Thesis (M. Sc.)--University of British Columbia, 2005. / Includes bibliographical references (leaves 33-41).

Acute leukemias are the main type of malignancy affecting children. They are defined by their precursor cell lineage: myeloid lineage for acute myeloid leukemia (AML) and lymphoid lineage for acute lymphoblastic leukemia (ALL). In this thesis, we use systems biology approaches to characterize transcription factor (TF) programs that define novel AML subtypes. We combine this approach with machine learning methods to group patients sharing similar TF programs and risk-stratify them. We identify a 9-cluster solution with statistically significant survival differences ranging from 84% for the best group to 41% for the worst. Each of the clusters is composed of patients with various cytogenetic aberrations that would not necessarily have been classified together. We identify top aberrantly activated TFs and potential master regulators or drug targets in each cluster. We also propose a novel stratification for FLT3-ITD patients with no other cytogenetic abnormalities. These patients are currently all classified as high-risk; however, we find a low-risk subtype and identify a TF signature that is predictive of risk in this subtype. Finally, we develop a binary classifier that is able to stratify the patients into two risk groups. We find that the activity of a large cluster of HOXA TFs is highly correlated with poor prognosis. In the second part, we characterize some mechanisms of relapse in B-ALL at a single-cell resolution focusing again on the patterns of activation and deactivation of TF activity in the course of the disease in matched trios of samples (diagnosis, remission and relapse). After a discussion on some of the technical aspects of differentiating normal cells and leukemic cells at a single-cell RNA sequencing resolution, we perform computational pseudo-lineage reconstruction based on groups of TFs whose activities rise and fall together through pseudotime. We find that each patient has unique mechanisms at the earliest pseudotimes but they seem to converge at the later pseudotimes into signatures in which the B-cell identity (in the case of B-ALL) gradually fades away. We also identify small populations of cells isolated at diagnosis in the later pseudotimes which is consistent with the view that many of the persistent cells in ALL pre-exist the malignancy and are selected by the treatment. This novel systems biology approach for characterizing clinical outcome in patients and defining lineage reconstruction identifies biochemical mechanisms and signaling pathways that are responsible for the development and maintenance of the malignancy and identifies potential therapeutic targets. The results exposed in this thesis will lead to a better understanding of some of the inner workings of pediatric acute leukemias and may lead to the development of improved targeted therapies.

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

No description available.

Chung, Po Yin. / Thesis submitted in: December 2006. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 128-155). / Abstracts in English and Chinese. / Thesis Abstract --- p.i / 論文摘要 --- p.iv / Acknowledgements --- p.vi / Abbreviations --- p.vii / Thesis Content --- p.xi / List of Figures --- p.xv / List of Tables --- p.xvii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1. --- Normal Hematopoiesis --- p.1 / Chapter 1.2. --- Hematological Malignancy and the Aberrant Development of Blood Cells --- p.2 / Chapter 1.3. --- Leukemia and Its Classification --- p.3 / Chapter 1.4. --- Childhood Acute Lymphoblastic Leukemia (ALL) --- p.5 / Chapter 1.4.1. --- Epidem iology --- p.5 / Chapter 1.4.2. --- Causes and Risk Factors --- p.6 / Chapter 1.4.3. --- Molecular Pathophysiology --- p.7 / Chapter 1.4.4. --- Clinical Presentation --- p.9 / Chapter 1.4.5. --- Classification --- p.10 / Chapter 1.4.5.1. --- Immunophenotyping --- p.10 / Chapter 1.4.5.2. --- French-American-British (FAB) Classification --- p.12 / Chapter 1.4.6. --- Diagnosis and Prognosis --- p.14 / Chapter 1.4.6.1. --- Morphological and Cytochemical Analysis --- p.15 / Chapter 1.4.6.2. --- Cytogenetic and Molecular Genetic Characterizations --- p.16 / Chapter 1.4.7. --- Treatment --- p.19 / Chapter 1.5. --- Overview of Epigenetics --- p.21 / Chapter 1.6. --- Concepts ofDNA Methylation --- p.23 / Chapter 1.6.1. --- CpG Islands --- p.23 / Chapter 1.6.2 --- Mechanisms of DNA Methylation --- p.24 / Chapter 1.6.3 --- Physiological Roles of DNA Methylation --- p.28 / Chapter 1.6.4 --- Initiation of Aberrant DNA Methylation --- p.30 / Chapter 1.7. --- DNA Methylation in Tumorigenesis --- p.31 / Chapter 1.7.1. --- Regional Hypermethylation --- p.33 / Chapter 1.7.2 --- Global and Regional Hypomethylation --- p.34 / Chapter 1.7.3 --- Microatellite Instability and Oncogeneic Mutation --- p.35 / Chapter Chapter 2 --- Literature Review --- p.37 / Chapter 2.1. --- Aberrant DNA Methylation in Childhood ALL --- p.37 / Chapter 2.1.1. --- Cell Cycle --- p.39 / Chapter 2.1.2. --- Apoptosis --- p.41 / Chapter 2.1.3. --- Tissue Invasion and Metastasis --- p.42 / Chapter 2.1.4. --- Transcription Factors and Metabolic Enzymes --- p.44 / Chapter 2.1.5. --- Putative Tumor Suppressor Genes --- p.44 / Chapter 2.1.6. --- Chromosome Instability --- p.46 / Chapter 2.2. --- Methodologies in DNA Methylation Analysis --- p.50 / Chapter 2.2.1. --- Principle of Methylation-sensitive Arbitrarily Primed PCR (MS-AP PCR) --- p.50 / Chapter 2.2.2. --- Combined Bisulfite Restriction Analysis (COBRA) --- p.53 / Chapter 2.2.3. --- Cloned Bisulfite Sequencing --- p.55 / Chapter 2.2.4. --- Experimental Use of Demethylating Agents --- p.55 / Chapter Chapter 3 --- Background of Research --- p.58 / Chapter 3.1. --- Current Methylation Studies in Childhood ALL --- p.58 / Chapter 3.2. --- Objectives of Research --- p.60 / Chapter 3.3. --- Study Approach and Experimental Design --- p.61 / Chapter Chapter 4 --- Materials and Methods --- p.63 / Chapter 4.1. --- Clinical Samples and ALL Cell Lines --- p.63 / Chapter 4.1.1. --- Clinical Samples from Pediatric Patients with ALL and Normal Healthy Donors --- p.63 / Chapter 4.1.2. --- ALL Cell Lines --- p.63 / Chapter 4.2. --- Genomic DNA Isolation from Clinical Samples and Cell Lines --- p.64 / Chapter 4.2.1. --- Ficoll Gradient Centrifugation --- p.64 / Chapter 4.2.2. --- DNA Extraction --- p.64 / Chapter 4.3. --- MS-AP PCR --- p.65 / Chapter 4.3.1. --- Methylation-sensitive Restriction Enzyme Digestion of Genomic DNA --- p.65 / Chapter 4.3.2. --- Arbitrarily Primed Polymerase Chain Reaction --- p.66 / Chapter 4.3.3. --- Isolation of Differentially Methylated DNA Fragments --- p.69 / Chapter 4.4. --- Cloning of Differentially Methylated DNA Fragments --- p.70 / Chapter 4.4.1. --- TA Cloning --- p.70 / Chapter 4.4.2. --- Screening of Positive Clones --- p.71 / Chapter 4.4.3. --- Preparation of Plasmid DNA by Alkaline Lysis Method --- p.72 / Chapter 4.5. --- DNA Sequence Analysis of Differentially Methylated DNA Fragments --- p.72 / Chapter 4.5.1. --- Dye-terminator Cycle Sequencing --- p.72 / Chapter 4.5.2. --- CpG islands Analysis of Differentially Methylated Sequences --- p.73 / Chapter 4.6. --- DNA Methylation Analysis --- p.74 / Chapter 4.6.1. --- Sodium Bisulfite Modification --- p.74 / Chapter 4.6.2. --- Combined Bisulfite Restriction Analysis --- p.75 / Chapter 4.6.3. --- Cloned Bisulfite Genomic Sequencing --- p.76 / Chapter 4.7 --- Gene Expression Study --- p.76 / Chapter 4.7.1. --- RNA Extraction from Clinical Samples and ALL Cell Lines --- p.76 / Chapter 4.1.2. --- Reverse Transcription PCR --- p.77 / Chapter 4.7.3. --- Semi-quantitative RT-PCR --- p.78 / Chapter 4.7.4. --- 5-aza-2 '-deoxycytidine Demethylation Treatment --- p.79 / Chapter Chapter 5 --- Results --- p.80 / Chapter 5.1. --- Generation of DNA Methylation Pattern by MS-AP PCR --- p.80 / Chapter 5.1.1. --- Differential Methylation Patterns of Childhood ALL --- p.84 / Chapter 5.1.2. --- Methylation Patterns of B and T lineages Childhood ALL --- p.86 / Chapter 5.2. --- UCSC BLAT Analysis of Differential Methylated DNA Sequences / Chapter 5.3. --- Identification of Candidate Gene --- p.89 / Chapter 5.4. --- Fibrillin 2 --- p.90 / Chapter 5.4.1. --- FBN2 CpG Islands: UCSC BLAT Search Analysis --- p.90 / Chapter 5.4.2. --- Verification ofFBN2 by ALL Cell Lines --- p.91 / Chapter 5.4.2.1. --- Semi-quantitative RT-PCR --- p.91 / Chapter 5.4.2.2. --- COBRA --- p.92 / Chapter 5.4.2.3. --- Cloned Bisulfite Sequencing --- p.94 / Chapter 5.4.2.4. --- Demethylation Treatment Resorted FBN2 mRNA Expression in ALL Cell Lines --- p.98 / Chapter 5.4.3. --- Studies ofFBN2 in Childhood ALL --- p.99 / Chapter 5.4.3.1. --- Methylation Analysis --- p.99 / Chapter 5.4.3.2. --- Semi-quantitative RT-PCR --- p.105 / Chapter Chapter 6 --- Discussion --- p.107 / Chapter 6.1. --- Genome-wide Screening Approach: MS-AP PCR --- p.107 / Chapter 6.2. --- Sample Selection in this Study --- p.109 / Chapter 6.2.1. --- MS-AP PCR --- p.109 / Chapter 6.2.2. --- Methylation Studies --- p.109 / Chapter 6.2.3. --- Studies in ALL Cell Lines --- p.110 / Chapter 6.3. --- Methylation Patterns in Childhood ALL --- p.111 / Chapter 6.4. --- Candidate Genes Selection Strategies in MS-AP PCR --- p.112 / Chapter 6.5. --- Fibrillin 2: mRNA Expression and Methylation Studies --- p.113 / Chapter 6.5.1 --- ALL Cell Lines --- p.113 / Chapter 6.5.2 --- Childhood ALL --- p.113 / Chapter 6.5.2.1 --- mRNA Expression and Methylation Studies --- p.113 / Chapter 6.5.2.2 --- Statistical Analysis --- p.115 / Chapter 6.5.3. --- Possible Roles of FBN2 in Leukemogenesis --- p.116 / Chapter 6.6. --- Clinical Application of FBN2 Aberrant Methylation --- p.119 / Chapter 6.6.1. --- Tumor Markers --- p.119 / Chapter 6.6.2. --- Use of Demethylating Drugs in Chemotherapy --- p.121 / Chapter 6.7. --- Limitations of Methylation Studies --- p.122 / Chapter 6.7.1. --- MS-AP PCR --- p.122 / Chapter 6.7.2. --- Techniques Used in Methylation Study --- p.122 / Chapter 6.7.3. --- Problems in Methylation Study --- p.123 / Chapter 6.8. --- Future Studies --- p.125 / Chapter Chapter 7 --- Conclusion --- p.127 / References --- p.128 / Appendix --- p.155

T-cell acute lymphoblastic leukemia (T-ALL) is a childhood cancer created through genetic alterations; most commonly upregulation of TALI and LMOI oncoproteins. T-ALL is treated with radiation and chemotherapy, but malignant T-cells are resistant to apoptotic stimulation. To study this disorder, AKR-DP-603 cells were transduced to express both oncoproteins. Western blots verified protein expression and each population was treated with etoposide. Caspase-3 and Annexin-V/FITC apoptosis assays were performed following treatment. When the response of control cells was compared to engineered cells, no difference was observed from the Annexin-V/FITC assay, and only LM01 cells showed a difference in the caspase-3 assay. Furthermore, cells were transfected with siRNA to TALI and LM01 and the apoptotic response was re-tested. Complete silencing was verified by Western and apoptotic activity varied in the TALI population for both assays. These differences might indicate that cells resisted etoposide induction and following silencing were sensitized apoptotic induction. / Department of Biology

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

Thesis (M.S.)--University of Michigan, 1991.

Thesis (M.S.)--University of Michigan, 1991.

Acute lymphocytic leukemia (ALL) is one of the most common types of pediatric cancers. Improvements in treatment within the last 20 years have resulted in reduced mortality and a greater focus upon quality of life. Several researchers have documented neuropsychological impairments in children following treatment for ALL; however, there have not been any comparative studies documenting differences in neuropsychological functioning based upon treatment modality despite the documented effects of radiation therapy and combined radiation/chemotherapy upon the developing brain. In addition, past studies have focused on unitary measures, ignoring the hierarchical relationship between basic cognitive functions and more abstract skills. This study examined the neuropsychological functioning of 81 children who were treated for ALL at a metropolitan children's hospital. All children were tested a minimum of two years after the final treatment session and were administered the NEPSY. Results do not support any interactions or main effects with the exception of the age of the child at diagnosis. Children diagnosed prior to the age of 5 showed greater impairments on tasks measuring attention, memory, and visuospatial reasoning in comparison to peers diagnosed after age 6.