Development of Target-Ligand Switchable Lactate Oxidase Systems for Cancer Therapy = 암 치료를 위한 Target-Ligand Switchable Lactate Oxidase System 개발

다국어 초록 (Multilingual Abstract)

The aggressive tumor formation often causes excessive anaerobic glycolysis leading to the massive production of lactate and its accumulation to the tumor microenvironment (TME). Therefore, it is important to control the lactate concentration in TME to properly modulate surrounding tumor cells and suppress tumor growth. Lactate Oxidase (LOX) is a tetrameric enzyme converting lactate to pyruvate and H2O2 in the presence of oxygen and target-ligand (vSIRPα, EGFRAfb, HER2Afb) is a ligand that interacts with receptor frequently overexpressed on the surface of cancer cells. To control locally accumulated lactate properly, LOX and target-ligand were used as a potential therapeutic enzyme and a tumor cell targeting ligand, respectively, and LOX/ target-ligand conjugates were constructed through a SpyTag/SpyCatcher protein ligation system. LOX/target-ligand selectively bound to the specific receptor overexpressing tumor cells and effectively consumed lactate produced by tumor cells generating adequate amounts of H2O2, which induce drastic necrotic tumor cell death. Local treatments of B16-F10 tumor-bearing mice with LOX/vSIRPα significantly suppressed tumor growth without any severe side effects. Tumor-targeting vSIRPα may allow longer retention of LOX onto tumor sites effectively consuming surrounding lactate in TME and locally generating adequate amounts of H2O2 to
suppress tumor growth. The approach controlling the local lactate concentration and H2O2 in TME using LOX and various target-ligand would offer new opportunities for developing enzyme/target-ligand conjugate-based therapeutic tools for tumor treatment.

목차 (Table of Contents)

• Abstract .....................................................................................................................................1
• Contents .................................................................................................................................... 3
• List of Figures ........................................................................................................................... 5
• Abbreviations ............................................................................................................................ 8
• Chapter 1. Introduction
• 1.1.Importance of cancer therapy
• 1.1.1 Cancer …………………………………………………………………………….. 9
• 1.1.2 Cancer types ………………………………………………………………………. 9
• 1.1.3 Tumor microenvironment ………………………………………………………… 10
• 1.1.4 Types of tumor therapy …………………………………………………………… 12
• 1.2.Protein-based cancer therapy
• 1.2.1. The function of the protein ………………………………………………………... 13
• 1.2.2. Bioenzyme-based nanomedicines for enhanced tumor therapy…………………… 13
• 1.2.3. Monomeric protein for tumor targeting …………………………………………… 14
• 1.3.Functionalization of the protein ……………………………………………………………. 18
• 1.4.References ………………………………………………………………………………….. 20
• Chapter 2. Lactate Oxidase/target-ligand Complexes Efficiently Consume Tumorproduced Lactates and Locally Produce Tumor-suppressing Hydrogen Peroxide to
• Suppress Tumor Growth
• 2.1. Summary …………………………………………………………………………………… 23
• 2.2. Materials and Methods ……………………………………………………………………... 24
• 2.3. Results and Discussion ……………………………………………………………………... 28
• 2.4. Conclusions ……………………………………………………………………………….... 45
• Chapter 3. The Lactate Oxidase/EGFRAfb complex efficiently consumes tumorgenerating lactate and significantly kills tumor cells in vitro.
• 3.1. Summary …………………………………………………………………………………... 46
• 3.2. Results and Discussion ……………………………………………………………………. 47
• 3.3. Conclusions ……………………………………………………………………………….. 57
• Chapter 4. The Lactate Oxidase/HER2Afb complex efficiently consumes tumorgenerating lactate and significantly kills tumor cells in vitro.
• 4.1. Summary ………………………………………………………………………………….. 58
• 4.2. Results and Discussion …………………………………………………………………… 59
• 4.3. Conclusions ………………………………………………………………………………. 69
• Acknowledgement ……………………………………………………………………………70