Genetics and Genomics Commons^™

Genomic And Transcriptomic Landscape Of Colorectal Premalignancy, Kyle Chang

Dissertations and Theses (Open Access)

Colorectal cancer (CRC) is the third most commonly diagnosed cancer among men and women in the United States, with 3 to 5 percent of the cases diagnosed in the background of a hereditary form of the disease. Biologically, CRC is divided into two groups: microsatellite instable (MSI) and chromosomally unstable (CIN). Genomic and transcriptomic characterization of CRC has emerged from large-scale studies in recent years due to the advancement of next-generation sequencing technologies. These studies have identified key genes and pathways altered in CRC and provided insights to the discovery of therapeutic targets. Despite the wealth of knowledge acquired in …

Mechanism Of Incorporation And Repair Of Uracil At Highly Transcribed Genes In Saccharomyces Cerevisiae, Norah Auma Owiti

Dissertations and Theses (Open Access)

Recombination and mutagenesis are elevated by high levels of transcription. The correlation between transcription and genome instability is largely explained by the topological and structural changes in DNA and the associated physical obstacles generated by the transcription machinery. However, such explanation does not directly account for the unique types of mutations originating from the non-canonical residues such as uracil, which are also elevated at highly transcribed regions. Apurinic/Apyrimic or Abasic (AP) sites derived from uracil excision, accumulate at a higher rate in actively transcribed regions of the genome in S. cerevisiae and are primarily repaired by base excision repair (BER) …

Omics Approaches To Uncover Germline And Somatic Variation Underlying Inherited Sarcomagenesis, Justin Wong

Dissertations and Theses (Open Access)

Sarcomas are rare mesenchymal tumors, making up 15% of all childhood and 1% of all adult tumors. They account for a disproportionate share of mortality in young adults, and if left untreated, are highly likely to metastasize. However, sarcoma etiology is poorly understood, and having numerous histological subtypes has complicated elucidation. To better understand factors underlying sarcomagenesis, we leveraged two rare inherited cancer predisposition syndromes, Li-Fraumeni Syndrome (LFS), and LFS-like (LFSL), both with a high incidence of sarcomas. LFS is caused by mutations in the tumor suppressor gene TP53 (p53), but has variable and incomplete penetrance, suggesting additional acquired …

Investigating Invasion In Ductal Carcinoma In Situ With To Pographical Single Cell Genome Sequencing, Anna Casasent, Anna Casasent

Dissertations and Theses (Open Access)

Synchronous Ductal Carcinoma in situ (DCIS-IDC) is an early stage breast cancer invasion in which it is possible to delineate genomic evolution during invasion because of the presence of both in situ and invasive regions within the same sample. While laser capture microdissection studies of DCIS-IDC examined the relationship between the paired in situ (DCIS) and invasive (IDC) regions, these studies were either confounded by bulk tissue or limited to a small set of genes or markers. To overcome these challenges, we developed Topographic Single Cell Sequencing (TSCS), which combines laser-catapulting with single cell DNA sequencing to measure genomic copy …

The Role Of Merlin And Apicobasal Polarity In Endometrial Development And Homeostasis, Erin Lopez

Dissertations and Theses (Open Access)

Apicobasal polarity and cell adhesion are necessary for the proper formation and organization of epithelial tissues. Merlin couples cell polarity and adhesion through correct localization of the polarity protein Par3 and maturation of apical junctions. Merlin and Par3 are necessary for the development and homeostasis of highly regenerative tissues like the epidermis. The continual repopulation of the endometrium after each menstrual cycle requires a constant reorganization of cell polarity and adhesion. The endometrium consists of a luminal epithelium that postnatally gives rise to the distinct glandular epithelium. Endometrial glands are necessary to secrete nutrients for the pre-implantation embryo. In addition, …

Psychiatric Impact Of Tuberous Sclerosis Complex And Utilization Of Mental Health Treatment, Kate Mowrey

Dissertations and Theses (Open Access)

Tuberous sclerosis complex (TSC) is a multi-system, neurocutaneous disorder with neuropsychiatric features known as TSC-associated neuropsychiatric disorders (TAND). While 90% of individuals with TSC have some TAND features, only 20% receive treatment, leading to a 70% treatment gap. This study evaluated perception of disease severity, presence of anxiety and depression, as well as the utilization and barriers towards mental health services among adults with TSC. Disease severity had a moderate and low-moderate association with anxiety and depression, respectively. Regardless of past utilization, respondents had a positive outlook towards the use of mental health services with the major barrier being cost.

Vascular Injury In Col3a1+/- Mice Model Of Vascular Ehler-Danlos Syndrome, Ping Zhou Ms

Dissertations and Theses (Open Access)

Vascular type of Ehlers-Danlos Syndrome (vEDS) is an inherited cardiovascular disease affecting the middle to large sized arteries, with an incidence rate of 1/5000. vEDS patients also show a significant phenotype of easily bruised skin, indicating aberrant wound healing and injury repair ability. Over 70% of the patients carry a glycine mutation located in their COL3A1 gene, which encodes the propeptide of type III collagen. Mutations in glycine residues lead to a disruption in the assembly and maturation of type III collagen. The goal and significance of the current study was to investigate the potential role of COL3A1 haploinsufficiency …

Patient Attitudes To Ward Genetic Testing For Inherited Predispositions To Hematologic Malignancies, Taylor Beecroft

Dissertations and Theses (Open Access)

Although inherited predispositions to hematologic malignancies have previously been considered extremely rare, approximately 12 causative genes have been implicated in the last decade. Since individuals diagnosed with leukemia have not historically been considered for evaluation of inherited predispositions, genetic testing is underperformed in this population. This study used focus group discussions to explore the attitudes, motivations, and barriers to genetic testing for 23 patients with leukemia. Participants generally exhibited a positive regard for the utility of genetic testing, and were primarily motivated by concern for their family and a sense of altruism toward all leukemia patients. While drawbacks and barriers …

Evolution Via Gene Duplication And Alternative Splicing In The Eukaryotic Ski7 And Hbs1 Genes, Alexandra Marshall

Dissertations and Theses (Open Access)

Gene duplication and alternative splicing are both recognized as important drivers of proteomic diversity and innovation during evolution, but the evolutionary changes over long periods of time or the interrelations of the two processes has not been extensively studied. Here I study these phenomena for the SKI7 and HBS1 gene pair. These Saccharomyces cerevisiae genes were created as part of a whole genome duplication (WGD) event and have since functionally diverged. Although both genes function in mRNA surveillance pathways, the two genes act on different RNAs and have different effects on the target mRNAs. Ski7 brings the Ski complex and …

Attitudes To Ward Updated Genetic Testing Among Patients With Unexplained Mismatch Repair Deficiency, Jessica Omark

Dissertations and Theses (Open Access)

Individuals who have colorectal cancer (CRC) or endometrial cancer (EC) displaying loss of immunohistochemical (IHC) staining of one or more mismatch repair (MMR) proteins without a causative germline mutation are said to have unexplained mismatch repair deficiency (UMMRD, also known as mutation-negative Lynch syndrome). Comprehensive genetic testing that could potentially further clarify Lynch syndrome (LS) carrier status is essential to provide tailored screening guidelines to affected individuals and their family members; however, patient understanding of the potential impact of updated genetic testing for LS is unclear. This study aimed to evaluate the interest in and perceived impact of updated genetic …

Functional Similarity Of Prd-Containing Virulence Regulators In Bacillus Anthracis, Malik Raynor

Dissertations and Theses (Open Access)

Bacillus anthracis produces three regulators, AtxA, AcpA, and AcpB, that control virulence gene expression and are members of an emerging class of regulators termed “PCVRs” (Phosphoenolpyruvate-dependent phosphotransferase regulation Domain-Containing Virulence Regulators). AtxA controls expression of the toxin genes; lef, cya, and pag, and is the master virulence regulator and archetype PCVR. AcpA and AcpB are less well studied. AcpA and AcpB independently positively control transcription of the capsule biosynthetic operon capBCADE, and culture conditions that enhance AtxA activity result in capBCADE transcription in strains lacking acpA and acpB. RNA-Seq was used to assess the regulons of the …

Investigating The Impact Of Intragenic Dna Methylation On Gene Expression, And The Clinical Implications On Tumor Cells And Associated Stroma, Michael Mcguire

Dissertations and Theses (Open Access)

Investigations into the function of non-promoter DNA methylation have yielded new insights into epigenetic regulation of gene expression. Previous studies have highlighted the importance of distinguishing between DNA methylation in discrete functional regions; however, integrated non-promoter DNA methylation and gene expression analyses across a wide number of tumor types and corresponding normal tissues have not been performed. Through integrated analysis of gene expression and DNA methylation profiles, we uncovered an enrichment of DNA methylation sites within the gene body and 3’UTR in which DNA methylation is strongly positively correlated with gene expression. We examined 32 tumor types and identified 57 …

Examining The Relationship Between Genetic Counselors’ Implicit Attitudes To Ward Disability And Their Practice Methods, Helen W. Gould

Dissertations and Theses (Open Access)

Genetic counselors serve as a link between the medical community and the disability community as they are regularly the first exposure families have following a new diagnosis in a pregnancy, infant or child. This role requires genetic counselors to be responsible and compassionate when approaching conversations about disability. With a lack of research on how the specific attitudes of genetic counselors toward disability impact clinical practice, we aimed to understand these attitudes, what factors affect implicit attitudes toward disability, and how these attitudes affect counseling. Case scenarios involving disability were used to examine different counseling content preferences within a genetic …

Genetic Testing Practices Of Genetic Counselors, Geneticists, And Pediatric Neurologists With Regard To Childhood-Onset Neurogenetic Conditions, Sara Wofford

Dissertations and Theses (Open Access)

Identifying genetic diagnoses for neurological conditions with a considerable hereditary component, such as autism spectrum disorder (ASD), intellectual disability, and epilepsy, is critical to providing proper medical management for these patients and their families. However, many patients with these conditions are not tested appropriately or receive no genetic testing at all. The current study was designed to characterize the genetic testing practices of the providers most likely to evaluate or order genetic testing for these patients: pediatric neurologists, geneticists, and genetic counselors. The study noted significant variance between the testing strategies selected by pediatric neurologists compared to those of geneticists …

Outcomes Of Genetic Testing In A Genitourinary Genetics Clinic, Annelise Pace

Dissertations and Theses (Open Access)

Several known hereditary cancer syndromes confer an increased risk for genitourinary (GU)related malignancies. Various guidelines indicate when to refer patients to genetic counseling for GU-related hereditary cancer syndromes but there is limited research on the clinical picture of these patients, including their cancerous and non-cancerous features, the genetic testing strategy for this population, and the probability of having a positive germline mutation if testing is performed. The purpose of this study is to determine the most common indications for ordering genetic testing in a GU Genetics Clinic and evaluate whether there is a relationship between the indication for genetic testing …

Computational Insights Into The Generation Of Chromosomal Copy Number Changes, Yihua Liu

Dissertations and Theses (Open Access)

Deviations from a diploid configuration of the human genome, spanning single genes or entire chromosomes, can have wide-ranging impacts on the variation of human phenotypes, including Mendelian and complex forms of diseases. These chromosomal alterations — such as duplications, deletions or copy-neutral loss-of-heterozygosity — are thus important forms of genetic variation for phenotyping populations of individuals as well as populations of cells. Indeed, copy number variants (CNVs) serve as hallmarks of critical changes in the development of particular diseases such as cancer and thus may be used as biomarkers. These CNVs may be either inherited (transmitted by germ cells, originating …

Trim24 In Normal & Malignant Hematopoiesis, Justin Shaw

Dissertations and Theses (Open Access)

Treatment for acute myeloid leukemia (AML) has changed little in the past four decades. For the majority of AML patients, current treatment options include chemotherapy and allogeneic stem cell transplants, which also involves high-dose chemotherapy or radiation treatment. These options have little success in the long-run, as only an estimated 26% of patients survive five years post-diagnosis. In efforts to address this low survival rate, interest has increased for targeting epigenetic pathways in AML. This focus stems from the discovery that AML is frequently driven by blockades on hematopoietic stem cell differentiation, which involves a series of coordinated epigenetic changes. …

Phosphorylation Impairs Dicer1 Function To Accelerate Aging And Tumorigenesis In Vivo, Neeraj Aryal

Dissertations and Theses (Open Access)

Altered DICER1 protein levels are associated with developmental disorders, infertility, macular degenerative blindness, aging, and cancer in humans. Recently, post-translational regulation of Dicer1 via phosphorylation has been described in C. elegans. Oscillation of Dicer1 phosphorylation to regulate its activity is essential for germ cell development and embryogenesis in worms. These observations led us to posit that Dicer1 protein levels and activity are under tight regulation for normal mammalian homeostasis. To test whether phosphorylation of Dicer1 regulates its activity in mammals, I generated phospho-mimetic knock-in mouse models by replacing Serines 1712 and 1836 with Aspartic acids individually or together (dual …

Trim24 As An Oncogene In The Mammary Gland, Aundrietta Duncan

Dissertations and Theses (Open Access)

Despite the many advances made in breast cancer research and treatments, breast cancer remains one of the deadliest diseases plaguing women worldwide. While many findings on genetic mutations and their role in predisposing people to breast cancer have been uncovered, we are just beginning to understand the extent to which epigenetic regulators promote tumorigenic phenotypes, metastasis, and chemotherapeutic resistance. Moreover, new experimental tools offer the ability to address questions we were previously unable to assess. My project takes advantage of a new mouse model to understand the role of a proto-oncogenic, transcriptional co-regulator, TRIM24, in mammary gland development and disease. …

Identification And Utility Of Dna In Exosomes, Paul Kurywchak

Dissertations and Theses (Open Access)

Cancer-associated mortality has been declining for two decades but remains a significant public health problem, especially when patients initially present with advanced disease. Early detection methods have improved survival rates but remain unavailable for a majority of cancers due to a lack of sensitive biomarkers or numerous limitations associated with current diagnosis strategies. Approaches to develop “liquid biopsies” by detecting tumor cells or DNA in the blood have led to several breakthroughs and create the potential for non-invasive, routine assessment of diseases status. However, these biomarkers are rare and currently difficult to isolate, especially in the early stages of disease. …

The Regulation Of Dna Methylation In Mammalian Development And Cancer, Nicolas Veland

Dissertations and Theses (Open Access)

DNA methylation is an essential epigenetic modification in mammals, as it plays important regulatory roles in multiple biological processes, such as gene transcription, maintenance of chromosomal structure and genomic stability, genomic imprinting, retrotransposon silencing, and X-chromosome inactivation. Dysregulation of DNA methylation is associated with various human diseases. For example, cancer cells usually show global hypomethylation and regional hypermenthylation, which have been implicated in genomic instability and tumor suppressor silencing, respectively. Although great progress has been made in elucidating the biological functions of DNA methylation over the last several decades, how DNA methylation patterns and levels are regulated and dysregulated is …

Evaluating The Therapeutic Efficacy Of Restoring Wild-Type P53 Activity In P53-Mutant Tumors, Connie A. Larsson

Dissertations and Theses (Open Access)

The p53 transcription factor is the most frequently altered in human cancers usually via missense mutations that undermine its transcriptional activity. Clinically, TP53 mutations have been shown to be remarkably predictive of refractoriness to treatment, resulting in poor outcome. Consequently, the development of p53 pathway activating agents is rapidly evolving and gaining more attention in cancer therapeutics research, with several small molecule compounds currently in preclinical and clinical trials. However, it remains largely unknown what types or proportions of p53-mutant tumors will respond to p53 restoration-based therapies.

Using a mouse model of Li Fraumeni syndrome, we genetically restored wild-type …

Integrative Cancer Immunogenomic Analysis Of Serial Melanoma Biopsies Reveals Correlates Of Response And Resistance To Sequential Ctla-4 And Pd-1 Blockade Treatment, Whijae Roh

Dissertations and Theses (Open Access)

Melanoma is the most malignant form of skin cancer. The five-year survival rate for metastatic melanoma is 19.9%. Although targeted therapy of BRAF and MEK inhibitors were developed for melanoma, resistance to therapy is inevitable. Immune checkpoint blockade, which reverses the suppression of the immune system, on the other hand, has shown a durable response in 20-30% of patients with metastatic melanoma. However, more predictive and robust biomarkers of response to this therapy are still needed, and resistance mechanisms remain incompletely understood. To address this, we examined a cohort of metastatic melanoma patients treated with sequential checkpoint blockade against cytotoxic …

Quality Of Life: Socio-Demographic And Genetic Determinants As Well As Links With Cancer Outcomes, Jeanne Pierzynski

Dissertations and Theses (Open Access)

Quality of life (QOL) is an independent prognostic factor for cancer. Lung cancer is the leading cause of cancer death. Breast cancer is the most diagnosed. Bladder cancer is the most expensive cancer to treat because of its high recurrence rate. We set to perform comprehensive analyses of predictors of QOL in these cancer sites with the future goal of improving QOL and outcomes.

In 6,456 newly diagnosed lung cancer patients, we investigated the relationship between baseline patient characteristics and QOL to identify determinants of QOL. A QOL questionnaire (SF-12v1) measured patients’ physical component summary (PCS) and mental component summary …

Wisp1 Is An Overexpressed Driver Of Glioblastoma, Pushan R. Dasgupta

Dissertations and Theses (Open Access)

Despite current multimodal therapies for glioblastoma (GBM) the prognosis remains very grim. There is a tremendous need to identify new genetic drivers which can serve as potential therapeutic targets. In order to find new drivers, we leveraged genomic datasets to conduct a context specific in vivo functional genomic screen of overexpressed and/or amplified genes in GBM. We identified WISP1, a secreted extracellular matrix protein, to be an overexpressed driver in GBM. Overexpression of WISP1 was able to drive tumor growth in various in vivo models. Knockdown of WISP1 with shRNAs resulted in reduced colony formation in vitro and reduced tumor …

Functional Consequences Of Rna Exosome Complex Alteration By Conformational Changes And Cofactor Binding, Jaeil Han

Dissertations and Theses (Open Access)

The RNA exosome is an essential 3’-5 ribonuclease that processes or degrades a variety of RNA species in eukaryotes. It is composed of nine structural cores and one catalytic subunit, Rrp44. Structural studies captured two different conformations of Rrp44, Rrp44^ch (channel) and Rrp44^da (direct-access). The Rrp44^ch appears to recruit RNA substrates from the central channel formed by the core subunits, while the substrate is directly recruited to Rrp44^da bypassing the central channel. Although in vivo function of the Rrp44^ch-exosome is extensively studied, the function or even the presence of the Rrp44^da-exosome in …

Barriers To Expansion Of Supervision Networks At Genetic Counseling Training Programs, Jordan E. Berg

Dissertations and Theses (Open Access)

Job openings outpace new graduates due to exponential growth in genetic counseling, leading to a workforce shortage. Expanding training slots to meet this demand presumably is linked to the number of supervisors. Thus, there is a need to systematically review barriers to supervision. This study aimed to determine and compare barriers to expansion of supervision networks at genetic counseling training programs as perceived by current supervisors, non-supervisors, and Program Directors. Certified genetic counselors were recruited via National Society of Genetic Counselors e-blast with an invitation to complete an online survey; Program Directors were emailed personal letters of invitation. Twenty-three Program …

Statistical Methods For Two Problems In Cancer Research: Analysis Of Rna-Seq Data From Archival Samples And Characterization Of Onset Of Multiple Primary Cancers, Jialu Li

Dissertations and Theses (Open Access)

My dissertation is focused on quantitative methodology development and application for two important topics in translational and clinical cancer research.

The first topic was motivated by the challenge of applying transcriptome sequencing (RNA-seq) to formalin-fixation and paraffin-embedding (FFPE) tumor samples for reliable diagnostic development. We designed a biospecimen study to directly compare gene expression results from different protocols to prepare libraries for RNA-seq from human breast cancer tissues, with randomization to fresh-frozen (FF) or FFPE conditions. To comprehensively evaluate the FFPE RNA-seq data quality for expression profiling, we developed multiple computational methods for assessment, such as the uniformity and continuity …

Proteomic Identification Of Histone Post-Translational Modifications Induced By Dna Double-Strand Breaks And Novel Proteins Involved In The Dna Damage Response, Pingping Wang

Dissertations and Theses (Open Access)

Inaccurate repair of DNA double-strand breaks (DSBs) can lead to DNA mutation and chromosome rearrangements, causing human diseases such as cancer. Although we know the basic mechanisms of DSB repair, the added complexities in the chromatin context are unclear. This is partially due to the lack of unbiased systems for identifying proteins and post-translational modifications (PTMs) involved in DSB repair. In this work, we established a novel method, termed DSB-ChAP-MS (Double Strand Break-Chromatin Affinity Purification with Mass Spectrometry), for the affinity purification of a sequence-specific single copy endogenous chromosomal locus containing a DSB, followed by the proteomic identification of enriched …

Non-Coding Rnas Identify The Intrinsic Molecular Subtypes Of Muscle-Invasive Bladder Cancer, Andrea E. Ochoa

Dissertations and Theses (Open Access)

NON-CODING RNAS IDENTIFY THE INTRINSIC MOLECULAR SUBTYPES OF MUSCLE-INVASIVE BLADDER CANCER

Andrea Elizabeth Ochoa, B.S.

Advisory Professors: David J. McConkey, Ph.D. and Joya Chandra, Ph.D.

There has been a recent explosion of genomics data in muscle-invasive bladder cancer (MIBC) to better understand the underlying biology of the disease that leads to the high amount of heterogeneity that is seen clinically. These studies have identified relatively stable intrinsic molecular subtypes of MIBC that show similarities to the basal and luminal subtypes of breast cancer. However, previous studies have primarily focused on protein-coding genes or DNA mutations/alterations.

There is emerging evidence implicating …