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Anticancer Effects of Vitamin E Forms and Their Long-Chain Metabolites Via Modulation of Sphingolipid Metabolism Yumi Jang Purdue University

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Anticancer Effects of Vitamin E Forms and Their Long-Chain Metabolites Via Modulation of Sphingolipid Metabolism Yumi Jang Purdue University Purdue University Purdue e-Pubs Open Access Dissertations Theses and Dissertations January 2015 Anticancer Effects of Vitamin E Forms and Their Long-chain Metabolites via Modulation of Sphingolipid Metabolism Yumi Jang Purdue University Follow this and additional works at: https://docs.lib.purdue.edu/open_access_dissertations Recommended Citation Jang, Yumi, "Anticancer Effects of Vitamin E Forms and Their Long-chain Metabolites via Modulation of Sphingolipid Metabolism" (2015). Open Access Dissertations. 1119. https://docs.lib.purdue.edu/open_access_dissertations/1119 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Graduate School Form 30 Updated 1/15/2015 PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Yumi Jang Entitled Anticancer Effects of Vitamin E Forms and Their Long-chain Metabolites via Modulation of Sphingolipid Metabolism For the degree of Doctor of Philosophy Is approved by the final examining committee: Qing Jiang Chair Dorothy Teegarden John R. Burgess Yava Jones-Hall To the best of my knowledge and as understood by the student in the Thesis/Dissertation Agreement, Publication Delay, and Certification Disclaimer (Graduate School Form 32), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy of Integrity in Research” and the use of copyright material. Approved by Major Professor(s): Qing Jiang Approved by: Connie M. Weaver 9/2/2015 Head of the Departmental Graduate Program Date i ANTICANCER EFFECTS OF VITAMIN E FORMS AND THEIR LONG-CHAIN METABOLITES VIA MODULATION OF SPHINGOLIPID METABOLISM A Dissertation Submitted to the Faculty of Purdue University by Yumi Jang In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy December 2015 Purdue University West Lafayette, Indiana ii ACKNOWLEDGEMENTS I owe a debt of gratitude to many people who have made this dissertation possible. My deepest gratitude goes first to my advisor, Dr. Qing Jiang for her invaluable guidance and continued support throughout my Ph.D. study. I have been amazingly fortunate to have her as my advisor. Without her help, I could not have imagined the possibility of this achievement. I appreciate her mentorship, immense knowledge, enthusiasm, motivation and encouragement. I have learned a lot from her about experimental techniques, scientific critical thinking skills, professional knowledge, and so forth, which benefit me both for my graduate research and for my future career development as a scientist. She has been a tremendous mentor for me. I would also like to express my appreciation to my committee members, Dr. Dorothy Teegarden, Dr. John Burgess and Dr. Yava Jones-Hall for their insightful advice and help on my research and their precious time. I would like to thank the past and current Jiang lab members, Yun Wang, Ziying Jiang, Xiayu Rao, Agnetha Linn Rostgaard-Hansen, Na Young Park, Chao Yang, Tianlin Xu, Kilia Liu for their help, support, and companionship over the years. Many thanks go to my friends inside and outside of Purdue, who have supported me with constant friendship and encouragement. Special thanks to my coworker, Amber S. Jannasch in iii Bindley Bioscience Center of Purdue for her expertise and technical support in doing liquid chromatography tandem mass spectrometry. Last but not least, my great thanks go to my beloved family. Words cannot express how grateful I am to my parents and parents-in-law for their endless love. I would like to thank my son to be born soon, my lovely sunshine, who brought me happiness and energy when I felt sad and tired. I am especially grateful to my husband, my best friend, and my soulmate, Hyun Sung. Without his love and support, this journey would not have been possible. To him I dedicate this thesis. iv TABLE OF CONTENTS Page LIST OF TABLES ............................................................................................................. ix LIST OF FIGURES ............................................................................................................ x ABSTRACT ...................................................................................................................... xii CHAPTER 1. LITERATURE REVIEW ...................................................................... 1 1.1 Vitamin E .............................................................................................................. 1 1.1.1 Vitamin E Forms and Food Sources ............................................................. 1 1.1.2 Bioavailability and Metabolites .................................................................... 4 1.1.3 Bioactivities of Vitamin E ............................................................................ 7 1.2 Vitamin E Forms in Cancer Prevention .............................................................. 11 1.2.1 Cancer ......................................................................................................... 11 1.2.2 α-Tocopherol ............................................................................................... 12 1.2.3 Non-αT Forms of Vitamin E ....................................................................... 13 1.2.4 13’-Carboxychromanol, a Long-chain Vitamin E Metabolite .................... 16 1.3 Phytochemicals in Cancer Prevention ................................................................ 18 1.3.1 Overview of Phytochemicals ...................................................................... 18 1.3.2 Molecular and Cellular Targets of Phytochemicals for Cancer Prevention ................................................................................................... 23 1.3.2.1 NRF-KEAP1 Complex and Activation of NRF ...................................... 24 1.3.2.2 Suppressing NF-κB and AP1 Activation ................................................ 25 1.3.2.3 Downregulation of β-Catenin-mediated Signaling Pathway ................... 27 1.3.2.4 Induction of Apoptosis ............................................................................ 28 v Page 1.4 Sphingolipids Metabolism and Their Biological Activities ............................... 29 1.4.1 Overview of Sphingolipids ......................................................................... 29 1.4.1.1 De novo Sphingolipids Biosynthesis ....................................................... 30 1.4.1.2 Synthesis of Complex Sphingolipids ...................................................... 35 1.4.1.3 Catabolism of Complex Sphingolipids and Ceramides .......................... 37 1.4.2 Bioactive Sphingoid Bases and Their Roles in Cell Growth, Survival, and Death ........................................................................................................... 38 1.4.2.1 Sphingosine ............................................................................................. 39 1.4.2.2 Ceramide ................................................................................................. 40 1.4.2.3 Dihydrosphingosine and Sphingosine-1-phosphate ................................ 44 1.4.2.4 Dihydroceramide ..................................................................................... 46 CHAPTER 2. SPHINGOLIPID METABOLISM IS THE INITIAL PRIMARY TARGET OF GAMMA-TOCOTRIENOL AND PLAYS A ROLE IN CELL DEATH INDUCTION .............................................................. 50 2.1 Abstract ............................................................................................................... 50 2.2 Introduction ........................................................................................................ 51 2.3 Materials and Methods ....................................................................................... 54 2.3.1 Materials and reagents ................................................................................ 54 2.3.2 Cell culture and treatment ........................................................................... 54 2.3.3 MTT assay .................................................................................................. 55 2.3.4 Lipid extraction ........................................................................................... 55 2.3.5 Measurement of sphingolipids using liquid chromatography tandem mass spectrometry (LC-MS/MS) ......................................................................... 56 2.3.6 De novo sphingolipids analysis ................................................................... 57 2.3.7 In Situ dihydroceramide desaturase assay ................................................... 57 2.3.8 In Vitro dihydroceramide desaturase assay ................................................. 57 2.3.9 Transmission Electron Microscopy (TEM) ................................................ 58 2.3.10 Western Blotting ......................................................................................... 58 vi Page 2.3.11 Statistics ...................................................................................................... 59 2.4 Results ................................................................................................................ 59 2.4.1 Temporal changes of sphingolipids induced by γTE .................................. 59 2.4.2 De novo synthesis of sphingolipids with labeled serine ............................. 65 2.4.3 Direct evidence that γTE inhibits DEGS ...................................................
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