The 3-dimensional Structure Of Anticancer Drug-DNA Complexes Determined By X-ray Crystallography
Funder
National Health and Medical Research Council
Funding Amount
$264,358.00
Summary
Our main objective is to discover the molecular details of how cancer drugs interact with DNA and how these interactions differ from those of inactive chemically related compounds. We propose to use X-ray crystallography together with the successful methods we have developed for determining the 3-dimensional structures of the DNA complexes of a class of antitumour active drugs to study the complexes of other clinically or scientifically important DNA intercalating anticancer drugs. These agents ....Our main objective is to discover the molecular details of how cancer drugs interact with DNA and how these interactions differ from those of inactive chemically related compounds. We propose to use X-ray crystallography together with the successful methods we have developed for determining the 3-dimensional structures of the DNA complexes of a class of antitumour active drugs to study the complexes of other clinically or scientifically important DNA intercalating anticancer drugs. These agents act by poisoning the DNA binding enzyme topoisomerase. Crystallographic analysis will give us unequivocal answers at the atomic level as to the exact way in which the drug binds to DNA and how this binding differs between antitumour active and inactive compounds. We believe that a knowledge of the DNA binding mode of a class of intercalating anticancer drugs at the atomic level is valuable in guiding drug design within that class.Read moreRead less
Molecular Targeting To Telomerase And Cancer Cell Immortality By A Novel Inhibitor
Funder
National Health and Medical Research Council
Funding Amount
$430,812.00
Summary
Infinite growth of cancer cells is a hallmark of cancer. Telomerase is required for cancer cell immortality. Inhibition of telomerase may thus offer an opportunity to stop cancer cells. We have identified an inhibitor of telomerase. This project will study the mechanisms of action of the novel inhibitor, investigating how to control cancer cell immortality as a baseline for more applied anti-cancer therapeutic studies.
Synthetic Analogues Of The Actinomycin, Quinamycin And Nogalamycin Groups Of Antitumour Antibiotics
Funder
National Health and Medical Research Council
Funding Amount
$376,433.00
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 leakaemias 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. One way of subverting resistance is by the use of drugs whose mechanism of action is novel so that the tumour is challenged to devise a new defense. Here, we are attempting to develop synthetic analogues of a class of naturally- occurring antitumour antibiotic whose mechanism of action is unusual but which has not been exploited by medicinal chemists because of the difficulty of the chemistry involved. These antibiotics work by binding to DNA and inhibiting the first step in the process whereby genes are turned into proteins. We have designed compounds that are chemically accessible that our preliminary work suggests mimic the DNA-binding and biological properties of the natural antibiotics. The proposed work will enable us to evaluate whether this new class of agent has experimental antitumour activity, particularly amongst drug-resistant tumours.Read moreRead less
Selective Therapies Targeting Tumour Vasculature Of Colorectal Liver Metastases
Funder
National Health and Medical Research Council
Funding Amount
$519,279.00
Summary
Cancer of the bowel is the second highest cause of cancer related deaths in Australia. Over 70% of these deaths are due to bowel cancer spread to the liver or liver metastases. Treatment options for the majority of patients with liver spread are limited. Although chemotherapies are a standard treatment option, they cause significant side-effects as they are small in size and thereby distributed to both cancer and normal tissue. Given the limitations of chemotherapy, our objective is to investiga ....Cancer of the bowel is the second highest cause of cancer related deaths in Australia. Over 70% of these deaths are due to bowel cancer spread to the liver or liver metastases. Treatment options for the majority of patients with liver spread are limited. Although chemotherapies are a standard treatment option, they cause significant side-effects as they are small in size and thereby distributed to both cancer and normal tissue. Given the limitations of chemotherapy, our objective is to investigate two new strategies which selectively destruct tumours with minimal effect to normal tissues. Cancer growth is dependent on an efficient blood supply. One strategy uses drug delivery systems (DDS) to selectively target cancers by exploiting the unique properties of tumour blood vessels. The second strategy uses vascular targeting agents (VTA's) which act on tumour vessels to reduce blood flow and starve the tumour of oxygen, leading to its destruction. We will be testing two agents: SMA-Pirarubicin, a DDS and an innovative VTA, Oxi4503, in an animal model of colorectal cancer liver metastases. Although these drugs are successful in destroying the majority of tumour cells, they have a patchy effect and do not completely destroy the cancerous growth. The varied effects of these agents may be due to variations in tissue hypoxia, tumour vessel structure or factors which trigger blood vessel formation and breakdown. These features will be investigated using techniques established within our laboratory. We will also investigate the combined effect of other novel agents and hyperbaric oxygen administration to improve the effectiveness of these drugs. A successful outcome will result in the development of an improved treatment method which targets tumours, producing maximum destruction with minimum side-effects. This has the potential to replace standard chemotherapies as the preferred treatment for patients with bowel cancer spread, with overall significant patient benefits.Read moreRead less
Targeted Cancer Chemotherapy: The Potential Of L-Nucleoside Prodrugs
Funder
National Health and Medical Research Council
Funding Amount
$204,750.00
Summary
The aim of this project to develop novel anti-cancer agents. We plan to use an unusual sugar (an L-nucleoside) that is not normally found in the body. This unusual sugar has the property of being taken up by tumour cells but not normal cells. We will use this unusual sugar to transport a toxic compound inside tumour cells so that the tumour cells are killed. In this way, we will preferentially kill tumour cells but leave normal cells unaffected. Hence we will produce an anti-cancer agent that is ....The aim of this project to develop novel anti-cancer agents. We plan to use an unusual sugar (an L-nucleoside) that is not normally found in the body. This unusual sugar has the property of being taken up by tumour cells but not normal cells. We will use this unusual sugar to transport a toxic compound inside tumour cells so that the tumour cells are killed. In this way, we will preferentially kill tumour cells but leave normal cells unaffected. Hence we will produce an anti-cancer agent that is highly effective at killing tumour cells but has few side-effects because it does not enter normal cells. Experimentally we will synthesise compounds where the L-nucleoside is attached to a toxic agent, fluorouridine or cisplatin analogues. We will then assess the ability of these novel compounds to kill tumour cells grown in the laboratory as well as tumours growing in mice. Additionally we will attempt to determine the mechanism of action of these drugs by investigating the following: the transport properties of the drugs; how and where these drugs damage DNA; the effect of the gene, p53, which can act to stop tumour growth. The ultimate aim of this project is to develop a novel class of anti-tumour agent based on L-nucleosides. These L-nucleoside analogues are expected to be more efficient at killing tumour cells but have fewer side effects.Read moreRead less
Development Of DNA Targeted Platinum Agents As Potential Anticancer Drugs
Funder
National Health and Medical Research Council
Funding Amount
$410,250.00
Summary
A number of clinically useful anticancer drugs damage DNA. As a result of this damage these drugs kill cancer cells. This project aims to develop new platinum-containing compounds which are specifically targeted to DNA. Through this strategy it is possible that new and more useful anticancer drugs could emerge.
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
The Structural Basis For The Action Of Anticancer DNA-intercalating Topoisomerase Poisons
Funder
National Health and Medical Research Council
Funding Amount
$459,750.00
Summary
Cancer kills one in four people in the Western world and half of those afflicted will die from the disease. If the malignancy is detected early, surgery and radiotherapy will often effect a cure but if the disease is disseminated at presentation then treatment requires chemotherapy. Chemotherapy can be curative for some tumour types but it is generally only palliative for the overwhelming majority of solid cancers. Consequently, there is an urgent need to improve the efficacy of anticancer drugs ....Cancer kills one in four people in the Western world and half of those afflicted will die from the disease. If the malignancy is detected early, surgery and radiotherapy will often effect a cure but if the disease is disseminated at presentation then treatment requires chemotherapy. Chemotherapy can be curative for some tumour types but it is generally only palliative for the overwhelming majority of solid cancers. Consequently, there is an urgent need to improve the efficacy of anticancer drugs. Many of these drugs work by binding directly to DNA and poisoning the DNA-manipulating enzyme, topoisomerase. Our objective is to discover the molecular basis of how anticancer drugs act through their interaction with DNA and topoisomerase. We propose to use the successful X-ray crystallography methods we have developed for determining the 3-dimensional structures of the DNA complexes of a class of anti-tumour active drugs, to study the complexes of other clinically or scientifically important DNA intercalating anticancer drugs. Crystallographic analysis provides unequivocal data, at near atomic resolution, of the nature of the molecular interactions which provide specificity and selectivity in drug-DNA complexes. This information will be a valuable guide in the further development of this important class of topoisomerase poisons as anticancer drugs. We will initiate structural studies of ternary complexes between the topoisomerase enzyme, DNA and anticancer drugs. The solution of the X-ray crystal structures of these ternary complexes will allow the design of new antitumour topoisomerase poisons to be put on a completely rational basis.Read moreRead less
Investigating Tumour Maintenance Using Regulated RNA Interference
Funder
National Health and Medical Research Council
Funding Amount
$511,294.00
Summary
Inhibiting gene expression using the recently discovered process known as RNA interference (RNAi) can be used as an experimental tool to analyse specific genes, in cells and genetically engineered animal models of human disease. I propose to validate potential drug targets in cancer by using RNAi to inhibit specific genes in established mouse tumours. A further aim is to use RNAi to mimic human cancer gene mutations in mouse cancer models, to discover novel tumour suppressor genes.