary, synergistic or opposing responses? Hormones dictate cellular behaviour by activating pre-programmed responses. The sex hormone estrogen affects cell fate by regulating the gene expression, but it is unknown to which extent this response occurs via activation of genes or control of already transcribed gene. The project will investigate how the cell integrates the complex estrogen signals.