DOCSLIB.ORG

Discerning the Role of Lmo4 As a Global Modulator of G2/M Cell

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Discerning the Role of Lmo4 As a Global Modulator of G2/M Cell DISCERNING THE ROLE OF LMO4 AS A GLOBAL MODULATOR OF G2/M CELL CYCLE PROGRESSION AND CENTROSOME CYCLE IN BREAST CANCER CELLS by MARJORIE E. MONTAÑEZ-WISCOVICH Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Thesis Advisor: Dr. Ruth A. Keri Department of Pharmacology CASE WESTERN RESERVE UNIVERSITY January, 2010 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of _____Marjorie E. Montanez-Wiscovich________ candidate for the _Doctor of Philosophy_ degree *. (signed) _____George R. Dubyak_______ (chair of the committee) _______Yu-Chung Yang_______ _________Julian Kim_________ _________Ruth Keri__________ (date) _October 21, 2009____________ * We also certify that written approval has been obtained for any proprietary material contained therein. DEDICATION To Lelo and Lela for one day we will have a cure. TABLE OF CONTENTS Dedication iii Table of Contents iv List of tables viii List of figures ix Acknowledgments xi List of Abbreviations xiii Chapter 1 Introduction 1 1.1 Background 1 a. Origin of Molecular Subtypes 3 b. Gene Expression Profiling and Patient Care 5 1.2 Chromosome Cycle and Centrosome Cycle 6 1.3 Luminal-like breast cancer subtype 15 1.4 ErbB2-amplified breast cancer subtype 21 1.5 Basal-like breast cancer subtype 26 1.6 LIM-only protein 4 (LMO4) 31 1.7 Statement of Purpose 42 Chapter 2 LMO4 is an essential mediator of ErbB2/HER2/Neu-induced breast cancer cell cycle progression 44 2.1 Introduction 44 2.2 Results and Discussion 47 a. LMO4 mRNA and protein are increased in ErbB2-induced tumors. 47 b. ErbB2 and PI3K activity are necessary for LMO4 expression. 49 iv c. LMO4 regulates proliferation of ErbB2-dependent breast cancer cells. 54 d. LMO4 is required for maintenance of Cyclin D1 mRNA and protein expression in cells with constitutive ErbB2 signaling as well as for heregulin-induced upregulation of Cyclin D1. 56 e. LMO4 regulates G2/M transition by inducing cullin-3 expression. 58 f. LMO4 expression oscillates throughout the cell cycle with peak expression occurring at G2/M phase. 62 2.3 Materials and Methods 66 Chapter 3 Aberrant expression of LMO4 induces centrosome amplification and mitotic spindle abnormalities in breast cancer cells 74 3.1 Introduction 74 3.2 Results and Discussion 77 a. LMO4 mRNA is highly expressed in BRCA1 mutant and ERα-negative breast cancers. 77 b. LMO4 expression is elevated in tumors with high mitotic indices. 80 c. LMO4 regulates G2/M progression in luminal and basal-like breast cancer cells. 84 d. Alterations in LMO4 levels induce centrosome amplification. 87 e. Altered LMO4 levels induce the formation of abnormal mitotic spindles. 90 f. LMO4 localizes to the centrosome. 92 3.3 Materials and Methods 95 Chapter 4 Summary and Future Directions 101 4.1 Summary 101 v a. Does LMO4 directly regulate cul3 transcription? Does cul3 mediate LMO4- dependent G2/M arrest and/or centrosome amplification? 104 b. Does LMO4 regulate the G2/M checkpoint and/or the centrosome cycle by modulating BRCA1 activity? 107 c. Does LMO4 regulate centrosome amplification and/or G2/M arrest via transcriptional mechanisms? 110 d. Do hyperplastic glands and tumors derived from mammary-specific overexpression of LMO4 exhibit amplification of centrosomes and aneuploidy? Do embryonic fibroblasts from LMO4-null mice have centrosome amplification and aneuploidy? 111 e. Does LMO4 regulate the cellular response to ionizing radiation? 112 f. Does LMO4 bind to partners in a cell cycle specific manner? 113 Appendix 1 Protocols 115 A1.1 DNA Extraction from Cell Lines 115 A1.2 Protein Isolation from Cells 116 A1.3 Protein Isolation from Tissue 116 A1.4 Trizol RNA extraction from cells 117 A1.5 Removing DNA contamination from extracted RNA 118 A1.6 RT with SuperScript II (Invitrogen) 119 A1.7 Taqman ABI Assay 120 A1.8 Promoter Transfection and Luciferase Assay 121 A1.9 siRNA transfections 122 A1.10 Western Blot Protean Xi System 123 vi A1.11 Propidium Iodide Protocol for FACS 124 A1.12 BrdU Immunofluorescense 125 A1.13 γ-tubulin and α-tubulin staining 126 Bibliography 127 vii LIST OF TABLES Table 2.1: LMO4 mRNA expression in murine models of breast cancer. 48 Table 2.2: LMO4 overexpression is associated with high-grade, poorly differentiated breast cancers. 65 Table 3.1: LMO4 overexpression is associated with basal-type, BRCA1 mutation-associated and ER-negative breast cancers 80 viii LIST OF FIGURES Figure 1.1: Breast cancer is a heterogeneous disease. 2 Figure 1.2: The origins of breast cancer subtypes. 4 Figure 1.3: Regulation of the cell cycle. 7 Figure 1.4: Estrogen Receptor signaling mechanisms. 17 Figure 1.5: ErbB2 signaling pathways. 23 Figure 1.6: LMO4 regulates transcription in a context-dependent manner. 34 Figure 2.1: LMO4 mRNA and protein are increased in ErbB2-induced tumors. 48 Figure 2.2: LMO4 expression requires ErbB2 and PI3K activity. 50 Figure 2.3: ErbB2 and PI3K activity are necessary for LMO4 expression. 51 Figure 2.4: Overexpression of ErbB2 is sufficient to induce LMO4 expression. 53 Figure 2.5: LMO4 regulates proliferation of ErbB2-dependent breast cancer cells. 55 Figure 2.6: LMO4 is required for maintenance of Cyclin D1 mRNA and protein expression in cells with constitutive ErbB2 signaling as well as for heregulin-induced upregulation of Cyclin D1. 57 Figure 2.7: LMO4 regulates G2/M transition by inducing cullin-3 expression. 59 Figure 2.8: LMO4 expression oscillates throughout the cell cycle with peak expression occurring at G2/M phase. 63 Figure 2.9: LMO4 is an essential intermediate of ErbB2-induced proliferation. 64 Figure 3.1: LMO4 mRNA is highly expressed in BRCA1 mutant and ERα-negative breast cancers. 78 Figure 3.2: LMO4 expression is elevated in tumors with high mitotic indices. 82 Figure 3.3: Cytoplasmic LMO4 expression in human tumors. 83 ix Figure 3.4: LMO4 regulates G2/M progression in luminal and basal-like breast cancer cells. 85 Figure 3.5: Loss of LMO4 increases cell death in breast cancer cells representing luminal and basal subtypes. 86 Figure 3.6: Alterations in LMO4 levels induce centrosome amplification. 88 Figure 3.7: LMO4 overexpression in T47D breast cancer cells. 89 Figure 3.8: Altered LMO4 levels induce the formation of abnormal mitotic spindles. 91 Figure 3.9: LMO4 localizes to the centrosome. 93 Figure 3.10: LMO4 co-localizes to the centrosome in T47D cells. 93 Figure 4.1: Does LMO4 regulate the G2/M checkpoint and/or centrosome amplification by modulating BRCA1 activity? 107 x ACKNOWLEDGMENTS The best science is the work of many and I owe many special thanks. First, to Dr. Ruth Keri, thank you for taking me under your wings and teaching me all about transcription as well as tenacity and vision. Thank you also for all those yummy peanut butter blossom cookies! Second, I am especially grateful to my other thesis committee members – Yu-Chung Yang, George Dubyak, Julian Kim, David Schultz and Pamela Davis – for their helpful advice throughout the years and for keeping me focused. If I have learned one thing from my committee is to step back, analyze and question everything. Although this work has taken several years, I admit that it would not have been as full of fun experiences where I not in the Keri Lab. I am indebted to the Keri Lab members for throwing me into the pool of science and the labyrinth of life. Thank you also for helping me evaluate so many personal and scientific issues as well as for your guidance and patience. In particular, a belated apology to Kristen Lozada for suffering the brunt of (my few) obsessive- compulsive tendencies. Also, thanks Kris for lending me your magic centrosome yuyu! Thanks to Darcie Seachrist for her wonderful optimism and for providing a balance of sweetness for the Keri Lab’s sometimes way-too-frank attitude and many more thanks for your beautiful in situ and IHC expertise! I am also most obliged to Melissa Landis and Erin Milliken for their mentoring during my formative lab years. To Jonathan Mosley, thanks for all your statistical help and for sharing your perspective on life, “life is not a dress-rehearsal”, after all! I am also appreciative of Emhonta Johnson’s help with cloning and viral work but most of all for his attempts to keep me social and for improving my vocabulary with such terms as “jibby-jabba” and “excessive eye- xi ballage”. Many, many thanks to Gina for all our scientific ‘consultations’. I will never earn enough money to repay you! In addition, I am very grateful to Melissa for rejuvenating my interest in LMO4 and for introducing me to the magical world of Killer Bunnies and the sweet, sweet world of cake decorating. Muchas gracias también a mi nueva familia en Cleveland, mis hermanitas Dolly y Yeritza, y el desertor Carlitos as well as Candice and Jeremy for keeping my life merry. Finally, I appreciate my family’s constant support over the years. Moving to Cleveland was not an easy move and I am much obliged to my family (Mami, Papi and Ian) and my cousins, Yamil and Mairim, for taking time to visit and rescuing me from the every day routine. Furthermore, I am infinitely grateful to Matthew for being my pillar and my source of encouragement and laughter. Many more thanks for keeping me so well-fed and so much loved! xii LIST OF ABBREVIATIONS AIB1 Amplified In Breast Cancer AKT Murine thyme viral (v-AKT) oncogene homolog-1 APC/C Anaphase Promoting Complex ATM Ataxia Telangiectasia ATR Ataxia Telangiectasia and Rad3-related BARD BRCA1-Associated Ring Domain1 BMP Bone Morphogenetic Protein BRCA1/2 Breast Cancer
Load more

Recommended publications
  • Analysis of Estrogen Receptor Isoforms and Variants in Breast Cancer Cell Lines
    EXPERIMENTAL AND THERAPEUTIC MeDICINE 2: 537-544, 2011 Analysis of estrogen receptor isoforms and variants in breast cancer cell lines MAIE AL-BADER1, CHRISTOPHER FORD2, BUSHRA AL-AYADHY3 and ISSAM FRANCIS3 Departments of 1Physiology, 2Surgery, and 3Pathology, Faculty of Medicine, Kuwait University, Safat 13110, Kuwait Received November 22, 2010; Accepted February 14, 2011 DOI: 10.3892/etm.2011.226 Abstract. In the present study, the expression of estrogen domain C, the DNA binding domain; domains D/E, bearing receptor (ER)α and ERβ isoforms in ER-positive (MCF7, both the activation function-2 (AF-2) and the ligand binding T-47D and ZR-75-1) and ER-negative (MDA-MB-231, SK-BR-3, domains; and finally, domain F, the C-terminal domain (6,7). MDA-MB-453 and HCC1954) breast cancer cell lines was The actions of estrogens are mediated by binding to ERs investigated. ERα mRNA was expressed in ER-positive and (ERα and/or ERβ). These receptors, which are co-expressed some ER-negative cell lines. ERα ∆3, ∆5 and ∆7 spliced in a number of tissues, form functional homodimers or variants were present in MCF7 and T-47D cells; ERα ∆5 heterodimers. When bound to estrogens as homodimers, the and ∆7 spliced variants were detected in ZR-75-1 cells. transcription of target genes is activated (8,9), while as heterodi- MDA-MB-231 and HCC1954 cells expressed ERα ∆5 and ∆7 mers, ERβ exhibits an inhibitory action on ERα-mediated gene spliced variants. The ERβ1 variant was expressed in all of the expression and, in many instances, opposes the actions of ERα cell lines and the ERβ2 variant in all of the ER-positive and (7,9).
    [Show full text]
  • It's Better to Know! Learn the Signs. Act Early. Photo Novella
    It’s Better to Know! Learn the Signs. Act Early. Learning About Developmental Milestones All of us want our children to be happy and healthy. We want what is best for them. This story is about my family as we learn that “It’s Better To Know” about developmental milestones. Developmental milestones are things most children can do by a certain age. Children reach milestones in how they play, learn, speak, and act. Milestones offer important clues about a child’s development. The developmental milestones you will learn about in this fotonovela will give you a general idea of what to expect as your child grows. Not reaching these milestones, or reaching them much later than other children, could be a sign of a developmental delay. Trust your instincts. If you have concerns about your child’s development, the best thing to do is talk with your doctor. It’s Better To Know! was produced by the Organization for Autism Research with funding provided by the Department of Health and Human Services, Centers for Disease Control and Prevention. www.cdc.gov/actearly iii He’s fine. He’s more interested in Hi Carlitos! his cow! C-a-r-l-i-t-o-s. He doesn’t always look at us when we call his name. I wonder why. Have you talked to How’s my baby boy the doctor about doing? that? He’s okay, mom, but he doesn’t always look up when No, why, should I? we call him. Remember the last time we took him for a well- baby check-up and 9-month developmental screening? I picked up this pamphlet in the waiting room.
    [Show full text]
  • Expression of Estrogen Receptor-Beta Isoforms in Barrett's
    ANTICANCER RESEARCH 24: 2919-2924 (2004) Expression of Estrogen Receptor-Beta Isoforms in Barrett’s Metaplasia, Dysplasia and Esophageal Adenocarcinoma LIANG LIU, MINNI CHIRALA and MAMOUN YOUNES Departments of Pathology, Baylor College of Medicine and The Methodist Hospital, Houston, TX 77030, U.S.A. Abstract. We have previously shown that the majority of and beta (ER-B). ER-A is mainly expressed in female sex esophageal adenocarcinomas (EA), and its precursor Barrett’s organs, such as breast and uterus (2), whereas ER-B is metaplasia (BM), express estrogen receptor beta (ER-B). Several expressed in both sex organs and other tissues, such as isoforms of ER-B have been described and are presumed to have prostate, lung, thyroid, adrenal cortex and testis (3). Several different functions, but their distribution in BM and EA is not ER-B isoforms have been identified and characterized in known. The aim of this work was to determine which ER-B many non-gynecologic tumors including carcinomas of the isoforms are expressed in EA and BM. Sections of formalin-fixed lung (4), prostate (5), colon (6, 7) and stomach (8). and paraffin-embedded esophageal tissue from 33 esophageactomy Tamoxifen, a specific ER-B antagonist, has been successfully specimens, of which 27 had invasive EA, were stained for the ER- used in the treatment of patients with breast carcinoma B isoforms ER-B1, ER-B2, ER-B3 and ER-B5 utilizing the (9,10) and it has been shown that ER-B status is a significant immunoperoxidase method. ER-B1 was detected in 23 out of 27 predictor of survival in women with breast carcinoma treated (85%) EA compared to 3 out of 14 (21%) Barrett’s metaplasia with mastectomy and adjuvant tamoxifen (11).
    [Show full text]
  • DNA·RNA Triple Helix Formation Can Function As a Cis-Acting Regulatory
    DNA·RNA triple helix formation can function as a cis-acting regulatory mechanism at the human β-globin locus Zhuo Zhoua, Keith E. Gilesa,b,c, and Gary Felsenfelda,1 aLaboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892; bUniversity of Alabama at Birmingham Stem Cell Institute, University of Alabama at Birmingham, Birmingham, AL 35294; and cDepartment of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294 Contributed by Gary Felsenfeld, February 4, 2019 (sent for review January 4, 2019; reviewed by James Douglas Engel and Sergei M. Mirkin) We have identified regulatory mechanisms in which an RNA tran- of the criteria necessary to establish the presence of a triplex script forms a DNA duplex·RNA triple helix with a gene or one of its structure, we first describe and characterize triplex formation at regulatory elements, suggesting potential auto-regulatory mecha- the FAU gene in human erythroid K562 cells. FAU encodes a nisms in vivo. We describe an interaction at the human β-globin protein that is a fusion containing fubi, a ubiquitin-like protein, locus, in which an RNA segment embedded in the second intron of and ribosomal protein S30. Although fubi function is unknown, the β-globin gene forms a DNA·RNA triplex with the HS2 sequence posttranslational processing produces S30, a component of the within the β-globin locus control region, a major regulator of glo- 40S ribosome. We used this system to refine methods necessary bin expression. We show in human K562 cells that the triplex is to detect triplex formation and to distinguish it from R-loop stable in vivo.
    [Show full text]
  • Bioinformatic Analysis of Structure and Function of LIM Domains of Human Zyxin Family Proteins
    International Journal of Molecular Sciences Article Bioinformatic Analysis of Structure and Function of LIM Domains of Human Zyxin Family Proteins M. Quadir Siddiqui 1,† , Maulik D. Badmalia 1,† and Trushar R. Patel 1,2,3,* 1 Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 3M4, Canada; [email protected] (M.Q.S.); [email protected] (M.D.B.) 2 Department of Microbiology, Immunology and Infectious Disease, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive, Calgary, AB T2N 4N1, Canada 3 Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada * Correspondence: [email protected] † These authors contributed equally to the work. Abstract: Members of the human Zyxin family are LIM domain-containing proteins that perform critical cellular functions and are indispensable for cellular integrity. Despite their importance, not much is known about their structure, functions, interactions and dynamics. To provide insights into these, we used a set of in-silico tools and databases and analyzed their amino acid sequence, phylogeny, post-translational modifications, structure-dynamics, molecular interactions, and func- tions. Our analysis revealed that zyxin members are ohnologs. Presence of a conserved nuclear export signal composed of LxxLxL/LxxxLxL consensus sequence, as well as a possible nuclear localization signal, suggesting that Zyxin family members may have nuclear and cytoplasmic roles. The molecular modeling and structural analysis indicated that Zyxin family LIM domains share Citation: Siddiqui, M.Q.; Badmalia, similarities with transcriptional regulators and have positively charged electrostatic patches, which M.D.; Patel, T.R.
    [Show full text]
  • Ldb1 Is Essential for Development of Nkx2.1 Lineage Derived Gabaergic and Cholinergic Neurons in the Telencephalon
    Developmental Biology 385 (2014) 94–106 Contents lists available at ScienceDirect Developmental Biology journal homepage: www.elsevier.com/locate/developmentalbiology Ldb1 is essential for development of Nkx2.1 lineage derived GABAergic and cholinergic neurons in the telencephalon Yangu Zhao a,n,1, Pierre Flandin b,2, Daniel Vogt b, Alexander Blood a, Edit Hermesz a,3, Heiner Westphal a, John L. R. Rubenstein b,nn a Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA b Department of Psychiatry and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San Francisco, San Francisco, CA 94143, USA article info abstract Article history: The progenitor zones of the embryonic mouse ventral telencephalon give rise to GABAergic and cholinergic Received 1 June 2013 neurons. We have shown previously that two LIM-homeodomain (LIM-HD) transcription factors, Lhx6 and Received in revised form Lhx8, that are downstream of Nkx2.1, are critical for the development of telencephalic GABAergic and 8 October 2013 cholinergic neurons. Here we investigate the role of Ldb1, a nuclear protein that binds directly to all LIM-HD Accepted 9 October 2013 factors, in the development of these ventral telencephalon derived neurons. We show that Ldb1 is expressed Available online 21 October 2013 in the Nkx2.1 cell lineage during embryonic development and in mature neurons. Conditional deletion of Ldb1 Keywords: causes defects in the expression of a series of genes in the ventral telencephalon and severe impairment in the Differentiation tangential migration of cortical interneurons from the ventral telencephalon.
    [Show full text]
  • Open Dogan Phdthesis Final.Pdf
    The Pennsylvania State University The Graduate School Eberly College of Science ELUCIDATING BIOLOGICAL FUNCTION OF GENOMIC DNA WITH ROBUST SIGNALS OF BIOCHEMICAL ACTIVITY: INTEGRATIVE GENOME-WIDE STUDIES OF ENHANCERS A Dissertation in Biochemistry, Microbiology and Molecular Biology by Nergiz Dogan © 2014 Nergiz Dogan Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2014 ii The dissertation of Nergiz Dogan was reviewed and approved* by the following: Ross C. Hardison T. Ming Chu Professor of Biochemistry and Molecular Biology Dissertation Advisor Chair of Committee David S. Gilmour Professor of Molecular and Cell Biology Anton Nekrutenko Professor of Biochemistry and Molecular Biology Robert F. Paulson Professor of Veterinary and Biomedical Sciences Philip Reno Assistant Professor of Antropology Scott B. Selleck Professor and Head of the Department of Biochemistry and Molecular Biology *Signatures are on file in the Graduate School iii ABSTRACT Genome-wide measurements of epigenetic features such as histone modifications, occupancy by transcription factors and coactivators provide the opportunity to understand more globally how genes are regulated. While much effort is being put into integrating the marks from various combinations of features, the contribution of each feature to accuracy of enhancer prediction is not known. We began with predictions of 4,915 candidate erythroid enhancers based on genomic occupancy by TAL1, a key hematopoietic transcription factor that is strongly associated with gene induction in erythroid cells. Seventy of these DNA segments occupied by TAL1 (TAL1 OSs) were tested by transient transfections of cultured hematopoietic cells, and 56% of these were active as enhancers. Sixty-six TAL1 OSs were evaluated in transgenic mouse embryos, and 65% of these were active enhancers in various tissues.
    [Show full text]
  • Signaling Pathway Activities Improve Prognosis for Breast Cancer Yunlong Jiao1,2,3,4, Marta R
    bioRxiv preprint doi: https://doi.org/10.1101/132357; this version posted April 29, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. Signaling Pathway Activities Improve Prognosis for Breast Cancer Yunlong Jiao1,2,3,4, Marta R. Hidalgo5, Cankut Çubuk6, Alicia Amadoz5, José Carbonell- Caballero5, Jean-Philippe Vert1,2,3,4, and Joaquín Dopazo6,7,8,* 1MINES ParisTech, PSL Research University, Centre for Computational Biology, 77300 Fontainebleau, France; 2Institut Curie, 75248 Paris Cedex, Franc; 3INSERM, U900, 75248 Paris Cedex, France; 4Ecole Normale Supérieure, Department of Mathematics and their Applications, 75005 Paris, France; 5 Computational Genomics Department, Centro de Investigación Príncipe Felipe (CIPF), 46012 Valencia, Spain; 6Clinical Bioinformatics Research Area, Fundación Progreso y Salud (FPS), Hospital Virgen del Rocío, 41013, Sevilla, Spain; 7Functional Genomics Node (INB), FPS, Hospital Virgen del Rocío, 41013 Sevilla, Spain; 8 Bioinformatics in Rare Diseases (BiER), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), FPS, Hospital Virgen del Rocío, 41013, Sevilla, Spain *To whom correspondence should be addressed. Abstract With the advent of high-throughput technologies for genome-wide expression profiling, a large number of methods have been proposed to discover gene-based signatures as biomarkers to guide cancer prognosis. However, it is often difficult to interpret the list of genes in a prognostic signature regarding the underlying biological processes responsible for disease progression or therapeutic response. A particularly interesting alternative to gene-based biomarkers is mechanistic biomarkers, derived from signaling pathway activities, which are known to play a key role in cancer progression and thus provide more informative insights into cellular functions involved in cancer mechanism.
    [Show full text]
  • Lipid Droplets Protect Human Β Cells from Lipotoxic-Induced Stress and Cell
    bioRxiv preprint doi: https://doi.org/10.1101/2021.06.19.449124; this version posted June 20, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Lipid droplets protect human β cells from lipotoxic-induced stress and cell identity changes Xin Tong1 and Roland Stein1,2 1Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 2Corresponding author: [email protected]; Tel: 615-322-7026 1 bioRxiv preprint doi: https://doi.org/10.1101/2021.06.19.449124; this version posted June 20, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Abstract (200 words) Free fatty acids (FFAs) are often stored in lipid droplet (LD) depots for eventual metabolic and/or synthetic use in many cell types, such a muscle, liver, and fat. In pancreatic islets, overt LD accumulation was detected in humans but not mice. LD buildup in islets was principally observed after roughly 11 years of age, increasing throughout adulthood under physiologic conditions, and also enriched in type 2 diabetes. To obtain insight into the role of LDs in human islet β cell function, the levels of a key LD structural protein, perilipin2 (PLIN2), were manipulated by lentiviral-mediated knock-down (KD) or over-expression (OE) in EndoCβH2-Cre cells, a human cell line with adult islet β-like properties.
    [Show full text]
  • Download the Fall Commencement 2020 Program
    FALL 2020 ACADEMIC REGALIA Though our ceremonies look different this year, regalia traditions are beloved, timeless and span decades — and pandemics. Our graduates have earned the right to don regalia and adornments for the rest of their lives that reflect the dedication they have shown to their field and the love they have for their alma mater. The custom of recognizing the accomplishments of scholars through distinctive dress, color and ceremony began in the Middle Ages and has been adopted by various academic institutions throughout the world. American academic regalia developed from the English traditions that originated at the University of Cambridge and the University of Oxford and has been in continuous use in this country since Colonial times. Institutions of higher learning in the United States have adopted a system for identifying different academic degrees by use of specific gowns, hoods and colors. The baccalaureate (bachelor’s) gown is identified by long pointed sleeves. The master’s gown has a very long sleeve, closed at the bottom, and the wearer’s arm is placed through an opening in the front of the sleeve. Master’s gowns also are distinguished by green panels down the front of the gown. Doctoral gowns are distinguished by velvet panels around the neck and down the front of the gown. Three horizontal velvet bars on each sleeve also may mark the doctorate. The colorful hoods worn by master’s and doctoral graduates represent the specific degree earned and the degree-granting institution. Hoods for UNT are distinguished by a kelly-green-and-white chevron lining.
    [Show full text]
  • Common Single-Nucleotide Polymorphisms in the Estrogen Receptor B Promoter Are Associated with Colorectal Cancer Survival in Postmenopausal Women
    Published OnlineFirst November 13, 2012; DOI: 10.1158/0008-5472.CAN-12-2484 Cancer Prevention and Epidemiology Research Common Single-Nucleotide Polymorphisms in the Estrogen Receptor b Promoter Are Associated with Colorectal Cancer Survival in Postmenopausal Women Michael N. Passarelli1,2, Amanda I. Phipps1, John D. Potter1,2,3, Karen W. Makar1, Anna E. Coghill1,2, Karen J. Wernli3,4, Emily White1,2, Andrew T. Chan5,6, Carolyn M. Hutter1,2, Ulrike Peters1,2, and Polly A. Newcomb1,2 Abstract Loss of estrogen receptor b (ERb) expression in the gut is associated with colorectal cancer (CRC) initiation and progression. Germline single-nucleotide polymorphisms (SNP) in genes for the sex-steroid hormone receptors are not strongly associated with CRC risk; however, these SNPs have not previously been evaluated in relation to survival after diagnosis. We enrolled 729 women, ages 50 to 74, diagnosed with invasive CRC between 1997 and 2002 in 13 counties covered by the Seattle-Puget Sound Surveillance Epidemiology and End Results cancer registry. Participants provided germline DNA. We selected 99 tag-SNPs for the androgen receptor (AR), ERa (ESR1), ERb (ESR2), and progesterone receptor (PGR) genes. Mortality outcomes were ascertained from the National Death Index. During a median of 6.6 years of follow-up, 244 deaths occurred (161 from CRC). We identified 20 SNPs (12 of ESR2 and 8 of PGR) for replication in 1,729 women diagnosed with incident invasive CRC (555 deaths; 405 from CRC) from three prospective cohort studies that participate in the Genetics and Epidemiology of Colorectal Cancer Consortium. Three correlated SNPs in the promoter of ESR2 (rs2987983, rs3020443, and rs2978381) were statistically significant predictors of CRC-specific and overall survival.
    [Show full text]
  • Irf1) Signaling Regulates Apoptosis and Autophagy to Determine Endocrine Responsiveness and Cell Fate in Human Breast Cancer
    INTERFERON REGULATORY FACTOR-1 (IRF1) SIGNALING REGULATES APOPTOSIS AND AUTOPHAGY TO DETERMINE ENDOCRINE RESPONSIVENESS AND CELL FATE IN HUMAN BREAST CANCER A Dissertation Submitted to the Faculty of the Graduate School of Arts and Sciences of Georgetown University in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physiology & Biophysics By Jessica L. Roberts, B.S. Washington, DC September 27, 2013 Copyright 2013 by Jessica L. Roberts All Rights Reserved ii INTERFERON REGULATORY FACTOR-1 (IRF1) SIGNALING REGULATES APOPTOSIS AND AUTOPHAGY TO DETERMINE ENDOCRINE RESPONSIVENESS AND CELL FATE IN HUMAN BREAST CANCER Jessica L. Roberts, B.S. Thesis Advisor: Robert Clarke, Ph.D. ABSTRACT Interferon regulatory factor-1 (IRF1) is a nuclear transcription factor and pivotal regulator of cell fate in cancer cells. While IRF1 is known to possess tumor suppressive activities, the role of IRF1 in mediating apoptosis and autophagy in breast cancer is largely unknown. Here, we show that IRF1 inhibits antiapoptotic B-cell lymphoma 2 (BCL2) protein expression, whose overexpression often contributes to antiestrogen resistance. We proposed that directly targeting the antiapoptotic BCL2 members with GX15-070 (GX; obatoclax), a BH3-mimetic currently in clinical development, would be an attractive strategy to overcome antiestrogen resistance in some breast cancers. Inhibition of BCL2 activity, through treatment with GX, was more effective in reducing the cell density of antiestrogen resistant breast cancer cells versus sensitive cells, and this increased sensitivity correlated with an accumulation of autophagic vacuoles. While GX treatment promoted autophagic vacuole and autolysosome formation, p62/SQSTM1, a marker for autophagic degradation, levels accumulated.
    [Show full text]