Biological And Clinical Characterisation Of Human Phosphatidylinositide 3-kinase Mutations
Funder
National Health and Medical Research Council
Funding Amount
$33,626.00
Summary
The frequency of PI3K mutations in tumours, suggests that PI3K is one of the most common human oncogenes. Understanding the biological and biochemical significance of these mutations will provide new insights into the biology of human tumourigenesis and further our understanding of the consequence pathways and the progression of human tumours. Such knowledge will help us to identify more effective markers of prognosis, diagnosis, early detection of cancer and design new anti-cancer therapy.
This project seeks to evaluate the role of new cell growth regulating pathway in the development of moles and melanoma. In particular, we will determine at which stage during tumour progression disruption of this pathway occurs, and whether its loss is associated with melanoma patient survival. Identification of the cancer-related changes that occur when this pathway is aberrant may ultimately lead to the development of novel therapies to treat melanoma.
The Importance Of VEGF-D, An Angiogenic Protein, For Lymphangiogenesis, Tumor Growth And Metastasis.
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
Tumors attract blood vessels to obtain the nutrients for growth. Furthermore, the presence of blood vessels in a tumor enables tumor cells to enter the bloodstream and spread to distant parts of the body - a process known as metastatis that is the major cause of death in cancer patients. The growth of blood vessels - angiogenesis - is the mechanism by which tumors attract the vasculature. The capacity to block tumor angiogenesis would be of great benefit in the clinic as it would restrict both t ....Tumors attract blood vessels to obtain the nutrients for growth. Furthermore, the presence of blood vessels in a tumor enables tumor cells to enter the bloodstream and spread to distant parts of the body - a process known as metastatis that is the major cause of death in cancer patients. The growth of blood vessels - angiogenesis - is the mechanism by which tumors attract the vasculature. The capacity to block tumor angiogenesis would be of great benefit in the clinic as it would restrict both the growth and spread of tumors. Tumor cells attract blood vessels by secreting angiogenic growth factors that stimulate the proliferation of endothelial cells - the cells that form the inner lining of blood vessels. These Vascular Endothelial Growth Factors (VEGFs) are proteins. One VEGF, namely VEGF-D, was discovered in our laboratory at the Melbourne Branch of the Ludwig Institute for Cancer Research. VEGF-D stimulates the growth of blood vessels and possibly lymphatic vessels and is present in the most common human cancers including malignant melanoma and cancer of the breast and lung. We hypothesize that angiogenesis in some tumors is dependent on VEGF-D. Moreover, VEGF-D secreted by tumor cells may stimulate growth of lymphatic vessels - lymphangiogenesis. As metastatic spread often occurs via the lymphatic vessels, tumor lymphangiogenesis induced by VEGF-D may contribute to metastasis. The purpose of the research project is to determine the role of VEGF-D in tumor angiogenesis and lymphangiogenesis. Firstly we will thoroughly characterize the localization of VEGF-D in human cancer. Secondly, we will test VEGF-D for lymphangiogenic activity. Thirdly, the growth and metastatic spread in mice of tumors overexpressing VEGF-D will be analysed. Finally, aspects of VEGF-D biochemistry and gene regulation will be studied to develop strategies for inhibition of VEGF-D action in cancer.Read moreRead less
Phosphatidylinositol 3-kinase Mutations Associated With Ovarian, Colon And Breast Tumours
Funder
National Health and Medical Research Council
Funding Amount
$154,000.00
Summary
Colorectal and breast cancers are the two most common registrable cancers in Australia and are second only to lung cancer in the total number of cancer deaths each year (4,678 and 2,612 deaths in 1997 for colorectal and breast, respectively). Ovarian cancer kills a further 740 women each year (Source: Cancer in Australia 1997, AIHW and AACR 2000). Thus, on average, one Australian dies of colorectal, breast or ovarian cancer every hour! Clearly, these are major diseases with a significant impact ....Colorectal and breast cancers are the two most common registrable cancers in Australia and are second only to lung cancer in the total number of cancer deaths each year (4,678 and 2,612 deaths in 1997 for colorectal and breast, respectively). Ovarian cancer kills a further 740 women each year (Source: Cancer in Australia 1997, AIHW and AACR 2000). Thus, on average, one Australian dies of colorectal, breast or ovarian cancer every hour! Clearly, these are major diseases with a significant impact on our society. Unfortunately, though, we still do not understand the basic molecular and-or biochemical abnormalities that initiate and-or drive the development of these cancers. Recent functional and genetic studies in a number of different tumour types (including colon and ovarian) have suggested that members of the phosphatidylinositol 3-kinase (PI3K) enzyme family may be oncogenes (cancer-causing genes). However, strong evidence confirming a causal role for PI3K in human cancer is yet to be reported. Our research proposal outlines a study to address this issue. We have preliminary data demonstrating mutations in at least one member of this enzyme family in a number of tumours. We now propose to undertake a comprehensive analysis of the spectrum, and frequency, of PI3K mutations that occur in colon, breast and ovarian tumours. These studies will allow us to make a definitive assessment of the role of PI3K in the development human cancer. In addition to furthering our understanding of the processes involved in the initiation and progression of human tumours, this project also has the potential to identify new markers for the early detection of cancer and novel targets for new anti-cancer therapies.Read moreRead less
CHARACTERISATION OF A NOVEL REGULATOR OF PHOSPHOINOSITIDE 3-KINASE-MEDIATED CELL PROLIFERATION AND PLATELET SIGNALLING
Funder
National Health and Medical Research Council
Funding Amount
$500,091.00
Summary
Critical functions such as cell growth, cell death and metabolism, are tightly controlled by key proteins which respond to specific stimuli. Perturbation of this process may lead to uncontrolled growth and cancer. This project proposes to examine the potential of a novel protein (an enzyme) as a physiological regulator of cell growth. It is proposed that this enzyme may function as a brake in preventing the evolution of a cancerous state. We will also study the ability of the novel enzyme to inf ....Critical functions such as cell growth, cell death and metabolism, are tightly controlled by key proteins which respond to specific stimuli. Perturbation of this process may lead to uncontrolled growth and cancer. This project proposes to examine the potential of a novel protein (an enzyme) as a physiological regulator of cell growth. It is proposed that this enzyme may function as a brake in preventing the evolution of a cancerous state. We will also study the ability of the novel enzyme to influence other diverse functions, such as uptake of glucose, and blood clot initiation.Read moreRead less
The steroid hormone estrogen plays a critical role in the development of human breast cancer. Anti-estrogen therapy has been believed to be an effective treatment of breast cancer over more than 100 years. However, the anti-estrogen therapy is still restricted mainly because of that estrogen has fundamental physiological actions and a wide range of beneficial effects on bone, brain, cardiovascular and other targeted tissues. Thus, it has become a primary focus of inquiry to understand how estrog ....The steroid hormone estrogen plays a critical role in the development of human breast cancer. Anti-estrogen therapy has been believed to be an effective treatment of breast cancer over more than 100 years. However, the anti-estrogen therapy is still restricted mainly because of that estrogen has fundamental physiological actions and a wide range of beneficial effects on bone, brain, cardiovascular and other targeted tissues. Thus, it has become a primary focus of inquiry to understand how estrogen specifically functions in breast cancer but not in normal tissues. Estrogen serves different functions involving a series of biochemical reactions called signal transduction pathways that can couple estrogen to a specific function, such as cancer formation. We have recently found that a enzyme named sphingosine kinase (SK) activation triggers a novel signal transduction pathway in regulation of cell growth and tumour formation, and that this pathway was activated by estrogen in human breast cancer cells. Thus, we seek to identify how estrogen activate SK and how they contribute to the development of breast cancer. It will ultimately provide a potential target for therapeutic intervention and may yield new compounds that have clinical benefit for anti-breast-cancer.Read moreRead less
Regulation Of Mitogenic Signalling Via The Gab2 Docking Protein
Funder
National Health and Medical Research Council
Funding Amount
$141,750.00
Summary
Cell proliferation is regulated by growth factors which bind to specific receptors on the cell surface. These receptors then transmit a signal to the interior of the cell instructing it to divide. Inside the cell, the signal is transmitted by signalling proteins. Importantly, aberrant signalling by growth factor receptors or intracellular signalling molecules can contribute to cancer. We have recently demonstrated that the signalling protein Gab2 is overexpressed in a subset of breast cancers. F ....Cell proliferation is regulated by growth factors which bind to specific receptors on the cell surface. These receptors then transmit a signal to the interior of the cell instructing it to divide. Inside the cell, the signal is transmitted by signalling proteins. Importantly, aberrant signalling by growth factor receptors or intracellular signalling molecules can contribute to cancer. We have recently demonstrated that the signalling protein Gab2 is overexpressed in a subset of breast cancers. Furthermore, we have identified that another protein, termed PKB, can 'switch off' signalling by Gab2, and that deregulated signalling by Gab2 can make cells cancerous. The aim of this project is to characterize how PKB regulates Gab2, and to investigate whether this mechanism is impaired in human cancers, leading to enhanced Gab2 signalling. The research will provide important information regarding how growth factor signals are transmitted inside cells, and may identify a new cancer-causing gene.Read moreRead less
Development And Evaluation Of Biological Reagents Targeting And Inhibiting Function Of The EphA3 Receptor On Tumor Cells
Funder
National Health and Medical Research Council
Funding Amount
$490,500.00
Summary
Eph receptors and their ligands regulate morphogenesis in the embryo; they direct migration and positioning of cells during the formation of tissue layers and organ systems. There is little evidence for a function of Ephs in adult tissues. However, their abundant, un-scheduled occurrence in various malignant tumours, indicates a role in cancer. Human EphA3, the principle subject of this proposal, is not found in adult tissue but is present at high levels in lung, kidney and brain tumours, leukem ....Eph receptors and their ligands regulate morphogenesis in the embryo; they direct migration and positioning of cells during the formation of tissue layers and organ systems. There is little evidence for a function of Ephs in adult tissues. However, their abundant, un-scheduled occurrence in various malignant tumours, indicates a role in cancer. Human EphA3, the principle subject of this proposal, is not found in adult tissue but is present at high levels in lung, kidney and brain tumours, leukemia and malignant melanoma. High levels of EphA3 and corresponding ligands correlate with melanoma progression, and EphA3 stimulation triggers repulsion and detachment of melanoma cells. It is likely that Eph A3 is involved in release and spreading of tumour cells during melanoma progression. We have characterised reagents, the soluble EphA3 ligand and a monoclonal anti-EphA3 antibody, which bind EphA3 with high affinity and specificity. We will use these two proteins, or modified forms containing attached radiochemicals or cytotoxins, to target human tumours that were implanted into into immuno-deficient mice as animal model system. Our studies will determine if the specificity of our reagents, suggested from previous in-vitro studies, will allow imaging of EphA3 containing tumours, and effect their targeted killing. We will also use a tissue culture model, containing artificial epidermal and dermal layers of skin cells, to study if an inhibitory form of the EphA3 ligand will affect the invasiveness of EphA3 positive, metastatic melanoma cells. Furthermore, we will identify essential parts of this ligand to develop inhibitors with improved pharmacological properties. Together, our studies will establish the role for EphA3 in cancer progression and to assess the efficacy of EphA3 targeting for tumor killing and prevention of metastasis. We envision that this will provide the groundwork for Eph-specific reagents with anti-metastatic action in cancer therapy.Read moreRead less