Medical Genetics Commons^™

The Role Of The Rx3/ Otx Pathway In Zebrafish Eye Development, Navaneetha Krishnan Bharathan

Theses and Dissertations

Colobomas are a type of eye defect characterized by the presence of a hole in certain eye structures. In this study, the roles of the zebrafish Otx genes, otx2 and otx1a, as well as the Rx family gene, rx3, in choroid fissure closure, the disruption of which leads to the onset of colobomas, were studied. It was observed that while the otx2 loss-of-function mutant, otx2hu3237 displayed small colobomas and the otx1a mutant, otx1a6del, did not exhibit any morphological eye defects, zebrafish possessing both mutations presented with a range of colobomas, some of which were more severe than otx2 single mutants …

Comprehensive Review On The Existence Of Genomic Imprinting In Aves, Derek Gygax

Theses and Dissertations

Genomic imprinting results in monoallelic parent-of-origin gene expression. Therian mammals show conclusive evidence for imprinting, while the evidence in Aves is conflicting. It’s unclear if Aves have the proteins necessary for establishment and maintenance of imprinting loci. Every examined avian orthologue to mammalian imprinted genes shows biallelic expression providing evidence for a lack of imprinting in Aves. While the known parent-of-origin quantitative trait loci in chicken do not overlap with differentiated methylated regions, further analysis with a larger sample size is required. No transcript in the chicken transcriptome at incubation day 4.5 shows parent-of-origin expression, providing strong evidence for a …

D_Cdf Test Of Negative Log Transformed P-Values With Application To Genetic Pathway Analysis, Hongying Dai, Richard Charnigo

Manuscripts, Articles, Book Chapters and Other Papers

In genetic pathway analysis and other high dimensional data analysis, thousands and millions of tests could be performed simultaneously. p-values from multiple tests are often presented in a negative log-transformed format. We construct a contaminated exponential mixture model for −ln(P) and propose a D_CDF test to determine whether some −ln(P) are from tests with underlying effects. By comparing the cumulative distribution functions (CDF) of −ln(P) under mixture models, the proposed method can detect the cumulative effect from a number of variants with small effect sizes. Weight functions and truncations can be incorporated to the D_CDF test to improve power and …

Analysis Of The Regulation And Function Of Cip2a To Identify Candidate Biomarkers For Prostate Cancer, Diana Savoly

Graduate School of Biomedical Sciences Theses and Dissertations

Protein Phosphatase 2A (PP2A) is a tumor suppressor involved in the regulation of several signaling pathways and the cell cycle. PP2A becomes inactivated by several inhibitors, including Cancerous Inhibitor of PP2A (CIP2A). CIP2A has been identified as an oncogene, which is over-expressed in cancers and inhibits PP2A through direct interaction. CIP2A is recognized as a biomarker for cancer; however, it is not cancer-specific. Therefore, we identified and examined the use of CIP2A-regulated proteins as potential biomarkers in prostate cancer to better diagnose prostate cancer in patients. Currently, Prostate Specific Antigen (PSA) is widely used to detect prostate cancer; however, it …

Relating The Metatranscriptome And Metagenome Of The Human Gut, Eric A. Franzosa, Xochitl C. Morgan, Nicola Segata, Levi Waldron, Joshua Reyes, Ashlee M. Earl, Georgia Giannoukos, Matthew R. Boylan, Dawn Ciulla, Dirk Gevers, Jacques Izard, Wendy S. Garrett, Andrew T. Chan, Curtis Huttenhower

Department of Food Science and Technology: Faculty Publications

Although the composition of the human microbiome is now well-studied, the microbiota’s > 8 million genes and their regulation remain largely uncharacterized. This knowledge gap is in part because of the difficulty of acquiring large numbers of samples amenable to functional studies of the microbiota. We conducted what is, to our knowledge, one of the first human microbiome studies in a well-phenotyped prospective cohort incorporating taxonomic, metagenomic, and metatranscriptomic profiling at multiple body sites using self-collected samples. Stool and saliva were provided by eight healthy subjects, with the former preserved by three different methods (freezing, ethanol, and RNAlater) to validate self-collection. …

Metabotropic Glutamate Receptor-1 As A Novel Target For The Antiangiogenic Treatment Of Breast Cancer, Cecilia L. Speyer, Ali H. Hachem, Ali A. Assi, Jennifer S. Johnson, John Austin Devries, David H. Gorski

Department of Surgery

Metabotropic glutamate receptors (mGluRs) are normally expressed in the central nervous system, where they mediate neuronal excitability and neurotransmitter release. Certain cancers, including melanoma and gliomas, express various mGluR subtypes that have been implicated as playing a role in disease progression. Recently, we detected metabotropic glutamate receptor-1 (gene: GRM1; protein: mGluR1) in breast cancer and found that it plays a role in the regulation of cell proliferation and tumor growth. In addition to cancer cells, brain endothelial cells express mGluR1. In light of these studies, and because angiogenesis is both a prognostic indicator in cancer correlating with a poorer …

Celiac Disease As A Model For The Evolution Of Multifactorial Disease In Humans, Aaron Sams, John Hawks

Human Biology Open Access Pre-Prints

Celiac disease (CD) is a multifactorial chronic inflammatory condition that results in injury of the mucosal lining of the small intestine upon ingestion of wheat gluten and related proteins from barley and rye. Although the exact mechanisms leading to CD are not fully understood, the genetic basis of CD has been relatively well characterized. In this review we briefly review the history of discovery, clinical presentation, pathophysiology, and current understanding of the genetics underlying CD risk. Then, we discuss what is known about the current distribution and evolutionary history of genes underlying CD risk in light of other evolutionary models …

Towards A Better Treatment Of Parkinson's Disease, Bradley Darryl Karain

Loma Linda University Electronic Theses, Dissertations & Projects

Current therapies for Parkinson's Disease, the second most common neurodegenerative disorder, do not prevent disease progression, and induce extremely detrimental side-effects. Improving the best current pharmacological therapy, L-DOPA, carries important clinical benefits, partly by reducing the dose-related side-effects which occur after five to ten years of use. Thus the central aim of this proposal is to determine whether low doses of a D2 antagonist may, by selectively blocking the dopamine autoreceptor-mediated feedback inhibition of dopamine neurons, potentiate L-DOPA's effect on individual basal ganglia neurons and its antiparkinsonian effects in Parkinsonian animals. Electrophysiology (extracellular single-cell recording in the globus pallidus) and …

Retinoic Acid Regulation Of Thyroid Hormone Action In Bone Cells, Anjali Babbar

Loma Linda University Electronic Theses, Dissertations & Projects

Retinoic acid and thyroid hormone are known to play key roles in the regulation of endochondral ossification. However, the issue of whether these two hormones interact with each other to regulate bone functions remains to be established. We investigated how thyroid hormone and retinoic acid interact to regulate cells involved in endochondral bone formation. We demonstrate that thyroid hormone treatment stimulates differentiation of ATDC5 chondrocytes and promotes formation of mineralized nodules while retinoic acid treatment at high dose inhibits chondrocyte differentiation and formation of mineralized nodules. Furthermore, thyroid hormone induced mineralized nodule formation is inhibited by co-treatment with retinoic acid …

Genetics Of Peripheral Vestibular Dysfunction: Lessons From Mutant Mouse Strains, Sherri M. Jones, Timothy A. Jones

Department of Special Education and Communication Disorders: Faculty Publications

Background

A considerable amount of research has been published about genetic hearing impairment. Fifty to sixty percent of hearing loss is thought to have a genetic cause. Genes may also play a significant role in acquired hearing loss due to aging, noise exposure, or ototoxic medications. Between 1995 and 2012, over 100 causative genes have been identified for syndromic and nonsyndromic forms of hereditary hearing loss (see Hereditary Hearing Loss Homepage http://hereditaryhearingloss.org). Mouse models have been extremely valuable in facilitating the discovery of hearing loss genes, and in understanding inner ear pathology due to genetic mutations or elucidating fundamental mechanisms …

A Modified Generalized Fisher Method For Combining Probabilities From Dependent Tests., Hongying Dai, J Steven Leeder, Yuehua Cui

Manuscripts, Articles, Book Chapters and Other Papers

Rapid developments in molecular technology have yielded a large amount of high throughput genetic data to understand the mechanism for complex traits. The increase of genetic variants requires hundreds and thousands of statistical tests to be performed simultaneously in analysis, which poses a challenge to control the overall Type I error rate. Combining p-values from multiple hypothesis testing has shown promise for aggregating effects in high-dimensional genetic data analysis. Several p-value combining methods have been developed and applied to genetic data; see Dai et al. (2012b) for a comprehensive review. However, there is a lack of investigations conducted for dependent …

Human And Helicobacter Pylori Coevolution Shapes The Risk Of Gastric Disease, Nuri Kodaman, Alvaro Pazos, Barbara G. Schneider, M. Blanca Piazuelo, Robertino Mera, Rafal S. Sobota

Dartmouth Scholarship

Helicobacter pylori is the principal cause of gastric cancer, the second leading cause of cancer mortality worldwide. However, H. pylori prevalence generally does not predict cancer incidence. To determine whether coevolution between host and pathogen influences disease risk, we examined the association between the severity of gastric lesions and patterns of genomic variation in matched human and H. pylori samples. Patients were recruited from two geographically distinct Colombian populations with significantly different incidences of gastric cancer, but virtually identical prevalence of H. pylori infection. All H. pylori isolates contained the genetic signatures of multiple ancestries, with an ancestral African cluster …

Metabotropic Glutamate Receptor-1 Contributes To Progression In Triple Negative Breast Cancer, Malathi Banda, Cecilia L. Speyer, Sara N. Semma, Kingsley O. Osuala, Nicole Kounalakis, Keila E. Torres Torres, Nicola J. Barnard, Hyunjin J. Kim, Bonnie F. Sloane, Fred R. Miller, James S. Goydos, David H. Gorski

Department of Surgery

TNBC is an aggressive breast cancer subtype that does not express hormone receptors (estrogen and progesterone receptors, ER and PR) or amplified human epidermal growth factor receptor type 2 (HER2), and there currently exist no targeted therapies effective against it. Consequently, finding new molecular targets in triple negative breast cancer (TNBC) is critical to improving patient outcomes. Previously, we have detected the expression of metabotropic glutamate receptor-1 (gene: GRM1; protein: mGluR1) in TNBC and observed that targeting glutamatergic signaling inhibits TNBC growth both in vitro and in vivo. In this study, we explored how mGluR1 contributes to TNBC …

A New Rhesus Macaque Assembly And Annotation For Next-Generation Sequencing Analyses, Aleksey V. Zimin, Adam S. Cornish, Mnirnal D. Maudhoo, Robert M. Gibbs, Xiongfei Zhang, Sanjit Pandey, Daniel T. Meehan, Kristin Wipfler, Steven E. Bosinger, Zachary P. Johnson, Gregory K. Tharp, Guillaume Marçais, Michael Roberts, Betsy Ferguson, Howard S. Fox, Todd Treangen, Steven L. Salzberg, James A. Yorke, Robert B. Norgren Jr.

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: The rhesus macaque (Macaca mulatta) is a key species for advancing biomedical research. Like all draft mammalian genomes, the draft rhesus assembly (rheMac2) has gaps, sequencing errors and misassemblies that have prevented automated annotation pipelines from functioning correctly. Another rhesus macaque assembly, CR_1.0, is also available but is substantially more fragmented than rheMac2 with smaller contigs and scaffolds. Annotations for these two assemblies are limited in completeness and accuracy. High quality assembly and annotation files are required for a wide range of studies including expression, genetic and evolutionary analyses.

RESULTS: We report a new de novo assembly of the …

Complement Expression In The Retina Is Not Influenced By Short-Term Pressure Elevation, Konstantin Astafurov, Cecilia Q. Dong, Lampros Panagis, Gautam Kamtham, Lizhen Ren, Anna Rozenboym, Tarique D. Perera, Jeremy D. Coplan, John Danias

Publications and Research

Purpose: To determine whether short-term pressure elevation affects complement gene expression in the retina in vitro and in vivo.

Methods: Muller cell (TR-MUL5) cultures and organotypic retinal cultures from adult mice and monkeys were sub- jected to either 24-h or 72-h of pressure at 0, 15, 30, and 45 mmHg above ambient. C57BL/6 mice were subjected to microbead-induced intraocular pressure (IOP) elevation for 7 days. RNA and protein were extracted and used for analysis of expression levels of complement component genes and complement component 1, q subcomponent (C1q) and comple- ment factor H (CFH) immunoblotting. …

Mapping Genes With Longitudinal Phenotypes Via Bayesian Posterior Probabilities, Anthony Musolf, Alejandro Q. Nato Jr., Douglas Londono, Lisheng Zhou, Tara C. Matise, Derek Gordon

Biochemistry and Microbiology

Most association studies focus on disease risk, with less attention paid to disease progression or severity. These phenotypes require longitudinal data. This paper presents a new method for analyzing longitudinal data to map genes in both population-based and family-based studies. Using simulated systolic blood pressure measurements obtained from Genetic Analysis Workshop 18, we cluster the phenotype data into trajectory subgroups. We then use the Bayesian posterior probability of being in the high subgroup as a quantitative trait in an association analysis with genotype data. This method maintains high power (>80%) in locating genes known to affect the simulated phenotype …

Computational Analysis Of Transcriptional Circuitries In Human Embryonic Stem Cells Reveals Multiple And Independent Networks, Xiaosheng Wang, Chittibabu Guda

Journal Articles: Genetics, Cell Biology & Anatomy

It has been known that three core transcription factors (TFs), NANOG, OCT4, and SOX2, collaborate to form a transcriptional circuitry to regulate pluripotency and self-renewal of human embryonic stem (ES) cells. Similarly, MYC also plays an important role in regulating pluripotency and self-renewal of human ES cells. However, the precise mechanism by which the transcriptional regulatory networks control the activity of ES cells remains unclear. In this study, we reanalyzed an extended core network, which includes the set of genes that are cobound by the three core TFs and additional TFs that also bind to these cobound genes. Our results …

Phosphatidylinositol 3-Kinase (Pi3k) As A Therapeutic Target In Nsclc, Christopher W. Stamatkin

Theses and Dissertations--Pharmacy

Deregulated activation of phosphatidylinositol 3-kinase (PI3K) pathway is central to many human malignancies. The functions of this pathway are critical for normal cell metabolism, proliferation, and survival. In lung cancers, the PI3K pathway activity is often aberrantly driven by multiple mutations, including EGFR, KRAS, and PIK3CA. Molecules targeting the PI3K pathway are intensely investigated as potential anti-cancer agents. Although inhibitors of the pathway are currently in clinical trials, rational and targeted use of these compounds, alone or in combination, requires an understanding of isoform-specific activity in context. We sought to identify class IA PI3K enzyme (p110a/PIK3CA, p110b/PIK3CB, p110d/PIK3CD) activities using …

Expression And Splicing Of Alzheimer’S Disease Risk Gene Phosphatidylinositol-Binding Clathrin Assembly Protein, Ishita Parikh

Theses and Dissertations--Physiology

Recent Genome Wide Association Studies (GWAS) have identified a series of single nucleotide polymorphism (SNP)s that are associated with Alzheimer’s disease (AD). One of the SNPs, rs3851179 (G/A), is near the gene phosphatidylinositol-binding clathrin assembly protein (PICALM). To evaluate whether this SNP is associated with PICALM expression, we quantified PICALM mRNA in 56 brain cDNA samples. Using linear regression analysis, we analyzed PICALM expression relative to rs3851179, AD status, and cell type specific markers. An association was detected between rs3851179 and PICALM, microvessel mRNA, glial fibrillary acidic protein (GFAP) mRNA, and synaptophysin (SYN) mRNA. To gain clarity …

Structure-Functional Prediction And Analysis Of Cancer Mutation Effects In Protein Kinases, Anshuman Dixit, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

A central goal of cancer research is to discover and characterize the functional effects of mutated genes that contribute to tumorigenesis. In this study, we provide a detailed structural classification and analysis of functional dynamics for members of protein kinase families that are known to harbor cancer mutations. We also present a systematic computational analysis that combines sequence and structure-based prediction models to characterize the effect of cancer mutations in protein kinases. We focus on the differential effects of activating point mutations that increase protein kinase activity and kinase-inactivating mutations that decrease activity. Mapping of cancer mutations onto the conformational …

Chemopreventive Effects Of Pterostilbene In Metastatic Prostate Cancer Cells, Phillip A. Zook

PCOM Biomedical Studies Student Scholarship

Recent studies find that pterostilbene (PTS) exhibits more favorable drug properties and similar chemopreventive effects to its structural analogue resveratrol (RSV). However, few studies describe the activity of PTS in prostate cancer (PCa). Here, we conducted cell count experiments to assess the effects of PTS on metastatic PCa cell viability and to compare the potency of PTS to RSV in this respect. We also performed experiments to assess the effects of PTS on the androgen receptor (AR) and AR-mediated events. We used qPCR to measure the mRNA levels of the androgenresponsive gene (ARG), prostate-specific antigen (PSA), and Western blots to …

Parp Inhibition: A Method Of Treating And Preventing Certain Cancers, Chana Tropper

The Science Journal of the Lander College of Arts and Sciences

Breast cancer is one of the largest causes of cancer related deaths in women. Less than 5% of breast cancer cases are genetically inherited and most often develop after menopause. The BRCA gene mutation is a genetic inheritance which increases ones chances of developing breast cancer at a young age tenfold. Recent research has proposed a method of treatment in genetically inherited breast cancers by taking advantage of the impaired DNA repair pathway caused by the BRCA mutation. The combination of a BRCA mutation, which leads to deficient double strand DNA repair, and PARP inhibition, which leads to deficient single …

Conformational Changes And Translocation Of Tissue-Transglutaminase To The Plasma Membranes: Role In Cancer Cell Migration, Ambrish Kumar, Jianjun Hu, Holly A. Lavoie, Kenneth B. Walsh, Donald J. Dipette, Ugra S. Singh

Faculty Publications

Background

Tissue-transglutaminase (TG2), a dual function G-protein, plays key roles in cell differentiation and migration. In our previous studies we reported the mechanism of TG2-induced cell differentiation. In present study, we explored the mechanism of how TG2 may be involved in cell migration.

Methods

To study the mechanism of TG2-mediated cell migration, we used neuroblastoma cells (SH-SY5Y) which do not express TG2, neuroblastoma cells expressing exogenous TG2 (SHY_TG2), and pancreatic cancer cells which express high levels of endogenous TG2. Resveratrol, a natural compound previously shown to inhibit neuroblastoma and pancreatic cancer in the animal models, was utilized to …

Hypothesis Testing In Normal Admixture Models To Detect Heterogeneous Genetic Signals, Qian Fan, Richard Charnigo, Zohreh Talebizadeh, Hongying Dai

Manuscripts, Articles, Book Chapters and Other Papers

In this work we consider a three-component normal mixture model in which one component is known to have mean zero and the other two contaminating components have a nonnegative and a nonpositive mean respectively, while all three components share a common unknown variance parameter. One potential application of this model may be in prioritizing statistical scores obtained in biological experiments, including genetics data. Such a mixture model may be useful in describing the distribution of numerous Z test statistics corresponding to different genes or SNPs, such that a “significant” Z test statistic for a particular gene suggests its connection to …

The Roles Of Krüppel-Like Factor 1 (Klf1) In The Human Fetal Erythroid Compartment., Safa Mohamad

Theses and Dissertations

Erythroid Krüppel-like factor (EKLF or KLF1) is a transcription factor with roles in embryonic and adult erythropoiesis. KLF1 knockout mouse embryos die due to severe anemia. Dominant human mutations in KLF1 can cause hereditary persistence of fetal hemoglobin. We show that KLF1 positively regulates β-globin and Bcl11A gene expression using KLF1 knockdown in in vitro-differentiated CD34+ human umbilical cord blood cells. -globin expression appears dependent on KLF1; it is increased with modest KLF1 knockdown but not in cells with low KLF1. KLF2 mRNA amounts are usually increased in KLF1 knockdown. KLF1 knockdown in CD34+ cells results in reduced colony forming …

Novel Therapeutic Strategies For Pancreatic Cancer, Bridget A. Quinn

Theses and Dissertations

Pancreatic cancer is a devastating disease that leaves patients with a very poor prognosis and few therapeutic options. Many of the treatment options available are the same that have been used for almost 2 decades. There is a dire need for both novel treatments for this disease as well as novel strategies of treatment. This body of work will introduce and provide evidence in support of a novel combination therapy for pancreatic cancer treatment, a novel strategy of modifying currently used chemotherapeutics for pancreatic cancer therapy, and a novel transgenic preclinical mouse model of pancreatic cancer. Sabutoclax, an antagonist of …

Future Oversight Of Recombinant Dna Research: Recommendations Of An Institute Of Medicine Committee, Lawrence O. Gostin, Bruce M. Altevogt, Andrew M. Pope

Georgetown Law Faculty Publications and Other Works

The National Institutes of Health (NIH) established the Recombinant DNA Advisory Committee (RAC) in 1974 in response to public concerns about the safety of manipulating genetic material through recombinant DNA. The accumulation of 40 years of experience with gene transfer research has led to a better understanding of the risks. Yet, as gene transfer research has matured, the complexity of the overall regulatory environment has remained. Gene transfer research continues to be subjected to multiple layers of review: the Food and Drug Administration (FDA), institutional review boards, institutional biosafety committees, and the RAC. It is within the context of overlapping …