published_or_final_version / Medicine / Master / Master of Research in Medicine

published_or_final_version / Pathology / Master / Master of Medical Sciences

published_or_final_version / abstract / Medicine / Doctoral / Doctor of Philosophy

Multiple myeloma (MM) is an incurable haematological malignancy. It is characterized clinically by an asymptomatic precursor stage, known as monoclonal gammopathy of undetermined significance (MGUS), which will transform into symptomatic MM at a rate of 1% per year. Gene promoter hypermethylation by catalytic conversion of cytosine into 5?methylcytosine at promoter?associated CpG island is an alternative mechanism of gene inactivation. MicroRNA (miRNA) is a class of short, single?stranded, non?coding RNA molecules, which will repress the expression of target protein by sequence?specific binding to the three prime untranslated region of the corresponding messenger RNA. In carcinogenesis, miRNA can be either oncogenic when tumour suppressor genes are targeted, or tumour suppressive when oncogenes are targeted. Despite reports of hypermethylation of multiple protein?coding tumour suppressor genes, little is known about DNA methylation of non?coding tumour suppressor miRNA genes in MM. This thesis aimed to investigate the role of promoter hypermethylation of tumour suppressor miRNA genes in MM using a candidate miRNA approach. Moreover, the prognostic significance of tumour suppressor miRNA hypermethylation was studied in a uniformly?treated cohort of MM patients. The role of DNA methylation at the promoter of miR?203, miR?34a, miR?34b/c, miR?124?1, miR?129?2 and miR?224 were studied in MM. The tumour suppressor role of miR?34b/c, miR?124?1, miR?203 and miR?224 were demonstrated in human myeloma cell lines (HMCLs). In particular, restoration of miR?203 in MM cells was shown to inhibit cellular proliferation via targeting and hence direct downregulation of a proto?oncogene, cyclic AMP responsive element binding protein. There are several observations in primary MM samples. First, there was frequent methylation of miR?129?2, miR?203 and miR?224 but infrequent methylation of miR?34a, miR?34b/c and miR?124?1 in MM at diagnosis. Second, tumour?specific hypermethylation of each of the miR?203 and miR?224 promoters was detected at comparable frequencies in MGUS, diagnostic and relapsed/progressed MM, and hence implicated as an early event in myelomagenesis. Thirdly, miR?129?2 methylation was more frequent in diagnostic MM than MGUS, and hence implicated in MGUS progression to MM. On the other hand, despite rare miR?34b/c methylation at diagnosis, miR?34b/c methylation was frequent at relapse/progression, thereby implicating miR?34b/c methylation in MM relapse/progression. Fourthly, despite frequent miR?124?1 methylation in HMCLs, miR?124?1 methylation was rare in both diagnostic and relapsed MM marrow samples, suggesting that miR?124?1 methylation was acquired during in vitro cell culture. Finally, the prognostic significance of methylation of a panel of tumour suppressor miRNAs was studied in a uniformly?treated cohort of MM patients, which revealed that miR?224 hypermethylation as an independent favourable prognostic factor for survival. In conclusion, hypermethylation of tumour suppressor miRNAs is implicated in the pathogenesis (miR?203, miR?129?2, miR?224), progression (miR?34b/c), and prognostification (miR?224) of MM. / published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

Cheung Kin Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 87-105). / Abstracts in English and Chinese. / Abstract (English version) --- p.i / Abstract (Chinese version) --- p.iii / Acknowledgments --- p.vi / Table of Contents --- p.v / List of Tables --- p.viii / List of Figures --- p.iv / List of Abbreviations --- p.xi / Chapter CHAPTER 1 --- GENERAL INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.3 / Chapter 2.1 --- Multiple myeloma --- p.3 / Chapter 2.2 --- Epidemiology of MM --- p.3 / Chapter 2.3 --- Risk factors --- p.4 / Chapter 2.4 --- Pathophysiology of MM --- p.5 / Chapter 2.5 --- Clinical presentations and diagnosis --- p.6 / Chapter 2.5.1 --- Diagnosis --- p.6 / Chapter 2.5.1.1 --- Laboratory testing of blood and urine --- p.6 / Chapter 2.5.1.2 --- Radiographic evaluations --- p.1 / Chapter 2.5.1.3 --- Bone marrow biopsy --- p.7 / Chapter 2.6 --- Staging and classification --- p.9 / Chapter 2.6.1 --- Staging --- p.9 / Chapter 2.6.2 --- Classification --- p.11 / Chapter 2.6.2.1 --- Monoclonal gammopathy of undetermined significance --- p.11 / Chapter 2.6.2.2 --- Asymptomatic MM --- p.12 / Chapter 2.6.2.3 --- Smouldering MM --- p.12 / Chapter 2.6.2.4 --- Indolent MM --- p.12 / Chapter 2.6.2.5 --- Symptomatic MM --- p.12 / Chapter 2.7 --- Treatment --- p.14 / Chapter 2.8 --- Epigenetics: DNA methylation --- p.15 / Chapter 2.9 --- Fundamental aspects of DNA methylation --- p.16 / Chapter 2.9.1 --- CpG islands --- p.16 / Chapter 2.9.2 --- Roles of DNA methylation --- p.16 / Chapter 2.9.3 --- Proposed mechanisms of transcriptional repression mediated by methylation --- p.18 / Chapter 2.10 --- Possible mechanisms to initiate aberrant DNA methylation --- p.21 / Chapter 2.11 --- DNA methylation in tumorigenesis --- p.22 / Chapter 2.11.1 --- Oncogenic point C → T mutation --- p.22 / Chapter 2.11.2 --- Global DNA hypomethylation --- p.23 / Chapter 2.11.3 --- Regional DNA hypermethylation --- p.23 / Chapter 2.12 --- Aberrant DNA methylation in MM --- p.25 / Chapter 2.12.1 --- Self-sufficiency in growth signals --- p.25 / Chapter 2.12.2 --- Evading apoptosis --- p.26 / Chapter 2.12.3 --- Insensitivity to antigrowth signals --- p.26 / Chapter 2.12.4 --- Tissue invasion and metastasis --- p.27 / Chapter 2.12.5 --- Infinite replicative potential --- p.28 / Chapter 2.12.6 --- Genome instability --- p.30 / Chapter 2.13 --- Methodologies of DNA methylation analysis --- p.32 / Chapter 2.13.1 --- Genome wide screening method: MS.AP-PCR --- p.32 / Chapter 2.13.2 --- Combined bisulfite restriction analysis --- p.34 / Chapter 2.13.3 --- Cloned bisulfite genomic sequencing --- p.36 / Chapter 2.13.4 --- Treatment with demethylating agent --- p.36 / Chapter CHAPTER 3 --- MATERIALS AND METHODS --- p.38 / Chapter 3.1 --- MM specimens --- p.38 / Chapter 3.1.1 --- MM samples --- p.38 / Chapter 3.1.2 --- MM cell lines --- p.38 / Chapter 3.2 --- Magnetic cell sorting of CD138-positive plasma cells --- p.39 / Chapter 3.3 --- Isolation of nuclear pellet from PB --- p.41 / Chapter 3.4 --- "DNA extraction from MM cell lines, MM plasma cells and PB" --- p.41 / Chapter 3.5 --- MS.AP-PCR --- p.42 / Chapter 3.5.1 --- Restriction enzyme digestion of genomic DNA --- p.42 / Chapter 3.5.2 --- Arbitrarily primed polymerase chain reaction --- p.42 / Chapter 3.5.3 --- Isolation of differentially methylated DNA fragments --- p.43 / Chapter 3.6 --- Cloning of differentially methylated DNA fragments --- p.46 / Chapter 3.6.1 --- TA cloning --- p.46 / Chapter 3.6.2 --- Heat shock transformation --- p.46 / Chapter 3.6.3 --- Screening of positive clones by PCR --- p.46 / Chapter 3.6.4 --- Alkaline lysis for plasmid DNA preparation --- p.47 / Chapter 3.7 --- MS.AP-PCR sequence analysis --- p.47 / Chapter 3.7.1 --- Nucleotide sequencing --- p.47 / Chapter 3.7.2 --- CpG islands analysis of differentially methylated sequences --- p.48 / Chapter 3.8 --- DNA methylation analysis --- p.48 / Chapter 3.8.1 --- Sodium bisulfite modification --- p.48 / Chapter 3.8.2 --- Combined bisulfite restriction analysis --- p.49 / Chapter 3.8.3 --- Cloned bisulfite genomic sequencing --- p.49 / Chapter 3.9 --- Gene expression analysis --- p.50 / Chapter 3.9.1 --- RNA extraction --- p.50 / Chapter 3.9.2 --- Reverse transcription PCR --- p.50 / Chapter 3.9.3 --- 5'-aza-2'-deoxycytidine treatment --- p.51 / Chapter CHAPTER 4 --- RESULTS --- p.53 / Chapter 4.1 --- Generation of DNA methylation patterns by MS.AP-PCR --- p.53 / Chapter 4.1.1. --- Global methylation content in MM samples and normal PB lymphocytes --- p.56 / Chapter 4.1.2. --- Differential methylation in MM --- p.56 / Chapter 4.2 --- UCSC BLAT analysis of differentially methylated DNA fragments --- p.60 / Chapter 4.3 --- Identification of two candidate genes with downregulated expression --- p.60 / Chapter 4.4 --- Zinc fingers and homeoboxes 2 (ZHX2) --- p.62 / Chapter 4.4.1 --- ZHX2 CpG islands BLAT search analysis --- p.62 / Chapter 4.4.2 --- Hypermethylation of ZHX2 in MM cell lines --- p.63 / Chapter 4.4.3 --- Downregulated expression of ZHX2 in methylated MM cell lines --- p.66 / Chapter 4.4.4 --- Restoration of ZHX2 expression by 5-Aza-dC treatment --- p.67 / Chapter 4.4.5 --- Unmethylation of ZHX2 in primary MM tumors --- p.68 / Chapter 4.5 --- Ring finger protein 180 (RNF180) --- p.69 / Chapter 4.5.1 --- RNF180 CpG islands BLAT search analysis --- p.69 / Chapter 4.5.2 --- Hypermethylation of RNF180 in MM cell lines --- p.70 / Chapter 4.5.3 --- Downregulated expression of RNF180 in methylated MM cell lines --- p.73 / Chapter 4.5.4 --- Restoration of RNF180 expression by 5-Aza-dC treatment --- p.74 / Chapter 4.5.5 --- Methylation of RNF180 in primary MM tumors --- p.75 / Chapter CHAPTER 5 --- DISCUSSION --- p.76 / Chapter 5.1 --- Importance of methylation in MM --- p.76 / Chapter 5.2 --- Genome-wide screening approach by MS.AP-PCR --- p.76 / Chapter 5.3 --- Sample selection in MS.AP-PCR --- p.78 / Chapter 5.4 --- Methylation patterns in MM --- p.79 / Chapter 5.5 --- Candidate genes selection strategies --- p.81 / Chapter 5.6 --- Zinc fingers and homeoboxes 2 --- p.81 / Chapter 5.7 --- Ring finger protein 180 --- p.83 / Chapter 5.8 --- Limitations --- p.84 / Chapter CHAPTER 6 --- CONCLUSION --- p.86 / REFERENCES --- p.87

Cheung, Hing Yau Coty. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 111-132). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

Cheng Suk Hang. / "February 2005." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 142-160) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Ng Heung-ling, Margaret. / "April 2003." / Thesis (M.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 216-237). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

Wong, Ling Yee. / Thesis submitted in: August 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 110-127). / Abstracts in English and Chinese. / Thesis Abstract --- p.i / 論文摘要 --- p.iv / Acknowledgements --- p.vi / Abbreviations --- p.vii / Thesis Content --- p.xii / List of Figures --- p.xv / List of Tables --- p.xvii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature Review --- p.3 / Chapter 2.1. --- Multiple Myeloma (MM) --- p.3 / Chapter 2.1.1 --- Epidemiology --- p.4 / Chapter 2.1.2 --- Cause and Risk Factors --- p.5 / Chapter 2.1.3 --- Pathophysiology --- p.5 / Chapter 2.1.4 --- Diagnosis and Clinical Presentation --- p.6 / Chapter 2.1.5 --- Classification of Plasma Cell Disorders --- p.6 / Chapter 2.1.5.1 --- Monoclonal Gammopathy of Undetermined Significance (MGUS) --- p.6 / Chapter 2.1.5.2 --- Asymptomatic (Smouldering) MM --- p.7 / Chapter 2.1.5.3 --- Indolent MM --- p.7 / Chapter 2.1.5.4 --- Symptomatic MM --- p.8 / Chapter 2.1.6 --- Staging --- p.9 / Chapter 2.1.7 --- Treatment --- p.11 / Chapter 2.1.8 --- Molecular Abnormality --- p.12 / Chapter 2.2 --- DNA Microarray Analysis in MM --- p.13 / Chapter 2.2.1 --- MM Pathogenesis --- p.15 / Chapter 2.2.2 --- Molecular Classification of MM --- p.18 / Chapter 2.2.3 --- Anti-MM Drug Studies --- p.22 / Chapter 2.3 --- Cancer Treatment Response Prediction --- p.24 / Chapter 2.3.1 --- MP Treatment --- p.24 / Chapter 2.3.1.1 --- Melphalan --- p.25 / Chapter 2.3.1.2 --- Prednisone --- p.27 / Chapter 2.3.1.3 --- MP Treatment Response Prediction in MM --- p.29 / Chapter 2.3.2 --- Cancer Prognosis using DNA Microarray --- p.31 / Chapter Chapter 3 --- Materials and Methods --- p.36 / Chapter 3.1. --- Patient Specimens for Gene Expression Profiling and Quantitative Real-time PCR --- p.36 / Chapter 3.2. --- Magnetic Cell Sorting of CD138-positive Plasma Cells --- p.37 / Chapter 3.2.1 --- Density Gradient Centrifugation --- p.37 / Chapter 3.2.2 --- Positive Selection of CD138-positive Cells --- p.37 / Chapter 3.3 --- Generation of Gene Expression Profiles --- p.39 / Chapter 3.3.1 --- RNA Extraction --- p.39 / Chapter 3.3.2 --- RNA Assessment --- p.40 / Chapter 3.3.3 --- Synthesis and Purification of Double-strand cDNA --- p.40 / Chapter 3.3.4 --- In vitro Transcription (IVT) and Recovery of Biotin-labeled cRNA --- p.41 / Chapter 3.3.5 --- cRNA Fragmentation and Hybridization Reaction Mixture Preparation --- p.41 / Chapter 3.3.6 --- Hybridization --- p.42 / Chapter 3.3.7 --- Post-hybridization Wash --- p.42 / Chapter 3.3.8 --- Detection with Streptavidin-dye Conjugate --- p.43 / Chapter 3.3.9 --- Bioarray Scanning and Spot Signal Quantitation --- p.43 / Chapter 3.4 --- Microarray Data Analysis --- p.45 / Chapter 3.4.1 --- Normalization and Filtering --- p.45 / Chapter 3.4.2 --- Unsupervised Clustering Analysis --- p.45 / Chapter 3.4.3 --- Supervised Class Comparison Analysis --- p.46 / Chapter 3.5 --- Microarray Verification and Candidate Gene Validation --- p.47 / Chapter 3.5.1 --- RNA Extraction --- p.47 / Chapter 3.5.2 --- Reverse Transcription PCR --- p.47 / Chapter 3.5.3 --- Quantitative Real-time PCR --- p.48 / Chapter 3.6 --- Predictive Value Calculation --- p.49 / Chapter 3.7 --- Experimental Flow --- p.49 / Chapter Chapter 4 --- Results --- p.53 / Chapter 4.1 --- Gene Expression Profiling of Chinese MM --- p.53 / Chapter 4.1.1 --- Unsupervised Clustering Analysis --- p.53 / Chapter 4.1.1.1 --- Hierarchical Clustering --- p.53 / Chapter 4.1.1.2 --- Principal Component Analysis (PCA) --- p.54 / Chapter 4.1.2 --- Identification of Statistically Differentially Expressed Genes --- p.58 / Chapter 4.1.2.1 --- Two-Sample t-statistics --- p.58 / Chapter 4.1.2.2 --- Significance Analysis of Microarrays (SAM) --- p.58 / Chapter 4.1.2.3 --- Microarray Verification --- p.66 / Chapter 4.2 --- Development of MP Treatment Response Biomarker in MM --- p.70 / Chapter 4.2.1 --- Unsupervised Clustering Analysis --- p.70 / Chapter 4.2.1.1 --- Hierarchical Clustering --- p.70 / Chapter 4.2.1.2 --- PCA --- p.70 / Chapter 4.2.2 --- Identification of Statistically Differentially Expressed Genes --- p.74 / Chapter 4.2.2.1 --- Two sample t-statistics --- p.74 / Chapter 4.2.2.2 --- SAM --- p.74 / Chapter 4.2.3 --- Verification of Candidate Gene CYB5D1 --- p.76 / Chapter Chapter 5 --- Discussion --- p.79 / Chapter 5.1 --- Global Gene Expression Profiling: DNA Microarray --- p.79 / Chapter 5.2 --- Microarray Data Normalization and Gene Filtering --- p.81 / Chapter 5.3 --- Microarray Data Analysis --- p.83 / Chapter 5.3.1 --- Unsupervised Clustering Analysis --- p.83 / Chapter 5.3.1.1 --- Hierarchical Clustering --- p.83 / Chapter 5.3.1.2 --- PCA --- p.85 / Chapter 5.3.2 --- Identification of Statistically Differentially Expressed Genes --- p.86 / Chapter 5.4 --- Verification of Candidate Genes by Quantitative Real-time PCR --- p.89 / Chapter 5.5 --- Gene Expression Profiling of Chinese MM --- p.90 / Chapter 5.5.1 --- Comparison of Gene Expression Patterns of MM and Normal Plasma Cells --- p.90 / Chapter 5.5.2 --- Differentially Expressed Genes between MM and Normal Plasma Cells..… --- p.91 / Chapter 5.5.2.1 --- Common Differentially Expressed Genes with Previous Studies --- p.94 / Chapter 5.5.2.2 --- Potential Tumor Suppressor Genes in Differentially Expressed Genes..… --- p.96 / Chapter 5.5.2.3 --- Verified Differentially Expressed Genes --- p.98 / Chapter 5.5.3 --- Future Studies --- p.101 / Chapter 5.6 --- Development of MP Treatment Response Biomarker in MM --- p.103 / Chapter 5.6.1 --- Comparison of Gene Expression Patterns of MP Good Responders (GR) and Poor Responders (PR) --- p.103 / Chapter 5.6.2 --- Differentially Expressed Gene between MP GR and PR: CYB5D1 --- p.104 / Chapter 5.6.3 --- Possible Role of CYB5D1 in MP Resistance in MM Cells --- p.104 / Chapter 5.6.4 --- Potential Clinical Application of CYB5D1 in MP Treatment Response Prediction in MM --- p.106 / Chapter 5.6.5 --- Future Studies --- p.106 / Chapter Chapter 6 --- Conclusion --- p.108 / Chapter 6.1 --- Gene Expression Profiling of Chinese MM --- p.108 / Chapter 6.2 --- Development of MP Treatment Response Biomarker in MM --- p.108 / References --- p.110 / Appendix --- p.128