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
Preconditioning: The Molecular Basis For Protection From Hepatic Ischemia-reperfusion Injury
Funder
National Health and Medical Research Council
Funding Amount
$406,980.00
Summary
When the blood supply to the liver is cut off temporarily (ischemia) and later restored (reperfusion) the liver is damaged by a process called ischemia-reperfusion (IR) injury. This is a major problem during liver surgery and is also an underlying problem in liver transplantation; following storage of a donor liver ready for placing into the recipient it can undergo a similar process called preservation injury. We now understand a lot about how IR comes about, particularly by the formation of da ....When the blood supply to the liver is cut off temporarily (ischemia) and later restored (reperfusion) the liver is damaged by a process called ischemia-reperfusion (IR) injury. This is a major problem during liver surgery and is also an underlying problem in liver transplantation; following storage of a donor liver ready for placing into the recipient it can undergo a similar process called preservation injury. We now understand a lot about how IR comes about, particularly by the formation of damaging oxygen radicals within liver cells to start a process of programmed cell death, but it remains difficult to prevent or treat IR injury. A recent breakthrough has been recognition that subjecting the liver to only a short period (5 or 10 minutes) of ischemia protects against a later period of prolonged ischemia or IR. In the investigator s mouse model, for example, such preconditioning was 60 to 90% protective (depending on the time after IR). This project seeks to understand how preconditioning works to protect the liver against IR injury. Our idea is that preconditioning generates a limited amount of oxygen radicals, and that these turn on signalling pathways in the cell that regulate certain protective genes. Genes that encode antioxidant and other anti-stress pathways are likely to be important, but so are genes that prepare the cell to enter the cell cycle and divide into new cells that regenerate the liver. Conversely, genes that program cell death may be turned off. The outcomes of this research will be to understand the molecular and cellular basis of how preconditioning protects against ischemia-reperfusion injury of the liver. This will allow drug treatments to be devised that, by simulating preconditioning, prevent this common and severe type of liver damage.Read moreRead less
THE ROLE OF RESIDENT MAST CELLS IN ISCHAEMIA-REPERFUSION INJURY OF SKELETAL MUSCLE.
Funder
National Health and Medical Research Council
Funding Amount
$226,320.00
Summary
NHMRC 209113 LAY DESCRIPTION Ischaemia reperfusion injury occurs in skeletal muscle when the blood-oxygen supply is cut off (ischaemia) and later restored (reperfusion). If the duration of ischaemia is short some of the muscle survives. However, when blood flow and oxygen are restored the muscle is subjected to more injury, which is thought to be caused by oxygen and-or white blood cells. This type of injury occurs in muscle which has been crushed, limbs that have been broken or traumatized, in ....NHMRC 209113 LAY DESCRIPTION Ischaemia reperfusion injury occurs in skeletal muscle when the blood-oxygen supply is cut off (ischaemia) and later restored (reperfusion). If the duration of ischaemia is short some of the muscle survives. However, when blood flow and oxygen are restored the muscle is subjected to more injury, which is thought to be caused by oxygen and-or white blood cells. This type of injury occurs in muscle which has been crushed, limbs that have been broken or traumatized, in replantation of amputated parts, in transplantation, after some surgical procedures and after microsurgical transfer of muscle. Once established there is no effective treatment. Our experiments show that a particular cell, the mast cell, and a particular molecule, nitric oxide, are involved in causing ischaemia reperfusion injury. However, the extent of their involvement is unknown. In this proposal we will investigate the effect of replacing mast cells into muscles, in a unique variety of mice which normally don t contain mast cells and are resistant to ischaemia reperfusion injury. In one group of mice we will put back normal mast cells and in a second group of mice we will put back mast cells that cannot produce the nitric oxide molecule. These experiments will determine, unambiguously, the extent of involvement of mast cells and mast cell-derived nitric oxide. In the second part of this proposal will carry out a time course study, using pharmacologically induced mast cell degranulation, to determine when the mast cells become injurious to skeletal muscle. These experiments will identify the period during which mast cell behaviour can be modulated in order to protect the muscle from ischaemia reperfusion injury. Determination of the role of mast cells, and an understanding of the timing during which they become injurious would provide a logical basis for optimizing drug therapy in clinical applications of these findings.Read moreRead less
Three Dimensional Ex Vivo Modelling Of Neuromuscular Junction Formation
Funder
National Health and Medical Research Council
Funding Amount
$120,253.00
Summary
Re-establishing functional connections between neurons and muscle is an important step in the recovery process after neuromuscular injury or surgery. In order to study the connection forming process in isolation a biological model of nerve muscle connection formation is required. This study aims to buid a biological model consisting of neurons and muscles in a three dimensional environment and to assess the quality of the functional connections that develop.