Date of Completion

1-6-2020

Embargo Period

1-1-2021

Keywords

DNA oxidative damage, p53 tumor suppressor gene, protein damage, LC-MS/MS

Major Advisor

James F. Rusling

Associate Advisor

Dharamainder Choudhary

Associate Advisor

Jing Zhao

Field of Study

Chemistry

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

The xenobiotics such as carcinogens, drugs, or pollutants are chemical substances which are not naturally from human bodies. After entering human bodies, the xenobiotics will biotransformed into their metabolites by metabolic enzymes, which usually show higher toxicity. The reactive metabolites react with macromolecules including DNA, proteins, and lipids in cells to form adducts. During metabolism of xenobiotics, reactive oxygen species (ROS) are also produced, which would induce oxidative damage on macromolecules. The damaged DNA may cause mutations during DNA replication. If the mutations occur at critical genes, such as tumor suppressor gene or oncogenes, this would lead to cancers. The damage on proteins will change protein functions or provoke an antigen response. One theme of this research is to detect DNA oxidative damage on tumor suppressor gene by liquid chromatography and mass spectrometry (LC-MS). The other aim of this research is to develop methods to investigate drug induced protein damage by LC-MS.

In this thesis, Chapter 2 describes detection of oxidative sites on exon 7 of p53 tumor suppressor gene induced by catechol and Fenton’s reagent. By comparing our results with p53 database, we correlated these two oxidants with organ specific cancers. Chapter 3 describes an analytical method to investigate acetaminophen induced glutathione S-transferase adducts. Different metabolic enzymes were employed to monitor the relative amounts of adducts formation. Chapter 4 describes a quantitative method for therapeutic monoclonal antibody glycoforms in vivo by LC-MS. Overall, this research work has developed analytical methods to detect DNA and protein damage, which can be used to investigate carcinogen induced genotoxicity and drug induced toxicity.

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