Genetic Analysis Of Drug Resistance In Childhood Acute Lymphoblastic Leukaemia
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
Treatment for childhood leukaemia fails in approximately 25% of children owing to resistance to the drugs being used. Our recent evidence suggests that only a few rare leukaemic cells are initially resistant at the commencement of treatment. This project aims to isolate these rare cells and to look for genetic changes in them which might account for their resistance. Hopefully an understanding of the genetic basis for drug resistance will lead to better means of overcoming it.
MINIMAL RESIDUAL DISEASE IN ACUTE LYMPHOBLASTIC LEUKAEMIA
Funder
National Health and Medical Research Council
Funding Amount
$455,204.00
Summary
This project will study the extremely small numbers of leukaemic cells which are found in patients who are apparently healthy, but which sometimes lead to relapse. Very sensitive methods for measuring and studying low levels of leukaemic cells will be developed and used. To develop new better treatments in the long term, we will study why current treatment sometimes fails to eradicate the leukaemia, leading to patients relapsing. Clinicians currently need to obtain samples of bone marrow to asse ....This project will study the extremely small numbers of leukaemic cells which are found in patients who are apparently healthy, but which sometimes lead to relapse. Very sensitive methods for measuring and studying low levels of leukaemic cells will be developed and used. To develop new better treatments in the long term, we will study why current treatment sometimes fails to eradicate the leukaemia, leading to patients relapsing. Clinicians currently need to obtain samples of bone marrow to assess leukaemia, and the research will show whether this needs to be continued, or whether, with sensitive tests, samples of blood can be used instead. The study will involve collaboration with clinicians throughout Australia and overseas.Read moreRead less
The Role Of Intracellular Uptake And Retention Of Abl Kinase Inhibitors In Modifying Clinical Response In CML
Funder
National Health and Medical Research Council
Funding Amount
$465,210.00
Summary
Imatinib is one of the first targeted anticancer drugs to be clinically developed. It is designed to inhibit the kinase activity of BCR-ABL, a mutant protein found in some cases of leukaemia, particularly chronic myeloid leukaemia. Blocking the kinase activity of BCR-ABL has proven to be highly effective therapy for most patients, achieving prolonged remissions and significantly improving survival. However resistance to imatinib is a problem, including failure to respond to imatinib, loss of res ....Imatinib is one of the first targeted anticancer drugs to be clinically developed. It is designed to inhibit the kinase activity of BCR-ABL, a mutant protein found in some cases of leukaemia, particularly chronic myeloid leukaemia. Blocking the kinase activity of BCR-ABL has proven to be highly effective therapy for most patients, achieving prolonged remissions and significantly improving survival. However resistance to imatinib is a problem, including failure to respond to imatinib, loss of response, and long term persistence of low levels of leukaemia. New ABL kinase inhibitors (AKIs) have been developed that are more potent than imatinib, but they also appear to be prone to resistance. One potentially important cause of resistance to AKIs is the ability of some leukaemic cells to modify their cellular pathways to reduce the effective concentration of the drug by either reducing its movement into the cell (influx) or increasing its movement out (efflux). We will investigate the mechanisms used by resistant leukaemic cells to reduce intracellular drug levels of these AKIs and test ways of countering these effects by blocking the proteins responsible for drug efflux or promoting drug influx. These studies will use our stored collections of leukaemic cells from responsive and resistant patients to determine the importance of specific influx and efflux pumps. It will help to identify patients where this form of resistance is limiting response. This may allow us to develop more effective AKIs that are less prone to these forms of drug resistance. We will also test whether other anti-cancer drugs have an impact on AKI drug transport because this could reduce the effectiveness of combination treatment. The effects on drug transport of concomitant administration of commonly used drugs together with AKIs will also be studied because this can reduce the effectiveness of AKis or in some cases improve their effectiveness by increasing their uptake and retention.Read moreRead less
Use Of Retroviral Expression Libraries To Characterise Mechanisms Of Drug Resistance In Leukaemia.
Funder
National Health and Medical Research Council
Funding Amount
$362,545.00
Summary
At present, treatment of leukaemia is based either on established chemotherapeutic drug treatment or newly identified inhibitor drugs currently being tested as part of clinical trials. Both these treatments are known to induce or select for resistance to the drugs in some cases. Resistance usually reduces the success rate of any further treatment with the same or similar drugs. To discover possible ways of overcoming drug resistance it is important to understand the mechanisms that are responsib ....At present, treatment of leukaemia is based either on established chemotherapeutic drug treatment or newly identified inhibitor drugs currently being tested as part of clinical trials. Both these treatments are known to induce or select for resistance to the drugs in some cases. Resistance usually reduces the success rate of any further treatment with the same or similar drugs. To discover possible ways of overcoming drug resistance it is important to understand the mechanisms that are responsible. To date a number of mechanisms that cause resistance are known, but there are still unidentified mechanisms that are associated with drug resistance. The aim of our work is to use a new method to identify unknown drug resistance mechanisms in leukaemia. Once a mechanism is identified, we will determine its relevance in leukaemia by screening a number of patients that have shown resistance to treatment. If identified as a common mechanism of resistance in leukaemic patients, we will test possible agents able to prevent drug resistance that could be used in conjunction with drug during treatment, and to screen new drugs for susceptibility to resistance mechanisms. Diagnostic tests to detect the presence of the known resistance mechanisms prior to treatment could be used in selection of the most appropriate drug combinations for individual patients. Some of the known drug resistance mechanisms that occur in leukaemia are also operative in other forms of cancer and the project is of general relevance to cancer chemotherapy.Read moreRead less
Development And Assessment Of Novel Assays To Predict Response To Second-line TKI Therapy In Imatinib-resistant CML
Funder
National Health and Medical Research Council
Funding Amount
$491,308.00
Summary
Patients with chronic myeloid leukaemia (CML) respond well to imatinib, the first small molecule developed to block the kinase activity of the causative oncogene in CML, BCR-ABL. However some patients develop resistance. Several new kinase inhibitors are now available that are effective in some patients with imatinib resistance. We plan to develop biological and molecular assays to predict if a CML patient will respond to a specific second-line kinase inhibitor to optimise second-line therapy.
Zbtb11 is a druggable protein that is mis-expressed in blood cancers - second biggest cause of cancer death in Australia - and liver cancer, third leading cause of death from cancer worldwide. We have found that it interacts with 2 other proteins with potential roles in these diseases. Our studies examine the nature of these Zbtb11-partner interactions and their particular consequences for blood disorders. Zbtb11 contributions to disease development will be a target for novel disease therapy.
The Role Of Med12, A Subunit Of RNA Polymerase II Mediator, In Haemopoiesis
Funder
National Health and Medical Research Council
Funding Amount
$495,490.00
Summary
In a screen of zebrafish for mutations in blood cell development, we isolated a mutant called syrah. The mutation causing the blood defect was identified in a gene called med12, which encodes a component of the RNA transcription machinery in cells. To understand how this mutation causes a reduction in blood cells, we will identify the proteins that interact with the med12 protein. Understanding the pathway involved may lead to the discovery of new causes of human congenital blood diseases.
Platelet Receptor Regulation In Autoimmune Disease
Funder
National Health and Medical Research Council
Funding Amount
$507,536.00
Summary
In response to bleeding, blood platelets use receptors to form a thrombus (blood clot) and block further loss of blood and aid tissue repair. People treated with heparin prior to surgery, can form autoantibodies that attack platelets, leading to thombus and thrombocytopenia (dangerous loss of circulating platelets). This is a significant clinical problem that is difficult to diagnose. We will determine how platelet receptor shedding can aid the diagnosis of heparin-induced thrombocytopenia.
Antibody-mediated Dendritic Cell Depletion To Attenuate GVHD
Funder
National Health and Medical Research Council
Funding Amount
$434,510.00
Summary
Not all patients with leukemia will be cured by chemotherapy. Stem cell transplantation improves their chances of survival. Stem cell transplantation requires intensive chemotherapy and radiotherapy to eradicate the underlying disease and infusion of healthy stem cells to provide an anti-leukemic effect and normal blood cells. Recovery from transplantation is not straightforward. Recovery can be hampered by the immunological reaction of the donor cells against the patient (Graft versus Host Dise ....Not all patients with leukemia will be cured by chemotherapy. Stem cell transplantation improves their chances of survival. Stem cell transplantation requires intensive chemotherapy and radiotherapy to eradicate the underlying disease and infusion of healthy stem cells to provide an anti-leukemic effect and normal blood cells. Recovery from transplantation is not straightforward. Recovery can be hampered by the immunological reaction of the donor cells against the patient (Graft versus Host Disease [GVHD]), despite immunosuppression. GVHD produces serious damage to the internal organs and lining of the mouth and gut. Recovery can also be circumvented by leukemic relapse. GVHD is associated with an increased risk of death and dying after transplantation. To date therapy for GVHD has relied on eliminating the T cells that cause the disease. However for T cells to cause damage they must first be primed with antigen presented on activated dendritic cells. The intensive conditioning therapy required to eradicate the underlying disease before transplantation also activates dendritic cells. Our project seeks to investigate the effects of lethal and non-lethal conditioning on dendritic cells with the aim of validating the use of antibodies designed to deplete activated dendritic cells as therapy for graft versus host disease.Read moreRead less
Identification Of The Molecular Genetic Basis Of The Hepatic Veno-occlusive Disease With Immunodeficiency Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$224,250.00
Summary
One of the most serious complications of bone marrow transplantation is veno-occlusive disease (VOD), also termed sinusoidal obstruction syndrome (SOS). This condition occurs in 10% of transplanted patients and is characterised by abnormalities of liver function, enlargement of the liver, clotting abnormalities, fluid retention and finally failure of multiple organs and death in 30-50% of cases. The cause of VOD is unknown, and its occurrence cannot be predicted in individual patients. Eight fam ....One of the most serious complications of bone marrow transplantation is veno-occlusive disease (VOD), also termed sinusoidal obstruction syndrome (SOS). This condition occurs in 10% of transplanted patients and is characterised by abnormalities of liver function, enlargement of the liver, clotting abnormalities, fluid retention and finally failure of multiple organs and death in 30-50% of cases. The cause of VOD is unknown, and its occurrence cannot be predicted in individual patients. Eight families have been described in whom a number of individuals have succumbed to a condition which is clinically and histologically indistinguishable from VOD. Affected individuals also have a form of immunodeficiency (hence termed VODI), and the abnormalities are inherited in an autosomal recessive pattern. All eight are of Lebanese origin, suggesting that a single genetic ancestral mutation was responsible for the disorder in all families, who are distantly related. We have access to genetic material from three of these families, and are on the way to identifying the causative genetic abnormality. We hypothesise that understanding this abnormality will lead to an understanding of VOD which occurs after bone marrow transplantation. We have used 800 polymorphic genetic markers scattered throughout the genome to identify the location of the genetic abnormality, and have localised the defect to a region of chromosome 2 which contains approximately 37 known and predicted genes. We now aim to determine which of the gene(s) in the candidate region is responsible for VODI, and plan to examine DNA from individuals who have had VOD after transplantation to determine if they have a related abnormality. Finding the VODI gene will benefit these families through the availability of carrier detection and may also lead to an understanding of the veno-occlusive disease that occurs after bone marrow transplantation.Read moreRead less