published_or_final_version / Pathology / Master / Master of Medical Sciences

Thesis (Ph. D.)--Duke University, 2007.

Krüppel-like factors KLF1 and KLF2 are closely related transcription factors with three zinc finger domains in their carboxy-termini. KLF1 (erythroid Krüppel-like factor, or EKLF) plays essential roles in embryonic and adult erythropoiesis. KLF2 is a positive regulator of the mouse and human embryonic β- globin genes. KLF1 and KLF2 have overlapping roles in embryonic erythropoiesis, as demonstrated using single and double knockout (KO) mouse models. Ablation of the KLF1 or KLF2 gene causes embryonic lethality, and double KO embryos are more anemic and die sooner than either single KO. We have shown that KLF1 and KLF2 positively regulate the human ϵ- (embryonic) and γ-globin (fetal) genes during embryonic erythropoiesis. Chromatin immunoprecipitation assays (ChIP) show that KLF1 and KLF2 bind to the promoters of the human ϵ- and γ-globin genes, the mouse embryonic Ey- and βh1-globin genes, and also to the β-globin locus control region (LCR) in mouse embryonic erythroid cells. ChIP assays show that KLF1 but not KLF2 ablation results in abnormal histone modifications in the β-globin locus in mouse embryonic erythroid cells. H3K9Ac and H3K4me3, which correlate with open chromatin and active transcription, are both reduced in KLF1-/- primitive erythroid cells. Human CD34+ hematopoietic stem cells obtained from umbilical cord blood were in vitro differentiated along the erythroid lineage. ChIP assays indicate that both KLF1 and KLF2 bind to the promoter of γ-globin gene in this fetal erythroid model. KLF1 knockdown in these cells affects mainly adult β- globin gene expression. However, the decrease in β- globin gene expression in KLF1 knockdown also affects the ratio of γ- to β- globin in these cells. H3K9Ac and H3K4me3 were decreased only at the β- globin gene which coincides with lower recruitment of RNA polymerase II and its active form, RNA polymerase II phospho-serine 2. In conclusion, we showed using mouse primitive erythroid cells and cord blood definitive cells that KLF1 and KLF2 coordinate the regulation of the mouse and human β- globin genes by direct binding to the promoters and LCR in the β- globin locus. In conclusion, cord blood hematopoietic cells could serve as a complimentary system in addition to the transgenic mouse models to study the regulation of γ- globin gene expression.

Chan Kai Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 109-119). / Abstracts in English and Chinese. / Title --- p.i / Thesis committee --- p.ii / Statement --- p.iii / Acknowledgement --- p.iv / Abbreviations --- p.v / Abstract (English) --- p.vii / Abstract (Chinese) --- p.ix / Table of contents --- p.xi / List of Figures --- p.xvi / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter 1.1 --- Human Hemoglobin --- p.1 / Chapter 1.2 --- Hemoglobinopathies --- p.4 / Chapter 1.3 --- Hereditary Persistence of Fetal Hemoglobin (HPFH) and β - Thalassemias --- p.6 / Chapter 1.4 --- Globin Genes Switching --- p.7 / Chapter 1.5 --- Pharmaceutical Agents for γ-Globin Gene Reactivation --- p.9 / Chapter 1.6 --- Discovery of LC978: A Novel Fetal Hemoglobin Inducing Agent --- p.10 / Chapter 1.7 --- Aim of Study --- p.11 / Chapter Chapter 2: --- Specific Induction of Gamma Globin Gene Transcription in K562 Leukemia Cell Line by Lead Compound LC978 --- p.12 / Chapter 2.1 --- K562 Cell Line as a Model for Gamma Globin Gene Induction Studies --- p.12 / Chapter 2.2 --- LC978-Induced Fetal Hemoglobin Expression in K562 Cell Line --- p.12 / Chapter 2.3 --- Materials --- p.14 / Chapter 2.3.1 --- "Chemicals, Kits and Reagents" --- p.14 / Chapter 2.3.2 --- Buffers and Solutions --- p.15 / Chapter 2.3.3 --- Cell Line --- p.16 / Chapter 2.3.4 --- Instruments and Equipments --- p.16 / Chapter 2.3.5 --- Enzymes --- p.16 / Chapter 2.3.6 --- Nucleic Acids --- p.17 / Chapter 2.3.7 --- Oligo Primers --- p.17 / Chapter 2.4 --- Methods --- p.17 / Chapter 2.4.1 --- In vitro Bioassay for Total Hemoglobin Production --- p.17 / Chapter (a) --- Preparation of Treatment Cell Culture Plates --- p.17 / Chapter (b) --- Treatment of K562 Cells by LC978 --- p.18 / Chapter (c) --- Signal Development --- p.18 / Chapter 2.4.2 --- Detection of Fetal Hemoglobin Production by HbF Sandwich ELISA --- p.18 / Chapter (a) --- Treatment of K562 Cells by LC978 --- p.18 / Chapter (b) --- Preparation of Capture Antibody-Coated and BSA-Blocked ELISA Plate --- p.19 / Chapter (c) --- Preparation of K562 Cell Lysates --- p.19 / Chapter (d) --- Antigen Capture and Signal Development --- p.19 / Chapter 2.4.3 --- Detection of Gamma Globin mRNA Level by Real-time RT-PCR --- p.20 / Chapter (a) --- Treatment of K562 Cells by LC978 --- p.20 / Chapter (b) --- Preparation of K562 Cell Lysate in Guanidium Thiocyanate (GT) Solution --- p.20 / Chapter (c) --- Isolation of Total RNA from LC978-treated K562 Cells --- p.21 / Chapter (d) --- cDNA Synthesis from mRNA by Reverse Transcriptase (RT) --- p.22 / Chapter (e) --- Real-Time Quantitative Polymerase Chain Reaction (PCR) --- p.23 / Chapter 2.5 --- Results --- p.24 / Chapter (a) --- In vitro Bioassay for Total Hemoglobin Production --- p.24 / Chapter (b) --- Fetal Hemoglobin Sandwich ELISA --- p.24 / Chapter (c) --- LC978-Induced Gamma Globin mRNA Accumulation --- p.25 / Chapter 2.6 --- Discussion --- p.31 / Chapter Chapter 3: --- Construction of Promoter-Reporter Plasmid Constructs --- p.33 / Chapter 3.1 --- The Human Gamma Globin Gene Promoter --- p.33 / Chapter 3.2 --- SEAP as a Reporter Gene for Promoter Deletion Study --- p.34 / Chapter 3.3 --- Materials --- p.35 / Chapter 3.3.1 --- "Chemicals, Kits and Reagents" --- p.35 / Chapter 3.3.2 --- Buffers and Solutions --- p.35 / Chapter 3.3.3 --- Bacterial Strain --- p.36 / Chapter 3.3.4 --- Cell Line --- p.36 / Chapter 3.3.5 --- Enzymes --- p.37 / Chapter 3.3.6 --- Nucleic Acids --- p.37 / Chapter 3.3.7 --- Oligo Primers --- p.37 / Chapter 3.4 --- Methods --- p.38 / Chapter 3.4.1 --- Molecular Cloning of A-Gamma Globin Gene Promoter and 3' Enhancer into pBlueScript II SK (-) --- p.38 / Chapter (a) --- Design and Synthesis of Oligo Primers --- p.38 / Chapter (b) --- Isolation of Genomic DNA from K562 Cells --- p.39 / Chapter (c) --- PCR Amplification of Gamma Globin Gene Promoter and 3' Enhancer --- p.40 / Chapter (d) --- Ligation of PCR Fragments into EcoR V-cut pBlueScript II SK (-) --- p.41 / Chapter (e) --- Preparation of E coli DH5a Competent Cells --- p.43 / Chapter (f) --- Heat-Shock Transformation of E. coli DH5a Competent Cells --- p.44 / Chapter (g) --- PCR Screening and Plasmid Purification of Putative pBlu2SKM-γAP and pBlu2SKM-γAE --- p.44 / Chapter (h) --- Isolation of Putative pBlu2SKM-γAP and pBlu2SKM-γAE Plasmid DNA --- p.45 / Chapter (j) --- Nucleotide Sequencing of Putative pBlu2SKM-yAP and pBlu2SKM-γAE --- p.47 / Chapter (j) --- Graphical Summary of Section 3.6.1 Sub-cloning Procedures --- p.49 / Chapter 3.4.2 --- Molecular Cloning of A-Gamma Globin Gene Promoter and 3' Enhancer into pSEAP2-Enhancer --- p.51 / Chapter (a) --- Sub-cloning of Promoter Fragment into pSEAP2-Enhancer --- p.51 / Chapter (b) --- Sub-cloning of 3' Enhancer Fragment into p 1224γAP-SEAP2 --- p.52 / Chapter (c) --- Graphical Summary of Section 3.6.2 Sub-cloning Procedures --- p.54 / Chapter 3.4.3 --- Construction of p 1224γAP-SEAP2-γAE Promoter Deletions Constructs --- p.56 / Chapter (a) --- Restriction Digestion at 5' End of A-Gamma Promoter Deletions --- p.56 / Chapter (b) --- Restriction Digestion at 3' Ends of A-Gamma Promoter Deletions --- p.56 / Chapter (c) --- Blunting 5'-overhangs and Self-Ligation of Linearized Plasmid Constructs --- p.57 / Chapter (d) --- Graphical Summary of Section 3.6.3 5，Deletions Procedures --- p.58 / Chapter 3.5 --- Results --- p.59 / Chapter (a) --- Nucleotide Sequence Confirmed by Cycle Sequencing --- p.60 / Chapter (b) --- "Resulting Plasmid Constructs p 1224γAP-SEAP2-yAE, p754yAP-SEAP2-yAE and p205yAP-SEAP2-γAE" --- p.64 / Chapter 3.6 --- Discussion --- p.67 / Chapter Chapter 4: --- Mapping of LC978-Responsive Elements on Human A-Gamma Globin Gene Promoter --- p.69 / Chapter 4.1 --- Introduction --- p.69 / Chapter 4.2 --- pSV-β-Galactosidase as a Transfection Normalization Standard --- p.69 / Chapter 4.3 --- pSV-β-Galactosidase as a Transfection Normalization Standard --- p.70 / Chapter 4.4 --- Materials --- p.72 / Chapter 4.4.1 --- "Chemicals, Kits and Reagents" --- p.72 / Chapter 4.4.2 --- Buffers and Solutions --- p.73 / Chapter 4.4.3 --- Cell Line --- p.74 / Chapter 4.4.4 --- Nucleic Acids --- p.74 / Chapter 4.4.5 --- Instruments and Equipments --- p.74 / Chapter 4.5 --- Methods --- p.74 / Chapter 4.5.1 --- Determination of Optimal Dose of Transfection Reagent for --- p.74 / Chapter (a) --- Sterilization of Plasmid DNA for Transfection --- p.74 / Chapter (b) --- Transient Transfection of K562 Cells by pEGFP-N 1 --- p.75 / Chapter (c) --- Examination of EGFP Expression Level --- p.76 / Chapter 4.5.2 --- β-Galactosidase as Normalization Standard for K562 Transfections --- p.76 / Chapter (a) --- Transient Transfection of K562 Cells by pSV-β-Gal --- p.76 / Chapter (b) --- Determination of β-Galactosidase Expression Level --- p.76 / Chapter 4.5.3 --- Mapping of LC978-Responsive Elements on Human Gamma Globin Gene Promoter --- p.77 / Chapter (a) --- Co-Transfection of K562 Cells by p1224/754/205γAP-SEAP2 -γAE and pSV-β-Gal --- p.77 / Chapter (b) --- Treatment of Co-Transfected K562 Cells by LC978 --- p.77 / Chapter (c) --- Determination of β-Galactosidase Expression Level --- p.78 / Chapter (d) --- Determination of Secreted Alkaline Phosphatase (SEAP) Expression Level --- p.78 / Chapter (e) --- Determination of Fetal Hemoglobin Expression Level --- p.79 / Chapter 4.5.4 --- Mapping of Hydroxyurea-Responsive Elements on Human Gammm Globin Gene Promoter --- p.80 / Chapter (a) --- Determination of Optimal Biological Dose (OBD) of Hydroxyurea --- p.80 / Chapter (b) --- Co-Transfection of K562 Cells and Subsequent Treatment by Hydroxyurea --- p.80 / Chapter (c) --- "Assay for β-Galactosidase (β-Gal), Secreted Alkaline Phosphatase (SEAP) and Fetal Hemoglobin (HbF) Expression Level" --- p.81 / Chapter 4.5.5 --- Sodium Butyrate-Induced SEAP Expression --- p.81 / Chapter (a) --- Determination of Optimal Biological Dose (OB(d) of Sodium Butyrate --- p.81 / Chapter (b) --- Co-Transfection of K562 Cells and Treatment by Sodium Butyrate --- p.82 / Chapter (c) --- "Assay for p-Galactosidase (β-Gal), Secreted Alkaline Phosphatase (SEAP) and Fetal Hemoglobin (HbF) Expression Level" --- p.83 / Chapter 4.5.6 --- Data Analysis --- p.83 / Chapter (a) --- "Data Processing, Normalization and Graphing" --- p.83 / Chapter (b) --- Statistical Analysis --- p.83 / Chapter 4.6 --- Results --- p.84 / Chapter 4.6.1 --- Optimal Dose of Transfection Reagent for K562 --- p.84 / Chapter 4.6.2 --- β-Galactosidase as Normalization Standard for K562 Transfections --- p.84 / Chapter 4.6.3 --- LC978 Induction on Co-Transfected K562 Cells --- p.84 / Chapter 4.6.4 --- Hydroxyurea Induction on Co-Transfected K562 Cells --- p.85 / Chapter 4.6.5 --- Sodium Butyrate Induction on Co-Transfected K562 Cells --- p.86 / Chapter 4.7 --- Discussion --- p.98 / Chapter 4.7.1 --- Theme Question to be Answered --- p.98 / Chapter 4.7.2 --- Optimal Dose of DMRIE-C Transfection Reagent on K562 Cell Line --- p.98 / Chapter 4.7.3 --- pSV-β-gal as an Internal Normalization Control --- p.99 / Chapter 4.7.4 --- Responsive Element Mapping --- p.99 / Chapter (a) --- LC978-Induced Response --- p.100 / Chapter (b) --- Hydroxyurea-Induced Response --- p.100 / Chapter (c) --- Sodium Butyrate-Induced Response --- p.101 / Chapter 4.7.5 --- LCR-Dependent Gamma Globin Gene Reactivation --- p.101 / Chapter 4.7.6 --- Induction of Gamma Globin by Histone Deacetylase Inhibitor --- p.104 / Chapter 4.7.7 --- Basal SEAP Expression Levels of the Promoter-Reporter Constructs --- p.105 / Chapter 4.7.8 --- Summary --- p.105 / Chapter Chapter 5: --- General Discussion --- p.106 / References Cited --- p.109

Choi Wai-wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 120-138). / Abstracts in English and Chinese. / Statement --- p.i / Acknowledgements --- p.ii / Abstract --- p.iii / Abstract (Chinese Version) --- p.v / Table of Contents --- p.vii / List of Tables --- p.xii / List of Figures --- p.xiii / List of Abbreviations --- p.xv / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- "Hemoglobin ´ؤ Structures, Types and Functions" --- p.1 / Chapter 1.1.1 --- Structures of Hemoglobin --- p.1 / Chapter 1.1.2 --- Types of Hemoglobin --- p.2 / Chapter 1.1.3 --- Functions of Hemoglobin --- p.3 / Chapter 1.2 --- Human Globin Genes and Their Regulation --- p.5 / Chapter 1.2.1 --- Organization of the Human Globin Genes --- p.5 / Chapter 1.2.2 --- Regulation of Globin Gene Expression --- p.6 / Chapter 1.2.2.1 --- The Locus Control Region (LCR) --- p.6 / Chapter 1.2.2.2 --- Cis-Regulatory Elements --- p.7 / Chapter 1.2.2.2.1 --- Promoters --- p.7 / Chapter 1.2.2.2.2 --- Enhancers --- p.7 / Chapter 1.2.2.2.3 --- Silencers --- p.8 / Chapter 1.2.2.3 --- Trans-Acting Factors --- p.8 / Chapter 1.2.2.3.1 --- GATA Family --- p.9 / Chapter 1.2.2.3.2 --- Kruppel-like Factors --- p.9 / Chapter 1.2.2.3.3 --- Nuclear Factor-Erythroid (NF-E) --- p.9 / Chapter 1.2.2.4 --- Chromatin Remodelling --- p.10 / Chapter 1.2.2.5 --- Intergenic Sequences --- p.11 / Chapter 1.3 --- Mechanisms of Hemoglobin Switching --- p.12 / Chapter 1.3.1 --- Autonomous Silencing --- p.12 / Chapter 1.3.2 --- LCR and Globin Gene Interaction --- p.12 / Chapter 1.4 --- Hemoglobinopathies --- p.14 / Chapter 1.4.1 --- α -thalassemia --- p.14 / Chapter 1.4.2 --- β -thalassemia --- p.14 / Chapter 1.4.3 --- Sickle Cell Anemia --- p.16 / Chapter 1.5 --- Therapies for β-thalassemia --- p.16 / Chapter 1.5.1 --- Blood Transfusion --- p.16 / Chapter 1.5.2 --- Bone Marrow Transplantation --- p.17 / Chapter 1.5.3. --- Gene Therapy --- p.17 / Chapter 1.6 --- Gene Switch Therapy --- p.18 / Chapter "1.6,1" --- Pharmacological Induction of HbF --- p.18 / Chapter 1.6.1.1 --- Hydroxyurea --- p.19 / Chapter 1.6.1.2 --- Butyrate --- p.20 / Chapter 1.6.1.3 --- Summary --- p.21 / Chapter 1.7 --- Objectives --- p.22 / Chapter Chapter 2 --- Induction of HbF by LC978 in K562 / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.2 --- Materials --- p.26 / Chapter 2.2.1 --- Chemicals and Reagents --- p.26 / Chapter 2.2.2 --- Kits --- p.27 / Chapter 2.2.3 --- Buffers and Solutions --- p.27 / Chapter 2.2.4 --- Primers --- p.30 / Chapter 2.2.5 --- Equipment and Other Consumables --- p.30 / Chapter 2.2.6 --- Maintenance of K562 --- p.31 / Chapter 2.2.7 --- Handling and Treatment of utilities for RNA isolation --- p.31 / Chapter 2.3 --- Methods --- p.32 / Chapter 2.3.1 --- Dose-response and time-response study of LC978 in K562 by TMB assay --- p.32 / Chapter 2.3.2 --- Detection of γ -Globin Gene Expression in LC978-induced K562 by RT-PCR --- p.33 / Chapter 2.3.3 --- Fetal Hemoglobin Analysis by Human Fetal Hemoglobin (HbF) ELISA Quantitation Kit --- p.36 / Chapter 2.3.4 --- Statistical Analysis --- p.38 / Chapter 2.4 --- Results --- p.39 / Chapter 2.4.1 --- Dose-response and time-response study of LC978 in K562 by TMB assay --- p.39 / Chapter 2.4.2 --- Detection of γ -Globin Gene Expression in LC978-induced K562 by RT-PCR --- p.45 / Chapter 2.4.3 --- Fetal Hemoglobin Analysis by Human Fetal Hemoglobin (HbF) ELISA Quantitation Kit --- p.48 / Chapter 2.5 --- Discussions --- p.51 / Chapter Chapter 3 --- Signal Transduction Pathways Modulated by LC978 / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Materials --- p.57 / Chapter 3.2.1 --- Chemicals and Reagents --- p.57 / Chapter 3.2.2 --- Kits --- p.57 / Chapter 3.2.3 --- Buffers and Solutions --- p.58 / Chapter 3.2.4 --- Primers --- p.59 / Chapter 3.2.5 --- Equipment and Other Consumables --- p.60 / Chapter 3.2.6 --- Maintenance of K562 --- p.60 / Chapter 3.2.7 --- Handling and Treatment of utilities for RNA isolation --- p.60 / Chapter 3.3 --- Methods --- p.61 / Chapter 3.3.1 --- Identification of Signaling Pathways by Microarray --- p.61 / Chapter 3.3.2 --- Real-time RT-PCR --- p.65 / Chapter 3.4 --- Results --- p.67 / Chapter 3.4.1 --- Identification of Signaling Pathways by Microarray --- p.67 / Chapter 3.4.2 --- Real-time RT-PCR --- p.74 / Chapter 3.5 --- Discussions --- p.80 / Chapter Chapter 4 --- MAPK pathways and HbF induction by LC978 / Chapter 4.1 --- Introduction --- p.84 / Chapter 4.2 --- Materials --- p.87 / Chapter 4.2.1 --- Chemicals and Reagents --- p.87 / Chapter 4.2.2 --- Kits --- p.88 / Chapter 4.2.3 --- Buffers and Solutions --- p.88 / Chapter 4.2.4 --- Equipment and Other Consumables --- p.90 / Chapter 4.2.5 --- Maintenance of K562 --- p.90 / Chapter 4.3 --- Methods --- p.91 / Chapter 4.3.1 --- "Roles of three MAPKs ´ؤ ERK, JNK and p38 in LC978-mediated γ -globin gene induction in K562 using CASE´ёØ Kits" --- p.91 / Chapter 4.3.2 --- Effect of p38 inhibitor SB203580 on HbF induction --- p.94 / Chapter 4.3.3 --- Statistical Analysis --- p.97 / Chapter 4.4 --- Results --- p.98 / Chapter 4.4.1 --- "Roles of three MAPKs - ERK, JNK and p38 in LC978-mediated γ -globin gene induction in K562 using CASETM Kits" --- p.98 / Chapter 4.4.2 --- Effect of p38 inhibitor SB203580 on HbF induction --- p.106 / Chapter 4.5 --- Discussions --- p.110 / Chapter Chapter 5 --- Summary and Prospects / Appendix / References