Insulin-like Growth Factor (IGF)-II Binding Specificity Of IGF Binding Protein-6: Structural And Functional Studies.
Funder
National Health and Medical Research Council
Funding Amount
$265,630.00
Summary
Insulin-like growth factor II (IGF-II) is a protein which is involved in normal growth. However, in some circumstances it may also stimulate cancer growth. IGF binding protein-6 (IGFBP-6) binds to IGF-II and stops its activity. One of the major challenges of modern biology is understanding why some proteins bind to other proteins. Proteins fold in various ways and have specific three-dimensional structures. Two proteins which bind strongly to each other have structures which fit each other like ....Insulin-like growth factor II (IGF-II) is a protein which is involved in normal growth. However, in some circumstances it may also stimulate cancer growth. IGF binding protein-6 (IGFBP-6) binds to IGF-II and stops its activity. One of the major challenges of modern biology is understanding why some proteins bind to other proteins. Proteins fold in various ways and have specific three-dimensional structures. Two proteins which bind strongly to each other have structures which fit each other like a 'lock and key'. The aim of this project is to understand how IGFBP-6 binds to IGF-II by looking at its three-dimensional structure. Using this information, it may be possible to develop new treatments which can inhibit IGF-II activity and therefore may be useful in the treatment of some cancers.Read moreRead less
Structural And Functional Investigation Into The Cooperation Of IGF And Vitronectin-binding Receptors In Cell Migration
Funder
National Health and Medical Research Council
Funding Amount
$239,250.00
Summary
Breast cancer is the most commonly diagnosed form of cancer in Australian women, accounting for 26% of diagnosed cancers and 21% of cancer deaths among women. One in fourteen Australian and one in nine women worldwide will develop breast cancer in their lifetime. Significantly, approximately one in four of those diagnosed will die from their disease. The primary factor that determines survival is early diagnosis and treatment. Indeed, the primary tumour itself rarely causes death. Rather, the di ....Breast cancer is the most commonly diagnosed form of cancer in Australian women, accounting for 26% of diagnosed cancers and 21% of cancer deaths among women. One in fourteen Australian and one in nine women worldwide will develop breast cancer in their lifetime. Significantly, approximately one in four of those diagnosed will die from their disease. The primary factor that determines survival is early diagnosis and treatment. Indeed, the primary tumour itself rarely causes death. Rather, the dissemination of tumour cells to remote sites and the establishment of secondary tumours in critical sites in the body is the major mechanism of mortality. An understanding of the processes that lead to the establishment of secondary tumour bodies and strategies to halt the spread of cancer beyond the primary site are therefore highly valuable. Two factors thought to be pivotal in breast cancer metastasis are altered interactions with the microenvironment surrounding cells and exposure to increased levels of hormones and growth factors, such as the insulin-like growth factors (IGFs). We have recently found that IGFs form complexes with a protein called vitronectin, found in the microenvironment, and these complexes can stimulate increased migration of breast cancer cells. This project will examine the interaction of IGF and VN in stimulating cell migration and in particular, aims to identify the genes involved in the enhanced cell migration. In addition we will examine how the IGF:vitronectin complexes form and how these in turn interact with receptors on the surface of the cell. The data obtained will provide critical fundamental information that is necessary to develop targeted therapies for the treatment and control of breast cancer.Read moreRead less
Molecular Characterisation Of The Ligand-binding Domain Of The Mineralocorticoid Receptor
Funder
National Health and Medical Research Council
Funding Amount
$215,183.00
Summary
The steroid hormone aldosterone regulates blood pressure by controlling sodium retention. The important role of this hormone in blood pressure control is underlined by the fact that all known monogenetic hypertensive conditions involve aldosterone or sodium reabsorption. Aldosterone works by activating an intracellular 'receptor' protein that in turn switches on specific genes. The products of these genes act to produce sodium retention. Antagonists (blockers) of this receptor are used in the tr ....The steroid hormone aldosterone regulates blood pressure by controlling sodium retention. The important role of this hormone in blood pressure control is underlined by the fact that all known monogenetic hypertensive conditions involve aldosterone or sodium reabsorption. Aldosterone works by activating an intracellular 'receptor' protein that in turn switches on specific genes. The products of these genes act to produce sodium retention. Antagonists (blockers) of this receptor are used in the treatment of hypertension but have undesirable side effects. The design of new, more specific, antagonists has been slow because we do not understand how these drugs bind to the receptor and what effect they have on the protein. How the aldosterone receptor functions is poorly understood. This project aims to investigate the receptor in detail. We are in the process of determining regions of the receptor structure important for hormone binding. This information is vital for the design of new antagonists. The aldosterone receptor is unusual in that it is also activated by cortisol, a steroid hormone involved in stress and inflammation. By examining hormone binding it may be possible to determine if the two steroids activate the receptor in the same way. An understanding of how both natural hormones and synthetic antagonists function is impossible without thorough study of the receptor itself. We intend to examine fundamental aspects of aldosterone receptor function. In particular we wish to identify proteins that interact with the receptor. These proteins either enhance or inhibit the ability of the receptor to switch on genes and are vital to explaining the actions of both natural hormones and synthetic antagonists. Results from these experiments should advance our understanding of the basic biology of aldosterone action and its role in cardiovascular biology, and lead to the design of better receptor antagonists for use in the treatment of hypertension and cardiac fibrosis.Read moreRead less
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
Endocrine And Autocrine Regulation Of Breast Cancer Cell Growth By IGF Binding Protein-3 (IGFBP-3).
Funder
National Health and Medical Research Council
Funding Amount
$497,250.00
Summary
The insulin-like growth factor (IGF) system of growth factors and their regulatory proteins is essential for normal growth, but is also involved in a number of overgrowth disorders. Some clinical studies have shown that a high level of IGF-I in the blood increases the risk of breast cancer in some women, but if the protein which carries it in the circulation, IGFBP-3, is also high, the risk is reduced. It has therefore been suggested that IGFBP-3 may be useful in the treatment of breast cancer. ....The insulin-like growth factor (IGF) system of growth factors and their regulatory proteins is essential for normal growth, but is also involved in a number of overgrowth disorders. Some clinical studies have shown that a high level of IGF-I in the blood increases the risk of breast cancer in some women, but if the protein which carries it in the circulation, IGFBP-3, is also high, the risk is reduced. It has therefore been suggested that IGFBP-3 may be useful in the treatment of breast cancer. This is supported by laboratory studies showing that IGFBP-3 can inhibit cell division and stimulate cell death in many cell types, including breast cells. However, some cells are resistant to IGFBP-3 s inhibitory effects, and in some cases IGFBP-3 may stimulate cells to grow and divide. In fact, the amount of IGFBP-3 present in breast tumours is highest in the fastest growing, most malignant tumours, suggesting that IGFBP-3 may be stimulating their growth. Our laboratory data indicates that breast cancer cells which produce a high level of IGFBP-3 grow faster as tumours than cells which produce little or no IGFBP-3. We believe that this is because IGFBP-3 interacts with another hormone system which is involved in rapid tissue growth, the EGF system, and increases its ability to stimulate breast cells to divide. These observations raise a number of important questions: how does IGFBP-3 interact with the EGF system to stimulate tumour growth; does IGFBP-3 from the blood promote the growth of EGF-sensitive tumours; and can the interaction between IGFBP-3 and the EGF system be abolished, or switched from growth stimulatory to growth inhibitory, thus inhibiting tumour growth. Answering these questions will provide important new information regarding IGFBP-3 s stimulatory and inhibitory actions, and the role of endocrine IGFBP-3 in tumour growth, and have the potential to lead to the development of novel therapies involving IGFBP-3 for the treatment of overgrowth disorders.Read moreRead less
Determinants Of Insulin-like Growth Factor (IGF) Binding And Biological Actions Of IGF Binding Protein-6
Funder
National Health and Medical Research Council
Funding Amount
$399,750.00
Summary
Proteins are complex structures usually consisting of a number of distinct regions. Each of these regions may serve different roles. Insulin-like growth factors (IGFs) are important proteins involved in regulating the growth and other properties of cells. The actions of IGFs are in turn regulated by a family of binding proteins (IGFBPs). The aim of this project is to determine the range of actions of one of these IGFBPs and which parts of this IGFBP are involved in these actions. This may lead t ....Proteins are complex structures usually consisting of a number of distinct regions. Each of these regions may serve different roles. Insulin-like growth factors (IGFs) are important proteins involved in regulating the growth and other properties of cells. The actions of IGFs are in turn regulated by a family of binding proteins (IGFBPs). The aim of this project is to determine the range of actions of one of these IGFBPs and which parts of this IGFBP are involved in these actions. This may lead to new treatments for diseases in which cell growth is disturbed e.g. cancer and diabetes.Read moreRead less
Role Of IGF Binding Protein-3 (IGFBP-3) And IGFBP-5 As Modulators Of Nuclear Hormone Signalling
Funder
National Health and Medical Research Council
Funding Amount
$465,750.00
Summary
The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain ....The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain cells perform specialised functions. In test-tube experiments, IGFBP-3 and IGFBP-5 interact directly with the receptors that regulate the effects of these hormones. If the same thing happens inside the cell, IGFBP-3 and IGFBP-5 could change the way these receptors respond to signals from outside the cell. We will investigate what effect these IGFBPs have in living cells and in whole animals and how this may relate to human disease. If we are able to understand how IGFBP-3 and IGFBP-5 affect the way cells respond to vitamin A and D, then we may be able to develop new ways to treat certain human diseases.Read moreRead less
Pathways Involved In The Insulin-like Growth Factor (IGF)-independent Actions Of IGF Binding Protein-6
Funder
National Health and Medical Research Council
Funding Amount
$550,725.00
Summary
Insulin-like growth factors (IGFs) are important proteins that regulate growth. When not regulated properly, diseases such as cancer can occur. A family of IGF binding proteins regulates IGFs. IGFBPs may inhibit IGFs and we have shown that one of them, IGFBP-6, decreases growth of some experimental cancers. As well as regulating IGFs, some IGFBPs alter cell behaviour independently of IGFs, and we found that IGFBP-6 stimulates cell movement in this way. We will now determine how this happens.