E-cadherin is one of the major proteins responsible for mediating cell-to-cell adhesion in the body. During development, E-cadherin is essential for establishing the cellular architecture of epithelial organs and for maintaining epithelial function in the adult. In this context, E-cadherin acts to establish and maintain the polarity of epithelial cells. E-cadherin is also a powerful tumour suppressor and the loss of E-cadherin expression or function is a primary event in metastasis and cancer in ....E-cadherin is one of the major proteins responsible for mediating cell-to-cell adhesion in the body. During development, E-cadherin is essential for establishing the cellular architecture of epithelial organs and for maintaining epithelial function in the adult. In this context, E-cadherin acts to establish and maintain the polarity of epithelial cells. E-cadherin is also a powerful tumour suppressor and the loss of E-cadherin expression or function is a primary event in metastasis and cancer invasion. Proteins at the surface of epithelial cells must be sorted and trafficked, or transported, to different membrane domains. E-cadherin, for instance, must be trafficked to the lateral domain of cells in order to function in cell-cell adhesion. We recently discovered that cell surface E-cadherin is re-internalized and recycled back to the surface via a pathway that is poised to contribute to the regulation of cell adhesion. Our proposed studies aim to reveal how newly-synthesized E-cadherin and recycling E-cadherin are trafficked, which molecules and which vesicle carriers accomplish this transport. E-cadherin has specific amino acids that act as targeting signals for its sorting and trafficking; we have recently identified one such signal and will now seek the signal responsible for its endocytosis. Using specifically engineered mutants of E-cadherin we will also study other proteins that interact with E-cadherin during its trafficking for sorting and regulation. One of these is polycystin, a protein that is mutated in a common inherited kidney disease. Insights into this disease and normal kidney epithelial function will emerge from this work. A growing understanding of E-cadherin function and regulation is essential for the health of epithelial organs and for controlling and preventing cancer.Read moreRead less
Regulation Of Signal Transduction By Cbl: Investigation Of Effects On The Cytoskeleton, Cell Adhesion And Cell Motility
Funder
National Health and Medical Research Council
Funding Amount
$256,527.00
Summary
Changes in cell adhesion and motility have been implicated in a wide range of human pathologies (e.g. immune, reproductive, mental, and cancerous disorders) . Cell adhesion and motility are tightly regulated by a group of proteins known as Rho-GTPases. Novel pharmacological agents that target signalling by Rho-GTPases have been demonstrated to profoundly affect tumour metastasis, as well as central nervous system regeneration following injury. Further exploitation of Rho-GTPase signal modulation ....Changes in cell adhesion and motility have been implicated in a wide range of human pathologies (e.g. immune, reproductive, mental, and cancerous disorders) . Cell adhesion and motility are tightly regulated by a group of proteins known as Rho-GTPases. Novel pharmacological agents that target signalling by Rho-GTPases have been demonstrated to profoundly affect tumour metastasis, as well as central nervous system regeneration following injury. Further exploitation of Rho-GTPase signal modulation, by detailed studies of the molecular mechanisms involved, could lead to significant advances in medical sciences. In particular, treatment of cancer and spinal injuries are likely to benefit from further development of Rho-signalling research.Read moreRead less
Role Of PAK1 In Colorectal Cancer Growth And Metastasis Regulated By Gastrins
Funder
National Health and Medical Research Council
Funding Amount
$460,070.00
Summary
Increased level of PAK1(a protein kinase) was associated with the progression of colorectal (large bowel) cancer (CRC). Gastrin peptides are growth factors responsible for CRC development. The objective of this project is to determine the role of PAK1 in the regulation of CRC growth and metastasis by gastrin peptides. We will use cell culture, animal models and clinical samples in the program. A successful outcome will lead to the development of new CRC therapies such as inhibitors of PAK1.
The regulated movement of membrane receptors and ligands between the cell surface and intracellular compartments is vital to many cellular operations, including communication between cells and their environment. However, the molecular details of these sorting events remain poorly defined. Determination of the mechanisms that control the cellular distribution of receptors is critical for understanding normal cellular processes and in pathological processes like tumorigenesis.
Regulation Of BRCA1 And APC Tumour Suppressor Functions By Nuclear Export
Funder
National Health and Medical Research Council
Funding Amount
$433,500.00
Summary
Cancer cells are unique, in that their ability to divide and grow is no longer controlled. Moreover, the DNA of cancer cells is less stable, and vital control genes often gain small mutations which culminate in a more aggressive or malignant cancer cell. Cancers from different tissues progress and respond in different ways to treatment, and the eventual development of tailored treatments or therapies will require a detailed understanding of how cancers from different tissues arise. Our laborator ....Cancer cells are unique, in that their ability to divide and grow is no longer controlled. Moreover, the DNA of cancer cells is less stable, and vital control genes often gain small mutations which culminate in a more aggressive or malignant cancer cell. Cancers from different tissues progress and respond in different ways to treatment, and the eventual development of tailored treatments or therapies will require a detailed understanding of how cancers from different tissues arise. Our laboratory studies two proteins, BRCA1 and APC, which are encoded by the genes most often associated with breast and colon cancer, respectively. We have made important discoveries linking the movement and location of these proteins inside the cell with their cancer-causing activity. In this project, we will continue to study how and why APC and BRCA1 move between different compartments inside cancer cells, and how this movement can sometimes signal cancer cells to die. Detailed understanding of these processes is essential for the eventual design of drug, peptide or gene therapies aimed at correcting defects in the expression or localisation of APC or BRCA1 in breast or colon cancer cells, and hopefully provide clues for that magic bullet that specifically targets and kills cancer cells.Read moreRead less
Regulation Of The Tumour Suppressors APC And BRCA1 By Nuclear Export
Funder
National Health and Medical Research Council
Funding Amount
$530,874.00
Summary
Cancer cells lack the ability to control their own growth, and thus continously divide in their local environment, leading to tumour formation. Tumour suppressor proteins, like APC and BRCA1, normally function as regulators to help cells respond to outside signals and to stop growing when necessary. The inactivation and altered cellular localisation of tumour suppressor proteins can contribute to cancer development. We have found that the APC and BRCA1 proteins, whose inactivation leads to devel ....Cancer cells lack the ability to control their own growth, and thus continously divide in their local environment, leading to tumour formation. Tumour suppressor proteins, like APC and BRCA1, normally function as regulators to help cells respond to outside signals and to stop growing when necessary. The inactivation and altered cellular localisation of tumour suppressor proteins can contribute to cancer development. We have found that the APC and BRCA1 proteins, whose inactivation leads to development of colon cancer and breast cancer, respectively, contain signals that dictate their movement within the cell. Our novel preliminary findings reveal that APC and BRCA1 are able to move in and out of the cell nucleus. We aim to define how this occurs, and examine how the regulation of their cellular location affects the normal function of these cancer-suppressing proteins. Finally, abnormalities in the nuclear passage of APC or BRCA1 might explain their altered cellular location in cancer cells.Read moreRead less
Defining The Role And Contribution Of Cdc37 To Signal Transduction And Tumourigenesis By Src-family Kinases
Funder
National Health and Medical Research Council
Funding Amount
$411,430.00
Summary
Cells respond to extracellular stimuli, such as growth factors and hormones, by activating intracellular networks of signaling molecules. It is the activation of these signaling networks that is ultimately responsible for mediating the biological responses of cells to extracellular stimuli (e.g. insulin stimulating glucose metabolism by cells). Members of the Src-family of tyrosine kinases are paramount among signaling molecules, as they are able to directly initiate the activation of a cascade ....Cells respond to extracellular stimuli, such as growth factors and hormones, by activating intracellular networks of signaling molecules. It is the activation of these signaling networks that is ultimately responsible for mediating the biological responses of cells to extracellular stimuli (e.g. insulin stimulating glucose metabolism by cells). Members of the Src-family of tyrosine kinases are paramount among signaling molecules, as they are able to directly initiate the activation of a cascade of signaling networks that regulate the activity of the cell. Significantly though, the inappropriate activation of Src-family kinases has been implicated in the development of cancer, particularly breast and colon cancer, in humans. To fulfill their signaling functions however, Src-family kinases must first be folded into an active conformation upon their synthesis in the cell then be maintained in this conformation. Although previous studies, including our own, have implicated a class of proteins called molecular chaperones in this process, little is known about how the folding of Src-family kinases by these proteins is achieved and regulated. The overall aim of this study is to determine how the folding of Hck, one member of the Src-family of tyrosine kinases, into a conformation that enables it to participate in signaling networks is achieved and regulated. It is expected that the results from this study will provide significant new insight into how this process might influence the ability of cells to respond to extracellular stimuli and potentially contribute to the conversion of a normal cell into one with tumourigenic properties. Findings from this project may be particularly important in the context of human cancer. A better knowledge of how the signaling activity of Src-family kinases is regulated by molecular chaperones might provide a new avenue of investigation for the identification of novel chemotherapeutic agents.Read moreRead less
Escape From BRAF-induced Human Melanocyte Senescence In The Genesis Of Melanoma
Funder
National Health and Medical Research Council
Funding Amount
$601,776.00
Summary
Melanoma is the most lethal form of skin cancer and activation of the MAPK growth pathway is a crucial step in the initiation of this cancer, but alone is insufficient, as most melanocytes with active MAPK exist in a growth arrested state. The mechanisms responsible for arresting melanocytes in the presence of active MAPK will be investigated. This project will discover why some melanocytes develop into melanomas whereas most do not.