Hormone Transport By Alpha-2-Macroglobulin: Novel Roles In Regulating Hormone Activity
Funder
National Health and Medical Research Council
Funding Amount
$602,857.00
Summary
Alpha-2-macroglobulin is a large protein in the blood known to bind and transport numerous hormones in the circulation. Our previous studies published in BLOOD (2009) and JBC (2013) have discovered an important role for this molecule in the transport and regulation of a peptide hormone. The studies proposed in this application have important implications for understanding new roles of alpha-2-macroglobulin in hormone binding and regulating the activity of hormones in disease states.
Steroid hormones, such as oestrogen and cortisol, act in the body by binding a family of proteins (nuclear receptors) that bind directly to the DNA to regulate genes. The mechanisms underlying this process are complex and involve recruitment of additional molecules or coactivators to improve efficiency. Recently a novel coactivator was identified termed SRA, which remarkably is never made into protein in cells, rather exerting its effects as a RNA. We have identified a novel family of proteins t ....Steroid hormones, such as oestrogen and cortisol, act in the body by binding a family of proteins (nuclear receptors) that bind directly to the DNA to regulate genes. The mechanisms underlying this process are complex and involve recruitment of additional molecules or coactivators to improve efficiency. Recently a novel coactivator was identified termed SRA, which remarkably is never made into protein in cells, rather exerting its effects as a RNA. We have identified a novel family of proteins that bind to SRA in cancer cells, and may well play a critical role in regulating how SRA modulates genes. This project seeks to understand how this family interacts with SRA, the functional effects on breast cancer cells, and the detailed 3-dimensional structure of the family members coupled with SRA. This work will provide novel insight into how SRA regulates steroid hormone action, and may create new potential avenues for developing therapeutics in breast cancer.Read moreRead less
I am a reproductive physiologist investigating the nature and actions of hormones, particularly steroids and transforming growth factor-? superfamily members, regulating follicle growth and oocyte quality in the ovary, implantation and breakthrough bleedi
Novel Endocrine Approaches To Diagnosis & Treatment Of Men With Prostate Cancer
Funder
National Health and Medical Research Council
Funding Amount
$926,980.00
Summary
Most men are diagnosed with localised prostate cancer, others have advanced disease. Vision: Identify how tumours are insignificant vs aggressive (Aim 1.1 & 1.2). Predict which tumours will progress to incurable disease (Aim 1.3) and how to target them (Aim 1.4). Discover how each patient tumour is different (Aim 2.1) and pre-clinically test new therapies (Aim 2.2). Outcomes: practice changing discoveries that identify novel therapeutic targets & biomarkers improving diagnosis and treatment.
Steroid hormones, such as estrogen and androgens, act in the body by locking onto a family of proteins (nuclear receptors) that bind directly to the DNA to regulate genes. The mechanisms underlying this process are complex and involve recruitment of additional molecules or coactivators to improve efficiency. Recently a novel coactivator was identified, termed SRA, which exerts its effects as an RNA, rather than as a protein. SRA is aberrantly expressed in breast cancer, raising the possibility t ....Steroid hormones, such as estrogen and androgens, act in the body by locking onto a family of proteins (nuclear receptors) that bind directly to the DNA to regulate genes. The mechanisms underlying this process are complex and involve recruitment of additional molecules or coactivators to improve efficiency. Recently a novel coactivator was identified, termed SRA, which exerts its effects as an RNA, rather than as a protein. SRA is aberrantly expressed in breast cancer, raising the possibility that it plays an important role in breast cancer cell proliferation. To better understand how estrogen signals in breast cancer and identify proteins that bind to SRA in cancer cells, we established a collaboration with the O'Malley group at Baylor College of Medicine in Texas (who discovered SRA). We have identified several novel SRA-binding proteins, each of which plays an important role to regulate estrogen and androgen action. Up to this point, we have used a model that has enabled proof of principle studies in the same cancer cells from which SRA was discovered (non-breast or prostate cancer). However, we now need to carefully study the role of these proteins in cancer cells relevant to breast and prostate cancer. Thus, we plan to investigate how these proteins interact with SRA, how they influence nuclear receptor activity and breast and prostate cancer cell proliferation, examine their role in activating other pathways of cell growth in cancer cells, assay the levels of each protein in a series of human breast cancer specimens and solve the physcial 3-D structure of these proteins complexed to the SRA RNA. This work will provide novel insight into several key areas of hormone action in breast and prostate cancer. We hope to identify new markers that can be used for improved diagnosis and for prognosis, and provide structural information for the development of novel therapeutics.Read moreRead less
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
Impact Of Progesterone Receptor Subnuclear Localisation On Progesterone Action In Endocrine Target Cells
Funder
National Health and Medical Research Council
Funding Amount
$459,514.00
Summary
Breast cancer affects 10,000 Australian women annually and is a major cause of cancer death. The hormone progesterone, which is produced by the ovaries in women, is responsible for some aspects of the development of the normal breast in women and is also implicated in the development and response of breast and endometrial cancers. In normal cells progesterone acts via a specific protein (or receptor) in the nucleus, and we have shown that this protein accumulates into foci when it is active. We ....Breast cancer affects 10,000 Australian women annually and is a major cause of cancer death. The hormone progesterone, which is produced by the ovaries in women, is responsible for some aspects of the development of the normal breast in women and is also implicated in the development and response of breast and endometrial cancers. In normal cells progesterone acts via a specific protein (or receptor) in the nucleus, and we have shown that this protein accumulates into foci when it is active. We have noticed that in cancers, this accumulation is disrupted, and this is a bad sign for the cancer. As breast cancer develops, it causes many dramatic changes in the structure of cells of the breast, and particularly in the nucleus, which carries the genetic information that programs cancer cell behaviour. The nucleus normally is highly organised into compartments, which carry out different functions of the cell, such as duplication of the DNA, repair of DNA after damage, and switching on and off of particular genes important to the function of the cell. This organisation is altered dramatically in cancer cells, and it seems that this altered organisation is responsible for altered function. In this project we aim to work out what makes the receptor for progesterone form foci, how these foci are involved in the action of progesterone, and how the changed structure of the nucleus changes this process. This project will link the structure of the cell nucleus with the ability of progesterone to switch on or off particular genes, and this will provide the first signposts of how changes seen in cancer cell nuclei are reflected in changed hormonal signalling. Healthy women are regularly exposed to progestins in oral contraceptives and hormone replacement therapy. The known increased risk of breast cancer as a result of exposure to progestins creates an imperative to understand how progesterone may have aberrant effects. This project will address this important health issue.Read moreRead less
Dual Targeting Of The Androgen Receptor For Effective And Durable Control Of Lethal Prostate Cancer
Funder
National Health and Medical Research Council
Funding Amount
$946,177.00
Summary
Preventing binding of androgens to the androgen receptor is the mainstay treatment for advanced prostate cancer, but resistance inevitably develops and the disease becomes lethal. We will develop a new drug that targets a part of the androgen receptor unrelated to its androgen binding function to overcome resistance to current therapy. As this drug will be effective in all stages of prostate cancer, it has high potential to improve survival outcomes for men with prostate cancer.