Dissecting Isoform Selectivity Of PI3 Kinase Inhibitors. Uncovering Leads For Rational Drug Design.
Funder
National Health and Medical Research Council
Funding Amount
$518,989.00
Summary
The PI3 kinase enzyme controls many functions in cells and in many cases contributes to the onset and progression of diseases such as cancer, thrombosis and inflammatory diseases. Compounds that block PI3 kinase activity may be useful drugs but will need to act specifically to minimize side effects. We aim to understand the way in which inhibitors block the PI3 kinase activity with the belief that this information will allow us to make better drugs.
Structure, Assembly, And Inhibition Of The Human Telomerase Enzyme Complex
Funder
National Health and Medical Research Council
Funding Amount
$645,359.00
Summary
In contrast to the limited growth of normal human cells, cancer cells proliferate out of control and without limit. At least 85% of all human cancers rely on the enzyme TELOMERASE to sustain their unlimited proliferation. Telomerase is absent in most normal tissues and therefore represents a potentially effective and specific target for future cancer therapy. We aim to determine the precise 3-dimensional shape of human telomerase to provide a template for rational anti-telomerase drug design.
Biochemical Analysis Of Akt 3-specific Signal Transduction
Funder
National Health and Medical Research Council
Funding Amount
$349,375.00
Summary
The Akt family of enzymes consists of 3 protein kinases (Akt 1,2 and 3) and has been shown to regulate many normal cellular processes such as cell proliferation, growth, survival and motility, as well as the growth of new blood vessels. All these processes are critical for cancers to grow. However, few studies have distinguished the roles of the individual family members. Our preliminary data revealed Akt3 is far more active than the other two forms. Furthermore, using our unique Akt3 specific a ....The Akt family of enzymes consists of 3 protein kinases (Akt 1,2 and 3) and has been shown to regulate many normal cellular processes such as cell proliferation, growth, survival and motility, as well as the growth of new blood vessels. All these processes are critical for cancers to grow. However, few studies have distinguished the roles of the individual family members. Our preliminary data revealed Akt3 is far more active than the other two forms. Furthermore, using our unique Akt3 specific antibody, we find Akt 3 protein and activity levels are high in rapidly proliferating ovarian cancer cell lines and in primary ovarian tumours. The aim of this proposal is to characterise the mode and role of signalling via Akt3, including the identification of targeted substrates and signaling pathways and the outcomes of Akt3 driven signaling on cellular properties. These studies will provide important clues to understanding how this family member functions in both health and disease. Elucidation of the basis of Akt3 dependent signalling will open the possibility for the development of drugs that interfere with Akt3 function (for example in high Akt 3 expressing tumours like those of the ovary). In the long term, extension of our profiling studies to other tumour types will give a novel insight into the extent of Akt3 de-regulation as a key mediator of cancer formation.Read moreRead less
A New Approach To Explore The Role Of Selenoproteins In Health And Disease
Funder
National Health and Medical Research Council
Funding Amount
$374,284.00
Summary
Selenoproteins play an important role in a variety of major diseases. Yet knowledge of the biology of selenium and its role in disease prevention and progression is not sufficient to recommend selenium supplementation for disease prevention or treatment. The broad aim of this research is to identify and characterise the response of selenoproteins to selenium supplementation and disease states.
The Molecular Mechanism Of Sphingosine Kinase Activation
Funder
National Health and Medical Research Council
Funding Amount
$442,500.00
Summary
Many cell processes like growth, death and differentiation are controlled by hormones and other molecules that interact with receptors on the outside of the cell. When this type of molecule binds to a receptor, it often triggers the production of signaling molecules inside the cell that initiate a change in the cells behaviour. The lipid molecule, sphingosine phosphate has been identified as such a signaling molecule that appears to be involved in the regulation of a diverse array of important m ....Many cell processes like growth, death and differentiation are controlled by hormones and other molecules that interact with receptors on the outside of the cell. When this type of molecule binds to a receptor, it often triggers the production of signaling molecules inside the cell that initiate a change in the cells behaviour. The lipid molecule, sphingosine phosphate has been identified as such a signaling molecule that appears to be involved in the regulation of a diverse array of important mammalian cellular processes. Recent studies have found that sphingosine phosphate is involved in the inflammation of cells, and if its production can be blocked, inflammation is not seen. Therefore, this provides a potential target for therapeutic intervention in the inflammation process. However, the manner by which cells regulate sphingosine phosphate levels is not well known. It is known that sphingosine phosphate is produced by the enzyme sphingosine kinase, and strong evidence suggests that changes in this enzyme's activity in the cell regulate sphingosine phosphate levels. However, how the cell changes the levels of sphingosine kinase activity is completely unknown. This study will investigate this problem with the view that understanding this process will allow the development of new drugs to block increases in sphingosine kinase activity, preventing increases in sphingosine phosphate levels, and it turn, preventing cellular inflammation.Read moreRead less
Regulation Of The Tumour Suppressor PTEN By Phosphorylation And Oligomerization
Funder
National Health and Medical Research Council
Funding Amount
$241,650.00
Summary
The tumour suppressor PTEN is an enzyme involved in controlling cell growth, cell death, and cell migration. PTEN was identified as a tumour suppressor because many tumour cells were found to carry mutations in the PTEN gene that cause the loss of PTEN protein or the loss of PTEN enzyme activity. Hereditary mutations of the PTEN gene are the causes of a rare genetic disease called Cowden's disease. Cowden's disease patients are predisposed to developing skin, thyroid, and breast cancers. In labo ....The tumour suppressor PTEN is an enzyme involved in controlling cell growth, cell death, and cell migration. PTEN was identified as a tumour suppressor because many tumour cells were found to carry mutations in the PTEN gene that cause the loss of PTEN protein or the loss of PTEN enzyme activity. Hereditary mutations of the PTEN gene are the causes of a rare genetic disease called Cowden's disease. Cowden's disease patients are predisposed to developing skin, thyroid, and breast cancers. In laboratory conditions, increasing the abundance of PTEN in tumour cells such as brain and prostate tumour cells can suppress their growth, hence its role as a tumour suppressor. In addition to its role as a tumour suppressor, PTEN controls cancer cell spreading. Although much is known about the involvement of PTEN in cancer formation and the spreading of cancer cells, how PTEN suppresses tumour cell growth and spreading is not fully understood. The enzyme activity of PTEN enhances the removal of a chemical group called phosphate group from proteins and the fat-soluble compounds called phospholipids in the cell membrane. The ability of PTEN to suppress cell growth and spreading is due to its enzyme activity. However, exactly how the enzyme activity of PTEN is regulated is not well understood. In order for PTEN to efficiently enhance the removal of phosphate group from specific cellular proteins and phospholipids, PTEN needs to be located in close vicinity to these proteins and phospholipids. However, exactly how PTEN moves to the locations where these proteins and phospholipids are present remains elusive. This proposal aims at studying the regulation of PTEN enzyme activity and movement inside the cells. Results of the proposed studies will shed new light on how PTEN gene mutations contribute to cancer formation and the spreading of cancer cells and may facilitate the search for the cure of cancers.Read moreRead less
A Tumour Suppressor Pathway That Removes DNA-RNA Hybrids
Funder
National Health and Medical Research Council
Funding Amount
$935,780.00
Summary
DNA:RNA hybrids are found normally in our chromosomes. But, the regions where DNA:RNA hybrids form are linked to chromosome changes that occur during breast and blood cancer development. We have uncovered why these chromosome changes occur, and have linked it to the important function of a cancer-associated gene called FANCM. Our study is exploring this important finding that has implications for both the cause and treatment of cancer.
Design And Development Of Small Molecules To Regulate Protease Activated Receptor Type 2
Funder
National Health and Medical Research Council
Funding Amount
$439,500.00
Summary
A new class of proteins have been discovered on the surface of cells. These are activated by enzymes known as proteases and are therefore called Protease Activated Receptors (PARs). PARs appear to be very important 'sensors' of proteases outside cells, becoming activated in response to very low concentrations of proteases. This suggest that proteases may exert some of their biological effects through these receptors, which are now implicated in a growing number of diseases (e.g. thrombosis, card ....A new class of proteins have been discovered on the surface of cells. These are activated by enzymes known as proteases and are therefore called Protease Activated Receptors (PARs). PARs appear to be very important 'sensors' of proteases outside cells, becoming activated in response to very low concentrations of proteases. This suggest that proteases may exert some of their biological effects through these receptors, which are now implicated in a growing number of diseases (e.g. thrombosis, cardiovascular disorders, asthma, inflammatory bowel disease, Crohn's disease, pancreatitis, stomach and colon cancer, arthritis, and there may also be a role in wound healing). We are working towards dissecting the roles for one of these receptors (PAR2) in disease by developing small molecules for selective binding to this receptor. We will particularly distinguish between compounds that can activate (agonists) or deactivate (antagonists) the receptor. These experiments will involve computer-assisted compound design, structural comparisons between small molecules with activity and those without, and cellular studies designed to measure affinity, activation and deactivation of PAR2. The outcome will be a series of small molecules that bind tightly to the PAR2 receptor and have a well defined function (antagonist, agonist, partial agonist). While the above studies are in progress some peptides that are known to activate this receptor will be examined in rodent models of human disease (airways inflammation, pancreatitis, stomach and colon cancer, arthritis). Studies like this have been very revealing for us in the past (Nature 1999, 398, 156-160 A protective role for protease-activated receptors in the airways). Then the designed and developed compounds will also be examined for signs of therapeutic potential. The work will provide a better understanding of how this receptor works and a clearer picture of the role of this receptor in human disease.Read moreRead less
Characterization Of The 72 KDa Inositol Polyphosphate 5-phosphatase
Funder
National Health and Medical Research Council
Funding Amount
$454,050.00
Summary
Cells respond to external signals and the enviroment 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 (72 kDa 5-phosphatase) which resides inside the cell, which we have evidence plays a role in regulating both the movement of intracellular vesicles and also lipid signals stimulated by insulin. We have characterised the phospholipids that the enzyme cleaves and demonstrated the generation of new ....Cells respond to external signals and the enviroment 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 (72 kDa 5-phosphatase) which resides inside the cell, which we have evidence plays a role in regulating both the movement of intracellular vesicles and also lipid signals stimulated by insulin. We have characterised the phospholipids that the enzyme cleaves and demonstrated the generation of new cell signals at specific subcellular localizations on intracellular membranes. We predict the generation of these specific lipid signals may play a significant role in controlling the transport of intracellular cargo to specific sites in the cell. In this grant proposal we aim to examine the regulation of specialised cargo called the glucose transporter, which is found in fat and muscle cells, and also the mannose 6-phosphate receptor, which regulates the trafficking of specific enzymes which mediate digestion of proteins. These studies include the clarification of which phospholipid signals the enzyme terminates and where in the cell this occurs. Secondly, we will examine the movement of the glucose transporter GLUT-4 in unstimulated cells and in response to insulin and furthermore how expression of the novel enzyme regulates its movement. We will also examine the movement of the mannose 6-phosphate receptor and the specific phospholipid signals which control the route the receptor traffics, using inhibitors of lipid signals and expression of lipid phosphatases and kinases. We will also examine how our novel enzyme forms complexes with other molecules in the cell and characterise these novel molecules using basic biochemical assessment of enzyme activity and function. Finally we will examine the regulation of intracellular messages by our novel enzyme following insulin stimulation, which facilitates glucose uptake into the cell.Read moreRead less