MLL/KMT2A amplifications and translocations are prevalent in infant, adult and therapy-induced leukemia. However, the molecular contributor(s) to these alterations are unclear. Here we demonstrate that histone H3 lysine 9 mono- and di-methylation (H3K9me1/2) balance at the MLL/KMT2A locus regulates these amplifications and rearrangements. This balance is controlled by the cross-talk between lysine demethylase KDM3B and methyltransferase G9a/EHMT2. KDM3B depletion increases H3K9me1/2 levels and reduces CTCF occupancy at the MLL/KMT2A locus, and in turn, promotes amplification and rearrangements. Depleting CTCF is also sufficient to generate these focal alterations. Furthermore, the chemotherapy Doxorubicin (Dox), which associates with therapy-induced leukemia and promotes MLL/KMT2A amplifications and rearrangements, suppresses KDM3B and CTCF protein levels. KDM3B and CTCF overexpression rescues Dox-induced MLL/KMT2A alterations. G9a inhibition in human cells or mice also suppresses MLL/KMT2A events accompanying Dox treatment. Therefore, MLL/KMT2A amplifications and rearrangements are controlled by epigenetic regulators that are tractable drug targets, which has clinical implications. The data presented in this thesis were published in Cell in 2023. / Biomedical Sciences

Yes / The HOX genes encode a family of transcription factors that have key roles in both development and malignancy. Disrupting the interaction between HOX proteins and their binding partner, PBX, has been shown to cause apoptotic cell death in a range of solid tumors. However, despite HOX proteins playing a particularly significant role in acute myeloid leukemia (AML), the relationship between HOX gene expression and patient survival has not been evaluated (with the exception of HOXA9), and the mechanism by which HOX/PBX inhibition induces cell death in this malignancy is not well understood. In this study, we show that the expression of HOXA5, HOXB2, HOXB4, HOXB9, and HOXC9, but not HOXA9, in primary AML samples is significantly related to survival. Furthermore, the previously described inhibitor of HOX/PBX dimerization, HXR9, is cytotoxic to both AML-derived cell lines and primary AML cells from patients. The mechanism of cell death is not dependent on apoptosis but instead involves a regulated form of necrosis referred to as necroptosis. HXR9-induced necroptosis is enhanced by inhibitors of protein kinase C (PKC) signaling, and HXR9 combined with the PKC inhibitor Ro31 causes a significantly greater reduction in tumor growth compared to either reagent alone. / Funded in part through a grant to RA from the Cultural Bureau of the Kingdom of Saudi Arabia.

Abelson murine leukemia virus (A-MuLV)-induced transformation was investigated to determine whether cells not sensitive to TNF-α could be made sensitive to the cytolytic action of TNF-α when infected with this retrovirus. Mouse embryonic fibroblast cell line CL.7 was found to be relatively insensitive to TNF-α. Upon transformation with A-MuLV, these cells gave rise to a clone (3R.1) which was found to be insensitive to TNF-α and another clone (6R.1) which had an increased sensitivity to TNF-α. The differential cytotoxicity was observed when cells were treated with TNF-α, for 18 hr, at 0 to 100 units/ml, at 37°C. The mechanism of this differential cytotoxicity was further investigated. Thus, TNF-R levels on the cell surface were found to be not correlated with the differential TNF-α response. The A-MuLV transformation suppressed the epidermal growth factor-receptor (EGF-R) in 3R.1 clone and induced its levels significantly in the 6R.1 clone (p<0.05). Cell surface EGF-receptor (EGF-R) levels in CL.7 and 3R.1 clones were lower than the 6R.1 clone (p<0.05). Although the EGF-R levels in all the clones were induced with TNF-α, the expression of EGF-R correlated with the susceptibility to TNF-α. The role of antioxidants, such as α-tocopherol and β-carotene, (known anti-cancer agents) in modulating TNF-α-induced EGF-R expression was investigated. In both the untransformed and the transformed clones, f-carotene suppressed the constitutive and the TNF-α induced EGF-R levels whereas α-tocopherol was found to have an enhancing effects. Studies with metabolic inhibitors on TNF-R and EGF-R expression indicate that inhibitors of the arachidonic acid cascade and modulators of protein kinase-C (PK-C), could influence the binding and internalization of TNF-α and thereby controlling the physiologic future of the cells. The A-MuLV specific V-abl protein, p120, tyrosine phosphorylation was determined by a radio-labelled anti-phosphotyrosine antibody in an antigen capture assay. TNF-α had little effect on p120 phosphotyrosine levels of TNF-α insensitive CL.7 and 3R.1 clones. The, TNF-α sensitive, 6R.1 clone, however, was found to induce its p120 specific phosphotyrosine upon exposure to TNF-α for 8 hr. Thus, TNF-α modulated the tyrosine phosphorylation of p120 only in the TNF-α-sensitive cell line. The mitochondrial toxicity of TNF-α was determined by monitoring the rate of quenching of a cationic spin probe CAT 16. Mitochondrial preparation from CL.7 and 3R.1 clones had higher ability to quench CAT 16 signal with TNF-α incubation time than mitochondria from the 6R.1 cells. This indicates that the differential TNF-α cytotoxicity manifested in A-MuLV transformed clones may, in part, be due to the differential mitochondrial toxicity of this cytokine. The hypothesis that TNF-α cytotoxicity was mediated via an oxidative process was tested on the TNF-α sensitive L929 cells. Using a flow cytometric detection system it was determined that TNF-α produced intracellular hydrogen peroxide in these cells which was sensitive to concentration and incubation time of TNF-α. Superoxide radicals were also generated during TNF-α action on L929 cells, as determined by the use of the spin trap PBN in conjunction with EPR spectroscopic techniques. The PBN-OOH spin adduct spectrum peaked at 9 hr of TNF-α incubation and was inhibitable upto 30 % with 10 µM of desferral-Mn complex (a known SOD mimic). These data indicate that superoxide and hydrogen peroxide are common events in TNF-α dependent cell killing process. The differential TNF-α cytotoxicity was found to depend on differences in the antioxidant status of the target clones. Thus, it was found that Cu/Zn-SOD, Mn-SOD, GSH-Peroxidase and GSH-Reductase enzymes were all induced significantly in the CL.7 clone (p<0.05) upon incubation with 100 units/ml of TNF-α for 18 hrs. TNF-α had little effect on the antioxidant enzymes of both 3R.1 and 6R.1 cells. However, the constitutive levels of most antioxidant enzymes were found to be higher in 3R.1 cells than in the 6R.1 cells. Therefore, the susceptibility of 6R.1 to TNF-α may, in part, be due to a low level of antioxidant enzymes present in this clone. In conclusion we found that the differential cytotoxicity of TNF-a may, in part, due to: (1) differential EGF-R expression, (2) differential mitochondrial cytotoxicity, and (3) differential ability to modulate the tyrosine phosphorylation in untransformed and A-MuLV transformed cells and (4) differential antioxidant status of these cells to handle oxidative stress imposed by TNF-α. / Ph. D.

Yau Wai Lok. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 195-205). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / ABBREVIATIONS --- p.ii / ABSTRACT --- p.vii / 撮要 --- p.x / PUBLICATIONS --- p.xii / TABLE OF CONTENTS --- p.xiii / Chapter CHAPTER 1: --- GENERAL INTRODUCTION / Chapter 1.1 --- Hematopoiesis & Leukemia --- p.1 / Chapter 1.1.1 --- An Overview on Hematopoiesis --- p.1 / Chapter 1.1.2 --- An Overview of Leukemia --- p.4 / Chapter 1.1.2.2 --- Classification and Epidemiology of Leukemia --- p.5 / Chapter 1.1.2.3 --- Conventional Approaches to Leukemia Therapy --- p.8 / Chapter 1.1.2.4 --- Novel Approaches to Leukemia Therapy --- p.9 / Chapter 1.1.2.4.1 --- Differentiation Therapy --- p.10 / Chapter 1.1.2.4.2 --- Induction of Apoptosis --- p.10 / Chapter 1.1.2.4.3 --- Natural Products as a Source of Anti-leukemia Drug --- p.11 / Chapter 1.2 --- Cytokinins --- p.12 / Chapter 1.2.1 --- Historical Development and Occurrence of Cytokinins --- p.12 / Chapter 1.2.2 --- Functions of Cytokinins and the Signal Transduction of Cytokinins in Plants --- p.13 / Chapter 1.2.3 --- Phytochemistry and Metabolism of Cytokinins --- p.15 / Chapter 1.2.3.1 --- Chemical Structures of Cytokinins --- p.15 / Chapter 1.2.3.2 --- Biosynthesis of Cytokinins in Plants --- p.19 / Chapter 1.2.3.3 --- Metabolisms of Cytokinins in Plants and Animals --- p.22 / Chapter 1.2.4 --- Biological and Pharmacological Activities of Cytokinins in Animals --- p.23 / Chapter 1.2.4.1 --- Anti-aging Effect --- p.24 / Chapter 1.2.4.2 --- Anti-thrombosis Effect and Inhibition of Blood Platelet Aggregation --- p.24 / Chapter 1.2.4.3 --- Anti-tumor Effect --- p.25 / Chapter 1.3 --- Aims and Scopes of This Investigation --- p.27 / Chapter CHAPTER 2: --- MATERIALS AND METHODS / Chapter 2.1 --- Materials --- p.29 / Chapter 2.1.1 --- Animals --- p.29 / Chapter 2.1.2 --- Cell Lines --- p.29 / Chapter 2.1.3 --- "Cell Culture Medium, Buffers and Other Reagents" --- p.32 / Chapter 2.1.4 --- Reagents and Buffers for Flow Cytometry --- p.37 / Chapter 2.1.5 --- Reagents for DNA Extraction --- p.41 / Chapter 2.1.6 --- Cellular DNA Fragmentation ELISA Kit --- p.42 / Chapter 2.1.7 --- Reagents for Total RNA Isolation --- p.44 / Chapter 2.1.8 --- Reagents and Buffers for Reverse Transcription-Polymerase Chain Reaction (RT-PCR) --- p.46 / Chapter 2.1.9 --- Reagents and Buffers for Gel Electrophoresis for Nucleic Acids --- p.50 / Chapter 2.1.10 --- Reagents for Measuring Caspase Activity --- p.51 / Chapter 2.2 --- Methods --- p.54 / Chapter 2.2.1 --- Culture of the Tumor Cell Lines --- p.54 / Chapter 2.2.2 --- "Isolation, Preparation and Culture of Murine Peritoneal Macrophages" --- p.55 / Chapter 2.2.3 --- Determination of Cell Proliferation by [ 3H]-TdR Incorporation Assay --- p.55 / Chapter 2.2.4 --- Cytotoxicity Measurement by LDH Release Assay --- p.56 / Chapter 2.2.5 --- Determination of Cell Viability --- p.57 / Chapter 2.2.6 --- Determination of Anti-leukemic Activity In Vivo --- p.58 / Chapter 2.2.7 --- Analysis of Cell Cycle Profile/DNA Content by Flow Cytometry --- p.59 / Chapter 2.2.8 --- Measurement of Apoptosis --- p.59 / Chapter 2.2.9 --- Assessment of differentiation-associated characteristics --- p.63 / Chapter 2.2.10 --- Gene Expression Study --- p.67 / Chapter 2.2.11 --- Measurement of Caspase Activity --- p.68 / Chapter 2.2.12 --- Statistical Analysis --- p.70 / Chapter CHAPTER 3: --- STUDIES ON THE ANTI-PROLIFERATIVE EFFECT OF CYTOKININS ON LEUKEMIA CELLS / Chapter 3.1 --- Introduction --- p.71 / Chapter 3.2 --- Results --- p.72 / Chapter 3.2.1 --- Effect of Various Cytokinins and Their Riboside Derivatives on the Proliferation of Murine Myelomonocytic Leukemia WEHI-3B JCS Cells In Vitro --- p.72 / Chapter 3.2.2 --- Cytotoxicity of Kinetin and Kinetin Riboside on the WEHI-3B JCS Cells In Vitro --- p.86 / Chapter 3.2.3 --- Effects of Kinetin and Kinetin Riboside on the Proliferation of Various Leukemia Cell Lines In Vitro --- p.90 / Chapter 3.2.4 --- Cytotoxicity of Kinetin and Kinetin Riboside on Non-tumor Cell Lines and Primary Myeloid Cells In Vitro --- p.103 / Chapter 3.2.5 --- Kinetic and Reversibility Studies of the Anti-proliferative Effect of Kinetin and Kinetin Riboside on the WEHI-3B JCS Cells In Vitro --- p.107 / Chapter 3.2.6 --- Effects of Kinetin and Kinetin Riboside on the Cell Cycle Profile of WEHI-3B JCS Cells In Vitro --- p.115 / Chapter 3.2.7 --- Expression of Cell Cycle Related Genes in Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells In Vitro --- p.118 / Chapter 3.2.8 --- Effects of Kinetin and Kinetin Riboside on the In Vivo Tumorigenicity of WEHI-3B JCS Cells --- p.123 / Chapter 3.2.9 --- In Vivo Anti-tumor Effect of Kinetin and Kinetin Riboside on WEHI-3B JCS Cells --- p.126 / Chapter 3.3 --- Discussion --- p.129 / Chapter CHAPTER 4: --- STUDIES ON THE APOPTOSIS-INDUCING EFFECT OF CYTOKININS / Chapter 4.1 --- Introduction --- p.134 / Chapter 4.2 --- Results --- p.136 / Chapter 4.2.1 --- Induction of DNA Fragmentation of Cytokinins in the Murine Myeloid Leukemia WEHI-3B JCS Cells In Vitro --- p.136 / Chapter 4.2.2 --- Mitochondrial Membrane Potential of Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells In Vitro --- p.144 / Chapter 4.2.3 --- Caspase Activities of Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells In Vitro --- p.147 / Chapter 4.2.4 --- Induction of Reactive Oxygen Species in Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells In Vitro --- p.154 / Chapter 4.2.5 --- Expression of Apoptosis Regulatory Genes in Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells In Vitro --- p.157 / Chapter 4.3 --- Discussion --- p.163 / Chapter CHAPTER 5: --- STUDIES ON THE DIFFERENTIATION-INDUCING EFFECT OF CYTOKININS / Chapter 5.1 --- Introduction --- p.168 / Chapter 5.2 --- Results --- p.170 / Chapter 5.2.1 --- Morphology of Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells --- p.170 / Chapter 5.2.2 --- Cell Size and Granularity of Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells --- p.175 / Chapter 5.2.3 --- Changes in Surface Antigen Expression of Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells --- p.178 / Chapter 5.2.4 --- Monocytic Serine Esterase Activity in Kinetin- and Kinetin Riboside-treated WEHI-3B JCS Cells --- p.185 / Chapter 5.3 --- Discussion --- p.188 / Chapter CHAPTER 6: --- CONCLUSIONS AND FUTURE PERSPECTIVES --- p.190 / REFERENCES --- p.195

Lui Oi Lan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves [216]-240). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / ABBREVIATIONS --- p.ii / ABSTRACT --- p.vii / 撮要 --- p.x / PUBLICATIONS --- p.xiii / TABLE OF CONTENTS --- p.xiv / Chapter CHAPTER 1: --- GENERAL INTRODUCTION / Chapter 1.1 --- Hematopoiesis and Leukemia --- p.1 / Chapter 1.1.1 --- An Overview on Hematopoietic Development --- p.1 / Chapter 1.1.2 --- Leukemia --- p.8 / Chapter 1.1.2.1 --- General Diagnostic Tests for Leukemia --- p.9 / Chapter 1.1.2.2 --- Classification and Epidemiology of Leukemia --- p.10 / Chapter 1.1.2.3 --- Conventional Approaches to Leukemia Therapy --- p.17 / Chapter 1.1.2.4 --- Novel Approaches to Leukemia Therapy --- p.20 / Chapter 1.2 --- Conjugated Linoleic Acid --- p.23 / Chapter 1.2.1 --- Introduction: Historical Development and Occurrence of Conjugated Linoleic Acid --- p.23 / Chapter 1.2.2 --- Phytochemistry and Metabolism of Conjugated Linoleic Acid --- p.24 / Chapter 1.2.2.1 --- Chemical Structures of Conjugated Linoleic Acid Isomers --- p.24 / Chapter 1.2.2.2 --- Biosynthesis of Conjugated Linoleic Acid --- p.26 / Chapter 1.2.2.3 --- Metabolism of Conjugated Linoleic Acid --- p.30 / Chapter 1.2.2.4 --- Mode of Entry and Tissue Incorporation of Conjugated Linoleic Acid --- p.33 / Chapter 1.2.2.5 --- Toxicology of Conjugated Linoleic Acid --- p.33 / Chapter 1.2.3 --- Physiological Activities of Conjugated Linoleic Acid: Reported Health Benefits --- p.35 / Chapter 1.2.3.1 --- Anti-adipogenesis / Chapter 1.2.3.2 --- Anti-diabetogenesis --- p.36 / Chapter 1.2.3.3 --- Anti-atherosclerosis --- p.38 / Chapter 1.2.3.4 --- Anti-carcinogenesis --- p.39 / Chapter 1.2.3.5 --- Anti-tumor Activity --- p.40 / Chapter 1.2.3.6 --- Effects of Conjugated Linoleic Acid on Lipid Metabolism --- p.44 / Chapter 1.2.3.6.1 --- Actions on Phospholipids by Conjugated Linoleic Acid --- p.45 / Chapter 1.2.3.6.2 --- Conjugated Linoleic Acid as a Ligand for the PPAR System --- p.47 / Chapter 1.2.3.7 --- Immunomodulation --- p.47 / Chapter 1.3 --- Aims and Scopes of This Investigation --- p.50 / Chapter CHAPTER 2: --- MATERIALS AND METHODS / Chapter 2.1 --- Materials / Chapter 2.1.1 --- Animals --- p.52 / Chapter 2.1.2 --- Cell Lines --- p.52 / Chapter 2.1.3 --- "Cell Culture Medium, Buffers and Other Reagents" --- p.52 / Chapter 2.1.4 --- Reagents for 3H-Thymidine Incorporation Assay --- p.54 / Chapter 2.1.5 --- Reagents and Buffers for Flow Cytometry --- p.58 / Chapter 2.1.6 --- Reagents for DNA Extraction --- p.59 / Chapter 2.1.7 --- Cell Death Detection ELISAPLUS Kit --- p.63 / Chapter 2.1.8 --- Reagents for Measuring Caspase Activity --- p.65 / Chapter 2.1.9 --- Reagents for Total RNA Isolation --- p.66 / Chapter 2.1.10 --- Reagents and Buffers for RT-PCR --- p.69 / Chapter 2.1.11 --- Reagents and Buffers for Gel Electrophoresis of Nucleic Acids --- p.74 / Chapter 2.1.12 --- "Reagents, Buffers and Materials for Western Blot Analysis" --- p.75 / Chapter 2.2 --- Methods / Chapter 2.2.1 --- Culture of the Tumor Cell Lines --- p.80 / Chapter 2.2.2 --- "Isolation, Preparation and Culture of Mouse Peritoneal Macrophages" --- p.81 / Chapter 2.2.3 --- Determination of Cell Viability --- p.82 / Chapter 2.2.4 --- Determination of Cell Proliferation by [3H]-TdR Incorporation Assay --- p.83 / Chapter 2.2.5 --- In Vivo Tumorigenicity Study --- p.83 / Chapter 2.2.6 --- Analysis of Cell Cycle Profile / DNA Content by Flow Cytometry --- p.83 / Chapter 2.2.7 --- Measurement of Apoptosis --- p.84 / Chapter 2.2.8 --- Determination of the Mitochondrial Membrane Potential --- p.86 / Chapter 2.2.9 --- Measurement of Caspase Activity --- p.87 / Chapter 2.2.10 --- Study of Intracellular Accumulation of Reactive Oxygen Species (ROS) --- p.88 / Chapter 2.2.11 --- Study of the Scavenging Activity of Antioxidants --- p.88 / Chapter 2.2.12 --- Gene Expression Study --- p.89 / Chapter 2.2.13 --- Protein Expression Study --- p.92 / Chapter 2.2.14 --- Measurement of Cell Differentiation --- p.95 / Chapter 2.2.15 --- Statistical Analysis --- p.98 / Chapter CHAPTER 3: --- STUDIES ON THE ANTI-TUMOR ACTICITY OF CONJUGATED LINOLEIC ACID ON MYELOID LEUKEMIA CELLS / Chapter 3.1 --- Introduction / Chapter 3.2 --- Results --- p.99 / Chapter 3.2.1 --- Anti-proliferative Activity of CLA-mix and CLA Isomers on Various Myeloid Leukemia Cell Lines In Vitro --- p.101 / Chapter 3.2.2 --- Cytotoxic Effect of CLA-mix on the WEHI-3B JCS Cells In Vitro --- p.109 / Chapter 3.2.3 --- Cytotoxic Effect of CLA-mix on Primary Murine Myeloid Cells In Vitro --- p.111 / Chapter 3.2.4 --- Kinetic and Reversibility Studies of the Anti-proliferative Activity of CLA-mix on the WEHI-3B JCS Cells --- p.113 / Chapter 3.2.5 --- Effect of CLA-mix and its isomers on the Cell Cycle Profiles of the WEHI-3B JCS Cells In Vitro --- p.116 / Chapter 3.2.6 --- Effect of CLA-mix and its isomer on the Expression of Cell Cycle-regulatory Genes in the WEHI-3B JCS Cells --- p.123 / Chapter 3.2.7 --- Effect of CLA-mix and its isomer on the In V Tumorigenicity of the WEHI-3B JCS Cells ivo --- p.128 / Chapter 3.3 --- Discussion --- p.131 / Chapter CHAPTER 4: --- STUDIES ON THE APOPTOSIS-INDUCING ACTIVITY OF CONJUGATED LINOLEIC ACID ON MYELOID LEUKEMIA CELLS / Chapter 4.1 --- Introduction --- p.141 / Chapter 4.2 --- Results --- p.141 / Chapter 4.2.1 --- Induction of Apoptosis in Both Murine and Human Myeloid Leukemia Cells by CLA --- p.144 / Chapter 4.2.2 --- Effect of CLA and its Isomer on the Mitochondrial Membrane Potential of the WEHI-3B JCS Cells --- p.151 / Chapter 4.2.3 --- Effect of CLA-mix and its Isomer on the Expression of Apoptosis-regulatory Genes of the Bcl-2 Family in the WEHI-3B JCS Cells --- p.154 / Chapter 4.2.4 --- Effect of CLA-mix and its Isomer on the Expression of Apoptosis-regulatory Proteins in the WEHI-3B JCS Cells --- p.158 / Chapter 4.2.5 --- Effect of CLA-mix and its Isomer on the Induction of Caspase Activity in the WEHI-3B JCS Cells --- p.161 / Chapter 4.2.6 --- Effect of CLA-mix and its Isomer on the Induction of ROS in the WEHI-3B JCS Cells --- p.170 / Chapter 4.2.7 --- Effect of Antioxidants on the Induction of ROS by CLA-mix and its Isomer in the WEHI-3B JCS Cells --- p.173 / Chapter 4.2.8 --- Effect of Antioxidants on the Induction of Apoptosis by CLA-mix and its Isomer in the WEHI-3B JCS Cells --- p.176 / Chapter 4.2 --- Discussion / Chapter CHAPTER 5: --- STUDIES ON THE DIFFERENTIATION-INDUCING ACTIVITY OF CONJUGATED LINOLEIC ACID ON MYELOID LEUKEMIA CELLS / Chapter 5.1 --- Introduction --- p.187 / Chapter 5.2 --- Results --- p.190 / Chapter 5.2.1 --- Morphological Alterations in CLA-mix- and CLA isomer-treated WEHI-3B JCS Cells --- p.190 / Chapter 5.2.2 --- Effects of CLA-mix on the Cell Size and Granularity of WEHI-3B JCS Cells --- p.196 / Chapter 5.2.3 --- Studies of the Surface Phenotypic Changes in the CLA-mix-treated WEHI-3B JCS cells --- p.198 / Chapter 5.2.4 --- Studies on the Induction of Monocytic Serine Esterase (MSE) Activity in the CLA-mix-treated WEHI-3B JCS Cells --- p.200 / Chapter 5.2.5 --- Studies on the Induction of Endocytic Activity in the CLA-mix-treated WEHI-3B JCS Cells --- p.201 / Chapter 5.2.6 --- Studies on the Expression of the Differentiation-regulatory Cytokine Genes in the CLA-mix-treated WEHI-3B JCS Cells --- p.202 / Chapter 5.3 --- Discussion --- p.204 / Chapter CHAPTER 6: --- CONCLUSIONS AND FUTURE PERSPECTIVES REFERENCES --- p.208 / REFERENCES --- p.217

Acute Lymphoblastic Leukemia (ALL) is an aggressive hematologic tumor and is the most common malignancy in children (Horton and Steuber 2014). This disease is characterized by the infiltration of bone marrow by malignant immature lymphoid progenitor cells and is invariably fatal without treatment. Although multi-agent combination chemotherapy is curative in a significant fraction of ALL patients, treatment currently fails in approximately 20% of children and up to 50% of adults with ALL, making relapse and drug resistance the most substantial challenge in the treatment of this disease(Fielding, Richards et al. 2007, Aster and DeAngelo 2013). Understanding what causes treatment failure is of great medical importance as second line therapies also fail in the majority of relapse T-cell ALL (TALL) patients (Fielding, Richards et al. 2007, Aster and DeAngelo 2013). Using next-generation sequencing to compare the genomes of tumors before and after therapy, mutations in gene cytosolic 5’-nucleotidase II (NT5C2) were discovered in 19% of pediatric samples with relapsed T-ALL(Tzoneva, Carpenter et al. 2013). Preliminary structure function analysis and subsequent in vitro experimental nucleotidase activity assays confirmed that these mutations lead to hyperactive NT5C2 protein. Furthermore, NT5C2 mutant proteins conferred resistance to 6-mercaptopurine and 6-thioguanine chemotherapy drugs when expressed in ALL lymphoblasts, suggesting NT5C2 is responsible for the inactivation of nucleoside-analog chemotherapy drugs. In order to assess the ability of these mutations to lead to novel inhibitor schemes, the functional impact of each mutation was analyzed through robust structure function methods. The result of this in silico analysis, is the identification of a potential allosteric regulatory mechanism of negative feedback inhibition never before described. Most notably, the majority of NT5C2 mutations identified have characteristics that suggest they abrogate the function of this proposed mechanism, yielding a novel viable target for the development of allosteric inhibitors specific for constitutively active NT5C2 mutant proteins. Overall these findings support a prominent role for activating mutations in NT5C2 and chemotherapy resistance in ALL, and highlight new avenues for relapsed ALL therapy development in the future.

Chin, Chi Hou. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves [165]-178). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract in Chinese (摘要） --- p.iv / Acknowledgements --- p.vi / Abbreviations --- p.vii / List of Figures and Tables --- p.xi / Publications --- p.xv / Chapter Chapter 1 --- General Introduction / Chapter 1.1. --- Hematopoiesis and Leukemia --- p.2 / Chapter 1.1.1. --- Hematopoiesis --- p.2 / Chapter 1.1.2. --- Leukemia --- p.8 / Chapter 1.1.2.1. --- Overview of leukemia --- p.8 / Chapter 1.1.2.2. --- Symptoms and diagnosis of leukemia --- p.9 / Chapter 1.1.2.3. --- Classification of leukemia --- p.9 / Chapter 1.1.2.4. --- Epidemiology of leukemia --- p.13 / Chapter 1.1.2.5. --- Conventional treatments for leukemia --- p.15 / Chapter 1.1.2.6. --- Novel approaches to leukemia treatment --- p.18 / Chapter 1.2. --- Statins --- p.22 / Chapter 1.2.1. --- Overview of statins --- p.22 / Chapter 1.2.2. --- Chemical structures of statins --- p.24 / Chapter 1.2.3. --- Pharmacokinetics of statins --- p.26 / Chapter 1.2.4. --- Pleiotropic effects of statins --- p.29 / Chapter 1.2.4.1. --- Anti-inflammatory and immunomodulatory effects of statins --- p.29 / Chapter 1.2.4.2. --- Anti-angiogenic effects of statins --- p.30 / Chapter 1.2.4.3. --- Anti-tumor effects of statins --- p.31 / Chapter 1.3. --- Objectives and scope of the present study --- p.33 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1. --- Materials --- p.36 / Chapter 2.1.1. --- Animals --- p.36 / Chapter 2.1.2. --- Cell lines --- p.36 / Chapter 2.1.3. --- "Cell culture media, buffers and other reagents" --- p.37 / Chapter 2.1.3.1. --- Cell culture media and reagents --- p.37 / Chapter 2.1.3.2. --- Drugs and chemicals --- p.40 / Chapter 2.1.3.3. --- Reagents and buffers for primary culture --- p.42 / Chapter 2.1.3.4. --- Dye solutions --- p.43 / Chapter 2.1.3.5. --- Reagents for cell proliferation assays --- p.44 / Chapter 2.1.3.6. --- Reagents and buffers for flow cytometry --- p.44 / Chapter 2.1.3.7. --- Reagents for Hoechst staining --- p.45 / Chapter 2.1.3.8. --- Reagents and buffers for DNA isolation --- p.46 / Chapter 2.1.3.9. --- Reagents and buffers for DNA agarose gel electrophoresis --- p.48 / Chapter 2.1.3.10. --- Reagents and buffers for Cell Death ELISA --- p.50 / Chapter 2.1.3.11. --- Reagents and buffers for measuring caspase activity --- p.51 / Chapter 2.1.3.12. --- Reagents and buffers for Western blotting --- p.55 / Chapter 2.1.3.13. --- Reagents for determining nitric oxide production --- p.63 / Chapter 2.2. --- Methods --- p.64 / Chapter 2.2.1. --- Culture of tumor cell lines --- p.64 / Chapter 2.2.2. --- "Isolation, preparation and culture of murine peritoneal macrophages" --- p.64 / Chapter 2.2.3. --- Cell proliferation and cytotoxicity studies --- p.66 / Chapter 2.2.4. --- In vivo tumorigenicity study --- p.68 / Chapter 2.2.5. --- Cell cycle profile and flow cytometric analysis --- p.69 / Chapter 2.2.6. --- Hoechst staining --- p.69 / Chapter 2.2.7. --- DNA fragmentation analysis --- p.70 / Chapter 2.2.8. --- Cell Death ELISA --- p.71 / Chapter 2.2.9. --- Mitochondrial membrane potential analysis --- p.73 / Chapter 2.2.10. --- Measurement of caspase activity --- p.73 / Chapter 2.2.11. --- Protein expression study --- p.75 / Chapter 2.2.12. --- Cell morphological staining --- p.80 / Chapter 2.2.13. --- Cell size and granularity analysis by flow cytometry --- p.81 / Chapter 2.2.14. --- Determination of nitric oxide production by macrophages --- p.81 / Chapter 2.2.15. --- Statistical analysis --- p.82 / Chapter Chapter 3 --- Anti-Proliferative Effect of Statins on Myeloid Leukemia Cells / Chapter 3.1. --- Introduction --- p.84 / Chapter 3.2. --- Results --- p.86 / Chapter 3.2.1. --- Anti-proliferative effect of statins on various murine and human myeloid leukemia cells --- p.86 / Chapter 3.2.2. --- Cytotoxicity of fluvastatin on murine myelomonocytic leukemia WEHI-3B JCS cells --- p.93 / Chapter 3.2.3. --- Cytotoxicity of fluvastatin on primary murine myeloid cells --- p.96 / Chapter 3.2.4. --- Kinetic and reversibility studies on the anti-proliferative effect of fluvastatin on WEHI-3B JCS cells --- p.98 / Chapter 3.2.5. --- Relationship between the anti-proliferative effect of fluvastatin and the cholesterol biosynthesis pathway in WEHI-3B JCS cells --- p.102 / Chapter 3.2.6. --- Effect of fluvastatin on the in vivo tumorigenicity of WEHI-3B JCS cells --- p.106 / Chapter 3.2.7. --- Effect of fluvastatin on the cell cycle profile of WEHI-3B JCS cells --- p.108 / Chapter 3.2.8. --- Effect of fluvastatin on the expression of cell cycle regulatory proteins inWEHI-3B JCS cells --- p.113 / Chapter 3.3. --- Discussion --- p.116 / Chapter Chapter 4 --- Apoptosis- and Differentiation-inducing Effects of Fluvastatin on Murine Myelomonocytic Leukemia WEHI-3B JCS Cells / Chapter 4.1. --- Introduction --- p.124 / Chapter 4.2. --- Results --- p.128 / Chapter 4.2.1. --- Induction of chromatin condensation in WEHI-3B JCS cells by fluvastatin --- p.128 / Chapter 4.2.2. --- Induction of DNA fragmentation in WEHI-3B JCS cells by fluvastatin --- p.130 / Chapter 4.2.3. --- Effect of fluvastatin on the mitochondrial membrane potential in WEHI-3B JCS cells --- p.134 / Chapter 4.2.4. --- Effect of fluvastatin on the caspase activities in WEHI-3B JCS cells --- p.138 / Chapter 4.2.5. --- Effect of fluvastatin on the expression of pro-apoptotic protein AIF in WEHI-3B JCS cells --- p.144 / Chapter 4.2.6. --- Effect of fluvastatin on the morphology of WEHI-3B JCS cells --- p.147 / Chapter 4.2.7. --- Effect of fluvastatin on the cell size and granularity of WEHI-3B JCS cells --- p.149 / Chapter 4.2.8. --- Immunomodulation of murine peritoneal macrophages by fluvastatin --- p.151 / Chapter 4.3. --- Discussion --- p.153 / Chapter Chapter 5 --- Conclusions and Future Perspectives --- p.160 / References --- p.165

Thesis (Ph. D.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains xi, 185 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains viii, 146 p. : ill. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of North Texas, Aug., 2007. / Title from title page display. Includes bibliographical references.