Identifying Target Molecules Regulated By Nuclear Retention In Cancer And Development
Funder
National Health and Medical Research Council
Funding Amount
$267,173.00
Summary
Human DNA contains approximately 30000 genes; only twice as many as worms and flies, ten times as many as bacteria, and fewer than rice. Humans, however have considerably more complexity than these lower organisms. What are the factors responsible for the additional complexity? In the simplest scenario, one gene is transcribed to produce one message (mRNA), which is the blueprint for producing one protein. We now know that there are numerous mechanisms that potentially allow many different prote ....Human DNA contains approximately 30000 genes; only twice as many as worms and flies, ten times as many as bacteria, and fewer than rice. Humans, however have considerably more complexity than these lower organisms. What are the factors responsible for the additional complexity? In the simplest scenario, one gene is transcribed to produce one message (mRNA), which is the blueprint for producing one protein. We now know that there are numerous mechanisms that potentially allow many different proteins to be made from one gene. Also, it is the decisions about which gene will be made ( expressed ) into protein where and when in development, that is critical for our complexity. The control of gene expression is thus fundamental to all cellular processes and many diseases such as cancer and metabolic disorders are associated with some aspect of aberrant gene expression. The production of mRNA from DNA occurs in the human cell nucleus. The nucleus is not simply a bag of DNA, in fact, many important nuclear factors are organised into sub-nuclear bodies . Recently we discovered a novel sub-nuclear body, the paraspeckle and have been identifying its components and their function. Paraspeckles are involved in a previously undiscovered mechanism of the control of gene expression. Here, certain mRNA molecules are trapped in the nucleus until a signal is received from elsewhere in the cell, which causes the mRNA to be released and protein to be made. This Rapid Release Nuclear Retention mechanism effectively allows the quick production of specific proteins to be made on demand. In this project we propose to use cutting edge molecular and cell biology techniques to identify the special mRNA molecules that are trapped in paraspeckles in cancer cells. This will increase our understanding about the molecular details of this process, ultimately leading to potential uses in gene therapy, and should result in the discovery of important targets for cancer treatment.Read moreRead less
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
A Structural And Functional Basis For The Regulation Of Gene Expression By Nuclear Retention Of RNA
Funder
National Health and Medical Research Council
Funding Amount
$504,097.00
Summary
The nuclear retention mechanism is a novel way used by cells to control which genes are made into proteins - a fundamental process for all diseases, particularly cancers. This project will employ cutting edge structural and proteomic techniques to determine the molecular details underpinning nuclear retention. These insights will be important for the development of new tissue-restricted gene therapy applications and drugs targeting the cancers that rely on this mechanism.
Regulation Of The Tumour Suppressors APC And BRCA1 By Nuclear Export
Funder
National Health and Medical Research Council
Funding Amount
$530,874.00
Summary
Cancer cells lack the ability to control their own growth, and thus continously divide in their local environment, leading to tumour formation. Tumour suppressor proteins, like APC and BRCA1, normally function as regulators to help cells respond to outside signals and to stop growing when necessary. The inactivation and altered cellular localisation of tumour suppressor proteins can contribute to cancer development. We have found that the APC and BRCA1 proteins, whose inactivation leads to devel ....Cancer cells lack the ability to control their own growth, and thus continously divide in their local environment, leading to tumour formation. Tumour suppressor proteins, like APC and BRCA1, normally function as regulators to help cells respond to outside signals and to stop growing when necessary. The inactivation and altered cellular localisation of tumour suppressor proteins can contribute to cancer development. We have found that the APC and BRCA1 proteins, whose inactivation leads to development of colon cancer and breast cancer, respectively, contain signals that dictate their movement within the cell. Our novel preliminary findings reveal that APC and BRCA1 are able to move in and out of the cell nucleus. We aim to define how this occurs, and examine how the regulation of their cellular location affects the normal function of these cancer-suppressing proteins. Finally, abnormalities in the nuclear passage of APC or BRCA1 might explain their altered cellular location in cancer cells.Read moreRead less
The Tumour Cell-specific Nuclear Targeting Properties Of Chicken Anaemia Virus VP-3: Potential For Anti-tumour Therapy
Funder
National Health and Medical Research Council
Funding Amount
$465,210.00
Summary
Current trends indicate that cancer will cause 40% of all deaths in Australia by 2012, meaning that new anti-cancer strategies are urgently required. Our proposal intends to examine the subcellular targeting abilities of the unique tumour-cell specific agent apoptin (VP3 - viral protein 3), a small protein encoded by the genome of the chicken anaemia virus. Using various strategies, we have identified part of the apoptin molecule that confers efficient localisation in the nucleus of tumour cells ....Current trends indicate that cancer will cause 40% of all deaths in Australia by 2012, meaning that new anti-cancer strategies are urgently required. Our proposal intends to examine the subcellular targeting abilities of the unique tumour-cell specific agent apoptin (VP3 - viral protein 3), a small protein encoded by the genome of the chicken anaemia virus. Using various strategies, we have identified part of the apoptin molecule that confers efficient localisation in the nucleus of tumour cells, but not non-tumour cells. Our experimental program intends to define this tumour cell-specific targeting signal in detail, and determine the molecular basis of the differential subcellular localisation of apoptin in tumour compared to normal cells. This should contribute fundamental new information regarding the differences between cancer and normal cells. Additionally, we intend to optimise the targeting signal and perform initial experiments to test its efficacy in targeting anti-tumour drugs to the nucleus of tumour cells. Our long-term aim is to use the apoptin tumour cell-specific nuclear targeting signal as part of modular constructs to combat cancer efficiently, and above all, with minimal damage to normal cells and tissues.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