Cell death by a specialised process known apoptosis is a way of deleting unwanted and harmful cells from the body. As such, aberrant apoptosis is associated with a wide array of diseases including cancer. For example, abnormal levels of proteins that suppress apoptosis or enhance cell survival can result in cancer and often produce resistance to chemotherapy. To understand and treat cancers that result from aberrant apoptosis we need to know at a molecular level how apoptosis is regulated. Centr ....Cell death by a specialised process known apoptosis is a way of deleting unwanted and harmful cells from the body. As such, aberrant apoptosis is associated with a wide array of diseases including cancer. For example, abnormal levels of proteins that suppress apoptosis or enhance cell survival can result in cancer and often produce resistance to chemotherapy. To understand and treat cancers that result from aberrant apoptosis we need to know at a molecular level how apoptosis is regulated. Central to the apoptosis execution are a group of enzymes called caspases that target many cellular proteins for specific cleavage. In this proposal, we will investigate the function of one of the caspases (called caspase-2), in order to better understand its potential role in the apoptosis of cancer cells. A number of recent reports suggest that caspase-2 levels are reduced in many cancer cells. The human caspase-2 gene localizes to a chromosomal region frequently affected- deleted in leukaemia, and caspase-2 levels have been proposed to be predictors of remission and survival in patients with some types of leukaemia. We will study if loss of caspase-2 in cancer cells makes them resistant to killing by drugs and if mice lacking caspase-2 have an increased potential to develop cancer. Understanding caspase-2 function and its regulation is likely to provide new therapeutic opportunities and potential targets for cancer therapy.Read moreRead less
Caspase 8 Apoptotic Signalling Induced By The Inflammasome
Funder
National Health and Medical Research Council
Funding Amount
$603,126.00
Summary
The death of cells of our body can be an active and purposeful process. Programmed death occurs in response to infection or as a defence against cancerous changes. If a virally infected cell can die prior to replication of the virus, this will control the infection. We have investigated cell death in response to DNA found in the cytoplasm of cells, which can be an indication of infection. The novel cell death pathway we are characterising is relevant to defence against infection and tumours.
The Regulation And Role Of Puma And P53 In IL-3 Withdrawal Induced Cell Death
Funder
National Health and Medical Research Council
Funding Amount
$527,683.00
Summary
It is the ultimate fate of most of our cells to die by committing suicide, because they are no longer required, are no longer functioning, or are potentially harmful. This normal physiological process is termed apoptosis . When cell death fails to occur, abnormal cells can accumulate and lead to cancer. Signalling from growth-factors is required for many cell types to survive. When these signals are lost, the cells activate their cell death pathways. It is a hallmark of cancer cells that they ha ....It is the ultimate fate of most of our cells to die by committing suicide, because they are no longer required, are no longer functioning, or are potentially harmful. This normal physiological process is termed apoptosis . When cell death fails to occur, abnormal cells can accumulate and lead to cancer. Signalling from growth-factors is required for many cell types to survive. When these signals are lost, the cells activate their cell death pathways. It is a hallmark of cancer cells that they harbour mutations in cell death genes and their dependence on growth factors for survival is diminished or lost. The genes of the apoptosis pathway function either to promote or inhibit cell death. Some genes in the apoptosis pathway allow apoptosis to proceed rapidly, but do not decide the fate of the cell. Other genes are required for a cell to commit to die, and if they are mutated then a functional cell, that is capable of proliferating, survives. This is a crucial distinction because it is only the genes that decide cell fate that can act as cancer genes, and are valid targets for therapy. We have identified one particular gene, Puma, as an important regulator of cell survival. Without this gene, cells survive longer without growth-factor and, importantly, can proliferate when growth factor is restored. Understanding how this gene functions and is regulated will contribute to our understanding of the gene mutations that lead to cancer and may identify valid targets for cancer therapy. In our model we use growth factor dependent cell lines derived from mice lacking particular genes in the cell death pathway, including Puma. These cells proliferate in the presence of growth factor, and allow us to determine the role of the genes when growth factor is withdrawn. Using this system, we will determine how Puma is able to induce cell death, what other genes are required to regulate this process and how loss of Puma function may contribute to cancer development.Read moreRead less
Elucidating The Mechanism And Function Of Extracellular Vesicle Formation During Cell Death
Funder
National Health and Medical Research Council
Funding Amount
$318,768.00
Summary
In humans, billions of cells will die daily as part of normal turnover in various organs. It is vital that dying cells are rapidly removed as their accumulation has been linked to autoimmunity and inflammation. To aid efficient removal of dead cells, dying cells can disassemble into smaller fragments for neighbouring cells to engulf. We aim to understand the machinery that control how dying cells can disassemble into smaller pieces and their function in efficient cell clearance and autoimmunity.
Molecular Mechanisms Of Death In Cells With Defective Apoptotic Pathways
Funder
National Health and Medical Research Council
Funding Amount
$335,065.00
Summary
The body protects itself from cancer by killing any cell that poses a risk of becoming a tumour. The body kills these cells via a carefully orchestrated sequence (or pathway) of events, however many cancer cells have defects in cell death pathways that has permitted them to survive even though they have been told to die. In this proposal we set out a research program to investigate how to kill cancer cells that don't want to die. Various tumour cells have been shown to have increased levels of B ....The body protects itself from cancer by killing any cell that poses a risk of becoming a tumour. The body kills these cells via a carefully orchestrated sequence (or pathway) of events, however many cancer cells have defects in cell death pathways that has permitted them to survive even though they have been told to die. In this proposal we set out a research program to investigate how to kill cancer cells that don't want to die. Various tumour cells have been shown to have increased levels of Bcl-2, a proto-oncogene that blocks cell death induced by diverse stimuli. Cells that over-express Bcl-2 are also resistant to cytotoxic drugs. Understanding how to bypass Bcl-2 (or proteins that block cell death in tumours) will lead to a better understanding of cell death-cell survival and allow us to explore the possibility of tailoring treatment for patients in which specific defects in death pathways have been identified in their cancer cells. Cytotoxic lymphocytes (CL) are cells of the immune system that defend the body from cancer by specifically attacking and killing tumor cells. We have been pioneering studies of CL:tumour interactions in which we can define the morphology and kinetics of critical events in cell death and have shown that CL have the ability to kill target cells that over-express Bcl-2. Following the aims in this proposal, we will understand the mechanisms by which cytotoxic lymphocytes kill target cells that have defects in classical cell death pathways. These studies will therefore define alternative pathways to cell death in the event that a key component of the preferential pathway to cell death is inoperative. Since cytotoxic lymphocytes use a variety of ways to kill their targets and tumors may contain multiple defects in cell death pathways, we will explore which are the key defects, or the combination of multiple defects, in cell death pathways that prevent cytotoxic lymphocyte mediated cell death and permit tumour survival in vivo.Read moreRead less
Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and, in ....Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and, in general, to maintain the correct number of cells in the body. As such, misregulation of apoptosis is associated with the pathogenesis of a wide array of diseases. To understand, manage and treat disorders that result from aberrant apoptosis, we need to know at molecular and cellular level, how apoptosis is brought about and how it is regulated. We have been studying these processes in detail for several years. Central to the apoptotic execution of cell death are a group of proteases called caspases, that target many cellular proteins for specific cleavage. The activation of caspases is the crucial step in the initiation of apoptosis and therefore each cell has developed complex ways to control this process. If we understand how these regulatory mechanisms operate, we can then formulate strategies that are targeted towards pathologies involving abnormal apoptosis. In this proposal we will use vinegar fly as a model to study the function of caspases in development. We believe that results from this proposal will have several major benefits. Firstly, they will provide important insight into the mechanisms of developmental apoptosis thereby filling many gaps in our current knowledge. Secondly, the study will endeavour to identify new molecules-pathways that lead to caspase activation. Finally, the proposed studies will shed light on the function of caspases in non-apoptotic pathways.Read moreRead less
Defining The Molecular Regulators Of Apoptotic Cell Disassembly And Their Role In Cell Clearance And Lupus-like Autoimmune Disease
Funder
National Health and Medical Research Council
Funding Amount
$773,848.00
Summary
In humans, billions of cells will die daily as part of normal turnover in various organs. It is vital that dying cells are rapidly removed as their accumulation has been linked to autoimmunity and inflammation. To aid efficient removal of dead cells, dying cells can disassemble into smaller fragments for neighbouring cells to engulf. We aim to understand the machinery that controls how dying cells can disassemble into smaller pieces and their function in cell clearance and autoimmunity.
Elucidating The Mechanism And Function Of Cell Disassembly During Apoptosis
Funder
National Health and Medical Research Council
Funding Amount
$425,048.00
Summary
In humans, billions of cells will die daily in various organs as part of normal turnover and disease progression. During cell death, dying cells can disassembly in to smaller fragments, a process that could facilitate their removal, as well as mediate communication with other healthy cells. I aim to understand the machinery that control how dying cells can disassemble into smaller pieces and their function in influenza A infection.