Progesterone Signalling In Normal And Malignant Breast Relies On Chromosomal Positioning Of Progesterone Receptor
Funder
National Health and Medical Research Council
Funding Amount
$569,346.00
Summary
The cell nucleus carries genetic information that directs cell function. The nucleus is organised into compartments, which are altered in breast cancer, leading to altered function. The ovarian hormone progesterone acts via a receptor, which clumps into foci in the nucleus when active. In cancers, this clumping is disrupted. In this project we will work out how these foci control cell function, and how this leads to the specific functions of progesterone in normal breast and breast cancers.
Defining Mechanisms Of Androgen Receptor Action That Impede Breast Cancer Progression
Funder
National Health and Medical Research Council
Funding Amount
$770,619.00
Summary
Androgens (A), commonly considered male hormones, are present in women and may protect them from developing aggressive breast cancer by opposing the cancer-promoting effects of estrogen (E) hormones. We propose that a disturbance in the balance between A and E action in breast cancer worsens the disease and results in a poor outcome for afflicted women. We aim to define how A and E hormones interact in breast cancer, with a view to developing new ways to treat breast cancer and predict outcome.
Impact Of Progesterone Receptor Subnuclear Localisation On Progesterone Action In Endocrine Target Cells
Funder
National Health and Medical Research Council
Funding Amount
$459,514.00
Summary
Breast cancer affects 10,000 Australian women annually and is a major cause of cancer death. The hormone progesterone, which is produced by the ovaries in women, is responsible for some aspects of the development of the normal breast in women and is also implicated in the development and response of breast and endometrial cancers. In normal cells progesterone acts via a specific protein (or receptor) in the nucleus, and we have shown that this protein accumulates into foci when it is active. We ....Breast cancer affects 10,000 Australian women annually and is a major cause of cancer death. The hormone progesterone, which is produced by the ovaries in women, is responsible for some aspects of the development of the normal breast in women and is also implicated in the development and response of breast and endometrial cancers. In normal cells progesterone acts via a specific protein (or receptor) in the nucleus, and we have shown that this protein accumulates into foci when it is active. We have noticed that in cancers, this accumulation is disrupted, and this is a bad sign for the cancer. As breast cancer develops, it causes many dramatic changes in the structure of cells of the breast, and particularly in the nucleus, which carries the genetic information that programs cancer cell behaviour. The nucleus normally is highly organised into compartments, which carry out different functions of the cell, such as duplication of the DNA, repair of DNA after damage, and switching on and off of particular genes important to the function of the cell. This organisation is altered dramatically in cancer cells, and it seems that this altered organisation is responsible for altered function. In this project we aim to work out what makes the receptor for progesterone form foci, how these foci are involved in the action of progesterone, and how the changed structure of the nucleus changes this process. This project will link the structure of the cell nucleus with the ability of progesterone to switch on or off particular genes, and this will provide the first signposts of how changes seen in cancer cell nuclei are reflected in changed hormonal signalling. Healthy women are regularly exposed to progestins in oral contraceptives and hormone replacement therapy. The known increased risk of breast cancer as a result of exposure to progestins creates an imperative to understand how progesterone may have aberrant effects. This project will address this important health issue.Read moreRead less
Neuroactive Steroids In The Developing Brain: Potential For Preventing Perinatal Brain Damage
Funder
National Health and Medical Research Council
Funding Amount
$481,500.00
Summary
Complications during pregnancy, birth asphyxia or premature birth can lead to serious neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neuroactive steroids are a group of neuromodulators that are derived from the hormone progesterone. These steroids fall into two groups, those that appear to protect brain cells from damage caused by an inadequate supply of oxygen and those that may increase cell death. We have shown tha ....Complications during pregnancy, birth asphyxia or premature birth can lead to serious neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neuroactive steroids are a group of neuromodulators that are derived from the hormone progesterone. These steroids fall into two groups, those that appear to protect brain cells from damage caused by an inadequate supply of oxygen and those that may increase cell death. We have shown that protective neuroactive steroids are present in very large amounts in the fetal brain. Steroids produced by the placenta are converted to these neuroactive products by enzymes in the brain leading to the high levels that are seen during fetal life. Certain adverse conditions during pregnancy as well as preterm birth may cause marked changes in the balance of steroids that could increase susceptibility to brain injury. We have found that areas of the brain, where damage most often occurs, normally contain the highest amount of protective steroids, but only in late pregnancy. This suggests that disturbances that lower steroid production in these areas could contribute to the death of cells, particularly in mid-pregnancy and after premature birth. In the proposed studies, we will examine whether a toxic balance of steroids develops following adverse events in pregnancy as well as the areas of the brain where this is most pronounced. We will examine the changes in the expression of enzymes that can potentially cause the accumulation of protective steroids in the brain. We will then examine treatments that can raise the concentration of steroids and determine which combination of steroids best reduces cell death and brain injury following complications during pregnancy. The findings of this work will indicate the best therapeutic approach that may be adopted to modify the concentration of certain steroids so as to reduce the risk of brain damage in the fetus and neonate.Read moreRead less
Steroid hormones, such as oestrogen and cortisol, act in the body by binding a family of proteins (nuclear receptors) that bind directly to the DNA to regulate genes. The mechanisms underlying this process are complex and involve recruitment of additional molecules or coactivators to improve efficiency. Recently a novel coactivator was identified termed SRA, which remarkably is never made into protein in cells, rather exerting its effects as a RNA. We have identified a novel family of proteins t ....Steroid hormones, such as oestrogen and cortisol, act in the body by binding a family of proteins (nuclear receptors) that bind directly to the DNA to regulate genes. The mechanisms underlying this process are complex and involve recruitment of additional molecules or coactivators to improve efficiency. Recently a novel coactivator was identified termed SRA, which remarkably is never made into protein in cells, rather exerting its effects as a RNA. We have identified a novel family of proteins that bind to SRA in cancer cells, and may well play a critical role in regulating how SRA modulates genes. This project seeks to understand how this family interacts with SRA, the functional effects on breast cancer cells, and the detailed 3-dimensional structure of the family members coupled with SRA. This work will provide novel insight into how SRA regulates steroid hormone action, and may create new potential avenues for developing therapeutics in breast cancer.Read moreRead less
Neurosteroid Mediated Protection After Birth: Approaches For Maximising Protective Steroid Levels In The Neonatal Brain
Funder
National Health and Medical Research Council
Funding Amount
$450,703.00
Summary
Complications during pregnancy, birth asphyxia or premature birth can lead to neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neurosteroids are a group of steroids that regulate brain activity. These steroids protect brain cells from damage caused by an inadequate supply of oxygen by suppressing toxicity caused by excessive activity. We have shown that the levels of these protective steroids are remarkably high in the ....Complications during pregnancy, birth asphyxia or premature birth can lead to neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neurosteroids are a group of steroids that regulate brain activity. These steroids protect brain cells from damage caused by an inadequate supply of oxygen by suppressing toxicity caused by excessive activity. We have shown that the levels of these protective steroids are remarkably high in the fetal brain and levels rise further in response to fetal stress. The placenta contributes steroid precursors that help maintain these high neurosteroid levels. This placenta-fetal brain interaction comprises an internal mechanism that protects the fetal brain from adverse events during pregnancy. At birth, however, there is a dramatic decline in neurosteroid concentrations in the brain after the loss of the placental precursor supply. The fall in concentrations is even greater in animals that are born growth restricted. This suggests that newborns, particularly those from compromised pregnancies, are at increased risk of brain damage due to low neurosteroid levels. We believe that certain commonly used steroid therapies may also lower steroid levels in the brain and result in increased vulnerability to brain damage during birth or in the early neonatal period. Alternatively, we propose that replacement of neurosteroid precursors in the newborn may raise brain neurosteroid levels and protect against brain damage. In the proposed studies we will evaluate treatments that can raise the concentration of steroids and determine the best strategy for reducing brain injury following complications during pregnancy, at birth and during the early newborn period. This work will determine the best therapeutic approaches for maximising neurosteroid-induced brain protection and for reducing the risk of brain damage.Read moreRead less
Progesterone Regulation Of Epithelial Cell Lineages In The Breast
Funder
National Health and Medical Research Council
Funding Amount
$534,186.00
Summary
The ovaries play a pivotal role in breast cancer in ways that are unknown. Progesterone increases breast cancer risk, and response to hormonal treatments is critically associated with tumour progesterone receptor content, but how it does this is unknown. We will pursue our findings that progesterone influences cell types in the breast similar to those that become cancerous. This will uncover critical vulnerabilities in breast cancer development and potential targets for prevention and treatment.