I am a molecular pharmacologist investigating how the body eliminates fat-soluble chemicals, including drugs, toxins, steroids and waste products of metabolism.
Drugs are broken down in the body by the process of metabolism. Metabolism is important as both a detoxification and elimination mechanism, and determines dose rate for chronically administered drugs. Many drugs are metabolised by a reaction called glucuronidation. We will characterise the various components of the glucuronidation reaction in an integrated manner in order to understand and predict factors that influence an individual's capacity to metabolise drugs and other chemicals.
Novel Mechanisms Of Genotoxicity: Bioactivation Of Carboxylic Acid Drugs By UDP-glucuronosyltransferases
Funder
National Health and Medical Research Council
Funding Amount
$204,750.00
Summary
Before any new pharmaceutical products are approved for clinical use, they undergo extensive testing to demonstrate both efficacy and safety. Part of this testing involves ensuring that, within the body, they are not converted to chemically reactive forms able to damage DNA, since DNA damage can lead to cell toxicity or the development of cancer. Our laboratories have recently identified a new mechanism by which the body converts drugs to reactive chemicals called ester glucuronides. We have sho ....Before any new pharmaceutical products are approved for clinical use, they undergo extensive testing to demonstrate both efficacy and safety. Part of this testing involves ensuring that, within the body, they are not converted to chemically reactive forms able to damage DNA, since DNA damage can lead to cell toxicity or the development of cancer. Our laboratories have recently identified a new mechanism by which the body converts drugs to reactive chemicals called ester glucuronides. We have shown that some ester glucuronides can damage DNA. A large number of different drugs have the potential to form ester glucuronides. However, we do not know whether all ester glucuronides cause DNA damage or, if only some do, what properties determine their DNA damaging potential. In addition, most of the current pre-clinical screening of drugs can not detect DNA damage caused by ester glucuronides. We believe this lack of knowledge is of serious concern. Therefore, this project aims to: i) screen a large number of drugs for ester glucuronide-mediated DNA damage; ii) develop some preliminary methods of predicting the DNA damaging potency of these reactive chemicals; and iii) develop a screening test that may be more suitable for detecting DNA damage by ester glucuronides during pre-clinical testing. Such work is essential to ensure the ongoing safety of all pharmaceutical agents.Read moreRead less
UGT Enzymes In Chemotherapeutic Drug Metabolism: New Avenues To Improve Drug Response And Overcome Resistance
Funder
National Health and Medical Research Council
Funding Amount
$610,005.00
Summary
Tumours treated by chemotherapy often become resistant to the drugs, leading to relapse and reduced chance of survival. We will study one of the main pathways leading to drug resistance, which could lead to the development of new ways to overcome resistance and improve cancer treatment outcomes.
Over-expression Of Human Cytochrome P450 2J2 Activates Phase II Biotransformation Genes That Influence Anti-cancer Drug Efficacy
Funder
National Health and Medical Research Council
Funding Amount
$489,155.00
Summary
Increased expression of some enzymes in human tumours contributes to anticancer drug resistance. In many tumours the fatty acid epoxygenase cytochrome P450 2J2 (CYP2J2) is over-expressed. We have found that CYP2J2 activates the expression of phase II enzymes that eliminate anticancer drugs; this is mediated by fatty acid epoxides. In this project we will define the underlying mechanisms of these effects, which may lead to novel strategies to overcome anticancer drug resistance.
A Novel Metabolic Role For UDP Glycosyltransferase 8 (UGT8)
Funder
National Health and Medical Research Council
Funding Amount
$419,144.00
Summary
The UDP glycosyltransferases (UGTs) are a family of enzymes that remove drugs and toxins from the human body as well as control levels of naturally produced molecules such as bile acids and hormones. We found that a new member of this family called UGT8 processes bile acids in the kidney and intestine and can affect how bile acids act to regulate metabolism. Our studies uncover new roles for bile acids in liver, kidney and gut health and in metabolic disorders such as diabetes and obesity.
Regulation Of Drug Detoxifying UDP Glucuronosyltransferases
Funder
National Health and Medical Research Council
Funding Amount
$590,945.00
Summary
Some organs in the body are particularly sensitive to fat-soluble chemicals taken in from the environment or present in food. They are also sensitive to hormones and other small molecule products of metabolism. Controlling the levels of these potentially toxic chemicals is essential in order to maintain the health of the organ. In this work we will investigate the regulation of detoxifying enzymes that protect these organs by inactivating and hastening the elimination of fat-soluble chemicals.
Characterization Of The Novel Drug And Xenobiotic Metabolizing UGT3A Enzyme Family
Funder
National Health and Medical Research Council
Funding Amount
$578,352.00
Summary
The elimination of chemicals made in the body or from environmental sources is essential for the maintenance of good health and the prevention of debilitating diseases. We have discovered two enzymes that use glucose and other sugars to detoxify fat-soluble chemicals. In this project we will study how these enzymes work and how they are regulated in the body. With this knowledge, we may be able to target the processes of drug and chemical detoxification to make them more efficient.
Molecular Determinants Of UDP Glucuronosyltransferase 1A3 And 1A4 Expression
Funder
National Health and Medical Research Council
Funding Amount
$516,078.00
Summary
Enzymes in the liver and gastrointestinal tract have a crucial role in protecting against the toxic effects of fat-soluble chemicals. Two of these enzymes called UGT1A3 and UGT1A4 have a special role in protecting against drugs and toxins that contain nitrogen groups. The levels of these two enzymes in the liver and gut vary extensively between individuals. In this project we will determine how the levels of these enzymes are controlled and what is the cause of this variability between individua ....Enzymes in the liver and gastrointestinal tract have a crucial role in protecting against the toxic effects of fat-soluble chemicals. Two of these enzymes called UGT1A3 and UGT1A4 have a special role in protecting against drugs and toxins that contain nitrogen groups. The levels of these two enzymes in the liver and gut vary extensively between individuals. In this project we will determine how the levels of these enzymes are controlled and what is the cause of this variability between individuals. This will help us predict those individuals who are more at risk from the adverse effects of nitrogen-containing drugs and from the toxic effects of chemicals in the diet or the environment. This project will also help us develop methods to increase the levels of these protective enzymes and help reduce the effects of exposure to toxic chemicals.Read moreRead less