Regulation And Assembly Of Nuclear DNA Repair Centres
Funder
National Health and Medical Research Council
Funding Amount
$457,267.00
Summary
Genetic defects in DNA repair genes are associated with increased cancer risk in humans. For example, BRCA1 and BRCA2 gene mutations are the most common causes of familial breast cancer, and MLH1 gene mutations are the most common cause of familial non-polyposis colorectal cancer. We have identified a novel human DNA repair protein termed ASCIZ that performs a similar function to BRCA1 and BRCA2 in that it regulates the concentration of the RAD51 repair protein in specific DNA repair centres in ....Genetic defects in DNA repair genes are associated with increased cancer risk in humans. For example, BRCA1 and BRCA2 gene mutations are the most common causes of familial breast cancer, and MLH1 gene mutations are the most common cause of familial non-polyposis colorectal cancer. We have identified a novel human DNA repair protein termed ASCIZ that performs a similar function to BRCA1 and BRCA2 in that it regulates the concentration of the RAD51 repair protein in specific DNA repair centres in the cell nucleus. However, ASCIZ performs this function in response to different types of DNA damage than BRCA1-BRCA2, and it acts in concert with the MLH1 protein. Here we want to study how ASCIZ regulates the assembly of DNA repair centres, and if it does so with support by the BRCA1-BRCA2 proteins. We also want to know if DNA repair functions of the RAD51 protein are diminished when it is not located in repair centres, and we want to identify novel proteins involved in this process. Our preliminary data show that cells that lack ASCIZ become dramatically hypersensitive to DNA damaging agents that are similar to clinically used chemotherapy drugs. We hope that our studies may identify possible approaches to develop drugs against ASCIZ and related proteins in order to kill cancer cells more effectively.Read moreRead less
DNA Lesions Involved In Chemotherapy Responses And Their Repair
Funder
National Health and Medical Research Council
Funding Amount
$399,142.00
Summary
The integrity of the human genome is constantly threatened by spontaneous DNA damage from products of normal metabolism, for example DNA oxidation, or environmental mutagens and carcinogens such as UV light. Improperly repaired DNA damage is a major contributing factor to the onset of cancer. To prevent this, human cells have a multitude of specialised DNA repair mechanisms to repair distinct lesions in the best possible way. As a consequence, mutations in DNA repair genes lead to increased canc ....The integrity of the human genome is constantly threatened by spontaneous DNA damage from products of normal metabolism, for example DNA oxidation, or environmental mutagens and carcinogens such as UV light. Improperly repaired DNA damage is a major contributing factor to the onset of cancer. To prevent this, human cells have a multitude of specialised DNA repair mechanisms to repair distinct lesions in the best possible way. As a consequence, mutations in DNA repair genes lead to increased cancer risk. Common examples for cancer-associated DNA repair gene mutations include the BRCA1 and BRCA2 breast cancer genes, and the MLH1 gene mutated in familial non-polyposis colorectal cancer. We have identified a novel human DNA repair protein termed ASCIZ that performs a function similar to BRCA1 and BRCA2 in that it regulates the concentration of the RAD51 repair protein in specific DNA repair centres in the cell nucleus. However, compared to BRCA1-BRCA2, ASCIZ performs this function in response to different types of DNA damage and acts in concert with the MLH1 protein. Here we want to investigate what the specific DNA lesions are that are repaired by ASCIZ, and we want to determine if the repair involves a copy mechanism that utilises intact genes as repair templates. In addition, we want to generate animals in which the ASCIZ gene is mutated, as a model to study its role in cancer development in humans. Cells that lack ASCIZ are dramatically hypersensitive to DNA damaging agents that are similar to clinically used chemotherapy drugs. We hope that our studies may identify possible approaches to develop drugs against ASCIZ and related proteins in order to kill cancer cells more efficiently.Read moreRead less
Lung cancer is the most frequent cause of cancer deaths in many Western countries, including ours. Lung cancer is the third leading cause of death of Australians and the fifth leading cause of burden of disease in Australia. With exposure to cancer-causing agents such as cigarette smoke, parts of the lung may suffer permanent damage that increases the risk of lung cancer. Many of these changes include the genes in air passages and lung tissue. A certain change (called methylation) affects some g ....Lung cancer is the most frequent cause of cancer deaths in many Western countries, including ours. Lung cancer is the third leading cause of death of Australians and the fifth leading cause of burden of disease in Australia. With exposure to cancer-causing agents such as cigarette smoke, parts of the lung may suffer permanent damage that increases the risk of lung cancer. Many of these changes include the genes in air passages and lung tissue. A certain change (called methylation) affects some genes in the lungs, but it is not yet known how common this change is or how it affects smokers and people who have developed lung cancer. We will collect blood and sputum specimens from lung cancer patients to test to see if methylation is present, and also specimens from when patients have a routine bronchoscopy as part of their initial tests. If they have an operation for lung cancer, then the part of the lung that is removed and not needed for diagnosis will also be tested for methylation. In this study, we will study whether methylation is an accurate test for lung cancer, whether it is present in parts of the lung near from the lung cancer, and whether it predicts better or worse results after treatment. We hope that this research study will provide new information about the diagnosis and treatment of lung cancer.Read moreRead less
Identification Of Telomere-specific Recombination Pathways
Funder
National Health and Medical Research Council
Funding Amount
$540,075.00
Summary
Human cells stop to grow when the natural ends of chromosomes become too short. One way of how cancer cells evade this growth arrest is by using a copy-mechanism to extend short chromosome ends. Ironically, this copy mechanism is usually used by cells to keep the structure of chromosomes intact in order to prevent mutations that cause cancer. Here we will study a novel protein that contributes to the copy mechanism at short chromosome ends, but not as much in normal mutation prevention.
The Nature And Significance Of Clonal Evolution In Human Melanoma
Funder
National Health and Medical Research Council
Funding Amount
$665,420.00
Summary
Cancers can progress in patients by developing genetic changes that favor the growth, survival and spread of cancer cells. However, the rate at which genetic changes occur in human cancer is not known. This project will determine the degree and biological significance of genetic change in human melanoma by using a novel method of growing tumors from single cells and comparing genetic differences between them.
Molecular Epidemiology Of Ovarian Cancer: The Australian Ovarian Cancer Study National Clinical Follow-Up Core
Funder
National Health and Medical Research Council
Funding Amount
$883,244.00
Summary
Ovarian cancer is the seventh most common cancer in Australian women and fifth most common cause of cancer death, with approximately 1200 new cases diagnosed and 750 deaths each year. There is an urgent need to better understand the molecular, epidemiological and genetic characteristics of epithelial ovarian cancer and how these influence response to treatment and clinical outcome. Ovarian cancer is a histologically and clinically diverse disease and the variability in clinical outcome in ovaria ....Ovarian cancer is the seventh most common cancer in Australian women and fifth most common cause of cancer death, with approximately 1200 new cases diagnosed and 750 deaths each year. There is an urgent need to better understand the molecular, epidemiological and genetic characteristics of epithelial ovarian cancer and how these influence response to treatment and clinical outcome. Ovarian cancer is a histologically and clinically diverse disease and the variability in clinical outcome in ovarian cancer patients suggests that reliable predictive factors would be of clinical value. However, it is clear that the collection of hundreds of annotated biospecimens is essential if the interaction of genes and environment in the genesis of this disease is to be understood or the molecular features of this disease dissected. Recognizing that this can only be achieved through large-scale collaboration, the Australian Ovarian Cancer Study (AOCS) was established in 2000 by scientists from the Peter MacCallum Cancer Centre, the Queensland Institute for Medical Research, Melbourne University and Westmead Institute for Cancer Research in collaboration with clinicians across Australia. AOCS has recruited 1105 patients to date and this Research Proposal aims to complete the collection of clinical data on all AOCS patients nationally, to validate the use of microarray gene expression profiles to predict clinical outcome and to find genetic variants that may determine clinical outcome in individual patients. The creation of AOCS has provided a unique oportunity to collect one of the finest ovarian cancer biological sample sets in the world. We believe that this internationally significant study will shed light on the basis of response of ovarian cancer to treatment and provide an ongoing resource for research into the causes of ovarian cancer, and studies on the response to treatment.Read moreRead less
Polycomb Group Genes In Murine Lymphomagenesisand Their Impact On Drug Response.
Funder
National Health and Medical Research Council
Funding Amount
$476,815.00
Summary
The success of lymphoma treatment with current drugs is limited by drug resistance. Some crucial links between genes which cause cancer and genes which alter response to cancer treatment have been identified: the cellular machinery that cancer cells use to become cancer cells in the first place, is often the same machinery that cancer cells later use to become resistant to cancer treatments. The Polycomb Group family controls expression of other critical genes: that is, they dictate which genes ....The success of lymphoma treatment with current drugs is limited by drug resistance. Some crucial links between genes which cause cancer and genes which alter response to cancer treatment have been identified: the cellular machinery that cancer cells use to become cancer cells in the first place, is often the same machinery that cancer cells later use to become resistant to cancer treatments. The Polycomb Group family controls expression of other critical genes: that is, they dictate which genes are switched on, where, and when. This determines whether a cell behaves normally or whether it may turn into a cancer cell. When Polycomb Group genes themselves are expressed at the wrong time or place, they can cause cancer. In human lymphoma, these genes have been associated with more aggressive lymphoma. This has also been shown for other cancers such as breast and prostate cancer. In some cases these genes are associated with cancers that do worse following anti-cancer treatment. So far, no research has been published looking the direct impact of the Polycomb Group genes on the success of treatment in a controlled laboratory model. We have used a powerful laboratory mouse model of lymphoma, established in the host laboratory, in which over-expression of the c-myc oncogene in developing B cells causes lymphoma. This model is easy to manipulate and this provides us with a great deal of experimental control, much more than can be achieved from working with patient samples. Two family members, Bmi-1 and Cbx7, cause lymphoma to develop aggressively and we will ask whether two other members, Ezh2 and Rybp do this as well. We will determine whether these 4 genes cause drug resistance in lymphoma, with currently used chemotherapy and also with novel anti-cancer drugs. By increasing our understanding of drug resistance in lymphoma, drugs may be utilised more effectively and new markers identified to predict which drug will be successful in treating a particular lymphoma.Read moreRead less
A Vulvar Cancer Cluster In Young Indigenous Women In Arnhem Land: Investigation Of Community Knowledge, Genetic Susceptibility And Supportive Care Response
Funder
National Health and Medical Research Council
Funding Amount
$711,841.00
Summary
Cancer of the vulva is 50 times more common in young Aboriginal women in Arnhem Land than in other women. Human Papillomavirus (HPV), which also causes cervical cancer, is the usual cause of this cancer; initial investigations have found that HPV is present in these cancers but is not the reason for the excessive incidence. This study will investigate local knowledge about this disease, and whether inherited susceptibility or an environmental cancer-causing substance are the cause of the excess.
Detection Of Alternative Lengthening Of Telomeres In The Mouse
Funder
National Health and Medical Research Council
Funding Amount
$471,000.00
Summary
In each cell, DNA is packaged into units called chromosomes, the ends of which (i.e., telomeres) become slightly shorter every time they are replicated during the production of new cells. Continued cell replication and hence continued telomere shortening eventually results in the inability of cells to replicate themselves any further. Normal cells have mechanisms to slow down, but not completely prevent telomere shortening. The development of a cancer depends on its cells being able to replicate ....In each cell, DNA is packaged into units called chromosomes, the ends of which (i.e., telomeres) become slightly shorter every time they are replicated during the production of new cells. Continued cell replication and hence continued telomere shortening eventually results in the inability of cells to replicate themselves any further. Normal cells have mechanisms to slow down, but not completely prevent telomere shortening. The development of a cancer depends on its cells being able to replicate themselves many times, and therefore they need to find a method to prevent their telomeres shortening. We discovered one such method, called Alternative Lengthening of Telomeres (ALT), that is used by some cancers. It has been shown in principle that cancer cells can be killed by disrupting their ability to prevent telomere shortening. Therefore, in another project we are developing methods needed to find drugs that inhibit ALT. In the meantime, we have found the first evidence that some normal cells have an ALT-like mechanism. Our speculation is that cancer cells are able to dysregulate and subvert this normal mechanism in order to prevent their telomeres from shortening. In this project, we will analyse the ALT-like mechanism in mice, to determine its characteristics, and to determine what tissues use it. This information will provide critically important insights into the ALT mechanism itself, and the likely side effects of drugs that inhibit ALT.Read moreRead less
Interactions Between Hedgehog And Ras Signaling In Lung Adenocarcinoma
Funder
National Health and Medical Research Council
Funding Amount
$295,983.00
Summary
Lung cancer is a common and lethal disease in our community. In this project, we explore how signaling pathways that regulate the development of the lung in embryos contribute to the initation and progression of lung cancer. To do this, we use a mouse model of lung cancer in which we can activate embryonic signaling pathways in adult mice to study there effect on the disease. Understanding these pathways will help us to better treat and prevent lung cancer in humans.