Li, Sai Kam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 162-179). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract in Chinese (摘要） --- p.ii / Acknowledgements --- p.iii / Table of Content --- p.iv / Abbreviations --- p.xi / List of Figures --- p.xiv / List of Tables --- p.xvii / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Hepatitis B Virus / Chapter 1.1.1 --- General information --- p.1 / Chapter 1.1.2 --- Classification --- p.2 / Chapter 1.1.3 --- Virus life cycle and genome --- p.3 / Chapter 1.1.4 --- Hepatitis B virus X protein (HBx) --- p.7 / Chapter 1.2 --- Enigmatic functions of HB --- p.x / Chapter 1.2.1 --- HBx as a transactivator --- p.10 / Chapter 1.2.2 --- HBx as a cell cycle regulator --- p.12 / Chapter 1.2.3 --- HBx as an apoptosis modulator --- p.13 / Chapter 1.3 --- Etiology of HBV-mediated hepatocarcinogenesis --- p.14 / Chapter 1.4 --- Clinical mutants of HBV --- p.16 / Chapter 1.5 --- Hypothesis and aims of the research --- p.16 / Chapter 1.6 --- Basis of Tet-On system --- p.18 / Chapter CHPATER 2 --- EXPERIMENT MATERIALS / Chapter 2.1 --- Cell culture / Chapter 2.1.1 --- Cell-lines --- p.21 / Chapter 2.1.2 --- Culture medium --- p.22 / Chapter 2.1.3 --- Culture medium supplements --- p.23 / Chapter 2.2 --- Reagents for subcloning / Chapter 2.2.1 --- Reagents for polymerase chain reaction (PCR) --- p.24 / Chapter 2.2.2 --- Reagents for restriction enzyme digestion --- p.24 / Chapter 2.2.3 --- Reagents for ligation --- p.25 / Chapter 2.2.4 --- Reagents for electrophoresis --- p.25 / Chapter 2.2.5 --- Reagents for E. coli DH5a preparation --- p.25 / Chapter 2.2.6 --- Materials for bacterial culture work --- p.27 / Chapter 2.3 --- Reagents for subcellular localization study / Chapter 2.3.1 --- Reagents for cell staining --- p.28 / Chapter 2.3.2 --- Reagents for mounting slides --- p.29 / Chapter 2.3.3 --- Materials for site-directed mutagenesis --- p.29 / Chapter 2.4 --- Reagents for cell cycle analysis and cellular proliferation / Chapter 2.4.1 --- Reagents for cell cycle analysis --- p.29 / Chapter 2.4.2 --- Reagents for cellular proliferation study --- p.30 / Chapter 2.5 --- Reagents for protein expression study / Chapter 2.5.1 --- Cell lysis buffer --- p.30 / Chapter 2.5.2 --- Reagents for SDS-PAGE --- p.30 / Chapter 2.5.3 --- Reagents for Western blot --- p.33 / Chapter 2.5.4 --- Antibodies --- p.34 / Chapter 2.6 --- Reagents for gene expression study / Chapter 2.6.1 --- Reagents for RNA extraction --- p.36 / Chapter 2.6.2 --- Reagents for first strand cDNA synthesis --- p.37 / Chapter 2.6.3 --- Reagents for real-time PCR --- p.37 / Chapter 2.7 --- Reagents for establishment of Tet-On inducible stable cell-lines / Chapter 2.7.1 --- Reagents for MTT assay --- p.38 / Chapter 2.7.2 --- Reagents for selection of stable clones --- p.38 / Chapter 2.8 --- Vectors used in the project / Chapter 2.8.1 --- Vectors for subcellular localization study --- p.39 / Chapter 2.8.2 --- Vectors for establishment of Tet-on inducible cell-lines --- p.39 / Chapter 2.9 --- Primers used in the project / Chapter 2.9.1 --- Primers used for subcloning --- p.42 / Chapter 2.9.2 --- Primers used for site-directed mutagenesis --- p.43 / Chapter 2.9.3 --- Primers used in real-time chain polymerase reaction --- p.43 / Chapter CHAPTER 3 --- RESEARCH METHODS / Chapter 3.1 --- Subcloning of HBx and mutant genes into a green fluorescence protein (GFP) expression vector / Chapter 3.1.1 --- Amplification of HBxWt，HBxΔC44 and HBxAN60 genes --- p.45 / Chapter 3.1.2 --- Purification of PCR products --- p.46 / Chapter 3.1.3 --- Restriction enzyme digestion --- p.47 / Chapter 3.1.4 --- Ligation of gene products with pEGFP-C 1 vector --- p.47 / Chapter 3.1.5 --- Preparation of chemically competent bacterial cells E. coli strain DH5α --- p.47 / Chapter 3.1.6 --- Transformation of the ligation product into competent cells --- p.48 / Chapter 3.1.7 --- PCR confirmation of successful ligation --- p.48 / Chapter 3.1.8 --- Small scale preparation of bacterial plasmid DNA --- p.49 / Chapter 3.1.9 --- DNA sequencing of the cloned plasmid DNA --- p.50 / Chapter 3.1.10 --- Large scale preparation of target recombinant plasmid DNA --- p.50 / Chapter 3.2 --- Subcellular localization pattern study / Chapter 3.2.1 --- Cell transfection --- p.51 / Chapter 3.2.2 --- Mitochondria and nucleus staining --- p.52 / Chapter 3.2.3 --- Epi-fluorescence microscopy --- p.53 / Chapter 3.2.4 --- Analysis of fluorescence images --- p.53 / Chapter 3.2.5 --- In vitro site-directed mutagenesis --- p.53 / Chapter 3.3 --- Cell cycle phase analysis with flow cytometry / Chapter 3.3.1 --- Cell transfection --- p.55 / Chapter 3.3.2 --- Cell staining --- p.55 / Chapter 3.3.3 --- Flow cytometry --- p.55 / Chapter 3.4 --- Cellular proliferation quantification by BrdU proliferation assay / Chapter 3.4.1 --- Cell transfection --- p.57 / Chapter 3.4.2 --- BrdU ELISA measurement --- p.57 / Chapter 3.5 --- Protein expression / Chapter 3.5.1 --- Cell lysate collection --- p.58 / Chapter 3.5.2 --- Quantification of protein samples --- p.59 / Chapter 3.5.3 --- SDS-PAGE --- p.59 / Chapter 3.5.4 --- Western blot --- p.60 / Chapter 3.5.5 --- Western blot luminal detection --- p.60 / Chapter 3.6 --- Gene expression / Chapter 3.6.1 --- Primer design --- p.61 / Chapter 3.6.2 --- Cell transfection --- p.61 / Chapter 3.6.3 --- RNA extraction --- p.61 / Chapter 3.6.4 --- Reverse transcription for first strand complementary DNA (cDNA) --- p.63 / Chapter 3.6.5 --- Quantitative real-time PCR --- p.63 / Chapter 3.7 --- Establishment of Tet-On inducible stable cell-lines / Chapter 3.7.1 --- Subcloning of HBx gene into pTRE2 vector --- p.64 / Chapter 3.7.2 --- Construction of WRL68/Tet-On stable cell-lines --- p.64 / Chapter 3.7.3 --- Construction of WRL68/Tet-On HBx and mutants expression cell-lines --- p.68 / Chapter 3.7.4 --- Characterization of Tet-On gene expression monoclones --- p.69 / Chapter 3.8 --- Statistical analyses --- p.70 / Chapter CHPATER 4 --- STUDY ON MITOCHONDRIA TARGETING / Chapter 4.1 --- Establishment of pEGFP-Cl-HBx and mutants constructs --- p.71 / Chapter 4.2 --- Transactivation C-terminus domain is essential for granular localization --- p.73 / Chapter 4.3 --- Wild-type HBx localizes in mitochondria --- p.76 / Chapter 4.4 --- C-terminal transactivation domain is sufficient for mitochondria targeting --- p.79 / Chapter 4.5 --- Mapping of the HBx region crucial for mitochondria targeting --- p.81 / Chapter 4.6 --- The 111-117 amino acids in HBx do not work as a signal peptide --- p.83 / Chapter 4.7 --- Site-directed mutagenesis identifies the key amino acid at 115 in HBx for mitochondrial targeting --- p.85 / Chapter CHAPTER 5 --- CELL PROLIFERATION AND REGULATION / Chapter 5.1 --- Alteration of S-phase distribution in cell cycle --- p.88 / Chapter 5.2 --- Analysis of DNA synthesis using BrdU proliferation ELISA --- p.92 / Chapter 5.3 --- Differential molecular regulation of cell cycle --- p.94 / Chapter 5.4 --- Regulation of the mRNA expression levels of cyclin-dependent kinases inhibitors p2raf/cipl and p27kipl --- p.98 / Chapter CHAPTER 6 --- TRANSACTIVATION AND RAS/RAF/MAPK PHOSPHORYLATION / Chapter 6.1 --- Determination of p53-dependency of p21、vaf/cipl expression --- p.101 / Chapter 6.2 --- Ras/Raf/MAPK pathway activation by HBx variants / Chapter 6.2.1 --- ERK1/2 phophorylation by HBx variants --- p.104 / Chapter 6.2.2 --- ERK inhibition blocks the regulation effect on p53Wt and p21waf/cipl --- p.107 / Chapter 6.3 --- Transactivation activity on oncogenes/ proto-oncogenes / Chapter 6.3.1 --- Effect on c-myc (NM´ؤ002467) mRNA expression --- p.109 / Chapter 6.3.2 --- Effect on RhoC (NM_017744) and Rabl4 (NM´ؤ016322) mRNA expression --- p.112 / Chapter CHAPTER 7 --- CONSTRUCTION OF TET-ON INDUCIBLE CELL-LINES / Chapter 7.1 --- Establishment of WRL/Tet-On monoclonal cell-lines Page / Chapter 7.1.1 --- Determination of geneticin selection dosage --- p.116 / Chapter 7.1.2 --- Selection of the best WRL/TOn clone using luciferase assay --- p.118 / Chapter 7.2 --- Establishment of inducible WRL/TOn/Gene monoclonal cell-lines / Chapter 7.2.1 --- Determination of hygromycin selection dosage --- p.120 / Chapter 7.2.2 --- Selection of positive WRL/TOn/Gene clones with viral genes --- p.122 / Chapter 7.3 --- Characterization of TOXDC1 cell-line / Chapter 7.3.1 --- Cell morphology --- p.125 / Chapter 7.3.2 --- Growth pattern of TOXDC1 --- p.126 / Chapter 7.3.3 --- HBxAC44 induced p21waf/cipl mRNA expression --- p.127 / Chapter 7.3.4 --- Doxycycline concentration dependent HBxAC44 expression in TOXDC1 --- p.129 / Chapter CHAPTER 8 --- DISCUSSION / Chapter 8.1 --- Selection of cell model / Chapter 8.1.1 --- Selection of cell models --- p.130 / Chapter 8.1.2 --- Selection of truncation mutant --- p.131 / Chapter 8.2 --- Differential sub-cellular localization of HBx and its variants / Chapter 8.2.1 --- Mechanisms of mitochondria targeting --- p.132 / Chapter 8.2.2 --- Mitochondria as site of HBx-induced apoptosis --- p.134 / Chapter 8.2.3 --- Stimulation of calcium release from mitochondria by wild-type HBx --- p.135 / Chapter 8.3 --- Cell cycle distribution profiling and its regulations / Chapter 8.3.1 --- Cell cycle pattern and cell proliferation --- p.136 / Chapter 8.3.2 --- Differential cell cycle molecular pathway activation --- p.138 / Chapter 8.4 --- Ras/Raf/MAPK mediated transactivation by HBxWt and its mutants / Chapter 8.4.1 --- p53-mediated p21waf/cipl expression --- p.142 / Chapter 8.4.2 --- ERK-mediated p21waf/cipl and wild-type p53 mRNA expression --- p.143 / Chapter 8.4.3 --- Regulation of oncogenes/ proto-oncogenes expression --- p.147 / Chapter 8.5 --- General discussions on differential effects of HBxWt and HBxAC44 --- p.149 / Chapter 8.6 --- Establishment of Tet-On/HBxAC44 cell-line TOXDC1 --- p.153 / Chapter 8.7 --- Conclusions --- p.154 / Chapter 8.8 --- Future Prospects / Chapter 8.8.1 --- From mitochondria targeting to calcium signaling --- p.157 / Chapter 8.8.2 --- Construction of a complete cell cycle regulation pathway --- p.158 / Chapter 8.8.3 --- Elucidation of the transcriptional transactivation regulation --- p.159 / Chapter 8.8.4 --- To make the best use of the Tet-on stable cell-line TOXDC1 --- p.159 / Chapter 8.8.5 --- Study with other carboxy-terminal truncation mutants --- p.160 / Chapter 8.8.6 --- In vivo study --- p.160 / REFERENCES --- p.162