Androgen-regulated Proteins: Predictors Of Prostate Cancer Development And Progression
Funder
National Health and Medical Research Council
Funding Amount
$391,073.00
Summary
Use of PSA (prostate specific antigen) levels in blood to screen for prostate cancer has resulted in a) earlier detection of tumours and b) increased diagnosis of a premalignant disease of the prostate called PIN (prostatic intraepithelial neoplasia). PIN is thought to progressively change into cancer, which can invade the rest of the body. Growth of the cells of the prostate is regulated by male hormones called androgens. Small cancers localised to the prostate grow in response to androgens, bu ....Use of PSA (prostate specific antigen) levels in blood to screen for prostate cancer has resulted in a) earlier detection of tumours and b) increased diagnosis of a premalignant disease of the prostate called PIN (prostatic intraepithelial neoplasia). PIN is thought to progressively change into cancer, which can invade the rest of the body. Growth of the cells of the prostate is regulated by male hormones called androgens. Small cancers localised to the prostate grow in response to androgens, but larger cancers which have spread from the prostate grow steadily even after the androgen supply is cut off by removal of the testicles. In this project we will examine changes in the level of various proteins in the prostate, which are known to be produced in response to androgen, to see whether they discriminate: 1) those patients with PIN who will go on to develop prostate cancer, 2) those patients with small cancers within the prostate who progress to widespread cancer. We also propose to use a laser-controlled dissecting microscope to obtain pure populations of cancer cells from prostate tissues and then to isolate their DNA in order to: a) examine the DNA sequence of the protein which controls cellular growth in response to androgen (ie the androgen receptor) to see whether undesirable changes (mutations) have occurred in its structure during the development of the cancer, and b) identify proteins which mediate the effects of the androgen regulated proteins and control cancer development or spread. This will be done using the revolutionary technique of gene microarrays, where partial DNA sequences of approximately 4,000 different prostate genes are spotted onto small membrane filters, and which enable identification of genes that change in level with the onset of cancer and cancer spread. These 2 objectives will, in the case of a) prevent inappropriate treatment for prostate cancer, and b) identify targets for new treatments and for chemoprevention.Read moreRead less
REGULATION OF ANDROGEN RECEPTOR And ErbB-2 GENE EXPRESSION IN PROSTATE CANCER: ROLE OF THE HU PROTEINS
Funder
National Health and Medical Research Council
Funding Amount
$471,000.00
Summary
Carcinoma of the prostate (PCa) is the most common malignancy affecting males and causes enormous morbidity and mortality in Australia. It is the second leading cause of death in men in Western countries. About one third of men relapse after radical prostatectomy because of previously undetectable metastatic disease. Androgens, acting via the androgen receptor (AR) a nuclear transcription factor that regulates a set of largely unknown androgen-responsive genes, promote the growth of prostate can ....Carcinoma of the prostate (PCa) is the most common malignancy affecting males and causes enormous morbidity and mortality in Australia. It is the second leading cause of death in men in Western countries. About one third of men relapse after radical prostatectomy because of previously undetectable metastatic disease. Androgens, acting via the androgen receptor (AR) a nuclear transcription factor that regulates a set of largely unknown androgen-responsive genes, promote the growth of prostate cancer cells. Thus the AR is a major target for therapy. Even when the disease is unresponsive to androgen withdrawal, the AR is present. Furthermore, we know that these PCa cells recruit other androgen-independent pathways to activate growth. One such pathway is the erbB-2 signaling cascade, which drives the cells towards proliferation. Proteins that bind to RNA, the cellular messenger, are playing an increasing role in the biology of cancer. HuR, a member of the Hu-Elav family, augments growth of colon cancer cells, and is associted with poor outcomes in ovarian and brain malignancies. We have recently identified the first proteins that bind to AR and erbB-2 mRNA. Remarkably, HuR binds to both sequences. Furthermore, HuD, another member of the Hu-Elav family which is normally only found in the brain, is aberrantly expressed in human PCa. In this Project we will determine the effects of these proteins on the growth of human PCa cells in culture and in whole animal models. We will also evaluate their presence in a large array of human PCa specimens. It is envisaged that this work will develop novel links between the two pathways bringing them together in a previously unrecognised manner. We also aim to solve the molecular structure of Hu proteins bound to the AR mRNA. Outcomes of the work will include new potential tests for prostate cancer and improved prognosis prediction, and establishment of a foundation for the development of novel targets for therapy.Read moreRead less
CHARACTERISATION OF THE PROSTATE ANDROGEN-RESPONSE PROGRAM USING COMBINED TRANSCRIPT AND PROTEIN EXPRESSION PROFILING
Funder
National Health and Medical Research Council
Funding Amount
$232,200.00
Summary
Carcinoma of the prostate exhibits a wide range of biological variation influenced by genetic, racial, environmental, and other as yet undefined factors. For 1997 the Australian Bureau of Statistics estimates revealed that 27% of all deaths (> 34,000) were due to cancer. Among males, the second leading cause of death (13%) was prostate cancer. The development and progression of human prostate cancer is driven by the accumulation of genetic changes and influenced by a multitude of currently un ....Carcinoma of the prostate exhibits a wide range of biological variation influenced by genetic, racial, environmental, and other as yet undefined factors. For 1997 the Australian Bureau of Statistics estimates revealed that 27% of all deaths (> 34,000) were due to cancer. Among males, the second leading cause of death (13%) was prostate cancer. The development and progression of human prostate cancer is driven by the accumulation of genetic changes and influenced by a multitude of currently unknown events. In addition, a genetic predisposition to certain environmental elements may also provide susceptibility to the onset of prostate cancer. Inherent in identifying the mechanisms leading to prostate cancer is defining the molecular factors involved in the biological processes that influence the development, progression, and treatment of this malignancy. This proposal aims to address the lack of fundamental knowledge relating to the androgen hormone mediated molecular pathways through a comprehensive approach using genomic (DNA), transcribed (RNA) and translated (protein) information that will define the components of the androgen regulated events; i.e. identify the proteins and genes directly or indirectly regulated by androgenic hormones and their cognate receptors. Importantly we will apply technologies that can detect molecular changes in the cell without preconceived ideas about which information will be most valuable to monitor or which technologies will have the greatest impact. We anticipate that the characterisation of the prostate androgen-response will not only provide fundamental knowledge concerning androgen-mediated mechanisms of growth and cellular differentiation, but will also provide a molecular framework for therapeutic intervention through the identification of novel therapeutic targets suitable for a variety of interventions ranging from dietary modification to immunological and gene-therapy approaches.Read moreRead less
Investigation Of Steroidogenesis As A Mechanism Of Castration Resistance In Human Prostate Cancer
Funder
National Health and Medical Research Council
Funding Amount
$419,076.00
Summary
Prostate cancer is critically dependent upon continued testosterone stimulation, even when the disease becomes resistant to existing hormonal therapies that suppress serum levels. The source of this testosterone is currently unclear. This study aims to identify the site of testosterone synthesis in patients with prostate cancer, and determine the relevance of continued testosterone signalling in patients treated with 'super castrating' hormonal therapy.
Characterisation Of Alterations In The Androgen Signalling Axis That Contribute To Treatment Failure In Prostate Cancer
Funder
National Health and Medical Research Council
Funding Amount
$559,157.00
Summary
Prostate cancer is a major health problem in Western Countries including Australia, where it is the most common newly diagnosed invasive cancer and the second leading cause of cancer deaths in men. Although there have been improvements in the diagnosis of prostate cancer, many men are still diagnosed with disease that already has or will spread to other sites such as bone (ie metastatic disease). For those men with metastatic disease, reduction in testicular androgens by surgical or medical mean ....Prostate cancer is a major health problem in Western Countries including Australia, where it is the most common newly diagnosed invasive cancer and the second leading cause of cancer deaths in men. Although there have been improvements in the diagnosis of prostate cancer, many men are still diagnosed with disease that already has or will spread to other sites such as bone (ie metastatic disease). For those men with metastatic disease, reduction in testicular androgens by surgical or medical means (ie androgen ablation) is the only effective treatment option available. While androgen ablation is initially effective, treatment failure is common, resulting in a very poor overall survival rate. Evidence from our studies and others suggest that, the androgen receptor, which mediates the growth regulatory effects of androgens is often defective in prostate tumour cells. These altered or mutant receptors are activated inappropriately by other sex hormones such as estradiol and even agents used in the treatment of prostate cancer whereas the normal receptor is activated only by testicular androgens. This mechanism may explain why treatment fails in a subset of men with advanced prostate cancer. The major objective of our current studies is to define how these mutant androgen receptors cause treatment failure and facilitate prostate tumour growth. In addition, the current studies will evaluate a novel approach to treatment of prostate cancer which, based upon our preliminary results, has the potential to be effective even if alterations are present in the androgen receptor. The current studies therefore will provide a better understanding of factors controlling the growth of prostate tumours, and develop improved treatment approaches for advanced prostate cancer.Read moreRead less