Molecular And Cellular Mechanisms Of Skeletal Disease Mediated By Plasma Cell Dyscrasias
Funder
National Health and Medical Research Council
Funding Amount
$432,750.00
Summary
Osteolytic and osteosclerotic lesions of bone are common sequelae of primary and secondary bone cancers, including cancers of hematological origin. There is now strong evidence that tumor cells perturb the local balance between bone resorption and formation, and in cases of osteolysis, cause increased osteoclast (OC)-mediated bone resorption without a matching amount of bone formation. This proposal arises from our extensive clinical and basic science experience with multiple myeloma (MM) in add ....Osteolytic and osteosclerotic lesions of bone are common sequelae of primary and secondary bone cancers, including cancers of hematological origin. There is now strong evidence that tumor cells perturb the local balance between bone resorption and formation, and in cases of osteolysis, cause increased osteoclast (OC)-mediated bone resorption without a matching amount of bone formation. This proposal arises from our extensive clinical and basic science experience with multiple myeloma (MM) in addition to other skeletal tumors, and our strong background in both OC and osteoblast biology. MM is a hematological malignancy characterised by plasma cell dyscrasia, which typically causes progressive and severe destruction of the skeleton, with accompanying bone pain, fracture and finally, hypercalcaemia of malignancy. Two related diseases, MGUS and POEMS, have been chosen for study because of their key similarities and differences with MM, and are likely to shed new light on the activities of MM in the bone. MGUS does not cause identifiable bone defects, whereas POEMS can give rise to both osteolytic and osteosclerotic lesions. Comparison of these conditions will uniquely enable us to examine why these seemingly related neoplasms are able to mediate disparate skeletal disease states. Primarily, and since there are few curative therapies for MM at present, our proposed studies are designed to identify targets for therapy that will treat the most serious manifestation of this disease, namely its destruction of bone tissue.Read moreRead less
The Molecular And Cellular Mechanisms Responsible For The Skeletal Complications Associated With Multiple Myeloma.
Funder
National Health and Medical Research Council
Funding Amount
$212,036.00
Summary
Multiple myeloma is an incurable disease of the antibody-producing B cell. Patients with MM, nearly always present with bone pain and unexplained bone fractures. These fractures are caused by the cancerous MM B cells, which are found in large numbers in discrete pockets throughout the bone marrow, close to the inner bone surface. The way that the cancerous B cells cause the local bone lesions is thought to be through the heightened activation of recruitment of osteoclasts. Osteoclasts are cells ....Multiple myeloma is an incurable disease of the antibody-producing B cell. Patients with MM, nearly always present with bone pain and unexplained bone fractures. These fractures are caused by the cancerous MM B cells, which are found in large numbers in discrete pockets throughout the bone marrow, close to the inner bone surface. The way that the cancerous B cells cause the local bone lesions is thought to be through the heightened activation of recruitment of osteoclasts. Osteoclasts are cells which normally, in a controlled manner, resorb bone as part of the ongoing process of new bone formation. We propose that myeloma cells, which exhibit characteristics of osteoclasts, home to sites in the bone marrow and initiate this bone breakdown and furthermore secrete factors required for osteoclast maturation and activity. We believe that these molecules include the recently defined molecule, termed osteoclast differentiation factor, which is normally produced by bone-producing cells known as osteoblasts. Moreover, we feel that myeloma B cells alter the function of osteoblast cells, which results in a decrease in bone formation. Finally, we propose that this disease and its associated bone defects originate from changes in the expression of a number of genes. The results from theses studies should provide a greater understanding of the way in which this B cell cancer originates and how it causes bone defects. This will lead to the development of better treatments to improve the survival of patients with MM, and will lead to therapies to prevent the associated bone complications.Read moreRead less
The Role Of CXCL12 (SDF-1)/CXCR4 In Pathological Angiogenesis And Osteolytic Bone Disease In Multiple Myeloma
Funder
National Health and Medical Research Council
Funding Amount
$665,896.00
Summary
Multiple myeloma (MM) is the second most common haematological (or blood) cancer in western countries and is unique amongst blood cancers in its capacity to destroy the skeleton. MM is a cancer of plasma cells, which in their normal non-cancerous form, reside in lymph nodes and produce antibodies against infectious agents. When they become cancerous, they migrate or home to congenial sites within the bone marrow (BM). This directed movement or homing occurs under the influence of a chemokine mol ....Multiple myeloma (MM) is the second most common haematological (or blood) cancer in western countries and is unique amongst blood cancers in its capacity to destroy the skeleton. MM is a cancer of plasma cells, which in their normal non-cancerous form, reside in lymph nodes and produce antibodies against infectious agents. When they become cancerous, they migrate or home to congenial sites within the bone marrow (BM). This directed movement or homing occurs under the influence of a chemokine molecule called CXCL12 which acts as a calling card for plasma cells to leave the lymph node and migrate to the BM. Once within the BM, the cells rapidly grow in response to BM-derived growth factors. This rapid growth causes a depletion in oxygen availability within the tumour and it becomes hypoxic. In response to this hypoxia, the tumour expresses a gene called hypoxia-inducible factor-1 (HIF-1) which regulates the expression of many proteins, including the chemokine CXCL12. Our studies show that the abnormal expression of CXCL12 by the plasma cells acts to promote blood vessel formation within the tumour, which in turn leads to greater tumour growth. In addition, our studies suggest that abnormal CXCL12 expression also promotes the recruitment and activation of large numbers of osteoclast (OC) precursors form the peripheral blood. OC are cells which normally remove unwanted or damaged bone. This proposal will study the interplay between HIF and CXCL12 in the establishment and development of MM and the associated bone destruction.Read moreRead less
Investigate The Role Of PAF And CD40 Ligand In Regulating The Proinflammatory Properties Of Platelets
Funder
National Health and Medical Research Council
Funding Amount
$507,270.00
Summary
The cells of the blood play an important role in maintaining healthy blood vessels. We are interested in two types of blood cells, platelets and leukocytes, which together play a key role in vessel maintenance, by promoting blood clot formation and vessel wall repair following injury. However, while critical for normal blood vessel maintenance, these cells have also been demonstrated to contribute to disease states including atherosclerosis, thrombosis and inflammatory airway diseases. Underlyin ....The cells of the blood play an important role in maintaining healthy blood vessels. We are interested in two types of blood cells, platelets and leukocytes, which together play a key role in vessel maintenance, by promoting blood clot formation and vessel wall repair following injury. However, while critical for normal blood vessel maintenance, these cells have also been demonstrated to contribute to disease states including atherosclerosis, thrombosis and inflammatory airway diseases. Underlying the function of both blood cell types is their ability to stick (or adhere) to each other. However the way in which they coordinate this adhesion is very complex. New information from our laboratory has demonstrated that the sticky behaviour of each cell type is spatially and temporally regulated, and may involve may factors both inside and outside of the cells themselves. Our studies aim to define the key components regulating the 'stickiness' of these blood cells, in order to undertand how they contribute to maintaining healthy vessel walls, but also how their stickiness may also contribute to the promotion of diseased vessels. This information will not only increase our knowledge of the factors that regulate blood clot formation, but may also assist in the development of new therapies to prevent and-or treat vessel disease.Read moreRead less
The Role Of Ap2a2 In Self-renewal Of Haematopoietic And Leukemic Stem Cells
Funder
National Health and Medical Research Council
Funding Amount
$579,171.00
Summary
The daily replenishment of the blood system is dependent on the blood stem cell. A unique property of these stem cells is self-renewal where the stem cell function is preserved, whilst other daughter cells continue to divide. Our research investigates the molecular mechanisms that regulate stem cell self-renewal. This work has potential clinical application on at least two levels: expansion of stem cells for transplantation, and for attacking abnormal cancer cell self-renewal pathways.