HEREDITARY ENDOCRINE CANCER: A MODEL BASED ON PHAEOCHROMOCYTOMA- PARAGANGLIOMA SYNDROMES
Funder
National Health and Medical Research Council
Funding Amount
$875,894.00
Summary
Phaeochromocytomas and paragangliomas are tumours remarkable for their very high heritability. They have a high burden of disease themselves, and their associated hereditary syndromes include risks for other malignancies. Our study will rationalize the pathological approach to diagnosing these hereditary syndromes, find new therapeutic targets for metastatic disease, and provide a template for other cancers with high heritable component.
Novel Interactions Between GnRH Receptor And E2F4 Transcription Factor.
Funder
National Health and Medical Research Council
Funding Amount
$462,750.00
Summary
The reproductive endocrine system is under the control of gonadotropin-releasing hormone (GnRH), signalling via its G-protein coupled receptor (GPCR) in the anterior pituitary gland. The GnRH receptor (GnRHR) is the drug target for the treatment of a range of endocrine-related disorders as well as hormone-dependent cancers. Sustained treatment with either GnRH agonists or antagonists can block gonadotropin secretion indirectly, via down-regulation of the pituitary receptor resulting in a reducti ....The reproductive endocrine system is under the control of gonadotropin-releasing hormone (GnRH), signalling via its G-protein coupled receptor (GPCR) in the anterior pituitary gland. The GnRH receptor (GnRHR) is the drug target for the treatment of a range of endocrine-related disorders as well as hormone-dependent cancers. Sustained treatment with either GnRH agonists or antagonists can block gonadotropin secretion indirectly, via down-regulation of the pituitary receptor resulting in a reduction of gonadotropin secretion and consequent decline in steroid production. As the majority of tumours treated with GnRH analogues are hormone-dependent, this starves the tumour of the steroid support required for growth. However, the concept of a direct anti-tumour effect of GnRH, independent of the pituitary-gonadal axis, is supported by the in vitro inhibition of both cell growth and DNA synthesis in a number of tumour cell lines. Despite the wide use of GnRH analogues, the molecular basis of the growth inhibitory effects resulting from the activation of this receptor is not fully understood. Unravelling the protein interactions underlying receptor-mediated signalling events will provide valuable information towards understanding of receptor function in vivo. We have identified a novel interaction involving the GnRHR and E2F4, a transcription factor involved in suppression of the transcription of genes involved in cell cycle progression. In addition, over 80% of E2F4 knockout mice are sterile. Owing to the role of the GnRHR in the reproductive pathway we are interested in determining whether the GnRHR-E2F4 interaction has an influence on the development of the hypothalamic-pituitary-gonadal axis, hence affecting reproductive capacity. The interaction identified and studied in this proposal has implications for the treatment of reproductive tumours, such as those of the breast and prostate, and understanding the development of the hypothalamic-pituitary-gonadal axis.Read moreRead less
Regulation Of Bone Resorption And Formation In Health And Disease
Funder
National Health and Medical Research Council
Funding Amount
$5,596,183.00
Summary
Bone is continually being formed and broken down, and these two processes are critical forthe maintenance of a normal skeleton. These processes are dependent upon communication between the bone building and degrading cells, and the hormones growth factors and cytokines that are present in the circulation or produced in bone. The tightly regulated processes of bone formation and degradation need to remain equal, and are essential for the achievement and maintenance of skeletal strength and form. ....Bone is continually being formed and broken down, and these two processes are critical forthe maintenance of a normal skeleton. These processes are dependent upon communication between the bone building and degrading cells, and the hormones growth factors and cytokines that are present in the circulation or produced in bone. The tightly regulated processes of bone formation and degradation need to remain equal, and are essential for the achievement and maintenance of skeletal strength and form. Osteoporosis results from an excess of bone breakdown over formation, and our Program aims to identify the factors that regulate these processes, and develop new therapies that can modify them. We will also determine what it is about bone cell properties that make some cancers, especially those of breast and prostate, particularly prone to spread to bone.Read moreRead less
Overweight and obesity are at epidemic proportions in Australia, reflecting the pattern in the developed and developing world. The main cause appears to be an energy mismatch, with excessive caloric consumption. One response of the body to excessive nutrient supply is energy storage in fat tissue and to aid in this the body also generates new fat tissue, termed adipogenesis (also known in cells as fat cell differentiation). In many people who gain excess body weight, fat tissue is abnormal and d ....Overweight and obesity are at epidemic proportions in Australia, reflecting the pattern in the developed and developing world. The main cause appears to be an energy mismatch, with excessive caloric consumption. One response of the body to excessive nutrient supply is energy storage in fat tissue and to aid in this the body also generates new fat tissue, termed adipogenesis (also known in cells as fat cell differentiation). In many people who gain excess body weight, fat tissue is abnormal and does not respond well to the chemical insulin, thus causing insulin resistance. This insulin resistant fat tissue is especially present in a central body (visceral) site. Insulin resistance related to this visceral fat predisposes to both diabetes and premature death from cardiovascular disease. Understanding how fat tissue develops and how it might cause insulin resistance is thus important in human health. One of the factors in fat that prevents normal development of fat tissue and which induces insulin resistance is transforming growth factor- (TGF- ). We have generated new data showing that two proteins which are increased by TGF- , termed connective tissue growth factor (CTGF) and insulin like growth factor binding protein-3, (IGFBP-3), prevent adipogenesis. We have shown this in cultured cells, and have found that CTGF and IGFBP-3 are increased in visceral fat in animal models of obesity and insulin resistance. Our preliminary work has further indicated how CTGF and IGFBP-3 might each work in the fat cell to prevent adipogenesis. This proposal will determine if TGF- works through CTGF and IGFBP-3 to block adipogenesis, and it will define how CTGF and IGFBP-3 have their inhibitory effects on fat cell differentiation. Cells in culture will be utilised and an animal model of dietary induced obesity and insulin resistance will help to define whether CTGF and IGFBP-3 prevent adipogenesis in vivo, furthering our understanding in how abnormal fat tissue may develop.Read moreRead less
Inosine-5' Monophosphate Dehydrogenase (IMPDH) is an enzyme responsible for providing a form of energy to cells, so that they may undertake their correct functions. Recently, we have demonstrated that IMPDH also has a role in the formation of fat droplets within cells, when they are exposed to excessive nutrients. In mammals, excess consumed energy is stored as fat droplets within all cells. In fat cells, the energy is stored in very large droplets, and we see this as extra body fat. This is som ....Inosine-5' Monophosphate Dehydrogenase (IMPDH) is an enzyme responsible for providing a form of energy to cells, so that they may undertake their correct functions. Recently, we have demonstrated that IMPDH also has a role in the formation of fat droplets within cells, when they are exposed to excessive nutrients. In mammals, excess consumed energy is stored as fat droplets within all cells. In fat cells, the energy is stored in very large droplets, and we see this as extra body fat. This is sometimes associated with an alteration in the hormone production of the cells, leading to problems such as diabetes. In other cells, the excess energy is stored as tiny fat droplets (lipid bodies) that can adversely affect the function of the cell. We have shown that blocking the action of IMPDH can interfere with the accumulation of fat in both fat cells and other types of cell. This suggests that IMPDH has an important role in the development of obesity and associated problems such as diabetes. In this study we aim to investigate in detail the role of IMPDH in the accumulation of fat droplets in cells. We will do this by looking at the effects of different forms of IMPDH in different cell types, including human fat cells. We will also study cells and animals with increased or decreased amounts of IMPDH, and investigate the effects of this on the development of increased fat stores and insulin resistance. These studies will increase our understanding of the role of IMPDH in the development of obesity, and may lead to identification of new avenues of treatment for obesity and type 2 diabetes.Read moreRead less