Role Of The Growth Hormone Binding Protein As A Transcriptional Activator
Funder
National Health and Medical Research Council
Funding Amount
$387,226.00
Summary
Growth hormone is an important hormone therapeutic for treating dwarfism. Recently, many new therapeutic applications for growth hormone have been discovered, particularly in relation to its role as an anabolic agent. These include post surgery recovery, enhanced bone fracture healing, Crohns disease, dilated cardiomyopathy, infertility and of course, ageing. This proposal examines a novel way that GH could work, that is by sending the extracellular part of its receptor (GHBP) to the nucleus, wh ....Growth hormone is an important hormone therapeutic for treating dwarfism. Recently, many new therapeutic applications for growth hormone have been discovered, particularly in relation to its role as an anabolic agent. These include post surgery recovery, enhanced bone fracture healing, Crohns disease, dilated cardiomyopathy, infertility and of course, ageing. This proposal examines a novel way that GH could work, that is by sending the extracellular part of its receptor (GHBP) to the nucleus, where it can directly activate gene readout. This would have the effect of augmenting the normal action of GH to regulate gene readout. We have exciting preliminary data which makes us think this may be a new mechanism for hormone activation of genes. The level of GHBP in the nucleus is regulated, and if a defect in export of the GHBP occurred, this would lead to accumulation of nuclear GHBP and stimulate cell proliferation. This may be important in cancer cell proliferation, since we find nuclear GHBP in cancers.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
Role Of The Nuclear Growth Hormone Receptor In Cell Proliferation And Function
Funder
National Health and Medical Research Council
Funding Amount
$477,750.00
Summary
In addition to final height, growth hormone regulates many tissues in the body, and through these, regulates metabolism, body composition, vitality and aspects of ageing. However, there is some evidence that GH can also promote cancer, notably colon and blood cell cancers. Our discovery of the receptor for growth hormone in the cell nucleus, notably in many cancers, has led us to investigate the role of the nuclear GH receptor. We have found that targeting this receptor to the nucleus allows the ....In addition to final height, growth hormone regulates many tissues in the body, and through these, regulates metabolism, body composition, vitality and aspects of ageing. However, there is some evidence that GH can also promote cancer, notably colon and blood cell cancers. Our discovery of the receptor for growth hormone in the cell nucleus, notably in many cancers, has led us to investigate the role of the nuclear GH receptor. We have found that targeting this receptor to the nucleus allows the cell to divide without the need for the normal factors which initiate cell division and survival. We have also found that a part of the GH receptor acts as a gene activator, and have identified some of the nuclear proteins which bind to the receptor and make this so. This proposal aims to establish the link between the nuclear GH receptor and cell division, both mechanistically, and in live animals. We also plan to establish if nuclear localizing the receptor artificially results in cancer formation. The outcome would provide an index of risk from current GH therapy, and could lead to a new cancer therapy.Read moreRead less