• Gamma-diketone neuropathy : evaluation of the energy hypothesis

      Pearson, Jerry K; Department of Anatomy (1988-12)
    • [Gamma]-glutamyl transferase from hog kidney

      Pace, Judith Lee; Department of Cell and Molecular Biology (1970-05)
    • A Gata Ten Motif Found in the b-Globin LCR Possesses Insulator and Silencer Properties

      Ramchandran, Ramani; Department of Biochemistry and Molecular Biology (1997-08)
      In gene transfer experiments, transgene expression has been reported to be influenced by host sequences proximal to the integration sites. Such influences have been referred to as position effect of gene expression or position effect variegation (PEV) (Milot et al., 1996). The position effect (PEV) poses significant problems in the study of transgene regulation. However, studies on the human P-globin gene locus have shown that a 20 kb Locus Control Region (LCR) shields a as-linked transgene from position effects and thus confers position-independent expression of the transgene in transgenic mice (Grosveld et al., 1987). The LCR regulates the expression of the far downstream ay-linked P-like globin genes during erythroid development (Townes et al., 1985; Behringer et al., 1990; Enver et al., 1990). The 20 kb P-LCR is defined by four erythroid specific, DNase I hypersensitive sites, HS1, 2, 3, 4 and a unique HS5 site (Tuan et al., 1985; Forrester et al., 1987; Grosveld et al., 1987; Dhar et al., 1990). The unique HS5 site is located upstream of the HS 1-4 sites, at the apparent 5' border of the LCR (Tuan et al., 1985; Dhar et al., 1990). Like the boundary element of the chicken lysozyme gene (Steif et al., 1989), the HS5 site is located in a span of DNA found to be associated with the nuclear scaffold (Jarman et al., 1988). More recently, a 3 kb DNA fragment containing the HS5 site has been reported to possess insulator activity (Li et al., 1994; Yu et al., 1994). Insulators are DNA sequence elements that block activation of a promoter by an enhancer, but only when placed between them (Eissenberg et al., 1991). When placed upstream of an enhancer, an insulator shields transgene expression from position effects. HS5 fits this definition. When used to flank 5' or 3' of a transgene in transfected plasmids, the 3 kb HS5 fragment was capable of shielding the expression of the transgene from interference by host DNA proximal to the integration sites. Furthermore, when interposed between the promoter and enhancer of the transgene, the HS5 fragment was found to block enhancer-promoter communication, thus repressing the activity of the m-linked enhancer (Chung et al., 1993; Li et al., 1994). The properties of the HS5 fragment are similar to the insulator activity of the scs (Kellum et al., 1991; 1992) and gypsy (Cai and Levine, 1995; Roseman et al., 1993) elements of Drosophila and the A element of the chicken lysozyme gene locus (Steif et al., 1989). DNA Sequencing of the region between HS5 and HS4 has revealed a 40 bp DNA which consists of ten tandem GATA motifs found within 1 kb 3' of HS5 in the human genome (Figure 1). The (GATA)10 motif is unique in the 73 kb P-like globin gene domain, using a computer-aided analysis designed by Hardison et al. (1994). This (GATA)10 motif was named 5a. The question under study is whether or not the 5a sequence located proximal to HS5 contributes to the insulator function of HS5. In this study, we sought to characterize the function of 5a in recombinant plasmids, using transient and stable transfection assays. The experimental results show that: 1. When 5a was spliced either upstream or downstream of the HS2 enhancer in recombinant CAT plasmids, it repressed enhancer activity in erythroid K562 and HEL cells. 2. In non-erythroid N-Tera cells, 5a repressed HS2 enhancer activity when it was spliced upstream of the HS2 enhancer; however, 5a activated the HS2 enhancer when it was spliced downstream of the enhancer. 3. Further, the 5a sequence also possessed silencer activity (Brand et al., 1985). When spliced upstream of the promoter of the housekeeping phosphoglycerate kinase gene (Adra et al., 1987) in the enhancer-less plasmid, 5a did not activate but repressed promoter activity in both erythroid and non-erythroid cells. 4. Electrophoretic mobility shift assays using both K562 and N-Tera nuclear extracts showed that the 5a sequence is bound by the transcription factor GATA-1 but not detectably by GATA-2. 5. Also, mutation of the GATA motifs in the 5a sequence from a Head-Tail to a Head-Head orientation did not alter the function of the 5a sequence but affected the binding affinity for the GATA-1 transcription factor. The results suggest that in erythroid K562 and HEL cells the 5a sequence possesses both insulator and silencer activities and that transcription factor GATA-1 bound at 5a is a repressor of the cfr-linked promoter and the HS2 enhancer. From these findings we conclude that the 5a/GATA-l complex represses the activities of a proximal promoter and enhancer and contributes to the observed insulator activity of the HS5 fragment.
    • Gene regulation by the putative Campylobacter jejuni diguanylate cyclase CbrR

      Fulmer, Claudia; Department of Biochemistry and Cancer Biology (Augusta University, 2020-05)
      As a leading cause of bacterial gastroenteritis, Campylobacter jejuni incurs health care costs estimated at $290 million a year in the US and up to 40,000 deaths in children aged 5 and younger worldwide. As such, determining those proteins that regulate C. jejuni virulence factors are prime targets to possibly develop a prophylactic therapy, that as of yet does not exist. CbrR is a C. jejuni response regulator that is annotated as a diguanylate cyclase (DGC), the class of enzyme that catalyzes the synthesis of cyclic di-GMP, a universal bacterial second message molecule, from GTP. In C. jejuni strain DRH212, an unmarked deletion mutant, cbrR-, and complemented mutant, cbrR+, were constructed. Soft agar motility tests, biofilm formation assays, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were performed. Site-directed mutagenesis was performed on cbrR to make alanine substitutions in both the autoinhibitory site (I-site) and active site and differential radial capillary of action ligand (DRaCALA) assays were performed to determine nucleotide binding by wild-type CbrR and the CbrR point mutants. Soft agar motility assays indicated a hyper-motile phenotype associated with the C. jejuni cbrR- mutant, whereas motility was all but negated in the cbrR+ complement. Biofilm assays and SEM demonstrated similar formation and robustness of biofilms between wild type and cbrR- mutant, however cbrR+ was unable to form significant biofilms in 72 hours. TEM images showed similar cellular morphology between cbrR-, wild type, and cbrR+, however cbrR+ cells had fewer flagella. DRaCALA assays showed wild-type CbrR and the active site mutant were both able to bind GTP and cyclic di-GMP, whereas the I-site mutant lost the ability to bind cyclic di-GMP, indicating the product binding site on CbrR. The highly conserved diguanylate cyclase CbrR is the only annotated DGC in the C. jejuni genome. Though the active site sequence is highly variant when compared to the consensus sequence, this protein is able to bind both substrate and product of the chemical synthesis of cyclic di-GMP and has now been shown to be a negative regulator of motility, a critical virulence factor in C. jejuni pathogenesis.
    • Gene-Environment Interaction Modulates Schizophrenic Endophenotypes in Heterozygous Reeler Mice

      Howell, Kristy R.; Department of Psychiatry and Health Behavior (2013-07)
      Aim 1: To determine the effect of chronic stress on the VEGF signaling pathway. Aim 2: To determine the effects of prenatal hypoxia on VEGF signaling, behavioral activities, blood flow, and brain volume in heterozygous reeler mice during early adulthood. Aim 3: To evaluate long lasting effects of prenatal hypoxia on VEGF signaling, behavioral activities, blood flow, and brain volume in heterozygous reeler mice. Aim 4: To determine the correlation between serum VEGF levels and brain volumes in schizophrenia subjects.
    • Genetic labeling reveals novel cellular targets of schizophrenia susceptibility gene ERBB4 and neuregulin-1 – ERBB4 signaling in monoamine neurons

      Bean, Jonathan C; Department of Neuroscience and Regenerative Medicine (2015)
      Neuregulin 1 (NRG1) and its receptor ErbB4 are schizophrenia risk genes. NRG1-ErbB4 signaling plays a critical role in neural development and regulates neurotransmission and synaptic plasticity. Nevertheless, its cellular targets remain controversial. ErbB4 was thought to be expressed in excitatory neurons although recent studies have disputed this view. Utilizing mice that express a fluorescent protein under the promoter of the ErbB4 gene, I determined in what cells ErbB4 is expressed and their identity. ErbB4 was widely expressed in the mouse brain, being highest in amygdala and cortex. Almost all ErbB4-positive cells were GABAergic in cortex, hippocampus, basal ganglia, and most of amygdala in neonatal and adult mice, suggesting GABAergic transmission as a major target of NRG1-ErbB4 signaling in these regions. Non-GABAergic, ErbB4-positive cells were present in thalamus, hypothalamus, midbrain and hindbrain. In particular, ErbB4 was expressed in both dopamine neurons in the substantia nigra and ventral tegmental area and in serotoninergic neurons of raphe nuclei, but not in norepinephrinergic neurons of the locus coeruleus. In hypothalamus, ErbB4 was present in neurons that express oxytocin. ErbB4 was expressed in a group of cells in the subcortical areas that are positive for S100β. These results identify novel cellular targets of NRG1-ErbB4 signaling. Finally, perfusion of NRG1 into the medial prefrontal cortex enhanced both dopamine and serotonin release but with differing time courses.
    • Genetic Modeling and Pathophysiological Analysis of FAM109A, a Putative Human Disease Gene

      Ates, Kristin Marie; Department of Neuroscience and Regenerative Medicine (Augusta University, 2019-05)
      A critical barrier in the treatment of endocytic diseases is the lack of information and understanding of the in vivo mechanisms of endocytosis. Part of this is due to the diverse array of endocytic adaptor proteins that have not yet been studied. We address this by investigating a key endocytic adaptor protein, FAM109A, which interacts with OCRL1, a causative gene for Lowe syndrome. Previous in vitro studies have identified FAM109A as a regulator for endosomal trafficking, particularly in the recycling of receptors in endosomes and sorting of cargo to lysosomes, based on knock-down studies. Here we conduct the first study into the developmental and physiological functions of FAM109A in vivo, utilizing the zebrafish model. We find that depletion of both zebrafish orthologs, zFAM109A and zFAM109B, in our maternal-zygotic homozygous mutant models (AB mutant) disrupts fluid-phase endocytosis and ciliogenesis in the pronephros. Partial knockdown of OCRL1 in the AB mutants exacerbates the endocytosis deficit, confirming that OCRL1 and FAM109 proteins are linked in a common endocytic pathway. In addition, we discover that zFAM109A/B mutant animals exhibit reduced jaw size and delay in chondrocyte maturation, indicating a novel role for zFAM109A and zFAM109B in craniofacial development. This is consistent with the phenotype in a patient within the NIH’s Undiagnosed Diseases Program (UDP). The UDP patient carries a de novo arginine (R) to cysteine (C) mutation (R6C) in FAM109A and presents with craniofacial abnormalities, developmental delay, auditory and vision impairments, and renal dysfunction. Expressing zFAM109A with the R6C mutation in zebrafish exacerbated craniofacial deficits, suggesting that the R6C allele acts in a dominant-negative manner. Together, these results show that FAM109A is involved in fluid-phase endocytosis and ciliogenesis in vivo. Moreover, we provide further insight into the potential pathogenesis of a UDP patient’s disease in association with a de novo mutation in FAM109A.
    • Genetic mutations cause primary aldosteronism

      Hattangady, Namita G; Department of Physiology (2014-10)
      The human adrenal glands are complex endocrine organs that are physiologically located above the kidney. The cortex of the adrenal gland may be considered as a combination of three different steroidogenic tissue-types which form concentric zones within each adrenal. The three cortical zones include zona glomerulosa (ZG), zona fasciculata (ZF) and zona reticularis (ZR). Each zone, under independent regulation, produces unique steroid(s) which exhibit specific functions. The outermost ZG layer secretes the steroid, aldosterone due to ZG specific expression of aldosterone synthase (CYP11B2). Aldosterone regulates sodium reabsorption, and therefore, blood pressure. Aldosterone production is tightly regulated by the renin-angiotensin-aldosterone system. Thus, aldosterone levels are in direct proportion with renin levels. Other known physiological regulators of aldosterone production include serum K+ and adrenocorticotrophic hormone. A type of endocrine hypertension termed ‘Primary Aldosteronism’ (PA), is characterized by aldosterone secretion under suppressed renin levels. PA accounts for almost 10 % of hypertension. More recently, genetic mutations in an inward rectifying K+ channel (KCNJ5) that occur as both, somatic and germline cases, have been implicated in the pathology of PA. The goal of this dissertation is to define the role of KCNJ5 mutations in PA. In this dissertation, I will summarize my studies that describe the acute and chronic events involved in mutated KCNJ5 mediated aldosterone excess. In addition, I will define a novel mutation in KCNJ5 of germline nature identified at Georgia Regents University. Finally, I will also describe some interesting lessons we learnt from the expression of mutated KCNJ5 in primary cultures of human adrenals. The prevalence of a hereditary form of PA termed as Familial Hyperaldosteronism type III (FH III) is very rare. Thus far, only a few mutations in the KCNJ5 gene, including T158A, G151R, G151E and I157S, are confirmed as causing FH III, following Mendelian genetics. Perhaps the most interesting feature of this disease is the varied phenotype between the different mutations. T158A-affected patients present with massive hyperplasia and require bilateral adrenalectomy. In contrast, patients affected by the G151E mutation have more severe hypertension, although their adrenals are near normal in appearance. In this study we identify a new germline mutation (Y152C). The index case was a 61 year old woman who underwent unilateral adrenalectomy. The patient with the Y152C mutation exhibited a milder hypertension phenotype (like the G151E-affected patient) with extensive hyperplasia (as seen in the T158A-affected patient). In vitro analyses of the Y152C mutation indicated a pathology similar to other known mutations in KCNJ5, including change in conductance to Na+ ions and elevated calcium levels, and increase in CYP11B2 mRNA and aldosterone production. The inherent challenge presented by current studies utilizing constitutive expression of KCNJ5 mutations is the limitation in studying acute temporal events such as post translational modifications of steroidogenic enzymes and transcription factors. To address this issue, we generated a doxycycline inducible cell model system for the T158A harboring KCNJ5 transgene. Herein, we demonstrate a useful system that was amenable to the study of acute and chronic events involved in mutant-KCNJ5 mediated aldosterone excess. Our findings suggest that mutant KNCJ5 increases CYP11B2 expression through the activation of transcriptional activators of CYP11B2. Additionally, this is the first study to demonstrate that mutant KCNJ5 also activates steroidogenic acute regulatory protein (StAR) at the levels of translation and post translational phosphorylation. We also demonstrate calcium channel blocker, verapamil as an efficient blocker of mKCNJ5 mediated aldosterone production. Finally, one of the sharp advantages of our study was the use of primary cultures of human adrenal cells to confirm the effects of mutated KCNJ5. Interestingly, transduction of cells with constitutive viruses for mutant KCNJ5, confirmed an increase in KCNJ5 mRNA, although no change in CYP11B2 expression levels was observed. Pilot data including treatment of primary cells with calcium ionophores indicated that ZF/ZR cells may have a phenotype that is ‘muted’ for calcium mediated pathways. We could also speculate that this may disprove some current hypotheses that APA harboring KCNJ5 mutations may originate from the ZF. Overall, this study has improved our knowledge regarding the pathogenesis of PA caused by KCNJ5 mutations and has identified verapamil as a potentially effective therapeutic strategy in the inhibition of aldosterone excess in this type of PA.
    • The Genetics of the Hemoglobins of the Domestic Goat

      Ray, Adams H.; Department of Cell and Molecular Biology (1970-09)
    • Genomic and Functional Analysis of Vesicular Inhibitory Amino Acid Transporter During Mouse Embryogenesis

      Oh, Won-Jong; Institute of Molecular Medicine and Genetics (2006-01)
      The specification of particular neuronal phenotypes during embryonic development requires the appropriate activation and regulation of genes encoding the proteins required for neurotransmitter synthesis, vesicular packaging and re-uptake from the synaptic cleft. Each neurotransmitter is packaged into synaptic vesicles by its own distinct vesicular transporter. In addition, neurotransmitter packaging is well controlled by other co-factors (reviewed in Ahnert-Hilger et al., 2003). Components of GABAergic neurons GABAergic neurons are the principal inhibitory neurons in the mammalian central nervous system (CNS), where GABA is synthesized from glutamate by two glutamate decarboxylases (GAD), namely GAD65 (Gad2) and GAD67 (Gad1) (Erlander et al., 1991). GABA is then loaded into synaptic vesicles by the vesicular inhibitory amino acid transporter (VIAAT, also known as VGAT). Four GABA transporters (GAT 1-4) are responsible for the re-uptake of GABA from the synaptic cleft through the plasma membrane. Inhibitory GABAergic transmission is mediated by binding of GABA to its ionotropic receptors, GABAA and GABAC, which are ligand-gated chloride channels, and its metabotropic receptor, GABAB (Fig. 1).
    • Genomic Predictions in Uterine Cancers

      Tran, Lynn Kim Hoang; Center for Biotechnology and Genomic Medicine (Augusta University, 2020-05)
      Introduction: Current uterine cancer classification provides suboptimal treatment stratification and often groups together patients with significant differences in survival outcome and/or response. We used transcriptomic information to devise genomic scores for improved prediction of uterine cancer patient outcomes and validated these scores in our institutional cohorts. Project 1: In an early iteration of our gene signature discovery pipeline, we developed USC73, a genomic score for uterine serous carcinoma patients, which grouped patients into a low score (lower 66.7 percentile), good prognosis group and a high score (upper 33.3 percentile), poor prognosis group (5-year overall survival: 83.3% and 13.3%, respectively). USC73 predicts survival independently of stage, and can be combined with stage for further resolution of patient survival. Poor survivors have faster-growing tumors and lower rates of complete response to primary therapy. Project 2: We applied our pipeline to uterine endometrioid carcinoma, the most common histotype of uterine cancer, and developed UEC_IGS, an immune gene score that separates early stage patients into a high lymphocytic infiltration, good prognosis group (IGS 1) and a low lymphocytic infiltration, poor prognosis group (IGS 2). UEC_IGS predicts overall survival independent of grade and treatment. IGS 1 patients have higher levels of CD8+ tumor infiltrating lymphocytes (TILs), more CD45RO+/CD3+ memory T cells, and lower levels of FOXP3+ Tregs compared to IGS 2. Conclusion: Using transcriptomic data, we can reliably stratify uterine cancer patients into good and poor survival groups. This information can be used to facilitate recruitment of only poor prognosis patients into clinical trials, mitigating some heterogeneity in patient response and allowing clinicians to better identify treatments for patients who will not survive on the current therapy. Additionally, biological functions (e.g. cellular proliferation or immune infiltration) are associated with each genomic score, and these can serve as potential pathways to target for improving the outcome of poor survival groups.
    • GET THEM HERE: KEEP THEM HERE: A STUDY OF THE RECRUITMENT AND RETENTION OF BLACK STUDENTS AT GREENWOOD UNIVERSITY

      Hodges, Jamel Antwon; Department of Advanced Studies and Innovation (Augusta University, 2019-05)
      Greenwood University, a Predominantly White Institution (PWI), has had difficulty recruiting Black students and retaining them throughout their undergraduate careers to graduation. Research shows the significant link between students’ perceptions of belonging and satisfaction at a university and their retention at that university. Race on a college campus is complex and requires intentional efforts to understand within the framework of higher education. The aim of this study is to determine specific causes that explain why Black students are not being recruited and retained at the same rate as their non-Black peers at Greenwood University. In doing so, the authors employed a mixed methods approach in which they conducted interviews from Black second and third year students, as well as faculty and staff, to explain the responses gathered from a recent Campus Climate Survey. A focus group of students also highlighted factors that impact the recruitment and retention of Black students. Among the responses received, factors such as support, connection, and representation among Black faculty and staff were shown to have a strong impact on Black students’ feelings of belonging, thus in many cases, their retention at Greenwood University. Based on the findings, it is recommended that universities prioritize intentional incentives to provide specialized support services and “spaces” for its students and to grow the numbers of faculty and staff who represent all of their institution’s student body. Keywords: enrollment, recruitment, retention, Black students, faculty, staff, Predominantly White Institution (PWI), Historically Black College or University (HBCU), Higher Education, Administrators
    • GET THEM HERE: KEEP THEM HERE: A STUDY OF THE RECRUITMENT AND RETENTION OF BLACK STUDENTS AT GREENWOOD UNIVERSITY

      Green, Garrett; Department of Advanced Studies and Innovation (Augusta University, 2019-05)
      Greenwood University, a Predominantly White Institution (PWI), has had difficulty recruiting Black students and retaining them throughout their undergraduate careers to graduation. Research shows the significant link between students’ perceptions of belonging and satisfaction at a university and their retention at that university. Race on a college campus is complex and requires intentional efforts to understand within the framework of higher education. The aim of this study is to determine specific causes that explain why Black students are not being recruited and retained at the same rate as their non-Black peers at Greenwood University. In doing so, the authors employed a mixed methods approach in which they conducted interviews from Black second and third year students, as well as faculty and staff, to explain the responses gathered from a recent Campus Climate Survey. A focus group of students also highlighted factors that impact the recruitment and retention of Black students. Among the responses received, factors such as support, connection, and representation among Black faculty and staff were shown to have a strong impact on Black students’ feelings of belonging, thus in many cases, their retention at Greenwood University. Based on the findings, it is recommended that universities prioritize intentional incentives to provide specialized support services and “spaces” for its students and to grow the numbers of faculty and staff who represent all of their institution’s student body. Keywords: enrollment, recruitment, retention, Black students, faculty, staff, Predominantly White Institution (PWI), Historically Black College or University (HBCU), Higher Education, Administrators
    • "Get Them Here: Keep Them Here: A Study of the Recruitment and Retention of Black Students at Greenwood University"

      Fisher, Jocelyn Stamps (Augusta University, 2019-05)
      Greenwood University, a Predominantly White Institution (PWI), has had difficulty recruiting Black students and retaining them throughout their undergraduate careers to graduation. Research shows the significant link between students’ perceptions of belonging and satisfaction at a university and their retention at that university. Race on a college campus is complex and requires intentional efforts to understand within the framework of higher education. The aim of this study is to determine specific causes that explain why Black students are not being recruited and retained at the same rate as their non-Black peers at Greenwood University. In doing so, the authors employed a mixed methods approach in which they conducted interviews from Black second and third year students, as well as faculty and staff, to explain the responses gathered from a recent Campus Climate Survey. A focus group of students also highlighted factors that impact the recruitment and retention of Black students. Among the responses received, factors such as support, connection, and representation among Black faculty and staff were shown to have a strong impact on Black students’ feelings of belonging, thus in many cases, their retention at Greenwood University. Based on the findings, it is recommended that universities prioritize intentional incentives to provide specialized support services and “spaces” for its students and to grow the numbers of faculty and staff who represent all of their institution’s student body. Keywords: enrollment, recruitment, retention, Black students, faculty, staff, Predominantly White Institution (PWI), Historically Black College or University (HBCU), Higher Education, Administrators
    • Glutamic Acid Decarboxylase Expression And Function In The Developing And Neonatal Mouse

      Maddox, Dennis M; Institute of Molecular Medicine and Genetics (2001-06)
      (First Paragraph) In the mouse, there are two distinct genes that encode isoforms of the enzyme glutamic acid decarboxylase (Gad). The G adl gene encodes the larger isoform that has a molecular mass of 67 kilodaltons and is termed "Gad67" (Erlander et al., 1991; Bu et al., 1992). The Gad2 gene encodes the other isoform that has a molecular mass of 65 kilodaltons and is termed "Gad65" (Erlander et al., 1991; Bu et al., 1992). These two isoforms are often co-expressed in GABAergic neurons (Feldblum et al., 1993; Esclapez et al., 1994; Katarova et al., 2000). The isoforms differ in subcellular localization, with Gad67 being found mainly in the soma and Gad65 being found mainly in axon terminals (Kaufman et al., 1991). Additionally, the two isoforms of Gad differ in their affinity for the required cofactor pyridoxal-5’-phosphate (PLP) (Kaufman et al., 1991). By catalyzing the decarboxylation of L-glutamic acid, the Gad enzymes are the rate-limiting step in the biosynthesis of y-aminobutyric acid (GABA) (Barker et al., 1998).
    • GLYCOSAMINOGLYCANS, CHONDROITINASE, AND MOLECULAR SUBTYPES IN BLADDER CANCER

      Morera, Daley S; Department of Biochemistry and Molecular Biology (Augusta University, 2020-05)
      There is a need for novel prognostic biomarkers and targeted treatments in bladder cancer (BC), even more so for muscle-invasive disease (MIBC). Discovery of molecular markers to predict outcome in BC patients may lead to identification of impactful therapeutic targets. The hyaluronic acid (HA) family of molecules and distinct molecular subtypes have both been investigated as potential prognostic markers. HA family and chondroitin sulfate proteoglycans, such as CD44, have been implicated in driving aggressiveness of disease; however, a chondroitinase enzyme that cleaves chondroitin sulfate proteoglycans has not been identified in any eukaryotic system. We evaluated molecular markers of BC and the first known eukaryotic/human chondroitinase, that we identified, for their ability to predict clinical outcome in patients, and for their roles as drivers of disease. We also investigated the anti-tumor effects of HA synthesis inhibitor 4-methylumbelliferone (4MU), a non-toxic orally bioavailable supplement. This study demonstrates that transcript levels of HA family members can predict metastasis and poor survival in BC patients. HA- family expression also correlated with epithelial mesenchymal transition (EMT) markers β -Catenin, Twist, Snail, and E-Cadherin. HA signaled through its receptors CD44/RHAMM and the PI3-K/AKT axis. 4MU targeted HA signaling, inhibiting proliferation and motility/invasion, inducing apoptosis in vitro, and preventing tumor growth in vivo. We discovered that a previously unidentified splice variant of HYAL-4 was elevated in bladder tumors. We named this variant "V1". Our studies showed that V1 had chondroitinase activity, cleaved chondroitin-6-sulfate from CD44, and consequently increased CD44 secretion. In vivo, V1-expressing urothelial cells formed muscle-invasive tumors and V1-expressing cancer cells developed metastatic tumors. Evaluation of the prognostic significance of the molecular subtypes of MIBC that were recently identified by other groups, showed the subtypes to have little to no predictive ability for clinical outcome in multivariate analyses that included standard clinical parameters. Consistently, clinical parameters such as histopathologic tumor grade, T-stage, and lymph node status, outperformed the molecular subtypes. Contrarily, V1 levels could independently predict metastasis and survival with high efficacy, suggesting that focusing on V1 as a functional biomarker may be a better strategy to improve clinical outcome of BC patients.
    • Gonadotrophin secretion by the isolated pituitary

      Greeley, George Horace; Department of Endocrinology (1974-09)
    • GPR109A as a link between gut flora and colonic health

      Cresci, Gail A.; School of Graduate Studies (2009-11)