Functions Of A Novel Conserved DNA Damage Response Protein Family In Telomere Stability
Funder
National Health and Medical Research Council
Funding Amount
$282,825.00
Summary
The free DNA ends of chromosomes, termed telomeres, generally resemble broken DNA. Because broken DNA is a major contributing factor to the onset of cancer, cells try to fix broken ends. However, in case of telomeres, such repair processes have to be prevented because otherwise different chromosomes would fuse with each other. Fused chromosomes are very fragile and cannot be evenly distributed between dividing cells, and are therefore another important trigger of cancer development. Therefore, c ....The free DNA ends of chromosomes, termed telomeres, generally resemble broken DNA. Because broken DNA is a major contributing factor to the onset of cancer, cells try to fix broken ends. However, in case of telomeres, such repair processes have to be prevented because otherwise different chromosomes would fuse with each other. Fused chromosomes are very fragile and cannot be evenly distributed between dividing cells, and are therefore another important trigger of cancer development. Therefore, chromosome ends are covered by a cap, which hides them from the DNA damage response machinery. From these considerations it is clear that there are close connections between the cellular DNA damage response and chromosome ends. Moreover, recently it has become clear that DNA damage proteins are also required to stop normal cells from growing, a process termed senescence. Senescence is a consequence of shortened chromosome ends, and does not occur in cancer cells. Altogether, it is clear that DNA breaks and senescence are two of the major questions for our understanding of cancer development. We have identified a novel conserved protein family that is involved in the response to DNA damage in yeast and humans. In addition, the yeast Mdt1 protein is a very sensitive indicator of changes in the telomere cap. Absence of proteins that organise the cap leads to the addition of several phosphate groups to the Mdt1 protein. We propose that phosphate-coupled Mdt1 prevents chromosome ends from fusion with each other, or from fusing with broken DNA ends after widespread damage. As a consequence, cells that have mild cap defects die at an >1000-fold increased rate in response to DNA damage when they also lack Mdt1. As part of this application we want to find out the precise mechanism by which Mdt1 stabilises chromosome ends, and test our hypothesis that the corresponding human protein termed ASCIZ also has similar functions in protecting chromosome ends.Read moreRead less
Noncoding RNAs As Prognostic Markers And Therapeutic Targets In Breast Cancer
Funder
National Health and Medical Research Council
Funding Amount
$550,283.00
Summary
Normal human development involves a symphony of genetic changes that control the growth and differentiation of different types of cells during embryogenesis. For many years it has been assumed that most genetic information is transacted by proteins, and that the remaining 98% of the human genome that does not encode proteins was (apart from a limited amount of associated regulatory elements) largely non-functional evolutionary junk. However, this may not be the case. Recent results from our labo ....Normal human development involves a symphony of genetic changes that control the growth and differentiation of different types of cells during embryogenesis. For many years it has been assumed that most genetic information is transacted by proteins, and that the remaining 98% of the human genome that does not encode proteins was (apart from a limited amount of associated regulatory elements) largely non-functional evolutionary junk. However, this may not be the case. Recent results from our laboratory and others have shown that most of our genome and that of other mammals is actually expressed as noncoding RNA, which appears to be developmentally regulated. These RNAs (of which there appear to be tens of thousands, well outnumbering the protein-coding mRNAs) have been referred to as the hidden layer or dark matter of our genome, as they have barely been studied, but appear to play a central role in both normal and abnormal development in humans. There is now increasing evidence that many noncoding RNAs, including small regulatory RNAs called microRNAs, are perturbed in cancer and that these perturbations may be directly involved in, and be an accurate indicator of, cancer state and the direction of cancer progression. If this is true we need to understand the expression and functions of these RNAs in order to develop better diagnostics and perhaps powerful new therapeutics for cancer, based on RNA technology and generic delivery systems. This project will explore the patterns of noncoding RNA expression in normal breast development and in breast cancer, to identify those RNAs that direct or accompany the differentiation of these tissues, and to test the effects of interfering with their expression on these processes. These foundation studies lie at the leading edge of a new understanding of human genetics and cancer, and will provide a platform for future applications in medicine that utilize this information and understanding.Read moreRead less
Genetic Models Of Cancer Development And Treatment
Funder
National Health and Medical Research Council
Funding Amount
$645,250.00
Summary
We are taking advantage of the powerful genetic tools in fruit flies to study the genetics of cancer. 72% of cancer genes are conserved between humans and fruit flies, making it a particularly suitable system. This project has two main aims: 1- to build tumours in fruit flies in an effort to understand better the individual genetic lesions that contribute to cancer It takes on average 4-7 mutations for a tumour to develop. While many genes associated with cancer have been identified, there are m ....We are taking advantage of the powerful genetic tools in fruit flies to study the genetics of cancer. 72% of cancer genes are conserved between humans and fruit flies, making it a particularly suitable system. This project has two main aims: 1- to build tumours in fruit flies in an effort to understand better the individual genetic lesions that contribute to cancer It takes on average 4-7 mutations for a tumour to develop. While many genes associated with cancer have been identified, there are many more that have not. What is more, it is still not clear precisely what mutations are responsible for a given tumour as tumours contain many genetic lesions most of which are incidental. We have a collection of fruit flies strains that represent various stages of the progress toward cancer development, and we intend to test different genetic combinations of these to determine which combinations result in cancer. 2- to identify a class of genes we have called 'oncogene suppressor genes' which may have the ability to prevent tumours from forming. Recently, it has been discovered that oncogenes may be required for both the INITIATION of tumours and the MAINTENANCE of tumours. This means that suppressing oncogene function may not only prevent tumour formation, but also tumour maintenance - in other words, it may make tumours go away. Thus, oncogene suppressor genes may represent exciting therapeutic targets for the treatment and possibly also prevention of cancer. At this time it is not clear whether oncogenes are generally required for tumour maintenance, or whether this is a property of only one or a few oncogenes. As these experiments are difficult and expensive to conduct in mammalian systems, we have devised simple, rapid tests in fruit flies instead. We plan to use these tests to investigate the effect of 'oncogene suppressor genes' on tumour initiation and maintenance in fruit flies. Ultimately, we believe these genes may represent therapeutic targets.Read moreRead less
Understanding how cells compact and segregate DNA in vertebrates. How a cell compacts and divides its DNA is still a major unanswered question in biology. This project will determine the way in which a cell compacts its DNA nearly ten thousand fold to allow the faithful and accurate segregation to daughter nuclei.
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0775778
Funder
Australian Research Council
Funding Amount
$196,000.00
Summary
A microarray platform for gene expression analysis and genotyping in biological systems. This technology has substantial benefits for basic science and biotechnology. The ability to rapidly study changes in gene expression in living organisms will benefit agriculture, animal and biomedical science and biotechnology. The Affymetrix platform creates opportunities for new avenues of research, such as studying epigenetic (DNA and protein modifications) mechanisms in development, ageing and disease. ....A microarray platform for gene expression analysis and genotyping in biological systems. This technology has substantial benefits for basic science and biotechnology. The ability to rapidly study changes in gene expression in living organisms will benefit agriculture, animal and biomedical science and biotechnology. The Affymetrix platform creates opportunities for new avenues of research, such as studying epigenetic (DNA and protein modifications) mechanisms in development, ageing and disease. The project falls within the designated national research priority areas of 'promoting and maintaining good health" and the priority goals of "a healthy start to life", "aging well", "aging productively" and "preventative health care."Read moreRead less
Discovering mechanisms of primary embryonic tissue migration through live cell imaging and novel genetic approaches. The studies proposed here will provide concepts and knowledge about the molecular basis of cell migration that will impact on diverse aspects of human health, such as the causes and nature of tumour metastasis and our understanding of the developmental basis of birth defects. In addition, understanding cell migration mechanisms will allow us to better predict or control the behav ....Discovering mechanisms of primary embryonic tissue migration through live cell imaging and novel genetic approaches. The studies proposed here will provide concepts and knowledge about the molecular basis of cell migration that will impact on diverse aspects of human health, such as the causes and nature of tumour metastasis and our understanding of the developmental basis of birth defects. In addition, understanding cell migration mechanisms will allow us to better predict or control the behaviour of therapeutic stem cells introduced into the body.Read moreRead less
How does Fat cadherin control organ size in Drosophila, and cancer in humans? The primary function of Fat cadherin is to dictate the appropriate size of organs in developing animals. Deficiency in the fat gene results in vastly overgrown organs and can lead to the formation of cancer in humans. Our study will provide important insights into how the size of organs are controlled during development. Our research findings will have important implications for several aspects of human health and biol ....How does Fat cadherin control organ size in Drosophila, and cancer in humans? The primary function of Fat cadherin is to dictate the appropriate size of organs in developing animals. Deficiency in the fat gene results in vastly overgrown organs and can lead to the formation of cancer in humans. Our study will provide important insights into how the size of organs are controlled during development. Our research findings will have important implications for several aspects of human health and biology, and will increase our understanding of diseases that arise due to aberrant tissue growth, such as cancer. Our research findings will thus be of substantial national benefit, given that cancer is now the biggest cause of death in Australia, and that more than 88,000 Australians are diagnosed with cancer each year. Read moreRead less
Investigating the role of gene loops in regulating gene expression. The ability to identify functional variants in regulatory elements will have implications for researchers in multiple fields of biology, from molecular medicine to agriculture. Transfer of expertise and application of the knowledge generated by our research to such fields stands to improve diagnosis of disease predisposition and to improve quality of animal and plant products. These outcomes will benefit all Australians. This kn ....Investigating the role of gene loops in regulating gene expression. The ability to identify functional variants in regulatory elements will have implications for researchers in multiple fields of biology, from molecular medicine to agriculture. Transfer of expertise and application of the knowledge generated by our research to such fields stands to improve diagnosis of disease predisposition and to improve quality of animal and plant products. These outcomes will benefit all Australians. This knowledge will also improve the education of Australian University students as it contributes to the development of advanced curricula and access to more powerful research methods. In addition, the project will foster important collaborations between Australian researchers and those overseas.Read moreRead less
CD151 and functional overlap in tetraspanins. The applicants are currently world leaders in the tetraspanin field. This project will enhance existing international collaborations to maintain and increase the applicants', and hence Australia's, international standing in this field and Australia's reputation in cell and molecular biology in general.
The project will greatly increase our understanding of this important but poorly understood family of proteins. It will also provide training opport ....CD151 and functional overlap in tetraspanins. The applicants are currently world leaders in the tetraspanin field. This project will enhance existing international collaborations to maintain and increase the applicants', and hence Australia's, international standing in this field and Australia's reputation in cell and molecular biology in general.
The project will greatly increase our understanding of this important but poorly understood family of proteins. It will also provide training opportunities for postgraduate students in state-of-the-art approaches in biotechnology.Read moreRead less