Cytochrome P450-mediated Epoxides Of Polyunsaturated Fatty Acids That Regulate Cell Death And Survival
Funder
National Health and Medical Research Council
Funding Amount
$495,710.00
Summary
Omega-3 polyunsaturated fatty acids (PUFAs) decrease cancer risk in man whereas omega-6 PUFA, which are common in western diets, increase risk. In cells cytochrome P450 converts PUFAs to epoxides. Omega-6 epoxides stimulate growth of cells and tumours but we have found that epoxides of the omega-3 eicosapentaenoic acid inhibit cell growth. We will now evaluate the mechanisms of these effects, which could lead to new anticancer treatments, perhaps based on altered diet.
Alteration Of Glucose Metabolism By GPCR Activation
Funder
National Health and Medical Research Council
Funding Amount
$444,796.00
Summary
In type 2 diabetes the effect of insulin to stimulate glucose transport in fat cells and skeletal muscle is impaired so there is great interest in identifying insulin-independent mechanisms that increase glucose transport. Several G protein-coupled receptors (GPCRs) regulate glucose transport independently of insulin but the mechanisms involved in these effects are largely unknown. This project investigates how GPCRs regulate glucose homeostasis and will evaluate them as potential treatments.
The Structural Basis Of The Interaction Of Insulin-like Peptide 3, A Key Regulator Of Fertility, With Its Receptor.
Funder
National Health and Medical Research Council
Funding Amount
$555,693.00
Summary
The hormone, insulin-like peptide 3, has recently been shown to act directly on male and female germ cells to cause their maturation. It has considerable promise as a therapeutic agent for the regulation of fertility. Drugs based on the peptide may be used to assist in cases of infertility, and drugs that block its action have great potential as male and female contraceptives. Towards these goals, our project aims to understand how this peptide exerts its unique biological effects.
Hormonal Modulation Of Prostatic Growth And Contractility
Funder
National Health and Medical Research Council
Funding Amount
$324,237.00
Summary
With increasing age human males are likely to develop benign prostatic hyperplasia (BPH), a disorder characterized by urethral obstruction due to an increase in size of the prostate gland. Drug treatments of this condition are not entirely satisfactory and the current project is to examine the mechanisms by which the prostate grows and occludes the urethra. We will use human prostate cells grown in artificial conditions to determine which hormones alter the types of cells and especially examine ....With increasing age human males are likely to develop benign prostatic hyperplasia (BPH), a disorder characterized by urethral obstruction due to an increase in size of the prostate gland. Drug treatments of this condition are not entirely satisfactory and the current project is to examine the mechanisms by which the prostate grows and occludes the urethra. We will use human prostate cells grown in artificial conditions to determine which hormones alter the types of cells and especially examine those cells which can contract as these may be of critical importance in the urethral obstruction. We hypothesize that an enzyme called protein kinase C may be implicitly involved in both cell growth and contractile function and we will examine the role of protein kinase C with a view ultimately to develop drugs which may interfere with this process and therefore aid in non-surgical treatment of the condition.Read moreRead less
Understanding The Mechanisms Used By G-protein Coupled Receptors To Regulate Insulin-independent Glucose Transport
Funder
National Health and Medical Research Council
Funding Amount
$105,590.00
Summary
In type 2 diabetes, stimulation of glucose transport in fat cells and skeletal muscle by insulin is impaired. As a result there is great interest in identifying insulin-independent mechanisms that increase glucose transport. Several G-protein coupled receptors (GPCRs) regulate glucose transport independently of insulin but the mechanisms involved in these effects are largely unknown. This project investigates how GPCRs regulate glucose transport for potential as treatments.
Development Of DNA Phosphate Crosslinking Agents As Potential Anticancer Drugs
Funder
National Health and Medical Research Council
Funding Amount
$392,545.00
Summary
The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar ....The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar scenario in the treatment of adults with leukaemias and non-Hodgkins lymphomas. The underlying cause of drug resistance is the genetic instability of cancer cells which results in tumours that are heterogeneous, making it almost inevitable that a cancer cell will arise that is resistant to treatment. There are many mechanisms of resistance, some of which are peculiar to particular drug types, some are permeability barriers and some involve genetic deregulation of the biochemistry of cell death. Alkylating agents are one of the most important classes of anticancer drug. They bind irreversibly to the bases in DNA and weld the two strands of the double helix together. This cross-link is a powerful block to DNA replication and leads to the death of cancer cells by the process of programmed cell death. Cancer cells generally become resistant to alkylating agents by invoking repair mechanisms that remove the drug from the DNA bases, a response which breaks the cross-link and returns the DNA to its normal state. In this project, we are developing a new type of alkylating agent that reacts not with the DNA bases but with the phosphate groups of the DNA backbone. By this means the strands of DNA can again be cross-linked but now the linkage is between parts of the DNA that cancer cells cannot separate. In this way, we hope to be able to devise new drugs that are resistant to the normal mechanisms of DNA repair so that they will be active against drug-resistant tumours.Read moreRead less
Alternate Signalling Pathways Regulating The Human Arachidonate Epoxygenase CYP2J2 In Response To Stress Stimuli
Funder
National Health and Medical Research Council
Funding Amount
$369,000.00
Summary
Hypoxia, or oxygen deprivation, is caused by the decreased supply of blood to cells and is a component of ischaemic injury to the cardiovascular system (e.g. stroke, atherosclerosis) and numerous other organs (e.g. cancer and chemical mediated injury). It is now known that an important group of proteins that switch on specialised target genes in response to hypoxia is Activator-Protein-1 (AP-1). We have found that cytochrome P450 2J2 (CYP2J2), which is an enzyme that forms beneficial fatty acid ....Hypoxia, or oxygen deprivation, is caused by the decreased supply of blood to cells and is a component of ischaemic injury to the cardiovascular system (e.g. stroke, atherosclerosis) and numerous other organs (e.g. cancer and chemical mediated injury). It is now known that an important group of proteins that switch on specialised target genes in response to hypoxia is Activator-Protein-1 (AP-1). We have found that cytochrome P450 2J2 (CYP2J2), which is an enzyme that forms beneficial fatty acid products inside cells, is decreased in hypoxia and that this is due to increased activity of AP-1. We know that similar stressful stimuli can also result in a loss of CYP2J2. Again, AP-1 is involved but we have further evidence for the role of another pathway. This project will explore how these pathways operate individually and together to decrease CYP2J2. Studying the regulation of human genes is difficult because we can not readily monitor their levels in cells in either healthy or sick individuals. So we will make transgenic mouse models to study human CYP2J2 regulation, which will provide information on the human situation. In this project we will identify which factors switch off the CYP2J2 transgene and will analyse the signalling pathways within cells that control this response. The importance of these studies is that they will help us to design pharmacological strategies to prevent the loss of CYP2J2 in cells that are stressed. Such agents may be effective in the treatment of ischaemic injury seen in stroke and atherosclerosis. If we can maintain CYP2J2 levels we may be able to maintain the beneficial fatty acid levels in cells and have a novel therapeutic approach for keeping cells alive.Read moreRead less