Use Of Expression Profiling To Identify Genes Influencing Cardiovascular Risk In The Norfolk Island Population Isolate
Funder
National Health and Medical Research Council
Funding Amount
$697,409.00
Summary
This study will use a unique population isolate from Norfolk Island. We aim to identify genes that play a role in cardiovascular disease risk. Norfolk has a population of ~1200 permanent residents, most of whom are direct descendents of 18th century English Bounty mutineers and Polynesian women. We will undertake gene expression mapping to identify genomic loci that influence cardiovascular disease using samples from this population isolate.
Investigation Into The Alternative Splicing Of Steroid Hormone Regulated Genes In Breast Cancer.
Funder
National Health and Medical Research Council
Funding Amount
$292,216.00
Summary
Steroid hormones have imortant roles in breast tissue growth and differentiation. We have identified several proteins called PRMT6 and CAPER's , that are involved in steroid hormone signaling and control the alternative splicing of RNA, the process in which several different proteins can be produced from a single gene. Our aim is to study these proteins in an effort to understand how they influence alternative splicing and to identify genes they control in relation to breast cancer.
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
Alternative Splicing Of GLI1 And Its Role In Tumourigenesis
Funder
National Health and Medical Research Council
Funding Amount
$392,640.00
Summary
Gene expression involves the transfer of information from DNA to proteins and is mediated by a third molecule called messenger RNA (mRNA). The process is tightly controlled since unregulated gene expression is harmful and can result in diseases such as developmental disorders and cancer. The genetic information in DNA is first copied to an RNA molecule in a process called transcription. This RNA molecule then undergoes a series of maturation steps before the information it carries can be transla ....Gene expression involves the transfer of information from DNA to proteins and is mediated by a third molecule called messenger RNA (mRNA). The process is tightly controlled since unregulated gene expression is harmful and can result in diseases such as developmental disorders and cancer. The genetic information in DNA is first copied to an RNA molecule in a process called transcription. This RNA molecule then undergoes a series of maturation steps before the information it carries can be translated into a protein. One of these maturation steps involves the removal of sequences (called introns) that do not contain protein coding information from the sequences (called exons) that will be present in the mature mRNA. Some genes contain no introns while others contain 20 or more, which are dispersed throughout the gene. The removal of intron sequences from immature RNA molecules is called splicing and is carried out by a macromolecular complex that recognises the intron sequences, cuts them out of the RNA and then rejoins the RNA to make a contiguous sequence. This process has to be precise otherwise spurious sequences will be present in the mRNA, which will result in the production of abnormal proteins. In addition, for some genes mRNAs are produced that have differences in a portion of their sequence. These alternative sequences are generated by the inclusion or exclusion of alternative exons. Because, RNA splicing is critical to the production of mature mRNAs and because it can generate sequence diversity it is tightly regulated. We have recently found that expression of a cancer gene (called GLI1) is regulated in part by the use of alternative GLI1 mRNAs. Moreover, we found that the expression of one of these alternative GLI1 mRNAs is associated with skin cancer. In this project we will investigate the molecular mechanisms that regulate alternative splicing in GLI1 and identify whether changes in these mechanisms result in cancer.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.
Post Transcriptional Regulation Of Plasminogen Activator Inhibitor Type 2 Gene Expression
Funder
National Health and Medical Research Council
Funding Amount
$318,000.00
Summary
The process of wound healing, cell migration and the spread of cancers requires the recruitment of specialised proteases to the cell surface . These proteases act to degrade other proteins, mainly in the extracellular space, which in turn allows cells to move around, wounds to close, and blood clots to disappear. The plasminogen activating system is one of the enzyme systems involved in these events. One of the proteases that cleaves plasminogen to its active form, plasmin, is urokinase (u-PA) a ....The process of wound healing, cell migration and the spread of cancers requires the recruitment of specialised proteases to the cell surface . These proteases act to degrade other proteins, mainly in the extracellular space, which in turn allows cells to move around, wounds to close, and blood clots to disappear. The plasminogen activating system is one of the enzyme systems involved in these events. One of the proteases that cleaves plasminogen to its active form, plasmin, is urokinase (u-PA) and the activity of u-PA is regulated by its natural inhibitor called plasminogen activator inhibitor type 2 (PAI-2). u-PA is strongly implicated in the progression of metastatic cancer and high levels of PAI-2 relative to u-PA is regularly seen as a positive prognostic indicator for metastatic cancer. In this situation, PAI-2 acts to limit the activity of u-PA thereby restricting the migration potential of the cancer. PAI-2 is unusual because it exists both inside and outside the cell. Outside the cell, PAI-2 acts to inhibit u-PA activity, while inside the cell, PAI-2 also plays a role in the inhibition of cell growth and differentiation. It is therefore important to understand how the production of PAI-2 is regulated in cells. A significant component of PAI-2 regulation occurs post-transcriptionally, particularly at the level of mRNA stability. We have identified some of the proteins that bind to PAI-2 mRNA and influence its longevity in the cell. This project aims to further undertand how these as well as other PAI-2 mRNA binding proteins influence the expression of the PAI-2 gene.Read moreRead less
Gene Transcription In Activated T Cells: A Model Of Chromatin Remodeling.
Funder
National Health and Medical Research Council
Funding Amount
$477,500.00
Summary
Cells of the immune system respond to invasion of the body by infectious or other damaging agents by switching on the production of a large array of proteins that are critical for an orchestrated immune response. Some of these proteins, referred to as cytokines, are secreted by the cells and act as intercellular messengers to affect the function of other cells need for an immune response. Switching on the production of these cytokines requires the genes that produce them to interpret the complex ....Cells of the immune system respond to invasion of the body by infectious or other damaging agents by switching on the production of a large array of proteins that are critical for an orchestrated immune response. Some of these proteins, referred to as cytokines, are secreted by the cells and act as intercellular messengers to affect the function of other cells need for an immune response. Switching on the production of these cytokines requires the genes that produce them to interpret the complex signaling pattern to which the cell has been exposed. These complex signaling patterns are interpreted in the nucleus by molecular switches that lie beside the genes in the DNA. The incorrect production of these proteins is involved in immune diseases such as autoimmunity, allergy and leukemia. Genes are housed in the nucleus of the cell, packaged into a structure known as chromatin. When the gene is not producing protein it is tightly packaged in chromatin but when it is activated to produce protein this packaging is altered to allow the gene to see the signals being received by the cell and produce protein. We have identified a protein within the nucleus that is critical in allowing certain cytokine genes to see the signals being received in the nucleus. By investigating the role of this protein (called c-Rel) in chromatin reorganization in immune cells, we hope to better define the steps required for appropriate gene activation in an immune response. This knowledge, in turn, will lead to the identification of novel therapeutic targets to control immune responsesRead moreRead less
Variable Expressivity And Epigenetic Inheritance At The Axin Fused Locus In The Mouse
Funder
National Health and Medical Research Council
Funding Amount
$242,545.00
Summary
Genes influence the way we look and variations in gene sequence can account for the differences between individuals. Family traits are often credited to gene variants that are passed down through generations of families. There is now intriguing evidence, some coming from our laboratory, that gene sequence is not the only thing we inherit from our parents. Modifications that alter the expression but not the sequence of a gene, known as epigenetic modifications can, it turns out, be inherited in m ....Genes influence the way we look and variations in gene sequence can account for the differences between individuals. Family traits are often credited to gene variants that are passed down through generations of families. There is now intriguing evidence, some coming from our laboratory, that gene sequence is not the only thing we inherit from our parents. Modifications that alter the expression but not the sequence of a gene, known as epigenetic modifications can, it turns out, be inherited in mammals. An epigenetic modification is a mark, present on some genes that determines whether the gene is expressed (switched on) or silent. Animals are thought to acquire this mark during development and it is retained throughout life except in germ cells where the mark is generally, but not always, erased. The establishment of the mark appears to be a stochastic event at the cellular level resulting in mosaic expression. The percentage of marked cells can differ from one individual to another . In theory, this could help to explain why individuals with identical genetic information, such as identical twins, can have different phenotypic characteristics. The fact that these modifications can be inherited implies that there is an alternative mode of inheritance of genetic traits which does not involve mutation but which can be carried from generation to generation in a semipermanent way. Understanding the mechanisms underlying these events is important if we wish to predict or modify the phenotype of an invidual or that of his or her offspring.Read moreRead less
Effects Of The Atrial Natriuretic Factor Enhancer And The 5'HS4 Insulator On The Probability Of Gene Expression.
Funder
National Health and Medical Research Council
Funding Amount
$534,628.00
Summary
Complex organisms contain many different types of cells, which can have completely different appearances and functions. All of these cells contain the same genes; the differences between them are achieved by the selective use of the genes. The means by which the selective use of genes is accomplished is a key to understanding how complex organisms develop, and how that development goes awry in cancer, heart disease, and other common disorders. A very large body of evidence indicates that gene re ....Complex organisms contain many different types of cells, which can have completely different appearances and functions. All of these cells contain the same genes; the differences between them are achieved by the selective use of the genes. The means by which the selective use of genes is accomplished is a key to understanding how complex organisms develop, and how that development goes awry in cancer, heart disease, and other common disorders. A very large body of evidence indicates that gene regulation is accomplished by the interaction of protein factors with segments of DNA flanking the gene. One hypothesis underlying our work is that the flanking DNA elements act primarily to increase the probability that a gene will be active rather than silent. We will ask if removing a known regulatory element from the gene for Atrial Natriuretic Factor (ANF) in mice reduces the likelihood of ANF being expressed by heart cells when the heart is stressed. This experiment will also shed new light on an extremely common disease state in humans (cardiac hypertrophy). In a second experiment, we will use a new experimental system we have developed to ask if a gene regulatory element is able to dial up the amount of expression from a gene, as well as to switch the gene on. Our previous work suggested this was not the case, but we wish to conduct a more rigorous test. Another hypothesis is that no DNA element is able to completely shield a transferred gene from the regulatory elements surrounding it. Accordingly, we will test a DNA element that has been proposed to insulate any gene from all influences of surrounding genes, and ask if it is able to create an autonomously expressing gene at any site within the genome. Because they deal with functions that are common to all genes, these experiments will provide information that should be applicable to a broad array of efforts to manipulate gene expression.Read moreRead less
Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the r ....Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the reactivation of their foetal haemoglobin genes, (a distinct set of genes that would have been active in utero but are normally silenced around the time of birth). It is widely accepted that if pharmaceutical means can be found for reactivating the foetal haemoglobin genes then many patients would benefit. The regulation of the foetal globin genes, like most human genes, is complicated and there are few obvious means of increasing their activity. Nevertheless, it is believed that by investigating the molecular mechanisms by which they are controlled it will be possible to devise therapeutic agents that mimic these mechanisms or to develop agents that prevent the shutdown of the foetal genes around birth. To this end we have been working on the molecules that regulate the activity of the haemoglobin genes. We have recently cloned a number of DNA-binding proteins, and their co-factors, that appear to be involved in silencing foetal globin gene expression. This grant proposal is concerned with learning how these new molecules operate to silence gene expression as a first step towards designing agents that will prevent the silencing.Read moreRead less