Ng Yeung Lam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 180-209). / Abstracts in English and Chinese. / acknowledgements --- p.i / abstract --- p.ii / abstract in chinese --- p.vi / table of contents --- p.ix / list of tables --- p.xiii / list of figures --- p.xi v / list of abbreviations --- p.xvi / Chapter 1 --- chapter1 introduction and literature review --- p.1 / Chapter 1.1 --- Introduction of brain tumors --- p.1 / Chapter 1.2 --- Oligodendroglial tumors (OTs) --- p.3 / Chapter 1.2.1 --- Oligodendroglioma (OD) and anaplastic oligodendroglioma (AOD) --- p.3 / Chapter 1.2.1.1 --- WHO's definition and grading --- p.3 / Chapter 1.2.1.2 --- "Incidence, age, sex distribution, tumor location and survival rate" --- p.3 / Chapter 1.2.1.3 --- Clinical presentation --- p.4 / Chapter 1.2.1.4 --- Macroscopy and histopathology --- p.4 / Chapter 1.2.1.5 --- Immunohistochemistry --- p.5 / Chapter 1.2.1.6 --- Treatment --- p.6 / Chapter 1.2.2 --- Oligoastrocytoma (OA) and anaplastic oligoastrocytoma (AOA) --- p.11 / Chapter 1.2.2.1 --- WHO's definition and grading --- p.11 / Chapter 1.2.2.2 --- "Incidence, age, sex distribution, tumor location and survival rate" --- p.12 / Chapter 1.2.2.3 --- Clinical features --- p.12 / Chapter 1.2.2.4 --- Macroscopy and histopathology --- p.12 / Chapter 1.3 --- Overview of Genetic and Epigenetic Aberrations of OTs --- p.14 / Chapter 1.3.1 --- Chromosomal and genetic aberrations in OTs --- p.14 / Chapter 1.3.2 --- Candidate regions and genes on 1 p --- p.15 / Chapter 1.3.3 --- Candidate regions and genes on 19q --- p.20 / Chapter 1.3.4 --- Other aberrations in WHO grade II OTs --- p.24 / Chapter 1.3.5 --- Progression-associated aberrations in ODs --- p.25 / Chapter 1.3.6 --- Chromosomal and genetic aberrations in OAs --- p.29 / Chapter 1.4 --- Correlation of genetic alterations with response to therapy and survival --- p.31 / Chapter 1.4.1 --- Response to PCV chemotherapy correlates with lp and combined lp/19q status in patients with AODs --- p.31 / Chapter 1.4.2 --- Survival of patients with AODs correlates with lp/19q status --- p.32 / Chapter 1.4.3 --- WHO grade II ODs behavior and lp/19q status --- p.32 / Chapter 1.4.4 --- Response to other therapies (temozolomide and radiotherapy) and lp/19q status in patients with ODs --- p.33 / Chapter 1.4.5 --- lp and 19q loss in OAs and diffuse astrocytomas --- p.34 / Chapter 1.5 --- Microarray-based expression profiling of OTs --- p.35 / Chapter 1.6 --- Description of p73 protein --- p.37 / Chapter 1.6.1 --- Introduction of p73 --- p.37 / Chapter 1.6.2 --- p73: gene structure and splicing variants --- p.37 / Chapter 1.6.3 --- Signaling in p73 --- p.40 / Chapter 1.6.4 --- Regulation ofp73 protein stability and transcriptional activity --- p.43 / Chapter 1.6.4.1 --- Regulation by DNA damage --- p.43 / Chapter 1.6.4.2 --- Regulation by oncogenes --- p.44 / Chapter 1.6.4.3 --- Interaction with viral proteins --- p.44 / Chapter 1.6.5 --- Role of p73 in the nervous system --- p.45 / Chapter 1.6.6 --- p73 in cancer --- p.45 / Chapter 1.6.6.1 --- p73 knockout mice --- p.45 / Chapter 1.6.6.2 --- Alteration of p73 expression in human cancers --- p.46 / Chapter 1.6.7 --- p73 and chemosensitivity --- p.50 / Chapter CHAPTER2 --- AIMS OF STUDY --- p.51 / Chapter CHAPTER3 --- MATERIALS AND METHODS --- p.53 / Chapter 3.1 --- Tumor and blood samples --- p.53 / Chapter 3.2 --- Cell culture --- p.53 / Chapter 3.3 --- DNA extraction from frozen tissues and blood samples --- p.54 / Chapter 3.4 --- Detection of allelic loss of chromosome lp --- p.58 / Chapter 3.4.1 --- LOH analysis --- p.58 / Chapter 3.4.2 --- Fluorescence in situ Hybridization (FISH) analysis on Paraffin and Frozen Sections --- p.60 / Chapter 3.6 --- DNA sequencing analysis --- p.62 / Chapter 3.7 --- Analysis of Methylation --- p.63 / Chapter 3.7.1 --- Bisulfite sequencing --- p.63 / Chapter 3.7.2 --- Methylation-specific polymerase chain reaction (MSP) --- p.66 / Chapter 3.8 --- Northern Blot analysis --- p.68 / Chapter 3.9 --- RNA isolation and cDNA preparation --- p.70 / Chapter 3.10 --- Laser microdissection and RNA extraction from microdissected tumor cells --- p.71 / Chapter 3.10.1 --- Conventional RT-PCR --- p.71 / Chapter 3.11 --- Primer design for TP73 and its isoforms --- p.74 / Chapter 3.12 --- Real-time RT-PCR --- p.77 / Chapter 3.12.1 --- Real-time RT-PCR for TP73 and its isoforms --- p.78 / Chapter 3.12.2 --- Real-time RT-PCR for KIAA0495 --- p.79 / Chapter 3.13 --- Statistical analyses --- p.81 / Chapter CHAPTER4 --- RESULTS --- p.82 / Chapter 4.1 --- Genes annotated in the minimally deleted regions --- p.82 / Chapter 4.2 --- Expression analyses of TP73 and its isoforms in ODs by quantitative real-time RT-PCR --- p.85 / Chapter 4.3 --- Methylation analysis of TP73 in ODs by methylation sensitive PCR (MSP) --- p.97 / Chapter 4.4 --- A rapid screen of candidate genes for aberrant expression in microdissected tumors --- p.100 / Chapter 4.5 --- Quantitative real-time RT-PCR of KIAA0495 gene --- p.103 / Chapter 4.6 --- Mutation analysis of KIAA0495 gene --- p.110 / Chapter 4.7 --- Methylation analysis of KIAA0495 in ODs by bisulfite sequencing…… --- p.112 / Chapter 4.8 --- Detection of allelic loss of lp by LOH analysis and interphase FISH --- p.121 / Chapter 4.9 --- Two-hit inactivation of KIAA0495 gene in ODs --- p.126 / Chapter 4.10 --- Tissue distribution of KIAA0495 gene --- p.130 / Chapter 4.11 --- Bioinformatics of KIAA0495 --- p.133 / Chapter CHAPTER5 --- DISCUSSION --- p.146 / Chapter 5.1 --- Expression analysis of TP73 and its isoforms in ODs by isoform-specific RT-PCR --- p.148 / Chapter 5.2 --- Methylation status ofTP73 in ODs --- p.153 / Chapter 5.3 --- A rapid screening of candidate genes for aberrant expressionin microdissected tumors --- p.156 / Chapter 5.4 --- Expression pattern of KIAA0495 mRNA in a large cohort of ODs --- p.157 / Chapter 5.5 --- No somatic mutation in coding region of KIAA0495 --- p.158 / Chapter 5.6 --- Methylation status of putative promoter region of KIAA0495 in ODs --- p.159 / Chapter 5.7 --- Status of chromosome lp in ODs --- p.161 / Chapter 5.8 --- Two-hit inactivation of KIAA0495 gene in ODs by promoter hypermethylation and allelic loss of lp --- p.162 / Chapter 5.9 --- Evaluation of expression of KIAA0495 gene as a marker for the response to chemotherapy and prognostic marker in patients with OTs --- p.164 / Chapter 5.10 --- Tissue distribution of KIAA0495 --- p.166 / Chapter 5.11 --- "KIAA0495 cDNA sequence, protein sequence and potential functional features" --- p.167 / Chapter 5.12 --- Candidate tumor suppressor genes on lp in other type of tumors with loss of lp --- p.171 / Chapter CHAPTER6 --- CONCLUSIONS --- p.174 / Chapter CHAPTER7 --- FUTURE STUDIES --- p.177 / Chapter CHAPTER8 --- REFERENCES --- p.180

Yu, Pui Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 68-78). / Abstracts in English and Chinese. / Acknowledgements --- p.iv / Abstract --- p.v / Table of Contents --- p.ix / List of Figures --- p.xii / List of Tables --- p.xiv / List of Abbreviations --- p.xv / Chapter Chapter 1. --- General Introduction --- p.1 / Chapter Chapter 2. --- Literature Review --- p.5 / Chapter 2.1 --- The importance of terpenoids --- p.5 / Chapter 2.2 --- The difficulties in synthesizing terpenoids --- p.8 / Chapter 2.3 --- Structure and classification of terpenoids --- p.9 / Chapter 2.4 --- MVA and MEP pathways of terpenoid biosynthesis in higher plants --- p.12 / Chapter 2.4.1 --- The MVA pathway --- p.16 / Chapter 2.4.2 --- The MEP pathway --- p.18 / Chapter 2.5 --- The crosstalk between MVA and MEP routes --- p.20 / Chapter 2.6 --- The farnesyl diphosphate is a key enzyme in terpenoid biosynthetic pathway --- p.20 / Chapter 2.7 --- The glutaredoxin system --- p.22 / Chapter Chapter 3. --- Materials and Methods --- p.25 / Chapter 3.1 --- Plant materials and growth condition --- p.25 / Chapter 3.2 --- DNA extraction and screening of fps mutants --- p.25 / Chapter 3.3 --- Validation of the fps mutant by semi-quantitative RT-PCR --- p.26 / Chapter 3.4 --- Semi-quantitative RT-PCR analysis of the fps mutants --- p.28 / Chapter 3.5 --- Genechip analysis of fps mutants --- p.29 / Chapter 3.6 --- Enzyme assays --- p.29 / Chapter 3.7 --- Triterpene and sterol analysis of fps mutants --- p.30 / Chapter 3.8 --- Preparation of carotenoid standards for carotenoid analysis --- p.31 / Chapter 3.9 --- Carotenoids analysis of fps mutants by HPLC --- p.31 / Chapter 3.10 --- Subcellular localization of FPS 1 and FPS2 by transient expression --- p.33 / Chapter Chapter 4. --- Results --- p.36 / Chapter 4.1 --- Screening of fpsl and fps2 homozygous mutants --- p.36 / Chapter 4.2 --- Validation of fps mutants by RT-PCR and enzyme activity assay --- p.36 / Chapter 4.3 --- Genechip analysis of two fps mutants --- p.40 / Chapter 4.3.1 --- Quality control and normalization of microarray sample --- p.40 / Chapter 4.3.2 --- Normalization and identification of differentially expressed genes --- p.42 / Chapter 4.3.3 --- GO annotation of differentially expressed genes in fps mutants --- p.43 / Chapter 4.3.4 --- Genes participate in stress and defense response were differentially expressed in both fpsl and fps2 mutants --- p.48 / Chapter 4.3.5 --- Genes in the plastidial pathway were down-regulated --- p.51 / Chapter 4.4 --- Effects of FPS mutations on pathway enzymes --- p.53 / Chapter 4.5 --- Effects of fps mutants on terpenoids and sterol metabolism --- p.55 / Chapter 4.6 --- Comparison on carotenoids and chlorophyll contents --- p.55 / Chapter 4.7 --- Subcellular localization of FPS 1 and FPS2 --- p.61 / Chapter Chapter 5. --- Discussion --- p.62 / Chapter Chapter 6. --- Conclusion --- p.67 / Reference --- p.68 / Appendices --- p.79 / Appendix A. Primers designed for homozygous mutant screening for fps mutants --- p.79 / "Appendix B. Primer pairs designed for fps ORF, common sequence and fpsl specific region" --- p.80 / Appendix C. Primer pairs designed for studying expression level of the downstream genes of FPS --- p.81 / Appendix D. Annotations of differentially expressed genes in fpsl mutant --- p.82 / Appendix E. Annotations of differentially expressed genes in fps2 mutant --- p.84 / Appendix F. Log fold changes of terpenoid pathway genes involved in FPS mutants --- p.94

Qi, Yan. / Thesis submitted in: December 2008. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 63-79). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.III / ABSTRACT --- p.IV / TABLE OF CONTENTS --- p.VII / LIST OF ABBREVIATIONS --- p.XI / Chapter CHAPTER 1. --- LITERATURE REVIEW --- p.1 / Chapter 1.1 --- the Plant of Artemisia annua L --- p.1 / Chapter 1.2 --- The disease of malaria --- p.3 / Chapter 1.2.1 --- The life cycle of Plasmodium parasites --- p.4 / Chapter 1.2.2 --- The Artemisinin-based combination therapies (ACTs) for the treatment of malaria --- p.5 / Chapter 1.3 --- Artemisinin --- p.8 / Chapter 1.3.1 --- The content and distribution of artemisinin --- p.8 / Chapter 1.3.2 --- The mechanism of artemisinin action --- p.9 / Chapter 1.3.2.1 --- The proposed non-specific mechanisms of action --- p.10 / Chapter 1.3.2.2 --- The proposed parasite-specific mechanisms of action --- p.11 / Chapter 1.3.3 --- The biosynthesis of artemisnin in vivo --- p.12 / Chapter 1.3.4 --- The biosynthesis of artemisinin in vitro --- p.16 / Chapter 1.4 --- Trichomes --- p.18 / Chapter 1.4.1 --- Non-glandular trichomes --- p.19 / Chapter 1.4.2 --- Glandular trichome --- p.20 / Chapter 1.4.3 --- Trichomes of Artemisia annua L --- p.21 / Chapter 1.5 --- DNA Sequencing Methods --- p.24 / Chapter 1.5.1 --- The basic principle of pyrosequencing --- p.25 / Chapter 1.5.2 --- 454 pyrosequencing and its application --- p.27 / Chapter CHAPTER 2. --- MATERIALS AND METHODS --- p.32 / Chapter 2.1 --- Chemicals --- p.32 / Chapter 2.2 --- Plant materials --- p.32 / Chapter 2.3 --- Preparation of the cDNA sample for 454 sequencing --- p.33 / Chapter 2.3.1 --- Scanning electron microscopy --- p.33 / Chapter 2.3.2 --- Isolation of glandular trichomes --- p.34 / Chapter 2.3.3 --- cDNA synthesis and normalization --- p.34 / Chapter 2.4 --- 454-EST SEQUENCING AND PROCESSING --- p.36 / Chapter 2.5 --- Analysis of 454 sequencing data --- p.37 / Chapter 2.6 --- Establishment of regeneration system of A. annua L --- p.37 / Chapter 2.6.1 --- Shoots induction from leaf discs --- p.37 / Chapter 2.6.2 --- The sensitivity of the explants to Kanamycin --- p.38 / Chapter 2.6.3 --- Rooting of the regenerated seedlings --- p.38 / Chapter CHAPTER 3. --- RESULTS AND DISCUSSION --- p.40 / Chapter 3.1 --- Glandular trichome isolation and cDNA preparation --- p.40 / Chapter 3.1.1 --- The distribution of glandular trichomes on A. annua --- p.40 / Chapter 3.1.2 --- The isolation of glandular trichomes --- p.42 / Chapter 3.1.3 --- The preparation of ds cDNA for 454 sequencing --- p.43 / Chapter 3.2 --- Pre-process of 454 pyrosequencing data --- p.44 / Chapter 3.3 --- Functional annotation of the 454-EST data --- p.47 / Chapter 3.4 --- Comparison of two sequencing runs --- p.49 / Chapter 3.5 --- Analysis of the 454 ESTs involved in secondary metabolisms --- p.50 / Chapter 3.6 --- Selection of the candidate genes --- p.55 / Chapter 3.7 --- Establishment of regeneration system of A. annua L --- p.57 / Chapter 3.7.1 --- Shoots induction from leaf discs --- p.57 / Chapter 3.7.2 --- Roots induction from shoots --- p.57 / Chapter 3.7.3 --- Sensitivity of A. annua to Kan --- p.59 / Chapter CHAPTER 4. --- CONCLUSION --- p.61 / REFERENCES --- p.63

高通量大規模並行測序技術，又称為二代測序（NGS），極大的加速了生物和醫學研究的進程。隨著測序通量和複雜度的不斷提高，在分析大量的資料以挖掘其中的資訊的過程中，生物訊息學變得越發重要。在我的博士研究生期間（及本論文中），我主要從事於以下兩個領域的生物訊息學演算法的開發：DNA甲基化資料分析和基因間區長鏈非編碼蛋白RNA（lincRNA）的鑒定。目前二代測序技術在這兩個領域的研究中有著廣泛的應用，同時急需有效的資料處理方法來分析對應的資料。 / DNA甲基化是一種重要的表觀遺傳修飾，主要用來調控基因的表達。目前，全基因組重亞硫酸鹽測序（BS-seq）是最準確的研究DNA甲基化的實驗方法之一，該技術的一大特點就是可以精確到單個堿基的解析度。為了分析BS-seq產生的大量測序數據，我參與開發並深度優化了Methy-Pipe軟體。Methy-Pipe集成了測序序列比對和甲基化程度分析，是一個一體化的DNA甲基化資料分析工具。另外，在Methy-Pipe的基礎上，我又開發了一個新的用於檢測DNA甲基化差異區域（DMR）的演算法，可以用於大範圍的尋找DNA甲基化標記。Methy-Pipe在我們實驗室的DNA甲基化研究項目中得到廣泛的應用，其中包括基於血漿的無創產前診斷（NIPD）和癌症的檢測。 / 基因間區長鏈非編碼蛋白RNA（lincRNA）是一種重要的調節子，其在很多生物學過程中發揮作用，例如轉錄後調控，RNA的剪接，細胞老化等。lincRNA的表達具有很強的組織特異性，因此很大一部分lincRNA還沒有被發現。最近，全轉錄組測序技術（RNA-seq）結合基因從頭組裝，為新的lincRNA鑒定以及構建完整的轉錄組列表提供了最有力的方法。然而，有效並準確的從大量的RNA-seq測序數據中鑒定出真實的新的lincRNA仍然具有很大的挑戰性。為此，我開發了兩個生物訊息學工具：1）iSeeRNA，用於區分lincRNA和編碼蛋白RNA（mRNA）；2）sebnif，用於深層次資料篩選以得到高品質的lincRNA列表。這兩個工具已經在多個生物學系統中使用並表現出很好的效果。 / 總的來說，我開發了一些生物訊息學方法，這些方法可以幫助研究人員更好的利用二代測序技術來挖掘大量的測序數據背後的生物學本質，尤其是DNA甲基化和轉錄組的研究。 / High-throughput massive parallel sequencing technologies, or Next-Generation Sequencing (NGS) technologies, have greatly accelerated biological and medical research. With the ever-growing throughput and complexity of the NGS technologies, bioinformatics methods and tools are urgently needed for analyzing the large amount of data and discovering the meaningful information behind. In this thesis, I mainly worked on developing bioinformatics algorithms for two research fields: DNA methylation data analysis and large intergenic noncoding RNA discovery, where the NGS technologies are in-depth employed and novel bioinformatics algorithms are highly needed. / DNA methylation is one of the important epigenetic modifications to control the transcriptional regulations of the genes. Whole genome bisulfite sequencing (BS-seq) is one of the most precise methodologies for DNA methylation study which allows us to perform whole methylome research at single-base resolution. To analyze the large amount of data generated by BS-seq experiments, I have co-developed and optimized Methy-Pipe, an integrated bioinformatics pipeline which can perform both sequencing read alignment and methylation state decoding. Furthermore, I’ve developed a novel algorithm for Differentially Methylated Regions (DMR) mining, which can be used for large scale methylation marker discovery. Methy-Pipehas been routinely used in our laboratory for methylomic studies, including non-invasive prenatal diagnosis and early cancer detections in human plasma. / Large intergenic noncoding RNAs, or lincRNAs, is avery important novel family of gene regulators in many biological processes, such as post-transcriptional regulation, splicing and aging. Due to high tissue-specific expression pattern of the lincRNAs, a large proportion is still undiscovered. The development of Whole Transcriptome Shotgun Sequencing, also known as RNA-seq, combined with de novo or ab initio assembly, promises quantity discovery of novel lincRNAs hence building the complete transcriptome catalog. However, to efficiently and accurately identify the novel lincRNAs from the large transcriptome data stillremains a bioinformatics challenge.To fill this gap, I have developed two bioinformatics tools: I) iSeeRNAfor distinguishing lincRNAs from mRNAs and II) sebnif for comprehensive filtering towards high quality lincRNA screening which has been used in various biological systems and showed satisfactory performance. / In summary, I have developed several bioinformatics algorithms which help the researchers to take advantage of the strength of the NGS technologies(methylome and transcriptome studies) and explore the biological nature behind the large amount of data. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Sun, Kun. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 118-126). / Abstracts also in Chinese.

Despite improvements in the clinical management of soft tissue sarcomas (STS), 50% of patients will die of metastatic disease that is largely unresponsive to conventional chemotherapeutic agents. The aims of this study were to identify genes and pathways that are dysregulated in progressive and metastatic STS. In addition to this, cell lines from fresh tumours were initiated and established, thus increasing the repository of cell lines available for functional studies. Recent advances in the understanding of the molecular biology of STS have thus far not resulted in the use of molecular markers for clinical prognostication. Identifying novel genes and pathways will lead to molecular diagnostic methods to better stratify prognostic groups and could identify cellular targets for more efficacious treatments. Gene expression profiling of sarcoma cell lines of increasing metastatic potential revealed over-expression of genes involved in the epidermal growth factor (EGF) and transforming growth factor beta (TGFb) pathways. Factors involved in invasion and metastasis such as integrins and MMPs were over-expressed in the cell lines with higher metastatic potential. The developmental Notch pathway and cell cycle regulators were also dysregulated. NDRG1 was significantly over-expressed in the high grade sarcoma cell line, a novel finding in sarcomas. The expression of EGFR, NDRG1 and other genes from the above pathways was validated using quantitative RT-PCR in real time (qRT-PCR). A tissue microarray (TMA) comprising STS of varying tumour grades was constructed for high throughput assessment of target proteins. EGFR, its activated form and its signal transducers were investigated using immunohistochemistry (IHC). Activated EGFR (HR 2.228, p < 0.001) and phosphorylated Akt (HR 2.032, p = 0.003) were found to be independent predictors of overall survival and both correlated with tumour grade. Of the several STS cultures initiated and maintained, two of these cell lines were fully characterised in terms of cytogenetics, telomerase and alternate lengthening of 5 telomeres (ALT) status, KIT and TP53 mutation and the expression of certain biomarkers using both qRT-PCR and IHC. In summary, transcript profiling identified several potential biomarkers of tumour progression and metastasis in STS. Crucially, activated EGFR and pAkt were found in a cohort of STS samples to correlate with clinical outcome, identifying them as potential diagnostic and therapeutic targets in the treatment of STS. Activated EGFR can be used as a diagnostic marker for patient selection, as well as for target effect monitoring. Furthermore, the cell lines established in this project will serve as valuable tools in future preclinical studies.

<p>Cancer therapy operates by inflicting damage in malignant cells. The most lethal target is the genomic DNA. As a single double strand DNA break has the potential to kill the cell, mechanisms have evolved to detect and block propagation of the damage. Genes and their products function in a highly connected network-structure with ample cross-talk between different pathways. This interplay can be studied by genome-wide experiments, such as expression profiling. The aim of this thesis is to study the cellular effects of DNA damaging agents.</p><p>A theoretical framework is explored to improve understanding of expression profiling results. To analyse large datasets, computational methods were developed to model the data. Further, the response to DNA damage was investigated in different cellular systems. As late radiation toxicity is a severe limitation of radiotherapy of cancer patients, patients were enrolled in a study to search for a molecular signature to identify high-risk patients. Ex vivo irradiation of lymphocytes revealed a signature of functionally related gene sets that were capable to separate patients with regard to toxicity status. </p><p>The gene set analysis was also applied to a dataset where mouse embryonic stem cells had been exposed to various doses of cisplatin. At several time-points after administration of the drug, expression profiles were determined. In addition to the expected increase of genes related to apoptosis and cell cycle progression, damaged cells also seemed to have embarked upon a p53-dependent differentiation programme. Finally, in a study of cardiac rodent cells, the genotoxic treatment with irradiation was compared to the mechanical stress induced in heart tissue.</p><p>In conclusion, this thesis presents evidence for the advantage of using functionally related sets of genes in analysis and interpretation of genome-wide experiments. This strategy may improve clinical understanding of the effects of DNA damaging agents used for cancer therapeutics.</p>

Today’s rapid development of powerful tools for geneexpression analysis provides unprecedented resources forelucidating complex molecular events. The objective of this workhas been to apply, combine andevaluate tools for analysis of differential gene expressionusing atherosclerosis as a model system. First, an optimisedsolid-phase protocol for representational difference analysis(RDA) was applied to twoin vitromodel systems. Initially, The RDA enrichmentprocedure was investigated by shotgun cloning and sequencing ofsuccessive difference products. In the subsequent steps,combinations of RDA and microarray analysis were used tocombine the selectivity and sensitivity of RDA with thehigh-throughput nature of microarrays. This was achieved byimmobilization of RDA clones onto microarrays dedicated forgene expression analysis in atherosclerosis as well ashybridisation of labelled RDA products onto global microarrayscontaining more than 32,000 human clones. Finally, RDA wasapplied for the investigation of the focal localisation ofatherosclerotic plaques in mice usingin vivotissue samples as starting material. A large number of differentially expressed clones wereisolated and confirmed by real time PCR. A very diverse rangeof gene fragments was identified in the RDA products especiallywhen they were screened with global microarrays. However, themicroarray data also seem to contain some noise which is ageneral problem using microarrays and should be compensated forby careful verification of the results. Quite a large number of candidate genes related to theatherosclerotic process were found by these studies. Inparticular several nuclear receptors with altered expression inresponse to oxidized LDL were identified and deserve furtherinvestigation. Extended functional annotation does not liewithin the scope of this thesis but raw data in the form ofnovel sequences and accession numbers of known sequences havebeen made publicly available in GenBank. Parts of the data arealso available for interactive exploration on-line through aninteractive software tool. The data generated thus constitute abase for new hypotheses to be tested in the field ofatherosclerosis. <b>Keywords:</b>representational difference analysis, geneexpression profiling, microarray analysis, atherosclerosis,foam cell formation

Cancer therapy operates by inflicting damage in malignant cells. The most lethal target is the genomic DNA. As a single double strand DNA break has the potential to kill the cell, mechanisms have evolved to detect and block propagation of the damage. Genes and their products function in a highly connected network-structure with ample cross-talk between different pathways. This interplay can be studied by genome-wide experiments, such as expression profiling. The aim of this thesis is to study the cellular effects of DNA damaging agents. A theoretical framework is explored to improve understanding of expression profiling results. To analyse large datasets, computational methods were developed to model the data. Further, the response to DNA damage was investigated in different cellular systems. As late radiation toxicity is a severe limitation of radiotherapy of cancer patients, patients were enrolled in a study to search for a molecular signature to identify high-risk patients. Ex vivo irradiation of lymphocytes revealed a signature of functionally related gene sets that were capable to separate patients with regard to toxicity status. The gene set analysis was also applied to a dataset where mouse embryonic stem cells had been exposed to various doses of cisplatin. At several time-points after administration of the drug, expression profiles were determined. In addition to the expected increase of genes related to apoptosis and cell cycle progression, damaged cells also seemed to have embarked upon a p53-dependent differentiation programme. Finally, in a study of cardiac rodent cells, the genotoxic treatment with irradiation was compared to the mechanical stress induced in heart tissue. In conclusion, this thesis presents evidence for the advantage of using functionally related sets of genes in analysis and interpretation of genome-wide experiments. This strategy may improve clinical understanding of the effects of DNA damaging agents used for cancer therapeutics.

<p>Today’s rapid development of powerful tools for geneexpression analysis provides unprecedented resources forelucidating complex molecular events.</p><p>The objective of this workhas been to apply, combine andevaluate tools for analysis of differential gene expressionusing atherosclerosis as a model system. First, an optimisedsolid-phase protocol for representational difference analysis(RDA) was applied to two<i>in vitro</i>model systems. Initially, The RDA enrichmentprocedure was investigated by shotgun cloning and sequencing ofsuccessive difference products. In the subsequent steps,combinations of RDA and microarray analysis were used tocombine the selectivity and sensitivity of RDA with thehigh-throughput nature of microarrays. This was achieved byimmobilization of RDA clones onto microarrays dedicated forgene expression analysis in atherosclerosis as well ashybridisation of labelled RDA products onto global microarrayscontaining more than 32,000 human clones. Finally, RDA wasapplied for the investigation of the focal localisation ofatherosclerotic plaques in mice using<i>in vivo</i>tissue samples as starting material.</p><p>A large number of differentially expressed clones wereisolated and confirmed by real time PCR. A very diverse rangeof gene fragments was identified in the RDA products especiallywhen they were screened with global microarrays. However, themicroarray data also seem to contain some noise which is ageneral problem using microarrays and should be compensated forby careful verification of the results.</p><p>Quite a large number of candidate genes related to theatherosclerotic process were found by these studies. Inparticular several nuclear receptors with altered expression inresponse to oxidized LDL were identified and deserve furtherinvestigation. Extended functional annotation does not liewithin the scope of this thesis but raw data in the form ofnovel sequences and accession numbers of known sequences havebeen made publicly available in GenBank. Parts of the data arealso available for interactive exploration on-line through aninteractive software tool. The data generated thus constitute abase for new hypotheses to be tested in the field ofatherosclerosis.</p><p><b>Keywords:</b>representational difference analysis, geneexpression profiling, microarray analysis, atherosclerosis,foam cell formation</p>

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009.