Loss Of Cytostatic Regulation By TGF-beta During EGFR-driven Tumor Development
Funder
National Health and Medical Research Council
Funding Amount
$605,031.00
Summary
Growth factor and cytokine signalling networks control many aspects of cell behaviour such as proliferation, survival, migration, invasive capabilities, transformation and differentiation. In normal cells, these complex signalling pathways are tightly regulated. Alterations of these signals are often found to cause, directly or indirectly, tumour formation. Transforming Growth Factor-b (TGF-b) and Epidermal Growth Factor (EGF) signalling pathways are both independently implicated as key regulato ....Growth factor and cytokine signalling networks control many aspects of cell behaviour such as proliferation, survival, migration, invasive capabilities, transformation and differentiation. In normal cells, these complex signalling pathways are tightly regulated. Alterations of these signals are often found to cause, directly or indirectly, tumour formation. Transforming Growth Factor-b (TGF-b) and Epidermal Growth Factor (EGF) signalling pathways are both independently implicated as key regulators in tumour formation and as such they are potential therapeutic targets. However, while both pathways have been studied extensively, little is known about the cross-talk between the TGF-b and EGF pathways. This project will establish the generality of a new tumor signaling axis, namely EGFR-Stat3-Smad7-TGF-b in EGFR-overexpressing tumors. Practically, it will provide guidelines for the development of new approaches for treating effectively the EGFR-driven tumors.Read moreRead less
Characterization Of HLS5, A Novel Tumor Suppressor Gene
Funder
National Health and Medical Research Council
Funding Amount
$406,980.00
Summary
HLS5 is a novel gene that we recently discovered in our laboratory. Preliminary investigations suggest that HLS5 is similar to a family of genes which act as DNA regulators. We have shown that HLS5 is found on a region of chromosome 8 which is often deleted in human cancers, suggesting that HLS5 is a new tumour suppressor gene i.e.. damage to this gene may be responsible for the formation of certain types of cancer (specifically breast and prostate). Other evidence to support the claim that HLS5 ....HLS5 is a novel gene that we recently discovered in our laboratory. Preliminary investigations suggest that HLS5 is similar to a family of genes which act as DNA regulators. We have shown that HLS5 is found on a region of chromosome 8 which is often deleted in human cancers, suggesting that HLS5 is a new tumour suppressor gene i.e.. damage to this gene may be responsible for the formation of certain types of cancer (specifically breast and prostate). Other evidence to support the claim that HLS5 is a tumour suppressor gene comes from the proteins it associates with these partner molecules are involved in DNA repair or DNA regulation. When we introduced HLS5 into cancer cells, it slowed their growth and reduced their ability to form tumours. The aim of this project therefore, is to undertake a detailed analyses of the HLS5 gene and to determine the function of its protein product. A combination of approaches will be used in this study. We will: (i) alter the amount of HLS5 expression in cancer cells, (ii) characterize the proteins which bind to HLS5, (iii) determining where HLS5 localizes in the cell, (iv) analyze mice with lack the gene for HLS5, (v) assess the involvement of HLS5 in a human leukemia (vi) analyze HLS5 messenger RNA which produces the protein, and (vii) determining the structure of HLS5 protein. These studies should provide valuable information on how HLS5 functions, as well as its role in cancer formation.Read moreRead less
The Role Of The 72 KDa Inositol Polyphosphate 5-phosphatase In Cellular Function.
Funder
National Health and Medical Research Council
Funding Amount
$549,196.00
Summary
Cells respond to external signals and the environment to undergo cell growth, secretion and-or other specialized functions including control of cell death and-or cell size. We have identified a new enzyme (72kDa 5-phosphatase) which resides inside the cell and regulates signals generated by an enzyme called PI3-kinase. Two of the PI3-kinase signals have been demonstrated to regulate the activity of an oncogene involved in breast and ovarian cancer. We aim to determine the specific role each of t ....Cells respond to external signals and the environment to undergo cell growth, secretion and-or other specialized functions including control of cell death and-or cell size. We have identified a new enzyme (72kDa 5-phosphatase) which resides inside the cell and regulates signals generated by an enzyme called PI3-kinase. Two of the PI3-kinase signals have been demonstrated to regulate the activity of an oncogene involved in breast and ovarian cancer. We aim to determine the specific role each of these PI3-kinase signals plays in the activation of the oncogene. In addition the levels of the 72kDa enzyme is altered in some cervical and lymphoma cancers. We will image live cells containing specific fluorescent probes under different conditions and study the activation and location of these probes in order to understand how different PI3-kinase signals are regulated in time and space. In addition to regulating signals that are involved in cancer, PI3-kinase controls signals that are important for proper immune function. Phagocytosis is a biological process where specialised immune cells (macrophages) take up and remove harmful particles such as bacteria or tumour cells from the circulation. This process depends on PI3-kinase and the signals it produces. We will determine whether the 72 kDa enzyme, which is expressed in macrophages, plays a role in regulating these signals during phagocytosis. We have shown that the 72 kDa enzyme can interact with several different proteins which may affect its location and activity within the cell. We will examine the effect of these interactions on the PI3-kinase signals which are involved in cell survival and immune responses. We will study the function of the enzyme in the intact animal by producing mice which lack this enzyme. Given the possible role of this enzyme in cancer, these mice will be examined for their susceptibility to develop tumours.Read moreRead less
Adhesion between cells is important during health and disease. Cell-cell interactions are necessary both as the embryo forms and to preserve tissues and organs in later life. Important disease states arise when cell-cell adhesion is broken. Only by understanding the molecular mechanisms that hold cells together can we analyse how they are perturbed to cause diseases such as cancer and inflammation.
Preserving Barriers: How Cadherin Signaling Coordinates Dynamic Adhesion And Tight Junction Assembly In Epithelial Cell.
Funder
National Health and Medical Research Council
Funding Amount
$557,939.00
Summary
Epithelia protect the body from its environment. Breakdown of the epithelial barrier in tissues such as the skin and intestine, as occurs in burns and inflammation, leads to invasion of bacteria and severe metabolic disturbances. In this project we study the cell signaling mechanisms that maintain epithelial barriers in healthy tissues that undergo turnover and remodelling. Understanding these signaling pathways provides a foundation to understand how they are perturbed in disease.
Interactions Between IGFBP-3 And TGFbeta In The Inhibition Of Breast Cancer Cell Growth
Funder
National Health and Medical Research Council
Funding Amount
$662,970.00
Summary
A protein first identified by our research group, called insulin-like growth factor binding protein-3 or IGFBP-3, has been shown to be a potent inhibitor of the growth of cancer cells. High levels of IGFBP-3 in the bloodstream are associated with a decreased risk of several cancer types, including breast cancer. However, the way in which this protein prevents cancer cells from growing is poorly understood. This project will investigate an entirely novel idea, developed in our laboratory, that th ....A protein first identified by our research group, called insulin-like growth factor binding protein-3 or IGFBP-3, has been shown to be a potent inhibitor of the growth of cancer cells. High levels of IGFBP-3 in the bloodstream are associated with a decreased risk of several cancer types, including breast cancer. However, the way in which this protein prevents cancer cells from growing is poorly understood. This project will investigate an entirely novel idea, developed in our laboratory, that the actions of IGFBP-3 are intimately connected with the actions of another known cell growth inhibitor called transforming growth factor beta (TGFbeta). We have found that these two proteins initiate the same sequence of events leading to growth inhibition in breast cancer cells, and that a receptor protein required for TGFbeta activity is also needed for IGFBP-3 to be inhibitory. Our work has the potential to explain for the first time exactly how IGFBP-3 stops cancer cells from growing. This is important because it is an abundant protein in the body, and understanding how it acts may lead to the development of new approaches to cancer therapy that exploit our findings.Read moreRead less
Regulation Of Dynamic Cell-cell Adhesions By Coordinated Action Of Lipid Kinases And Phosphatases
Funder
National Health and Medical Research Council
Funding Amount
$529,565.00
Summary
This research project studies the molecular mechanisms that allow cells to attach to, and recognize, one another. Such cell-to-cell adhesion is mediated by the cadherin family of molecules, which reside on the surfaces of cells. Cadherins allow cells to recognize one another and, upon recognition, to adhere to each other. By this means, populations of individual cells can be linked together into cohesive populations - i.e. the tissues and organs of the body. The importance of cadherin adhesion i ....This research project studies the molecular mechanisms that allow cells to attach to, and recognize, one another. Such cell-to-cell adhesion is mediated by the cadherin family of molecules, which reside on the surfaces of cells. Cadherins allow cells to recognize one another and, upon recognition, to adhere to each other. By this means, populations of individual cells can be linked together into cohesive populations - i.e. the tissues and organs of the body. The importance of cadherin adhesion is exemplified by the fact that disruption of cadherin adhesion contributes to many important diseases, especially inflammation and cancer. Thus understanding how cadherins hold cells together is necessary for us to understand the molecular basis of common diseases. In this project we study how cadherins signal to regulate cellular behaviour. We build on our recent discovery that E-cadherin can activate a lipid in the cell membrane, PIP3, that is known to be a key regulator of many cellular activities. We aim to understand how this signal is generated in response to E-cadherin adhesion and how it elicits normal cellular responses to cadherin adhesion.Read moreRead less
The Role Of Membrane Condensation In T Lymphocyte Activation And Signal Transduction
Funder
National Health and Medical Research Council
Funding Amount
$82,421.00
Summary
T cell lymphocytes are essential cells in our immune system. They respond to signals from foreign bodies to mount an immune response. Many diseases arise from errors in their activation processes. The key steps in the translation of the initial arrival of a foreign-body to a T cell into an immune response will be examined in these studies, where we will look at the cooperation of components of the cell membrane during T cell activation. This will help us to understand and treat immune disorders.
Members Of The CMRF-35 Leukocyte Receptor Complex On Human Chromosome 17q22-24 Modulate Immune Function
Funder
National Health and Medical Research Council
Funding Amount
$489,750.00
Summary
We have identified and characterized a group of proteins on the surface of different white blood cells called the CMRF-35 molecules. We hypothesize that these molecules play a role in regulating an immune response by acting as thermostat molecules i.e. molecules able to trigger or inhibit the immune response. This project aims to define the role of two of these molecules in regulating white blood cells in their response to foreign molecules or antigens. This project will have significant impact ....We have identified and characterized a group of proteins on the surface of different white blood cells called the CMRF-35 molecules. We hypothesize that these molecules play a role in regulating an immune response by acting as thermostat molecules i.e. molecules able to trigger or inhibit the immune response. This project aims to define the role of two of these molecules in regulating white blood cells in their response to foreign molecules or antigens. This project will have significant impact on understanding whether these triggering and inhibitory signals initiated from the CMRF-35 molecules effects i) how the cells divide, ii) what molecules are secreted by the cells, iii) whether the cells can mature or iv) whether a cell survives or dies. Some of the molecules involved in sending these signals will be identified. The ability to trigger or inhibit cellular effects through these molecules may be important in some forms of myeloid leukemia and in the ability to help manipulate the immune response to fight tumors.Read moreRead less