Computational Biology Commons^™

Regulation Of Müllerian Duct Mesenchyme Transcription During Mammalian Sex Differentiation, Haowen Li, Richard R Behringer, Rachel D Mullen

Dissertations and Theses (Open Access)

Sp7/Osterix (Osx) encodes a zinc-finger transcription factor of the Specificity-protein family discovered by Nakashima et al. at the MD Anderson Cancer Center. While primarily recognized for its role in osteogenesis, Osx has also been implicated in mammalian reproductive development, particularly in male sex differentiation, where Müllerian Duct (MD) regression occurs, mediated by anti-Müllerian hormone (AMH) signaling. AMH-induced regression signals are transduced by the mesenchymal tissue surrounding the ductal structure, known as the Müllerian Duct mesenchyme (MDM). It was discovered that AMH signaling is necessary and sufficient for driving Osx expression in MDM. A previous transgenic mouse reporter …

Understanding Epigenomic Landscapes In Cancer Progression And Immunotherapy Response, Jonathan Schulz

Dissertations and Theses (Open Access)

Nonmutational epigenomic reprogramming has emerged as a key hallmark of cancer that plays crucial roles in tumor evolution during its progression and response to therapy. However, the extent and nature of epigenomic reprogramming remains poorly understood. This dissertation examines how epigenetic regulation shapes cancer progression and response to immunotherapy. Working at the intersection of cancer biology and computational genomics, it develops analytical frameworks for characterizing chromatin structure and DNA methylation across diverse tumor contexts and uses these frameworks to address two complementary biological questions: how promoter-associated chromatin organization varies across cancer types, and how epigenetic perturbation modulates tumor immunogenicity in …

Predicting Genetic Interactions Using Functional Interaction Networks, Iulia Veronica Gheorghe

Dissertations and Theses (Open Access)

Mapping genetic interactions is central to understanding cellular systems and identifying therapeutic vulnerabilities, particularly in the context of cancer. Among these interactions, synthetic lethality, where simultaneous loss of two genes is lethal but loss of either alone is tolerated, offers a powerful framework for selectively targeting tumor-specific dependencies. In model organisms like S. cerevisiae, comprehensive double-knockout screens have revealed detailed genetic interaction maps, enabling systems-level insights into pathway structure, gene function, and cellular organization. Replicating this achievement in human cells, however, is complicated by the scale and complexity of the human genome. Recent advances in genome-wide CRISPR knockout screening have …

Elucidating The Multi-Omics Of Early-Onset Colorectal Cancer, Jumanah Alshenaifi

Dissertations and Theses (Open Access)

The incidence and mortality rates of sporadic early-onset colorectal cancer have increased in recent decades, but there is no clear etiological basis for this trend. EOCRC is commonly defined as colon and rectal cancers diagnosed before the age of 50 years. The rising incidence of EOCRC has made it the second most common cancer and the third leading cause of cancer death in this age group. The rising incidence of EOCRC is also documented internationally in more than 20 countries across different continents. Clinically, EOCRC has a distinct, more aggressive clinical profile than LOCRC. While approximately 15% of EOCRC cases …

Timigp: A Computational Framework To Determine The Tumor Immune Microenvironment Associated With Prognosis And Immunotherapy Response, Chenyang Li

Dissertations and Theses (Open Access)

Accumulating evidence has suggested that the tumor immune microenvironment (TIME) drastically impacts cancer patients’ clinical outcomes, including prognosis and immunotherapy response. However, understanding TIME remains challenging due to its complexity and heterogeneity. In this dissertation, we introduce TimiGP (Tumor Immune Microenvironment Illustration based on Gene Pairs), a computational framework designed to address this challenge. Leveraging single-cell RNA-seq (scRNA-seq) and bulk gene expression data alongside clinical information, TimiGP constructs a cell-cell interaction network that elucidates the relationship between immune cell function and relevant clinical outcomes, such as prognosis and treatment response. With immunological insights, these cell-cell interactions also facilitate the development …

Investigating The Rare Aneuploid Cells In Normal Breast And Therapeutic Resistance In Triple Negative Breast Cancer Using Single Cell Genomics, Yiyun Lin

Dissertations and Theses (Open Access)

Aneuploid epithelial cells are common in breast cancer, however their presence in normal breast tissues is not well understood. To address this question, we applied single cell DNA sequencing to profile copy number alterations (CNAs) in 83,206 epithelial cells from breast tissues of 49 healthy women and single cell DNA&ATAC co-assays to 19 women. Our data shows that all women harbored rare aneuploid epithelial cells (median 3.19%) that increased with age. Many aneuploid epithelial cells (median 82.22%) in normal breast tissues underwent clonal expansions and harbored CNAs reminiscent of invasive breast cancers (gains of 1q, losses of 10q, 16q and …

Early Onset Alzheimer’S Disease Markers In Mouse Hippocampus Unveiled By Single-Cell Transcriptomic Analysis Following Cranial Radiotherapy, Tuba Aksoy

Dissertations and Theses (Open Access)

Cranial radiation therapy plays an integral role in the treatment of brain tumors but can lead to progressive cognitive deficits in survivors by mechanisms that are poorly understood. To develop preventive or mitigative strategies, it is crucial to better understand the underlying pathogenesis of radiation-induced cognitive impairments. The study investigated single-cell transcriptomics and DNA methylation changes as potential drivers of persistent cellular dysfunction after radiation exposure, specifically concentrating on the CA1-3 regions of the hippocampus and the prefrontal cortex due to their role in cognitive functions. Thirteen-week-old mice underwent whole-brain radiation at clinically relevant doses. Following whole-brain radiation, an assessment …

Utilizing The In4mer Crispr/Cas12a Multiplex Knockout Platform To Investigate Synthetic Lethality In The Human Genome, Xingdi Ma

Dissertations and Theses (Open Access)

The emergence of high-throughput sequencing technologies and the development of targeted cancer therapies have significantly advanced our understanding of cancer genomics and prolonged patient survival. Despite these advances, durable response remains difficult to achieve in the clinic. The concept of synthetic lethality has gained traction as a promising opportunity to discover novel cancer-specific vulnerabilities and therapeutic targets. Unfortunately, initial technologies for combinatorial genetic perturbation in mammalian cells suffer from inefficiency and are challenging to scale. In this dissertation, I report: 1) paralog selection method to select candidate synthetic lethal paralogs; 2) our Cas12a multiplex platform “IN4MER” that provides superior sensitivity …

Mismatch Repair Deficient Neoantigen And Associated Circulating T-Cell Receptor Repertoires In Lynch Syndrome, Ana Bolivar

Dissertations and Theses (Open Access)

Lynch Syndrome (LS) is the most common inherited colorectal cancer (CRC) syndrome. It constitutes the perfect model to understand DNA mismatch repair deficient (MMRd) carcinogenesis, which underlies 15% of early-stage CRC. LS patients develop MMRd tumors with high loads of shared neoantigens (neoAgs), which are recognized by the immune system. Previous research has concentrated on discovering neoAgs and their potential as targets for vaccines in LS patients. However, these studies have primarily identified shared neoAgs from cancers, lacking detailed information on targetable neoAgs present in precancerous lesions. Understanding this landscape of pre-cancer derived neoAgs is crucial for intercepting cancer development …

Uncovering Capillary Endothelial Cells Response During Lung Injury-Repair, Celine Shuet Lin Kong

Dissertations and Theses (Open Access)

Once thought to be a homogenous population, capillary endothelial cells (ECs) have embodied organotypic specialization and heterogenous properties, both during homeostasis and tissue injury. In the lung, capillary ECs consist of two distinct populations, CAP1 and CAP2s; how each population responds to diverse tissue injury is incompletely understood. In this thesis, I report the induction and function of a truncated isoform of Ntrk2, Ntrk2^-tk (lacking the tyrosine kinase domain) in multiple injury models. Using a combinatorial approach of single-cell multiome, mouse genetics and viral infection models, I found that Ntrk2^-tk is broadly induced in CAP1s after the initial …

Epigenetic Modification As A Therapeutic Target In Brafv600e-Mutated Metastatic Colorectal Cancer, Hey Min Lee

Dissertations and Theses (Open Access)

Patients with BRAF^V600E-mutated metastatic colorectal cancer (mCRC) experience a worse prognosis and demonstrate only a 5% response rate to BRAF inhibitor treatment. In this study, adaptive resistance, and a potential combination of standard therapies in BRAF^V600E CRC were unveiled. Intriguingly, a robust association of BRAF^V600E mutation and DNA hypermethylation suggests this is a unique subgroup harboring aberrant epigenetic phenotype. Firstly, DNA methyltransferase (DNMT) inhibitor treatment induced profound DNA hypomethylation in vivo, but minimal change in gene expression due to adaptive elevation of the repressive histone methylation, H3K27me3, leading to compensatory suppression of key tumor suppressor genes, …

The In4mer Crispr/Cas12a Multiplex Knockout Platform And Its Applications, Nazanin Esmaeili Anvar

Dissertations and Theses (Open Access)

Discovering synthetic lethal interactions between genes holds the key to uncovering cancer vulnerabilities, enabling the development of more effective drugs for patients. However, identifying these vulnerabilities in the complex genome of human, which comprises thousands of genes, poses a significant challenge. One alternative approach to investigate these interactions involves exploring enriched sources of synthetic lethal interactions, such as paralog pairs. In recent years, a couple of studies have conducted dual-gene knockout experiments on paralog pairs using different approaches to identify synthetic lethal interactions. In this study, we conducted a meta-analysis of CRISPR genetic interaction screens. We identified a candidate set …

Analyzing Extracellular Vesicles For Disease Monitoring In Metastatic Colorectal Cancer Patients, Vahid Bahrambeigi

Dissertations and Theses (Open Access)

Colorectal cancer (CRC) is the second leading cause of cancer deaths in the United States. Metastases are the main cause of cancer-related death, and the most frequent metastatic sites in patients with CRCs are liver and lung. To confirm the diagnosis of metastatic CRC (mCRCs) and to classify mCRCs, tumor biopsy of a suspected metastasis is often required. The consensus molecular subtype (CMS) classification which is based on gene expression profiles of CRC tumor specimens, is a predictive factor for treatment outcomes of standard chemotherapies for mCRCs. The practicality of repeated tumor biopsies for disease monitoring in mCRC patients is …

Landscape Of Ecdna-Borne Non-Coding Rnas In Glioblastoma, Dexin Yang

Dissertations and Theses (Open Access)

Recent advances in cancer genetics found that strong oncogene transcription can occur on a form of non-chromosome DNAs that is often amplified to tens or hundreds of copies, and that can exist in more than half of cancer types. This type of genetic material was termed extrachromosomal DNA (ecDNA). ecDNA appears to be epigenetically highly accessible and transcriptionally active compared with chromosomal DNA, which may partially underlie their critical roles in driving oncogene overexpression and cancer evolution. However, the full molecular mechanisms and regulators that confer the exceptional transcriptional activity of ecDNA-associated genes are incompletely understood.

Enhancers are key genetic …

Unique Transcriptional Profiles Underlie Osteosarcomagenesis Driven By Different P53 Mutants, Dhruv Chachad

Dissertations and Theses (Open Access)

Missense mutations in the DNA binding domain of the Trp53 gene are characterized as structural (p53R172H) or contact (p53R245W) mutations based on their effect on the conformation of the protein. These mutations show gain-of-function activities such as increased metastatic incidence as compared to p53 loss, often mediated by their interaction with a repertoire of transcription factors. These interactions are largely context specific. In order to understand the mechanisms by which these mutations drive osteosarcoma progression, we created a mouse model, wherein either the p53 structural mutant p53R172H, or the contact mutant, p53R245W, are expressed specifically in …

Reconstructing Mutational Lineages In Breast Cancer By Multi-Patient-Targeted Single Cell Dna Sequencing, Jake Leighton

Dissertations and Theses (Open Access)

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer with high rates of metastasis and recurrence, where TNBC patients have a poor 5-year survival and ~50% are non-responsive to chemotherapy. Aneuploidy is a cancer hallmark that is pervasive in over 90% of breast cancer patients and is indicative of complex genomic rearrangements that are acquired during tumor initiation. Although copy number aberrations have been extensively studied in relation to aneuploidy and TNBC initiation, little is currently known regarding the timing and impact of single nucleotide variants (SNVs) contributing to these early transformative genomic events. Paramount to novel …

Haplotype-Informed Allelic Imbalance Detection From Rna In Cancer, Zuhal Ozcan

Dissertations and Theses (Open Access)

Comprehensive genomic and transcriptomic characterization of tumors has uncovered enrichment for distinct aneuploidy and expression patterns, demonstrating the utility of molecular based classification of cancers and their subtypes. Existing cohorts with transcriptomic profiling from next-generation sequencing contain an untapped potential to also relate genomics with rich clinical phenotypes. Yet, derivation of somatic copy number and expression profiles from analyses of RNA has remained elusive. Further, DNA analysis in these cohorts is not always feasible due to limited tissue availability or financial constraints. Here, we present a statistical approach that overcomes these challenges using haplotype information to aid detection of somatic …

Decoding Copy Number Substructure And Evolution From Single Cell Genomics, Darlan Conterno Minussi

Dissertations and Theses (Open Access)

Aneuploidy is a prominent feature in Triple-Negative Breast Cancers (TNBC), however, the evolution of genotypes during tumor expansion remains poorly understood. The prevalent model of TNBC evolution is the Punctuated Copy Number Evolution (PCNE), in which tumors undergo a period of elevated genomic instability, acquiring complex genomic rearrangements within a short timeframe followed by clonal stasis. However, these observations rely on limited cell numbers and inherent experimental bias from first-generation single cell technologies. Therefore, the evolutionary trajectory after the punctuated burst remains unknown. To address this question, we sequenced 9,765 cells from 8 primary TNBCs and 6,413 cells from 4 …

Development Of Graphical Models And Statistical Physics Motivated Approaches To Genomic Investigations, Yashwanth Lagisetty

Dissertations and Theses (Open Access)

Identifying genes involved in disease pathology has been a goal of genomic research since the early days of the field. However, as technology improves and the body of research grows, we are faced with more questions than answers. Among these is the pressing matter of our incomplete understanding of the genetic underpinnings of complex diseases. Many hypotheses offer explanations as to why direct and independent analyses of variants, as done in genome-wide association studies (GWAS), may not fully elucidate disease genetics. These range from pointing out flaws in statistical testing to invoking the complex dynamics of epigenetic processes. In the …

Investigating The Ecology And Evolution Of Normal Breast Tissues And Breast Cancer With Single Cell Genomics, Tapsi Kumar, Tapsi Kumar

Dissertations and Theses (Open Access)

There is vast cellular heterogeneity in human breast tissues, with different transcriptional programs in the stromal, epithelial, and immune components, however, it remains unclear how their reprogramming and interplay leads to the progression of invasive phenotypes such as Triple- Negative Breast cancer (TNBC). To do define the microenvironmental alterations that occur during cancer, we first established a human breast cell atlas, a reference of normal breast cell types from disease free women. We profiled 535,941 cells from 62 women and 124,024 nuclei from 20 women revealing 11 major cell types and 52 cell states that reflect different biological functions that …

An Investigation Of Epigenetic Mechanisms Driving The Biology Of Head And Neck Squamous Cell Carcinoma, Scot Carson Callahan

Dissertations and Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide and is associated with significant morbidity and mortality. To date, the majority of work in the field has focused on genomic alterations such as mutations and copy number alterations. However, the clinical success of targeted therapies that exploit known genomic alterations, such as EGFR mutations, has remained mixed. Over the past decade, the importance of epigenetic regulators has come to the forefront, with the realization that many of these genes are mutated in cancer. Despite this realization, the role of epigenetics in regulating tumorigenesis, progression and …

Computational Approaches To Understand Chemoresistance & Tumor Evolution Using Longitudinal Clinical Data And Lineage Tracing, Sahil Seth

Dissertations and Theses (Open Access)

Tumors are highly heterogeneous and dynamic, continually adapting and evolving in response to their microenvironment as well as external perturbations. Multi-region (spatial) and single cell sequencing has enabled us to anatomize the heterogeneity further and provide evidence of its association with chemo and drug resistance. To investigate this further we took two different approaches to understand the chemo-resistance, and functional heterogeneity in Triple negative breast cancer (TNBC) and Pancreatic ductal carcinoma in situ (PDAC) from an evolutionary perspective.

The first approach was to leverage tumor profiling from an ongoing randomized clinical trial in triple-negative breast cancer (ARTEMIS) to assess mechanisms …

Rare Coding Variants In 35 Genes Associate With Circulating Lipid Levels-A Multi-Ancestry Analysis Of 170,000 Exomes, George Hindy, Peter Dornbos, Mark D Chaffin, Dajiang J Liu, Minxian Wang, Margaret Sunitha Selvaraj, David Zhang, Joseph Park, Carlos A Aguilar-Salinas, Lucinda Antonacci-Fulton, Diego Ardissino, Donna K Arnett, Stella Aslibekyan, Gil Atzmon, Christie M Ballantyne, Francisco Barajas-Olmos, Nir Barzilai, Lewis C Becker, Lawrence F Bielak, Joshua C Bis, John Blangero, Eric Boerwinkle, Lori L Bonnycastle, Erwin Bottinger, Donald W Bowden, Matthew J Bown, Jennifer A Brody, Jai G Broome, Noël P Burtt, Brian E Cade, Federico Centeno-Cruz, Edmund Chan, Yi-Cheng Chang, Yii-Der I Chen, Ching-Yu Cheng, Won Jung Choi, Rajiv Chowdhury, Cecilia Contreras-Cubas, Emilio J Córdova, Adolfo Correa, L Adrienne Cupples, Joanne E Curran, John Danesh, Paul S De Vries, Ralph A Defronzo, Harsha Doddapaneni, Ravindranath Duggirala, Susan K Dutcher, Patrick T Ellinor, Leslie S Emery, Jose C Florez, Myriam Fornage, Barry I Freedman, Valentin Fuster, Ma Eugenia Garay-Sevilla, Humberto García-Ortiz, Soren Germer, Richard A Gibbs, Christian Gieger, Benjamin Glaser, Clicerio Gonzalez, Maria Elena Gonzalez-Villalpando, Mariaelisa Graff, Sarah E Graham, Niels Grarup, Leif C Groop, Xiuqing Guo, Namrata Gupta, Sohee Han, Craig L Hanis, Torben Hansen, Jiang He, Nancy L Heard-Costa, Yi-Jen Hung, Mi Yeong Hwang, Marguerite R Irvin, Sergio Islas-Andrade, Gail P Jarvik, Hyun Min Kang, Sharon L R Kardia, Tanika Kelly, Eimear E Kenny, Alyna T Khan, Bong-Jo Kim, Ryan W Kim, Young Jin Kim, Heikki A Koistinen, Charles Kooperberg, Johanna Kuusisto, Soo Heon Kwak, Markku Laakso, Leslie A Lange, Jiwon Lee, Juyoung Lee, Seonwook Lee, Donna M Lehman, Rozenn N Lemaitre, Allan Linneberg, Jianjun Liu, Ruth J F Loos, Steven A Lubitz, Valeriya Lyssenko, Ronald C W Ma, Lisa Warsinger Martin, Angélica Martínez-Hernández, Rasika A Mathias, Stephen T Mcgarvey, Ruth Mcpherson, James B Meigs, Thomas Meitinger, Olle Melander, Elvia Mendoza-Caamal, Ginger A Metcalf, Xuenan Mi, Karen L Mohlke, May E Montasser, Jee-Young Moon, Hortensia Moreno-Macías, Alanna C Morrison, Donna M Muzny, Sarah C Nelson, Peter M Nilsson, Jeffrey R O'Connell, Marju Orho-Melander, Lorena Orozco, Colin N A Palmer, Nicholette D Palmer, Cheol Joo Park, Kyong Soo Park, Oluf Pedersen, Juan M Peralta, Patricia A Peyser, Wendy S Post, Michael Preuss, Bruce M Psaty, Qibin Qi, D C Rao, Susan Redline, Alexander P Reiner, Cristina Revilla-Monsalve, Stephen S Rich, Nilesh Samani, Heribert Schunkert, Claudia Schurmann, Daekwan Seo, Jeong-Sun Seo, Xueling Sim, Rob Sladek, Kerrin S Small, Wing Yee So, Adrienne M Stilp, E Shyong Tai, Claudia H T Tam, Kent D Taylor, Yik Ying Teo, Farook Thameem, Brian Tomlinson, Michael Y Tsai, Tiinamaija Tuomi, Jaakko Tuomilehto, Teresa Tusié-Luna, Miriam S Udler, Rob M Van Dam, Ramachandran S Vasan, Karine A Viaud Martinez, Fei Fei Wang, Xuzhi Wang, Hugh Watkins, Daniel E Weeks, James G Wilson, Daniel R Witte, Tien-Yin Wong, Lisa R Yanek, Amp-T2d-Genes, Myocardial Infarction Genetics Consortium, Nhlbi Trans-Omics For Precision Medicine (Topmed) Consortium, Nhlbi Topmed Lipids Working Group, Sekar Kathiresan, Daniel J Rader, Jerome I Rotter, Michael Boehnke, Mark I Mccarthy, Cristen J Willer, Pradeep Natarajan, Jason A Flannick, Amit V Khera, Gina M Peloso

Faculty, Staff and Student Publications

Large-scale gene sequencing studies for complex traits have the potential to identify causal genes with therapeutic implications. We performed gene-based association testing of blood lipid levels with rare (minor allele frequency < 1%) predicted damaging coding variation by using sequence data from >170,000 individuals from multiple ancestries: 97,493 European, 30,025 South Asian, 16,507 African, 16,440 Hispanic/Latino, 10,420 East Asian, and 1,182 Samoan. We identified 35 genes associated with circulating lipid levels; some of these genes have not been previously associated with lipid levels when using rare coding variation from population-based samples. We prioritize 32 genes in array-based genome-wide association study (GWAS) loci based on aggregations of rare coding variants; three (EVI5, …

Unveiling Global Roles Of G-Quadruplexes And G4-22 In Human Genetics, Ruth Barros De Paula

Dissertations and Theses (Open Access)

G-quadruplexes are non-B DNA structures formed by four or more runs of repeated guanines that confer unique features to living organism’s genomes. These sequences are enriched in regulatory regions, such as promoters and 5’ UTRs, and have distinct regulatory roles in both health and disease states. Even though previous studies showed the impact of G4 in gene expression, none of them summarized the location-specific effect of G4. Also, there is no broad understanding about the most common G4 repeat in the human genome, named here as G4-22, and how it links to the evolution of mammals and their biology. In …

Impact Of Intratumor Heterogeneity And The Tumor Microenvironment In Shaping Tumor Evolution And Response To Therapy, Akash Mitra

Dissertations and Theses (Open Access)

Intratumor heterogeneity (ITH) is a crucial challenge in cancer treatment. The genotypic and phenotypic heterogeneity underlying diverse cancer types leads to subclonal variation, which may result in mixed or failed response to therapy. The heterogeneity at the tumor level, along with the tumor microenvironment (TME), often shapes tumor evolution and ultimately clinical outcome. Given that modern treatment paradigms increasingly expose patients with metastatic disease to multiple treatment modalities through the course of their disease, there exists a need to characterize robust and predictive biomarkers of response to therapy. In order to accurately characterize tumor evolution, we need to account for …

Biases And Blind-Spots In Genome-Wide Crispr-Cas9 Knockout Screens, Merve Dede

Dissertations and Theses (Open Access)

Adaptation of the bacterial CRISPR-Cas9 system to mammalian cells revolutionized the field of functional genomics, enabling genome-scale genetic perturbations to study essential genes, whose loss of function results in a severe fitness defect. There are two types of essential genes in a cell. Core essential genes are absolutely required for growth and proliferation in every cell type. On the other hand, context-dependent essential genes become essential in an environmental or genetic context. The concept of context-dependent gene essentiality is particularly important in cancer, since killing cancer cells selectively without harming surrounding healthy tissue remains a major challenge. The toxicity of …

Computational Approaches To Delineate Transcriptional And Functional Heterogeneity In Pancreatic Cancer, Sanjana Srinivasan

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is an incurable disease characterized by poor survival, dense desmoplastic stroma and activating mutations in KRAS (>90%). These tumors are highly complex ecosystems composed of molecularly distinct sub-populations that exhibit a spectrum of genetic features and associated phenotypes. Despite recent advances in the transcriptomic characterization of PDAC into at least two tumor subtypes, this alone has been insufficient to define more specific patterns of oncogenic dependency. To fully leverage advancements in next generation sequencing and functional genomics, we have sought to establish computational methodologies to aid in refined target discovery, and to develop a novel …

Rare Variant Association Studies In Crohn’S Disease And Colorectal Cancer: Methods And Applications, Jiun-Sheng Chen

Dissertations and Theses (Open Access)

Genetic factors account for a substantial portion of Crohn’s disease and colorectal cancer (CRC) risk. Patients with Crohn’s disease, a condition that causes chronic inflammation of the gastrointestinal tract, are at increased risk of colorectal cancer morbidity and mortality. Genome-wide association studies using single marker approaches have identified loci responsible for these diseases, but disease susceptibility from rare variants is incompletely understood. This dissertation includes three chapters, two association studies for Crohn’s disease and CRC, and a statistical method to improve the power of statistical tests.

For Crohn’s disease, we performed targeted sequencing of 101 genes in 205 children with …

Decoding The Evolutionary Response To Prostate Cancer Therapy Using Plasma Genome Sequencing, Naveen Ramesh

Dissertations and Theses (Open Access)

Investigating genome evolution in response to therapy is difficult in human tissue samples due to the difficulty in accessing metastatic tumor sites and logistical challenges of collecting longitudinal samples. To overcome these issues, we developed an unbiased whole-genome plasma DNA sequencing approach called PEGASUS that concurrently measures genomic copy number and exome mutations from archival cryostored plasma samples. This approach was applied to study longitudinal blood plasma samples from prostate cancer patients. A molecular characterization of archival plasma DNA from 233 patients and genomic profiling of 101 patients identified clinical correlations of aneuploid plasma DNA profiles with poor survival, increased …

Investigation Of Proliferation Suppressors In Genetic Fitness Screens, Walter Frank Lenoir Iv

Dissertations and Theses (Open Access)

Innovation of CRISPR gene-editing technology has provided scientists genome manipulation tools that allowed rapid advancement of scientific capabilities and thus improved our ability to systematically study mammalian genetic functional profiles. Genome-wide CRISPR knockout screens conducted in collections of human cell lines can knock out genes at multiple loci, and have provided new insights into functional roles for independent genes. This method has launched massive efforts in looking across genetic backgrounds for context specific genetic vulnerabilities within cancer. Much of the research effort thus far has been spent on optimizing phenotype distinctions between essential, genes required for cell fitness, and non-essential, …