Phosphatidylinositol 3-kinase Mutations Associated With Ovarian, Colon And Breast Tumours
Funder
National Health and Medical Research Council
Funding Amount
$154,000.00
Summary
Colorectal and breast cancers are the two most common registrable cancers in Australia and are second only to lung cancer in the total number of cancer deaths each year (4,678 and 2,612 deaths in 1997 for colorectal and breast, respectively). Ovarian cancer kills a further 740 women each year (Source: Cancer in Australia 1997, AIHW and AACR 2000). Thus, on average, one Australian dies of colorectal, breast or ovarian cancer every hour! Clearly, these are major diseases with a significant impact ....Colorectal and breast cancers are the two most common registrable cancers in Australia and are second only to lung cancer in the total number of cancer deaths each year (4,678 and 2,612 deaths in 1997 for colorectal and breast, respectively). Ovarian cancer kills a further 740 women each year (Source: Cancer in Australia 1997, AIHW and AACR 2000). Thus, on average, one Australian dies of colorectal, breast or ovarian cancer every hour! Clearly, these are major diseases with a significant impact on our society. Unfortunately, though, we still do not understand the basic molecular and-or biochemical abnormalities that initiate and-or drive the development of these cancers. Recent functional and genetic studies in a number of different tumour types (including colon and ovarian) have suggested that members of the phosphatidylinositol 3-kinase (PI3K) enzyme family may be oncogenes (cancer-causing genes). However, strong evidence confirming a causal role for PI3K in human cancer is yet to be reported. Our research proposal outlines a study to address this issue. We have preliminary data demonstrating mutations in at least one member of this enzyme family in a number of tumours. We now propose to undertake a comprehensive analysis of the spectrum, and frequency, of PI3K mutations that occur in colon, breast and ovarian tumours. These studies will allow us to make a definitive assessment of the role of PI3K in the development human cancer. In addition to furthering our understanding of the processes involved in the initiation and progression of human tumours, this project also has the potential to identify new markers for the early detection of cancer and novel targets for new anti-cancer therapies.Read moreRead less
DNA methylation is a mechanism used by many organisms, including humans, to keep certain regions of DNA inactive, i.e. in a state where they will not be read. Errors in this process may result in inappropriate inactivation of a gene, termed epimutation; this may occur even when no DNA sequence changes (i.e. mutations) are present. Some individuals are born with high levels of an epimutation that predisposes them to developing multiple cancers. Little is known about whether low levels of epimutat ....DNA methylation is a mechanism used by many organisms, including humans, to keep certain regions of DNA inactive, i.e. in a state where they will not be read. Errors in this process may result in inappropriate inactivation of a gene, termed epimutation; this may occur even when no DNA sequence changes (i.e. mutations) are present. Some individuals are born with high levels of an epimutation that predisposes them to developing multiple cancers. Little is known about whether low levels of epimutations (only a portion of the body's cells affected) are important in development of sporadic (common) cancer. The aim of this project is to determine the levels of epimutations in the normal tissues of healthy individuals, and compare these with the levels in normal tissues of people who have had certain types of cancers. In doing this we hope to find out if low level epimutations contribute to the risk of developing sporadic cancer.Read moreRead less
Resistant forms of childhood acute lymphoblastic leukaemia (ALL) constitute a leading cause of cancer-related deaths in children. Despite tremendous improvements in therapy, 25-30% of patients still experience a relapse and many of them occur in patients stratified as low risk. Further treatment is often toxic, frequently unsuccessful and carries the risk of significant long-term morbidity. For the design of more appropriate therapy, information on the biology of relapsed ALL is urgently require ....Resistant forms of childhood acute lymphoblastic leukaemia (ALL) constitute a leading cause of cancer-related deaths in children. Despite tremendous improvements in therapy, 25-30% of patients still experience a relapse and many of them occur in patients stratified as low risk. Further treatment is often toxic, frequently unsuccessful and carries the risk of significant long-term morbidity. For the design of more appropriate therapy, information on the biology of relapsed ALL is urgently required. The sequencing of the human genome and advanced screening technology (microarrays) allow the detailed analysis of expression patterns in large numbers of specimens. We propose to study the genetic features of this disease by investigating 28 childhood ALL patients from whom we have stored specimens received at two time points, one at diagnosis and one at relapse. The hypothesis of this study is that relapsed leukaemias display genetic features which are correlated to their resistance to therapy. The specific questions we will be asking are: (1) Which genes are expressed at high levels in leukaemia specimens at the time of relapse while not expressed (or expressed at lower levels) at the time of diagnosis and vice versa? (2) What is the function of differentially expressed genes? (3) Is the pattern of gene expression correlated with resistance to the particular drug therapy used? (4) Is the leukaemia clone at relapse related or unrelated to the clone present at diagnosis, as determined by receptor rearrangement? The expression levels of identified discriminator genes will be confirmed by real-time quantitative polymerase chain reaction (PCR). The quality of this set of specimens makes them particularly suited to achieve the stated goals, providing a unique opportunity to investigate drug resistance in childhood ALL. The data generated will provide the basis for the examination of genes suitable as new therapeutic targets.Read moreRead less