This project will unleash the potential of peptide drugs by overcoming their final barrier to widespread use, their synthesis. Plants naturally produce ultra-stable cyclic peptides. We will co-opt their machinery to produce in seeds, two drug leads that have potential as treatments for prostate cancer and chronic neuropathic pain. As an �organic� drug source, seeds have the potential to improve patient compliance and low-tech production systems will allow technology transfer to third-world natio ....This project will unleash the potential of peptide drugs by overcoming their final barrier to widespread use, their synthesis. Plants naturally produce ultra-stable cyclic peptides. We will co-opt their machinery to produce in seeds, two drug leads that have potential as treatments for prostate cancer and chronic neuropathic pain. As an �organic� drug source, seeds have the potential to improve patient compliance and low-tech production systems will allow technology transfer to third-world nations.Read moreRead less
Role Of Gastrin Prohormones In The Development Of Gastrointestinal Cancers
Funder
National Health and Medical Research Council
Funding Amount
$612,885.00
Summary
Gastrin is a stomach hormone which increases acid secretion and the growth of the stomach and bowel. This growth promoting effect may be involved in a number of cancers particularly colon cancer. The different types of gastrin have different effects but we do not know which forms are important and whether all are active. The types and activity of different gastrins will be investigated using cell lines, animal models and colon cancer patients with the view of establishing new treatments.
Functional Relationships Of Gastrin And Its Regulators In The Developing And Diseased Gastrointestinal Tracts
Funder
National Health and Medical Research Council
Funding Amount
$607,832.00
Summary
Gastrin is a hormone from the stomach which aids digestion by stimulating acid secretion. However too much acid can cause ulcers of the gastrointestinal tract. Gastrin also stimulates growth of the lining of the stomach and intestines. This growth promoting effect is important for the development of the gastrointestinal tract before birth and may also be involved in a number of cancers especially colon cancer. Several different forms of gastrin are made by endocrine cells of the stomach and by c ....Gastrin is a hormone from the stomach which aids digestion by stimulating acid secretion. However too much acid can cause ulcers of the gastrointestinal tract. Gastrin also stimulates growth of the lining of the stomach and intestines. This growth promoting effect is important for the development of the gastrointestinal tract before birth and may also be involved in a number of cancers especially colon cancer. Several different forms of gastrin are made by endocrine cells of the stomach and by cancers of the colon. It seems that the different types of gastrins have different effects and act through distinct receptors. The production and effects of gastrin are mediated in part by the local factor histamine and modified by the hormone somatostatin. The amount, type and activity of gastrin, and the interactions with histamine and somatostatin, will be measured in foetal and newborn animals, and people with or at risk of developing colon cancer.Read moreRead less
Peptides Derived From ProGRP As Growth Factors For Gastrointestinal Cancers
Funder
National Health and Medical Research Council
Funding Amount
$589,544.00
Summary
Our objective is to determine the roles of a growth factor termed bombesin. This peptide, known as GRP in the human, is a growth factor in certain lung cancers but little is known about its role in tumours of the colon. This project is based on our novel observation that the precursor of GRP (proGRP) previously thought to be inactive is in fact active in stimulating the growth of colon cancer cells. A successful outcome will result in novel treatments such as proGRP antagonists.
Crystallographic Studies Of Non-canonical Peptides Binding To MHC Class I Molecules.
Funder
National Health and Medical Research Council
Funding Amount
$489,750.00
Summary
Virus infected cells and cancer cells are recognised and eliminated from our body by specialised cells called T-cell lymphocytes. This recognition process is the key step in the immune response and some fundamental questions in immunology are centred on the nature of this process. At the molecular level, the recognition is mediated by the specific interaction between proteins on the surface of the cells. On the T-cell lymphocyte, the T-cell receptor (TCR) binds specifically to a protein called t ....Virus infected cells and cancer cells are recognised and eliminated from our body by specialised cells called T-cell lymphocytes. This recognition process is the key step in the immune response and some fundamental questions in immunology are centred on the nature of this process. At the molecular level, the recognition is mediated by the specific interaction between proteins on the surface of the cells. On the T-cell lymphocyte, the T-cell receptor (TCR) binds specifically to a protein called the MHC on the surface of the target cell. The target cell can be a cancer cell, or an infected antigen presenting cell (specialised cells in the body which present protein fragments (peptides) on their surface via MHC). The structure of a TCR and TCR-MHC have been solved in terms of the shape of the molecules at atomic resolution, bringing detailed information on how these two proteins interact with each other. In this proposal the structural basis of antigen presentation and recognition in cell-mediated immunity will be determined by three-dimensional structures of different peptides on MHC by x-ray crystallography. Cell surface antigen presentation by MHC molecules is crucial for initiating the cellular immune response against invading pathogens and cancer. This proposal encompasses a combined biochemical, immunological, and biophysical approach to understand the range of ligands which can bind to MHC which are subsequently recognised by the TCR. To understand the antigenic properties of modified peptides at the structure level, the x-ray structure of MHC with modified bound synthetic peptides will be determined.Read moreRead less
Mimicking Protein Surfaces With Cyclic Peptides: W-conotoxin GVIA Mimics As Novel Analgesic And Neuroprotective Agents
Funder
National Health and Medical Research Council
Funding Amount
$216,412.00
Summary
The omega-conotoxins are small polypeptides (of around 25 residues) cross-linked by three disulfide bonds. At least two of these, omega-conotoxins GVIA and MVIIA, are potent and selective blockers of N-type voltage-gated calcium channels. Administered to the CNS via an intrathecal catheter, MVIIA and GVIA are analgesic in acute, chronic and neuropathic pain models, and protective following ischaemia-induced neuronal injury, such as occurs following stroke. They do not suffer from the development ....The omega-conotoxins are small polypeptides (of around 25 residues) cross-linked by three disulfide bonds. At least two of these, omega-conotoxins GVIA and MVIIA, are potent and selective blockers of N-type voltage-gated calcium channels. Administered to the CNS via an intrathecal catheter, MVIIA and GVIA are analgesic in acute, chronic and neuropathic pain models, and protective following ischaemia-induced neuronal injury, such as occurs following stroke. They do not suffer from the development of tolerance, in contrast with the opioids, such as morphine, which lose their analgesic potency over time and have undesirable side effects. We have determined the three-dimensional structure of GVIA and mapped onto that structure its calcium channel binding surface. This information is a starting point for the structure-based design of truncated and stabilised peptidic analogues of GVIA, which should have several advantages over the native polypeptides as candidates for the treatment of chronic pain and ischaemia-induced neuronal damage. In the course of this work we shall also generate a range of libraries of experimentally determined and predicted structures based on small, cyclic peptides. These libraries will be valuable tools for mimicking key functional regions of protein surfaces in small molecules that are easily (and cheaply) synthesised and have potentially favourable bioavailability. Thus, this project will also increase our understanding of the attributes of small cyclic peptides as mimics of functionally important protein surfaces and provide valuable tools for the design and evaluation of such peptides.Read moreRead less
Colorectal carcinoma (cancer of the large bowel) is the second most common cause of cancer death. Colorectal carcinomas in common with other cancer types such as cancer of the prostate and lung often produce their own growth factors and receptors. Activation of the receptor by the growth factor further stimulates the tumour's growth and spread throughout the body. The objective of this project is to deterrmine the potential roles of a growth factor termed bombesin. This peptide, now known as GRP ....Colorectal carcinoma (cancer of the large bowel) is the second most common cause of cancer death. Colorectal carcinomas in common with other cancer types such as cancer of the prostate and lung often produce their own growth factors and receptors. Activation of the receptor by the growth factor further stimulates the tumour's growth and spread throughout the body. The objective of this project is to deterrmine the potential roles of a growth factor termed bombesin. This peptide, now known as GRP in mammalian systems, is an established growth factor in certain lung cancers but little is known about its role in tumours of the large bowel. This project is based on our novel observation that the precursor of GRP (proGRP) previously thought to be inactive is in fact biologically active in stimulating the growth of colorectal carcinoma cells. We will determine which parts of the GRP precursor (proGRP) are bioactive, and test the effects of the bioactive regions on growth and cancer spread using a variety of colorectal cancer cell lines. We will also investigate the effects of the bioactive regions of proGRP on the development of colorectal cancer in three animal models, which represent different stages of the progression to invasive cancer. We will then compare the intracellular pathways by which proGRP and GRP communicate with the cell nucleus, and investigate the structure of the cell-surface receptor that binds the proGRP. Finally we will determine the types and amounts of proGRP derived peptides produced by CRC cell lines and by tumours obtained from patients with colorectal cancer. A successful outcome will result in the development of assays for the early diagnosis and monitoring of bowel cancer and the potential for novel treatments such as proGRP receptor antagonists and radioactive proGRP analogues for radiotherapy.Read moreRead less