The Role Of Protein Tyrosine Phosphatases Regulating Eph RTK-signalling And Modulating Invasive Tumour Cell Properties.
Funder
National Health and Medical Research Council
Funding Amount
$303,828.00
Summary
The Ephs and interacting ephrins are proteins on the cell surface, which enable orientation of cells that move within the body tissues and organs, but also in tumours. Eph proteins have tyrosine kinase enzyme activity that becomes active after binding ephrins on neighbouring cells. Once active, they instruct these cells to change their shape and their adhesion to the substratum or between each other, and to become more motile. In adult organisms Ephs and ephrins are low in most cells, but they r ....The Ephs and interacting ephrins are proteins on the cell surface, which enable orientation of cells that move within the body tissues and organs, but also in tumours. Eph proteins have tyrosine kinase enzyme activity that becomes active after binding ephrins on neighbouring cells. Once active, they instruct these cells to change their shape and their adhesion to the substratum or between each other, and to become more motile. In adult organisms Ephs and ephrins are low in most cells, but they re-appear in many tumors. For example, when normal cells in the skin (melanocytes) become tumor cells, they often will have Ephs and ephrins on their surface. It is believed that these proteins will now affect if these melanoma cells will migrate and to which locations within the body. In our studies we will examine what controls the activity of Eph proteins. In particular, a class of enzymes called tyrosine phosphatases are known to regulate the function of tyrosine kinase receptors, however it is not clear which particular phosphatase regulates EphA3, the focus of our studies. We will find out, which set of phosphatases regulates EphA3 function and whether exposure to oxidative conditions, such as UV radiation, also activates Ephs and instructs tumour cells to become more motile and to invade other areas of the body. The understanding of this mechanism will help to understand the cause of cancers such as melanoma and might offer possibilities to optimise new strategies for its treatment.Read moreRead less
EphA3-modulated Cell Positioning In Tumour Invasion And Neovascularisation.
Funder
National Health and Medical Research Council
Funding Amount
$647,232.00
Summary
During the progression of human cancers, tumor cells increasingly lose their ability to communicate and co-exist in a regulated fashion with normal cells to maintain the status quo. Because they multiply uncontrollably, tumour cells spread into surrounding tissue and can invade other organs of the body. The Ephs and interacting ephrins are proteins on the cell surface, and their communication controls the position of cells within the body tissues and organs, but also in tumours. Together with co ....During the progression of human cancers, tumor cells increasingly lose their ability to communicate and co-exist in a regulated fashion with normal cells to maintain the status quo. Because they multiply uncontrollably, tumour cells spread into surrounding tissue and can invade other organs of the body. The Ephs and interacting ephrins are proteins on the cell surface, and their communication controls the position of cells within the body tissues and organs, but also in tumours. Together with collaborators at the Ludwig Institute for Cancer Research and the Queensland Institute for Medical Research we produced two proteins, an antibody and a recombinant ephrin that bind one of the Eph proteins on tumour cells. The antibody allowed us to locate Eph in tumours, where it appears surprisingly not only on tumour cells but also on tumour blood vessels. When attached to a redioactive compund it selectively targets the cancer cells and in an animal study prolonged the survival of mice with leukemia significantly. We will now investigate the exact role of this Eph protein in tumour blood vessels. We will then study what happens in tumours when a toxic antibody-drug compound targets this tumour and starts to kill tumour cells. Finally, we will devise a novel reagent that combines the properties of the antibody with the properties of the ephrin into a single protein, which can deliver a cell-killing drug exclusively and most efficiently to tumour cells containing the Eph protein on its surface.Read moreRead less