We have discovered a single tumour factor which causes cancer cachexia, a wasting condition that is one of the worst complications of malignancy, for which there is no current effective treatment. We have developed antibodies which effectively block this condition in preclinical models and have produced human/humanised version of this. This application is to characterise these human antibodies to allow us proceed to clinical trials.
Examination Of The Molecular Pharmacology Of Anthracyclines Induced Via Their Interaction With Iron
Funder
National Health and Medical Research Council
Funding Amount
$618,401.00
Summary
Anthracyclines are highly effective anti-cancer drugs, but their use is limited by toxic effects on the heart. This is thought to be due to these drugs directly binding iron (Fe). Indeed, we showed that anthracyclines induced marked changes in the way heart cells utilise Fe (DR1-3, 38; Mol. Pharmacol. 2002, 2003, 2004, 2005). We were the first to show that anthracyclines prevent Fe release from the criticial Fe storage protein ferritin. This prevents the use of Fe for vital processes eg. DNA and ....Anthracyclines are highly effective anti-cancer drugs, but their use is limited by toxic effects on the heart. This is thought to be due to these drugs directly binding iron (Fe). Indeed, we showed that anthracyclines induced marked changes in the way heart cells utilise Fe (DR1-3, 38; Mol. Pharmacol. 2002, 2003, 2004, 2005). We were the first to show that anthracyclines prevent Fe release from the criticial Fe storage protein ferritin. This prevents the use of Fe for vital processes eg. DNA and haem synthesis. Hence, this effect probably contributes to the cytotoxic activity of anthracyclines on the heart. We showed that novel drugs developed in my lab that bind Fe called chelators show high activity in animals (DR4) and prevent anthracycline-mediated Fe accumulation in ferritin. Importantly, Fe chelators have been shown to inhibit anthracycline-mediated cardiotoxicity. Indeed, the clinically used cardioprotective agent, ICRF-187, is actually an Fe chelator (5, DR6). However, ICRF-187 is not totally successful in terms of its cardioprotective effects and can cause myelosuppression (5, DR6). While the clinically used chelator, desferrioxamine (DFO), can prevent anthracycline-mediated cardiotoxicity, its poor membrane permeability limits its effectiveness. Our chelators are highly permeable and overcome the disadvantages of DFO (DR4). Thus, they are vital to examine for preventing anthracycline-mediated cardiotoxicity. In this proposal we will examine the changes in Fe metabolism induced by anthracyclines and test the hypothesis that novel Fe chelators may prevent the cardiotoxicity of these agents. We also aim to be the first to assess if preparation of anthracyclines which cannot bind iron prevents their cardiotoxicity. This will be done by preparing metal complexes of these drugs which prevent Fe-binding eg. anthracycline-zinc complexes. These studies are important for the development of less cardiotoxic forms of these very useful anti-tumour agents.Read moreRead less
Translational Research Initiatives In Acute Leukaemia
Funder
National Health and Medical Research Council
Funding Amount
$631,010.00
Summary
Recent research has focussed on molecular characterisation of high-risk acute leukaemia subtypes. This proposal will combine the power of genomic analysis, global analysis of protein kinases and stringent preclinical drug testing in order to improve the treatment of these high-risk acute leukaemia subtypes. Several innovative and interrelated projects within this Program will utilise a unique and clinically relevant experimental model to achieve their goals.
Pharmacology Of Potential Anti-Tumour Agents: Iron Chelators Of The BpT Class
Funder
National Health and Medical Research Council
Funding Amount
$585,455.00
Summary
Pharmacology of Potential Anti-Tumour Agents: Iron Chelators of the BpT Class Cancer cells have a high iron requirement for DNA synthesis and many clinical trials showed Fe chelators are effective anti-cancer drugs. Their potential to act as anti-tumour agents has been confirmed by the entrance of Triapine into widespread NCI clinical trials. In this NHMRC Renewal, we will perform pharmacological and preclinical studies to promote the development of BpT chelators as novel anti-tumour agents.
Mitochondrial Iron Overload And Friedreich's Ataxia: The Role Of Frataxin In Iron And Haem Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$285,990.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin i ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin is down-regulated by either erythroid differentiation or the haem precursor protoporphyrin IX (Becker and Richardson, submitted). These data strongly suggest a role for frataxin in iron metabolism. In the present study we will continue to assess if frataxin plays a role in the way cells handle iron. Using a unique model of mitochondrial iron overload developed in my lab (Richardson et al. (1996) BLOOD 87:3477), we will extensively investigate the iron metabolism of the mitochondrion in order to determine the function of frataxin and its role in Friedreich's ataxia. In addition, we have developed a series of new drugs known as iron chelators that can enter the mitochondrion due to their high lipid solubility (Becker and Richardson 1999 J. Lab. Clin. Med. 134:510). These latter drugs are far more effective than the chelator currently used to treat iron overload, desferrioxamine (DFO). Indeed, our chelators have been designed to result in high iron chelation efficacy but low toxicity (see Becker and Richardson, 1999). This exciting research may be crucial in understanding the development of FA and in creating new therapies such as the use of iron chelators.Read moreRead less
Mitochondrial Iron Overload And Friedreich's Ataxia: The Role Of Frataxin In Iron And Haem Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$606,000.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that c ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that cause severe damage. Further, cells deficient in frataxin are sensitive to oxidant stress and Fe chelators rescue oxidant-mediated death of cells from FA patients. Indeed, free radical scavengers have shown to be of use in the treatment of this disease. Studies in DR's lab during this NHMRC grant have shown that frataxin is down-regulated by erythroid differentiation or the haem precursor, protoporphyrin IX (BLOOD 2002;99:3813-22). These data indicate a role for frataxin in Fe metabolism and the pathogenesis of FA. In this study we will continue to examine the role of frataxin in the way cells handle Fe using experimental models developed under the current NHMRC grant. These include transfected cell lines with low frataxin expression generated using an expression vector containing anti-sense frataxin cDNA. Further we obtained the frataxin conditional KO mouse and generated a breeding colony. These animals display many of the pathological features of FA and are the best current model of the disease. Indeed, they will be critical for assessing the role of frataxin in Fe metabolism and as a model to test the ability of Fe-binding drugs to prevent the pathology observed. We designed lipid-soluble chelators that can enter the mitochondrion to bind Fe (Biochim Biophys Acta 2001;1536:133-140) and these ligands will be tested to prevent disease progression in the KO mice. This exciting research is crucial for understanding the pathogenesis of FA and in creating new therapies.Read moreRead less
Discovery And Mechanisms Of Host Cell Factors In HIV Uncoating
Funder
National Health and Medical Research Council
Funding Amount
$635,098.00
Summary
HIV entry into the host cell involves release of its capsid, a protein shell protecting the viral genome. The capsid hijacks host proteins to cloak itself from cellular defenses while the cell has evolved sensors that can block viral infection. This proposal aims to discover proteins involved in this arms race between host and virus and decipher how they control capsid disassembly. This insight will help design new drugs against HIV infection and new ways to deliver genes for gene therapies.
Structural And Functional Analysis Of A Cancer-linked Co-regulator Complex
Funder
National Health and Medical Research Council
Funding Amount
$729,571.00
Summary
We seek to understand the mechanisms by which genes are switched on and off throughout our lifetime. A number of multi-component protein machines are involved in this process but their make-up and mechanism of action is not understood. We will investigate the structure and function of one of these machines that has been strongly linked to cancer.
Antagonist Of Corticotrophin Releasing Hormone As Therapeutic Agents For The Prevention Of Premature Birth In Humans
Funder
National Health and Medical Research Council
Funding Amount
$376,650.00
Summary
In developed countries the most common cause of the death of a newborn baby is premature delivery. Pre-term delivery remains the greatest cause of neonatal mortality in the western world and a major consumer of health dollars (approx. $5-7B per year in the US alone). However, a delay in the onset of labour from 20 to 25 weeks has been shown to result in a 55% greater probability of infant survival (550 fewer deaths per 1000). This project will allow: The development of new drugs that will allow ....In developed countries the most common cause of the death of a newborn baby is premature delivery. Pre-term delivery remains the greatest cause of neonatal mortality in the western world and a major consumer of health dollars (approx. $5-7B per year in the US alone). However, a delay in the onset of labour from 20 to 25 weeks has been shown to result in a 55% greater probability of infant survival (550 fewer deaths per 1000). This project will allow: The development of new drugs that will allow the extension of pregnancy term The development of protocols that will in turn reduce neonatal mortality. Additionally we believe that these new agents will be useful in preventing the onset of labour after fetal surgery. Currently there are no effective treatments capable of substantially changing delivery dates. Available therapeutics delay the onset of labour, at best, 24 hours. However, recent exciting results from our laboratories show that rising concentrations of the placental peptide Corticotrophin Releasing Hormone (CRH) are associated with the onset of labour. Further, we have also delayed the onset of labour in pregnant sheep by infusing a relatively insoluble CRH antagonist into the sheep fetus. Labour commenced ONLY AFTER the drug was withdrawn from the mother. This project builds upon an interdisciplinary team: medicinal chemists, molecular modellers, pharmacologists and endocrinologists, to further develop an exciting Australian discovery. Successful completeion of this research will, for the first time, allow the control of pregnancy duration MAXIMISING the benefits to mother and child, reducing mortality and later life morbidities typically associated with premature birth.Read moreRead less
Prion-like Behaviour In Immunity: Super-sized Signalling Platforms?
Funder
National Health and Medical Research Council
Funding Amount
$611,995.00
Summary
Prions have been mostly associated with pathologies but recent discoveries show that prion-like behaviour may be beneficial, enhancing our immune response for example. To test this, we want to systematically explore all human proteins involved in the defence against pathogens, find new prion-like trends and probe their role in the innate immune response.