1
|
Heydari Z, Moeinvaziri F, Mirazimi SMA, Dashti F, Smirnova O, Shpichka A, Mirzaei H, Timashev P, Vosough M. Alteration in DNA methylation patterns: Epigenetic signatures in gastrointestinal cancers. Eur J Pharmacol 2024; 973:176563. [PMID: 38593929 DOI: 10.1016/j.ejphar.2024.176563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/20/2024] [Accepted: 04/03/2024] [Indexed: 04/11/2024]
Abstract
Abnormalities in epigenetic modifications can cause malignant transformations in cells, leading to cancers of the gastrointestinal (GI) tract, which accounts for 20% of all cancers worldwide. Among the epigenetic alterations, DNA hypomethylation is associated with genomic instability. In addition, CpG methylation and promoter hypermethylation have been recognized as biomarkers for different malignancies. In GI cancers, epigenetic alterations affect genes responsible for cell cycle control, DNA repair, apoptosis, and tumorigenic-specific signaling pathways. Understanding the pattern of alterations in DNA methylation in GI cancers could help scientists discover new molecular-based pharmaceutical treatments. This study highlights alterations in DNA methylation in GI cancers. Understanding epigenetic differences among GI cancers may improve targeted therapies and lead to the discovery of new diagnostic biomarkers.
Collapse
Affiliation(s)
- Zahra Heydari
- Institute for Regenerative Medicine, Sechenov University, Moscow, Russia
| | - Farideh Moeinvaziri
- Department of Regenerative Medicine, Cell Science Research Centre, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Seyed Mohammad Ali Mirazimi
- School of Medicine, Kashan University of Medical Sciences, Kashan, Iran; Kashan University of Medical Sciences, Kashan, Iran
| | - Fatemeh Dashti
- School of Medicine, Kashan University of Medical Sciences, Kashan, Iran; Kashan University of Medical Sciences, Kashan, Iran
| | - Olga Smirnova
- Institute for Regenerative Medicine, Sechenov University, Moscow, Russia
| | - Anastasia Shpichka
- Institute for Regenerative Medicine, Sechenov University, Moscow, Russia
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran.
| | - Peter Timashev
- Institute for Regenerative Medicine, Sechenov University, Moscow, Russia; World-Class Research Center "Digital Biodesign and Personalized Healthcare", Sechenov University, Moscow, Russia; Chemistry Department, Lomonosov Moscow State University, Moscow, Russia.
| | - Massoud Vosough
- Department of Regenerative Medicine, Cell Science Research Centre, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
| |
Collapse
|
2
|
Dhanisha SS, Guruvayoorappan C. Pathological Implications of Mucin Signaling in Metastasis. Curr Cancer Drug Targets 2023; 23:585-602. [PMID: 36941808 DOI: 10.2174/1568009623666230320121332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 01/11/2023] [Accepted: 01/25/2023] [Indexed: 03/23/2023]
Abstract
The dynamic mucosal layer provides a selective protective barrier for the epithelial cells lining the body cavities. Diverse human malignancies exploit their intrinsic role to protect and repair epithelia for promoting growth and survival. Aberrant expression of mucin has been known to be associated with poor prognosis of many cancers. However, the emergence of new paradigms in the study of metastasis recognizes the involvement of MUC1, MUC4, MUC5AC, MUC5B, and MUC16 during metastasis initiation and progression. Hence mucins can be used as an attractive target in future diagnostic and therapeutic strategies. In this review, we discuss in detail about mucin family and its domains and the role of different mucins in regulating cancer progression and metastasis. In addition, we briefly discuss insights into mucins as a therapeutic agent.
Collapse
Affiliation(s)
| | - Chandrasekharan Guruvayoorappan
- Laboratory of Immunopharmacology and Experimental Therapeutics, Division of Cancer Research, Regional Cancer Centre, Medical College Campus, University of Kerala, Thiruvananthapuram, Kerala, 695011, India
| |
Collapse
|
3
|
Gundamaraju R, Chong WC. Consequence of distinctive expression of MUC2 in colorectal cancers: How much is actually bad? Biochim Biophys Acta Rev Cancer 2021; 1876:188579. [PMID: 34139275 DOI: 10.1016/j.bbcan.2021.188579] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 12/18/2022]
Abstract
Colorectal cancer (CRC) exhibits complex pathogenesis via compromised intestinal mucosal barrier. It is accepted that goblet cells secrete mucin which line the intestinal mucosal barrier and offer wide range protection and maintain the gut integrity. The principal mucin in the small and large intestine which is Mucin2 (MUC2) is predominantly expressed in the goblet cells which play a pivotal role in intestinal homeostasis. Its disruption is associated with diverse diseases and carcinomas. MUC2 has lately been identified as a principal marker in various mechanisms and secretory cell lineage. While MUC2 expression is regulated by various modulators, alterations in its expression are associated with immunomodulation, differences in tumor immunity and also regulation of microbiota. In the light of current literature, the present review explicates the regulation, functional mechanisms and essential role of MUC2 in colorectal cancer and aids in providing deep understanding of pathogenesis of the disease and also specifies the importance of the MUC2 in gaining more insights about the subtypes of colorectal cancer and how it can succour in approximating the prognosis and survival of the patients.
Collapse
Affiliation(s)
- Rohit Gundamaraju
- ER Stress and Gut Mucosal Immunology Laboratory, School of Health Sciences, University of Tasmania, Launceston, Tasmania 7248, Australia.
| | - Wai Chin Chong
- Centre for Cancer Research, Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia; Department of Molecular and Translational Science, School of Medicine, Nursing, and Health Science, Monash University, Clayton, Victoria 3168, Australia
| |
Collapse
|
4
|
Characterization of the regulatory 5'-flanking region of bovine mucin 2 (MUC2) gene. Mol Cell Biochem 2021; 476:2847-2856. [PMID: 33730299 DOI: 10.1007/s11010-021-04133-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 03/06/2021] [Indexed: 10/21/2022]
Abstract
Throughout the intestinal epithelium surface there is an intricate polymer network composed by gel-forming mucins, which plays a protective role due to the formation of a physical, chemical and immunological barrier between the organism and the environment. Mucin 2 (MUC2) is the main mucin in the small and large intestine, and it is expressed specifically in the gastrointestinal tract (GIT), which makes its promoter region an important candidate for expression of heterologous genes of biotechnological interest in the GIT of bovine and other ruminants. In order to characterize the bovine MUC2 promoter we designed primers to amplify and isolate a candidate region for this promoter. The amplified sequence was confirmed by sequencing and cloned into a plasmid vector containing the luciferase (LUC) reporter gene. The regulatory sites of the MUC2 promoter already described in the literature were used to find the putative regulatory sites in the bovine MUC2 promoter region. With these data, some deletions were performed in order to find the promoter sequence with greatest expression capacity and specificity. The constructions were tested by transient transfection assays in LoVo cells (human colorectal adenocarcinoma) and bovine fibroblasts. The quantification of the relative expression of the promoter was measured using dual-luciferase assays. Real-time PCR was performed to analyze the expression of endogenous MUC2. The results presented herein prove that the isolated sequence corresponds to the promoter of bovine MUC2 gene, since it was able to induce expression of a reporter gene in an in vitro cell culture experimental platform.
Collapse
|
5
|
Yamashita MSDA, Melo EO. Mucin 2 (MUC2) promoter characterization: an overview. Cell Tissue Res 2018; 374:455-463. [PMID: 30218241 DOI: 10.1007/s00441-018-2916-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 08/13/2018] [Indexed: 12/24/2022]
Abstract
Transgenic livestock have been studied with a well-known interest in improving quantitative and qualitative traits. In order to direct heterologous gene expression, it is indispensable to identify and characterize a promoter suitable for directing the expression of the gene of interest (GOI) in a tissue-specific way. The gastrointestinal tract is a desirable target for gene expression in several mammalian models. Throughout the surface of the intestinal epithelium, there is an intricate polymer network, formed by gel-forming mucins (especially MUC2 and MUC5AC, of which MUC2 is the major one), which plays a protective role due to the formation of a physical, chemical and immunological barrier between the organism and the environment. The characterization of the gel-forming mucins is difficult because of their large size and repetitive DNA sequences and domains. The main mucin in the small and large intestine, mucin 2 (MUC2), is expressed specifically in goblet cells. MUC2 plays an important role in intestinal homeostasis and its disruption is associated with several diseases and carcinomas. This mucin is also an important marker for elucidating mechanisms that regulate differentiation of the secretory cell lineage. This review presents the state of the art of MUC2 promoter structure and functional characterization.
Collapse
Affiliation(s)
| | - Eduardo O Melo
- EMBRAPA Genetic Resources and Biotechnology, PqEB Av W5 Norte, Brasilia, DF, 70770-917, Brazil
| |
Collapse
|
6
|
Dhanisha SS, Guruvayoorappan C, Drishya S, Abeesh P. Mucins: Structural diversity, biosynthesis, its role in pathogenesis and as possible therapeutic targets. Crit Rev Oncol Hematol 2017; 122:98-122. [PMID: 29458795 DOI: 10.1016/j.critrevonc.2017.12.006] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/28/2017] [Accepted: 12/12/2017] [Indexed: 12/25/2022] Open
Abstract
Mucins are the main structural components of mucus that create a selective protective barrier for epithelial surface and also execute wide range of other physiological functions. Mucins can be classified into two types, namely secreted mucins and membrane bounded mucins. Alterations in mucin expression or glycosylation and mislocalization have been seen in various types of pathological conditions such as cancers, inflammatory bowel disease and ocular disease, which highlight the importance of mucin in maintaining homeostasis. Hence mucins can be used as attractive target for therapeutic intervention. In this review, we discuss in detail about the structural diversity of mucins; their biosynthesis; its role in pathogenesis; regulation and as possible therapeutic targets.
Collapse
Affiliation(s)
- Suresh Sulekha Dhanisha
- Laboratory of Immunopharmacology and Experimental Therapeutics, Division of Cancer Research, Regional Cancer Centre, Medical College Campus, Thiruvananthapuram 695011, Kerala, India
| | - Chandrasekharan Guruvayoorappan
- Laboratory of Immunopharmacology and Experimental Therapeutics, Division of Cancer Research, Regional Cancer Centre, Medical College Campus, Thiruvananthapuram 695011, Kerala, India.
| | - Sudarsanan Drishya
- Laboratory of Immunopharmacology and Experimental Therapeutics, Division of Cancer Research, Regional Cancer Centre, Medical College Campus, Thiruvananthapuram 695011, Kerala, India
| | - Prathapan Abeesh
- Laboratory of Immunopharmacology and Experimental Therapeutics, Division of Cancer Research, Regional Cancer Centre, Medical College Campus, Thiruvananthapuram 695011, Kerala, India
| |
Collapse
|
7
|
Rousseau K, Swallow DM. Mucin methods: genes encoding mucins and their genetic variation with a focus on gel-forming mucins. Methods Mol Biol 2012; 842:1-26. [PMID: 22259127 DOI: 10.1007/978-1-61779-513-8_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mucin genes encode the polypeptide backbone of the mucin glycoproteins which are expressed on all epithelial surfaces and are major constituents of the mucus layer. Mucins are, thus, expressed at the interface between the external and the internal environment of the organism, and represent the first line of defence of our body. These genes often have an extensive region of repetitive exonic sequence which codes for the heavily glycosylated domain, whose roles include bacterial interactions and gel hydration. This region shows, in several of the genes, considerable inter-individual variation in repeat number and sequence. Because of their site of expression and their high variability in this important domain, mucin genes are good candidates for conferring differences in genetic susceptibility to multifactorial epithelial and inflammatory disease. However, progress in characterizing the genes has been considerably slower than the rest of the genome because of their size and the GC-rich content of the large, repetitive variable region. Some of the issues relating to the study of these genes are discussed in this chapter. In addition, methods and approaches that have been used successfully are described.
Collapse
Affiliation(s)
- Karine Rousseau
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, UK.
| | | |
Collapse
|
8
|
Derrien M, van Passel MWJ, van de Bovenkamp JHB, Schipper RG, de Vos WM, Dekker J. Mucin-bacterial interactions in the human oral cavity and digestive tract. Gut Microbes 2010; 1:254-268. [PMID: 21327032 PMCID: PMC3023607 DOI: 10.4161/gmic.1.4.12778] [Citation(s) in RCA: 377] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 06/20/2010] [Accepted: 06/23/2010] [Indexed: 02/03/2023] Open
Abstract
Mucins are a family of heavily glycosylated proteins that are the major organic components of the mucus layer, the protective layer covering the epithelial cells in many human and animal organs, including the entire gastro-intestinal tract. Microbes that can associate with mucins benefit from this interaction since they can get available nutrients, experience physico-chemical protection and adhere, resulting in increased residence time. Mucin-degrading microorganisms, which often are found in consortia, have not been extensively characterized as mucins are high molecular weight glycoproteins that are hard to study because of their size, complexity and heterogeneity. The purpose of this review is to discuss how advances in mucus and mucin research, and insight in the microbial ecology promoted our understanding of mucin degradation. Recent insight is presented in mucin structure and organization, the microorganisms known to use mucin as growth substrate, with a specific attention on Akkermansia muciniphila, and the molecular basis of microbial mucin degradation owing to availability of genome sequences.
Collapse
Affiliation(s)
- Muriel Derrien
- TI Food and Nutrition; Wageningen University and Research Centre; Wageningen, The Netherlands,Laboratory of Microbiology; Wageningen University and Research Centre; Wageningen, The Netherlands
| | - Mark WJ van Passel
- Laboratory of Microbiology; Wageningen University and Research Centre; Wageningen, The Netherlands
| | - Jeroen HB van de Bovenkamp
- TI Food and Nutrition; Wageningen University and Research Centre; Wageningen, The Netherlands,Laboratory of Food Chemistry; Wageningen University and Research Centre; Wageningen, The Netherlands
| | - Raymond G Schipper
- TI Food and Nutrition; Wageningen University and Research Centre; Wageningen, The Netherlands,Laboratory of Food Chemistry; Wageningen University and Research Centre; Wageningen, The Netherlands
| | - Willem M de Vos
- Laboratory of Microbiology; Wageningen University and Research Centre; Wageningen, The Netherlands,Department of Basic Veterinary Sciences; University of Helsinki; Helsinki, Finland
| | - Jan Dekker
- TI Food and Nutrition; Wageningen University and Research Centre; Wageningen, The Netherlands
| |
Collapse
|
9
|
Sasaki M, Ikeda H, Nakanuma Y. Expression profiles of MUC mucins and trefoil factor family (TFF) peptides in the intrahepatic biliary system: physiological distribution and pathological significance. ACTA ACUST UNITED AC 2007; 42:61-110. [PMID: 17616258 DOI: 10.1016/j.proghi.2007.02.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mucin secreted by mucosal epithelial cells plays a role in the protection of the mucosal surface and also is involved in pathological processes. So far, MUC1-4, 5AC, 5B, 6-8, 11-13 and 15-17 genes coding the backbone mucin core protein have been identified in humans. Their diverse physiological distribution and pathological alterations have been reported. Trefoil factor family (TFF) peptides are mucin-associated molecules co-expressed with MUC mucins and involved in the maintenance of mucosal barrier and the biological behavior of epithelial and carcinoma cells. Intrahepatic biliary system is a route linking the bile canaliculi and the extrahepatic bile duct for the excretion of bile synthesized by hepatocytes. Biliary epithelial cells line in the intrahepatic biliary system, secreting mucin and other molecules involved in the maintenance and regulation of the system. In this review, the latest information regarding properties, expression profiles and regulation of MUC mucins and TFF peptides in the intrahepatic biliary system is summarized. In particular, we focus on the expression profiles and their significance of MUC mucins in developmental and normal livers, various hepatobiliary diseases and intrahepatic cholangiocarcinoma.
Collapse
Affiliation(s)
- Motoko Sasaki
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Takaramachi 13-1, Kanazawa 920-8640, Japan.
| | | | | |
Collapse
|
10
|
Yamada N, Hamada T, Goto M, Tsutsumida H, Higashi M, Nomoto M, Yonezawa S. MUC2 expression is regulated by histone H3 modification and DNA methylation in pancreatic cancer. Int J Cancer 2006; 119:1850-7. [PMID: 16721789 DOI: 10.1002/ijc.22047] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mucins are highly glycosylated proteins that play important roles in carcinogenesis. In pancreatic neoplasia, MUC2 mucin has been demonstrated as a tumor suppressor and we have reported that MUC2 is a favorable prognostic factor. Regulation of MUC2 gene expression is known to be controlled by DNA methylation, but the role of histone modification for MUC2 gene expression has yet to be clarified. Herein, we provide the first report that the histone H3 modification of the MUC2 promoter region regulates MUC2 gene expression. To investigate the histone modification and DNA methylation of the promoter region of the MUC2 gene, we treated 2 human pancreatic cancer cell lines, PANC1 (MUC2-negative) and BxPC3 (MUC2-positive) with the DNA methyltransferase inhibitor 5-azacytidine (5-aza), the histone deacetylase inhibitor trichostatin A (TSA), and a combination of these agents. The DNA methylation level of PANC1 cells was decreased by all 3 treatments, whereas histone H3-K4/K9 methylation and H3-K9/K27 acetylation in PANC1 cells was changed to the level in BxPC3 cells by treatment with TSA alone and with the 5-aza/TSA combination. The expression level of MUC2 mRNA in PANC1 cells exhibited a definite increase when treated with TSA and 5-aza/TSA, whereas 5-aza alone induced only a slight increase. Our results suggest that histone H3 modification in the 5' flanking region play an important role in MUC2 gene expression, possibly affecting DNA methylation. An understanding of these intimately correlated epigenetic changes may be of importance for predicting the outcome of patients with pancreatic neoplasms.
Collapse
Affiliation(s)
- Norishige Yamada
- Department of Human Pathology, Field of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
This review focuses on the role and regulation of mucin glycoproteins (mucins) in airway health and disease. Mucins are highly glycosylated macromolecules (> or =50% carbohydrate, wt/wt). MUC protein backbones are characterized by numerous tandem repeats that contain proline and are high in serine and/or threonine residues, the sites of O-glycosylation. Secretory and membrane-tethered mucins contribute to mucociliary defense, an innate immune defense system that protects the airways against pathogens and environmental toxins. Inflammatory/immune response mediators and the overproduction of mucus characterize chronic airway diseases: asthma, chronic obstructive pulmonary diseases (COPD), or cystic fibrosis (CF). Specific inflammatory/immune response mediators can activate mucin gene regulation and airway remodeling, including goblet cell hyperplasia (GCH). These processes sustain airway mucin overproduction and contribute to airway obstruction by mucus and therefore to the high morbidity and mortality associated with these diseases. Importantly, mucin overproduction and GCH, although linked, are not synonymous and may follow from different signaling and gene regulatory pathways. In section i, structure, expression, and localization of the 18 human MUC genes and MUC gene products having tandem repeat domains and the specificity and application of MUC-specific antibodies that identify mucin gene products in airway tissues, cells, and secretions are overviewed. Mucin overproduction in chronic airway diseases and secretory cell metaplasia in animal model systems are reviewed in section ii and addressed in disease-specific subsections on asthma, COPD, and CF. Information on regulation of mucin genes by inflammatory/immune response mediators is summarized in section iii. In section iv, deficiencies in understanding the functional roles of mucins at the molecular level are identified as areas for further investigations that will impact on airway health and disease. The underlying premise is that understanding the pathways and processes that lead to mucus overproduction in specific airway diseases will allow circumvention or amelioration of these processes.
Collapse
Affiliation(s)
- Mary Callaghan Rose
- Research Center for Genetic Medicine, Room 5700, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
| | | |
Collapse
|
12
|
Andrianifahanana M, Moniaux N, Batra SK. Regulation of mucin expression: mechanistic aspects and implications for cancer and inflammatory diseases. Biochim Biophys Acta Rev Cancer 2006; 1765:189-222. [PMID: 16487661 DOI: 10.1016/j.bbcan.2006.01.002] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 12/30/2005] [Accepted: 01/03/2006] [Indexed: 12/31/2022]
Abstract
Mucins are large multifunctional glycoproteins whose primary functions are to protect and lubricate the surfaces of epithelial tissues lining ducts and lumens within the human body. Several lines of evidence also support the involvement of mucins in more complex biological processes such as epithelial cell renewal and differentiation, cell signaling, and cell adhesion. Recent studies have uncovered the role of select mucins in the pathogenesis of cancer, underscoring the importance of a detailed knowledge about mucin biology. Under normal physiological conditions, the production of mucins is optimally maintained by a host of elaborate and coordinated regulatory mechanisms, thereby affording a well-defined pattern of tissue-, time-, and developmental state-specific distribution. However, mucin homeostasis may be disrupted by the action of environmental and/or intrinsic factors that affect cellular integrity. This results in an altered cell behavior that often culminates into a variety of pathological conditions. Deregulated mucin production has indeed been associated with numerous types of cancers and inflammatory disorders. It is, therefore, crucial to comprehend the underlying basis of molecular mechanisms controlling mucin production in order to design and implement adequate therapeutic strategies for combating these diseases. Herein, we discuss some physiologically relevant regulatory aspects of mucin production, with a particular emphasis on aberrations that pertain to pathological situations. Our views of the achievements, the conceptual and technical limitations, as well as the future challenges associated with studies of mucin regulation are exposed.
Collapse
Affiliation(s)
- Mahefatiana Andrianifahanana
- Department of Biochemistry and Molecular Biology, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 985870 Nebraska Medical Center, Omaha, 68198-5870, USA
| | | | | |
Collapse
|
13
|
Abstract
Mucins, which are complex glycoproteins that provide the viscoelastic properties of mucus that are essential for the protection of the airways, are characterized by a variable-number tandem repeats (VNTR) region that may undergo alternate splicing during transcription. Such transcripts may yield multiple proteins via diverse post-translational modifications involving glycosylation (within each VNTR). Fifteen distinct mucin genes have been identified, with several mapping to chromosomal clusters (ie, 7q22 and 11p15.5), possibly having evolved by gene duplication. The deduced protein sequences can be subdivided into both membrane-associated mucins and secreted mucins. Membrane-associated mucins consist of cytoplasmic, transmembrane, and extracellular domains. The membrane-associated mucins MUC1, MUC4, and MUC11 have been localized to the lung. In addition to VNTRs, secreted mucins possess repeated cysteine-rich D-domains (which are important in polymerization). Secreted mucins that are localized to the lung include MUC2 (in cells with and without secretory granules), MUC5AC (in surface and submucosal mucous cells), MUC5B and MUC8 (in submucosal mucous cells), and MUC7 (in submucosal serous cells). Currently, little is known about the regulation of mucins in COPD patients. Recent studies with acrolein and cigarette smoke have suggested that MUC5AC is inducible (accompanied by epidermal growth factor [EGF] ligand formation and the activation of EGF receptor-dependent pathways), whereas MUC5B is constitutively expressed (increasing through gland enlargement). Similarly, little is known about the genetic determinants that control mucus hypersecretion, but preliminary findings in animal models suggest that intrastrain differences in acrolein-induced mucin formation are amenable to genetic analysis. As our understanding of the functional genomics of mucin biology increases, further clinical targets and therapeutic strategies are likely to emerge.
Collapse
Affiliation(s)
- George D Leikauf
- Molecular Toxicology Division, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267-0056, USA.
| | | | | | | |
Collapse
|
14
|
Abstract
Mucins are glycoproteins that are common on the surfaces of many epithelial cells; they are deemed to mediate many interactions between these cells and their milieu. Several of these mucins form the mucus layer that is found in many hollow organs. The biophysical properties of mucins are related to their extensive O-linked glycosylation rather than directly to their polypeptide sequences. Despite the frequent absence of sequence homology, many human genes encoding mucins have been named MUC followed by a number, unjustly suggesting the existence of one large gene family. In this article, it is suggested that the mucin genes be renamed according to their sequence homologies.
Collapse
Affiliation(s)
- Jan Dekker
- Laboratory of Paediatrics, Erasmus University and Sophia Children's Hospital, Dr Molewaterplein 50, 3015GE, Rotterdam, The Netherlands.
| | | | | | | |
Collapse
|
15
|
Yu CJ, Shew JY, Liaw YS, Kuo SH, Luh KT, Yang PC. Application of mucin quantitative competitive reverse transcription polymerase chain reaction in assisting the diagnosis of malignant pleural effusion. Am J Respir Crit Care Med 2001; 164:1312-8. [PMID: 11673227 DOI: 10.1164/ajrccm.164.7.2102067] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Aberrant expression of mucin genes occurs frequently in advanced cancer. Using quantitative competitive reverse transcriptase/polymerase chain reaction (QC RT-PCR), the expression of three mucin genes--MUC1 (widely expressed in epithelial cells), MUC2 (mainly expressed in intestinal epithelial cells), and MUC5AC (mainly from airway and gastric epithelial cells)--was evaluated in 112 patients with pleural effusions (including 54 cytologically positive malignant pleural effusions, 35 benign exudative pleural fluids, and 23 cytologically negative pleural effusions from cancer patients). The expression ratios of MUC1 and MUC5AC, but not MUC2 gene, were significantly higher in malignant than benign pleural fluids (p < 0.000). The cutoff value, sensitivity, and specificity of MUC1 expression ratio were: 0.126, 64.6%, and 95.7%; and were 0.028, 72.3%, and 95.7%, respectively, for MUC5AC. In combined evaluation with both MUC1 and MUC5AC, the sensitivity was 86.1% and specificity was 91.5%. The positive and negative predictive values were 93.3%, and 82.7%, respectively. We considered mucin QC RT-PCR to be a useful tool in assisting the diagnosis of malignant pleural effusion.
Collapse
Affiliation(s)
- C J Yu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | | | | | | | | | | |
Collapse
|
16
|
|
17
|
Lin J, Ho S, Shekels L, Paparella MM, Kim Y. Mucin gene expression in the rat middle ear: an improved method for RNA harvest. Ann Otol Rhinol Laryngol 1999; 108:762-8. [PMID: 10453784 DOI: 10.1177/000348949910800809] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mucins are heavily glycosylated proteins characterized by high molecular weight and heterogeneous structure. Mucin genes are expressed in a tissue- or epithelium-specific manner. Although mucins are known to be important structural components of the mucociliary transport system that protects epithelium against invading microorganisms, very little is known about mucin gene expression unique to the middle ear. This study demonstrated that middle ear messenger RNA specifically hybridized with rat MUC2 and human MUC2 (SMUC-41) complementary DNA probes. MUC3 and MUC5AC mucin genes, dominantly expressed in rodent intestine and trachea, were not detected in the rat middle ears in this study. The middle ear MUC2 messenger RNA harvested by lavage was characterized by a single transcript--unlike its counterpart in intestine and airways, which is characterized by polydispersity--suggestive of a better method for RNA analysis. It was concluded that rat middle ears possess a MUC2 mucin gene or homologue of human MUC2 (SMUC-41).
Collapse
Affiliation(s)
- J Lin
- Department of Otolaryngology, University of Minnesota School of Medicine, Minneapolis 55455, USA
| | | | | | | | | |
Collapse
|
18
|
Campbell B. Biochemical and Functional Aspects of Mucus and Mucin-Type Glycoproteins. DRUGS AND THE PHARMACEUTICAL SCIENCES 1999. [DOI: 10.1201/b14099-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
19
|
Buisine MP, Desreumaux P, Debailleul V, Gambiez L, Geboes K, Ectors N, Delescaut MP, Degand P, Aubert JP, Colombel JF, Porchet N. Abnormalities in mucin gene expression in Crohn's disease. Inflamm Bowel Dis 1999. [PMID: 10028446 DOI: 10.1002/ibd.3780050105] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Alterations in the structure and/or quantity of mucins could alter the barrier function of mucus and play a role in initiating and maintaining mucosal inflammation in Crohn's disease. To investigate the hypothesis of a mucin gene defect in Crohn's disease, we analyzed the expression of the different mucin genes in the ileal mucosa of patients with Crohn's disease and controls. mRNA expression levels were assessed by a quantitative dot blot analysis and compared (i) between healthy and involved ileal mucosa of patients with Crohn's disease and (ii) between healthy mucosa of patients with Crohn's disease and controls. Expression of the different mucin genes was heterogeneous among controls and patients with Crohn's disease, except for MUC6 in controls. Nevertheless, MUC1 mRNA expression was significantly decreased in the involved ileal mucosa of patients with Crohn's disease when compared to the healthy mucosa (p = 0.02). Moreover, the expression levels of MUC3, MUC4, and MUC5B were significantly lower in both healthy and involved ileal mucosa of patients with Crohn's disease compared to controls (p < or = 0.05). The decrease of expression levels of some mucin genes (more particularly MUC3, MUC4, and MUC5B) in both healthy and involved ileal mucosa suggests a primary or very early mucosal defect of these genes in CD.
Collapse
Affiliation(s)
- M P Buisine
- Laboratoire de Biochimie et Biologie Moléculaire, Hôpital C. Huriez, CH&U Lille, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Buisine MP, Desreumaux P, Debailleul V, Gambiez L, Geboes K, Ectors N, Delescaut MP, Degand P, Aubert JP, Colombel JF, Porchet N. Abnormalities in mucin gene expression in Crohn's disease. Inflamm Bowel Dis 1999; 5:24-32. [PMID: 10028446 DOI: 10.1097/00054725-199902000-00004] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Alterations in the structure and/or quantity of mucins could alter the barrier function of mucus and play a role in initiating and maintaining mucosal inflammation in Crohn's disease. To investigate the hypothesis of a mucin gene defect in Crohn's disease, we analyzed the expression of the different mucin genes in the ileal mucosa of patients with Crohn's disease and controls. mRNA expression levels were assessed by a quantitative dot blot analysis and compared (i) between healthy and involved ileal mucosa of patients with Crohn's disease and (ii) between healthy mucosa of patients with Crohn's disease and controls. Expression of the different mucin genes was heterogeneous among controls and patients with Crohn's disease, except for MUC6 in controls. Nevertheless, MUC1 mRNA expression was significantly decreased in the involved ileal mucosa of patients with Crohn's disease when compared to the healthy mucosa (p = 0.02). Moreover, the expression levels of MUC3, MUC4, and MUC5B were significantly lower in both healthy and involved ileal mucosa of patients with Crohn's disease compared to controls (p < or = 0.05). The decrease of expression levels of some mucin genes (more particularly MUC3, MUC4, and MUC5B) in both healthy and involved ileal mucosa suggests a primary or very early mucosal defect of these genes in CD.
Collapse
Affiliation(s)
- M P Buisine
- Laboratoire de Biochimie et Biologie Moléculaire, Hôpital C. Huriez, CH&U Lille, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Buisine MP, Desseyn JL, Porchet N, Degand P, Laine A, Aubert JP. Genomic organization of the 3'-region of the human MUC5AC mucin gene: additional evidence for a common ancestral gene for the 11p15.5 mucin gene family. Biochem J 1998; 332 ( Pt 3):729-38. [PMID: 9620876 PMCID: PMC1219534 DOI: 10.1042/bj3320729] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human mucin gene MUC5AC is mapped clustered with MUC2, MUC5B and MUC6 on chromosome 11p15.5. We report here the isolation and characterization of a genomic cosmid clone, designated ELO9, spanning the 3'-region of MUC5AC and the 5'-region of MUC5B, allowing us to conclude that MUC5AC and MUC5B have the same transcriptional orientation. We determined the genomic organization and the entire sequence of the 3'-region of MUC5AC. The comparative molecular analysis of MUC5AC and MUC5B points to a remarkable similarity in the size and the distribution of exons, and in the type of splice sites, supporting the notion that MUC5AC and MUC5B have evolved from a single common ancestral gene. The derivation of the four genes of the 11p15.5 mucin gene family from a single ancestral gene is discussed.
Collapse
Affiliation(s)
- M P Buisine
- INSERM Unité 377, Place de Verdun, 59045 Lille Cedex, France
| | | | | | | | | | | |
Collapse
|
22
|
Göttke MU, Keller K, Belley A, Garcia RM, Hollingsworth MA, Mack DR, Chadee K. Functional heterogeneity of colonic adenocarcinoma mucins for inhibition of Entamoeba histolytica adherence to target cells. J Eukaryot Microbiol 1998; 45:17S-23S. [PMID: 9561779 DOI: 10.1111/j.1550-7408.1998.tb04519.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Mucins secreted from the gastrointestinal epithelium from the basis of the adherent mucus layer which is the host's first line of defense against invasion by Entamoeba histolytica. Galactose and N-acetyl-D-galactosamine residues of mucins specifically inhibit binding of the amebic 170 kDa heavy subunit Gal-lectin to target cells, an absolute prerequisite for pathogenesis. Herein we characterized the secretory mucins isolated from the human colon and from three human colonic adenocarcinoma cell lines: two with goblet cell-like (LS174T and T84) and one with absorptive cell-like morphology (Caco-2). By Northern blot analysis the intestinal mucin genes MUC2 and MUC3 were constitutively expressed by confluent LS174T and Caco-2 cells, whereas T84 cells only transcribed MUC2 and not MUC3 mRNA. 3H-glucosamine and 3H-threonine metabolically labeled proteins separated as high M, mucins in the void (Vo > 10(6) Da) of Sepharose-4B column chromatography and remained in the stacking gel of SDS-PAGE as depicted by fluorography. All mucin preparations contained high amounts of N-acetyl-glucosamine, galactose, N-acetyl-galactosamine, fucose and sialic acid, saccharides typical of the O-linked carbohydrate side chains. Mucin samples from the human colon and from LS174T and Caco-2 cells inhibited E. histolytica adherence to chinese hamster ovary cells, whereas mucins from T84 cells did not. These results suggest that genetic heterogeneity and/or posttranslational modification in glycosylation of colonic mucins can affect specific epithelial barrier function against intestinal pathogens.
Collapse
Affiliation(s)
- M U Göttke
- Institute of Parasitology, McGill University, Québec, Canada
| | | | | | | | | | | | | |
Collapse
|
23
|
Desseyn JL, Aubert JP, Van Seuningen I, Porchet N, Laine A. Genomic organization of the 3' region of the human mucin gene MUC5B. J Biol Chem 1997; 272:16873-83. [PMID: 9201995 DOI: 10.1074/jbc.272.27.16873] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
MUC5B, mapped clustered with MUC6, MUC2, and MUC5AC to chromosome 11p15.5, is a human mucin gene of which the genomic organization is being elucidated. We have recently published the sequence and the peptide organization of its huge central exon, 10,713 base pairs (bp) in length. We present here the genomic organization of its 3' region, which encompasses 10,690 bp. The genomic sequence has been completely determined. The 3' region of MUC5B is composed of 18 exons ranging in size from 32 to 781 bp, contrasting thus with the very large central exon. The sizes of the 18 introns range from 114 to 1118 bp. Some repetitive sequences were identified in four introns. The peptide deduced from the sequence of the 18 exons consists of an 808-amino acid peptide. This carboxyl-terminal region exhibits extensive sequence similarity to MUC2, MUC5AC, and von Willebrand factor, particularly the number and the positions of the cysteine residues, suggesting that this domain may be derived from a common ancestral gene. The presence in these components of a cystine knot also found in growth factors such as transforming growth factor-beta is of particular interest. Moreover, one part of this peptide is identical to the 196-amino acid sequence deduced from the cDNA clone pSM2-1, which codes for a part of the high molecular weight mucin MG1 isolated from human sublingual gland. Considering the expression pattern of MUC5B and the origin of MG1, we can thus conclude that MUC5B encodes MG1.
Collapse
Affiliation(s)
- J L Desseyn
- Unité 377 INSERM, Place de Verdun, 59045 Lille Cedex, France
| | | | | | | | | |
Collapse
|
24
|
Toribara NW, Ho SB, Gum E, Gum JR, Lau P, Kim YS. The carboxyl-terminal sequence of the human secretory mucin, MUC6. Analysis Of the primary amino acid sequence. J Biol Chem 1997; 272:16398-403. [PMID: 9195947 DOI: 10.1074/jbc.272.26.16398] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The distribution of MUC6 suggests that its primary function is protection of vulnerable epithelial surfaces from damaging effects of constant exposure to a wide range of endogenous caustic or proteolytic agents. A combination of genomic, cDNA. and 3' rapid amplification of cDNA ends techniques was used to isolate the carboxyl-terminal end of MUC6. The 3' nontandem repeat region contained 1083 base pairs of coding sequence (361 amino acids) followed by 632 base pairs of 3'-untranslated region. The coding sequence consists of two distinct regions; region 1 contained the initial 270 amino acids (62% Ser-Thr-Pro with no Cys residues), and region 2 contained the COOH-terminal 91 amino acids (22% Ser-Thr-Pro with 12% Cys). Although region 1 had no homology to any sequences in GenBank, region 2 had approximately 25% amino acid homology to the COOH-terminal regions of human mucins MUC2, -5, and -5B and von Willebrand factor. The shortness of region 2 would leave little of the peptide backbone exposed to a potentially hostile environment. Antibody studies suggest that MUC6 in its native form exists as a disulfide-bonded multimer. The conservation of the 11 cysteine positions in region 2 suggests the importance of this short region to mucin polymerization.
Collapse
Affiliation(s)
- N W Toribara
- Gastrointestinal Research Laboratory, Department of Veterans Affairs Medical Center and the Division of Gastroenterology, University of California, San Francisco, California 94121, USA
| | | | | | | | | | | |
Collapse
|
25
|
Velcich A, Palumbo L, Selleri L, Evans G, Augenlicht L. Organization and regulatory aspects of the human intestinal mucin gene (MUC2) locus. J Biol Chem 1997; 272:7968-76. [PMID: 9065467 DOI: 10.1074/jbc.272.12.7968] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The human MUC2 gene maps to chromosome 11p15, where three additional mucin genes have been located, and encodes the most abundant gastrointestinal mucin normally expressed in the intestinal goblet cell lineage. However, in pathological conditions, including colorectal cancer, MUC2 can be abnormally expressed. Therefore, it is of considerable interest to understand the regulation of the MUC2 gene and how the mechanism is altered in colon cancer. Toward this goal, we have isolated a group of overlapping clones (contig) spanning 85 kilobases harboring the entire MUC2 locus, including sequences located upstream of the gene. Detection of two DNase I-hypersensitive sites in the 5' region of the MUC2 gene suggests the presence of DNA regulatory elements. To better characterize this region, we have sequenced 12 kilobases of the upstream region and analyzed it for functional activity by cloning portions of it into a luciferase reporter vector and assaying for promoter/enhancer activity using a transient transfection assay. A fragment from the AUG translational initiation codon +1 to -848 confers maximal transcriptional activity in several intestinal cell lines. Elements located further upstream exert a negative effect on the expression of the reporter gene when tested in conjunction with homologous or heterologous promoters. The same pattern of expression is observed when the MUC2/luciferase constructs are transfected into HeLa cells, which do not express the endogenous MUC2 gene. However, the level of activity in HeLa cells is at least an order of magnitude higher, suggesting that additional sequences singularly or in combination are responsible for the tissue- and cell lineage-specific expression of MUC2. Finally, we have identified an additional mucin-like gene (MUCX), located upstream of MUC2. We show that this MUCX gene, that is transcribed in opposite orientation to that of MUC2, is expressed with a pattern distinct from that of MUC2, yet similar to that of MUC5B and MUC6, two additional mucin genes located at chromosome 11p15. Recent information on the order of the mucin genes at chromosome 11p15 suggests that MUCX may be MUC6, one of the already identified mucin genes, or a novel one, yet to be fully characterized.
Collapse
Affiliation(s)
- A Velcich
- Department of Oncology, Montefiore Medical Center/Albert Einstein Cancer Center, Bronx, New York 10467, USA.
| | | | | | | | | |
Collapse
|
26
|
Klinga-Levan K, Gum JR, Gendler SJ, Kim Y, Hansson GC. Chromosomal mapping of three mucin genes in the rat. Mamm Genome 1996; 7:248-50. [PMID: 8833262 DOI: 10.1007/s003359900075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- K Klinga-Levan
- Department of Genetics, Goteborg University, Gothenburg, Sweden
| | | | | | | | | |
Collapse
|
27
|
Chapter 11 Human mucosal mucins in diseases. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0167-7306(08)60297-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|
28
|
Shekels LL, Lyftogt C, Kieliszewski M, Filie JD, Kozak CA, Ho SB. Mouse gastric mucin: cloning and chromosomal localization. Biochem J 1995; 311 ( Pt 3):775-85. [PMID: 7487932 PMCID: PMC1136070 DOI: 10.1042/bj3110775] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mucins protect gastric epithelium by maintaining a favourable pH gradient and preventing autodigestion. The purpose of this study was to clone a mouse gastric mucin which would provide a foundation for analysis of mucin gene regulation. Mucin was purified from the glandular portion of gastric specimens and deglycosylated by HF solvolysis. Antibodies against native and deglycosylated mouse gastric mucin (MGM) were raised in chickens. Screening of a mouse stomach cDNA library with the anti-(deglycosylated MGM) antibody yielded partial clones containing a 48 bp tandem repeat and 768 bp of non-repetitive sequence. The 16-amino-acid tandem repeat has a consensus sequence of QTSSPNTGKTSTISTT with 25% serine and 38% threonine. The MGM tandem repeat sequence bears no similarity to previously identified mucins. The MGM non-repetitive region shares sequence similarity with human MUC5AC and, to a lesser extent, human MUC2 and rat intestinal mucin. Northern blot analysis reveals a polydisperse message beginning at 13.5 kb in mouse stomach with no expression in oesophagus, trachea, small intestine, large intestine, caecum, lung or kidney. Immunoreactivity of antibodies against deglycosylated MGM and against a synthetic MGM tandem repeat peptide was restricted to superficial mucous cells, antral glands and Brunner's glands in the pyloric-duodenal region. DNA analysis shows that MGM recognizes mouse and rat DNA but not hamster, rabbit or human DNA. The MGM gene maps to a site on mouse chromosome 7 homologous to the location of a human secretory mucin gene cluster on human chromosome 11p15. Due to sequence similarity and predominant expression in the stomach, the MGM gene may be considered a MUC5AC homologue and named Muc5ac.
Collapse
Affiliation(s)
- L L Shekels
- Department of Medicine, University of Minnesota, Minneapolis 55417, USA
| | | | | | | | | | | |
Collapse
|
29
|
Lesuffleur T, Roche F, Hill AS, Lacasa M, Fox M, Swallow DM, Zweibaum A, Real FX. Characterization of a mucin cDNA clone isolated from HT-29 mucus-secreting cells. The 3' end of MUC5AC? J Biol Chem 1995; 270:13665-73. [PMID: 7775418 DOI: 10.1074/jbc.270.23.13665] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
HT-29 cells resistant to 10(-6) M methotrexate (HT29-MTX) secrete mucins with gastric immunoreactivity (Lesuffleur, T., Barbat, A., Dussaulx, E., and Zweibaum, A. (1990) Cancer Res. 50, 6334-6343). A 3310-base pair mucin cDNA clone (L31) was isolated from an HT29-MTX expression library using a polyclonal serum specific for normal gastric mucosa. It shows a high level of identity (98.6%) to clone NP3a isolated from a nasal polyp cDNA library (Meerzaman, D., Charles, P., Daskal, E., Polymeropoulos, M. H., Martin, B. M., and Rose, M. C. (1994) J. Biol. Chem. 269, 12932-12939). However, as a result of changes in reading frame, the 1042-amino acid deduced peptide contains four regions of a low similarity to the NP3a peptide. The amino acid sequence shows 36.3% similarity to part of the carboxyl-terminal sequence of MUC2 including the so-called D4 domain and 21.3% to the pro von Willebrand factor. A short amino acid sequence is similar to cysteine-rich sequences repeated in tracheobronchial, gastric, and colonic mucin cDNAs. The gene corresponding to L31 is located in the mucin gene cluster on chromosome 11p15.5. The patterns of mRNA expression were indistinguishable from those revealed with the JER58 probe (MUC5AC). Southern blot analysis indicates that the L31 and JER 58 sequences are within 20 kilobase pairs of each other. Together, these results suggest that L31 clone is the 3' end of MUC5AC.
Collapse
|
30
|
Abstract
Mucins are a family of high molecular weight, highly glycosylated glycoproteins found in the apical cell membrane of human epithelial cells from the mammary gland, salivary gland, digestive tract, respiratory tract, kidney, bladder, prostate, uterus and rete testis. Increased synthesis of the core protein and alterations in the carbohydrates attached to these glycoproteins are believed to play important roles in the function and proliferation of tumour cells. Aberrant glycosylation leads not only to the production of novel carbohydrate structures, but also to the exposure of the core peptide. These novel epitopes may be candidates for diagnosis or therapy, by using either synthetic mucin fragments as vaccines, or monoclonal antibody-based reagents which detect these structures.
Collapse
Affiliation(s)
- P L Devine
- Medical Innovations Ltd., Labrador, Queensland, Australia
| | | |
Collapse
|
31
|
Guyonnet Duperat V, Audie JP, Debailleul V, Laine A, Buisine MP, Galiegue-Zouitina S, Pigny P, Degand P, Aubert JP, Porchet N. Characterization of the human mucin gene MUC5AC: a consensus cysteine-rich domain for 11p15 mucin genes? Biochem J 1995; 305 ( Pt 1):211-9. [PMID: 7826332 PMCID: PMC1136451 DOI: 10.1042/bj3050211] [Citation(s) in RCA: 156] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To date five human mucin cDNAs (MUC2, 5A, 5B, 5C and 6) mapped to 11p15.3-15.5, so it appears that this chromosome region might contain several distinct gene loci for mucins. Three of these cDNAs, MUC5A, B and C, were cloned in our laboratory and previously published. A common number, 5, was recommended by the Human Gene Mapping Nomenclature Committee to designate them because of their common provenance from human tracheobronchial mucosa. In order to define whether they are products of the same gene locus or distinct loci, we describe in this paper physical mapping of these cDNAs using the strategy of analysis of CpG islands by pulse-field gel electrophoresis. The data suggest that MUC5A and MUC5C are part of the same gene (called MUC5AC) which is distinct from MUC5B. In the second part of this work, complete sequences of the inserts corresponding to previously described (JER47, JER58) and novel (JER62, JUL32, MAR2, MAR10 and MAR11) cDNAs of the so-called MUC5AC gene are presented and analysed. The data show that in this mucin gene, the tandem repeat domain is interrupted several times with a subdomain encoding a 130 amino acid cysteine-rich peptide in which the TR3A and TR3B peptides previously isolated by Rose et al. [Rose, Kaufman and Martin (1989) J. Biol. Chem., 264, 8193-8199] from airway mucins are found. A consensus peptide sequence for these subdomains involving invariant positions of most of the cysteines is proposed. The consensus nucleotide sequence of this subdomain is also found in the MUC2 gene and in the MUC5B gene, two other mucin genes mapped to 11p15. The functional significance for secreted mucins of these cysteine-rich subdomains and the modular organization of mucin peptides are discussed.
Collapse
|
32
|
Lesuffleur T, Zweibaum A, Real FX. Mucins in normal and neoplastic human gastrointestinal tissues. Crit Rev Oncol Hematol 1994; 17:153-80. [PMID: 7865137 DOI: 10.1016/1040-8428(94)90053-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- T Lesuffleur
- Unité de Recherches sur la Différenciation Cellulaire Intestinale, INSERM U178, Villejuif, France
| | | | | |
Collapse
|
33
|
Chang SK, Dohrman AF, Basbaum CB, Ho SB, Tsuda T, Toribara NW, Gum JR, Kim YS. Localization of mucin (MUC2 and MUC3) messenger RNA and peptide expression in human normal intestine and colon cancer. Gastroenterology 1994; 107:28-36. [PMID: 8020672 DOI: 10.1016/0016-5085(94)90057-4] [Citation(s) in RCA: 207] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND/AIMS Several studies have reported Northern blot data showing that mucin is expressed in a tissue-specific manner. To determine whether expression is limited to specific cell types within these tissues requires histological analysis. METHODS Both immunocytochemistry and in situ hybridization were used to identify cell types expressing the MUC2 and MUC3 mucins in the human small intestine, colon, and colon carcinoma. RESULTS In the normal small intestine and colon, an antibody recognizing the MUC2 apomucin stained goblet cells. In contrast, an antibody recognizing the MUC3 apomucin stained both goblet and absorptive cells. Consistent with this, in situ hybridization showed MUC2 messenger RNA (mRNA) only in goblet cells and MUC3 mRNA in both goblet and absorptive cells. In several samples of moderately well-differentiated colon cancer, MUC2 and MUC3 showed distinct patterns of expression, but the expression level of each was reduced compared with levels in normal tissue; there was considerable tumor-to-tumor and cell-to-cell variability using both mucin antibodies and complementary DNA probes. CONCLUSIONS Individual mucin genes have distinct patterns of expression within mucin-producing tissues, suggesting that the various mucin gene products play distinct functional roles.
Collapse
Affiliation(s)
- S K Chang
- Gastrointestinal Research Laboratory, Veterans Affairs Medical Center, San Francisco, California
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Carrato C, Balague C, de Bolos C, Gonzalez E, Gambus G, Planas J, Perini JM, Andreu D, Real FX. Differential apomucin expression in normal and neoplastic human gastrointestinal tissues. Gastroenterology 1994; 107:160-72. [PMID: 8020658 DOI: 10.1016/0016-5085(94)90073-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND/AIMS The cloning of genes encoding human mucins is the basis for the study of their normal tissue distribution and the alterations associated with cancer. The aim of this study was to determine the normal and tumor tissue expression of MUC1, MUC2, MUC5B, and MUC5C. METHODS The reactivity of apomucin-specific antibodies with fresh normal and tumor tissues was analyzed using immunohistochemical techniques. RESULTS Anti-MUC1 antibodies reacted with most glandular epithelia. Anti-MUC2 antibody was mainly reactive with intestinal goblet cells and cervical mucous cells. Anti-MUC5B was reactive with a wide range of epithelial tissues whereas anti-MUC5C was reactive with stomach, trachea, and endocervix. Double-labeling experiments showed coexpression of MUC1/MUC2 and MUC2/MUC5C in colonic tissue. Multiple apomucins were detected in colon cancers, but no relationship to histochemical mucus stains was observed. CONCLUSIONS It is concluded that (1) each apomucin shows a distinct tissue expression pattern; (2) multiple apomucins are present in a single tissue and at the single cell level; and (3) altered apomucin expression takes place in pathological colonic tissue.
Collapse
Affiliation(s)
- C Carrato
- Departament d'Immunologia, Universitat Autònoma de Barcelona, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Meezaman D, Charles P, Daskal E, Polymeropoulos M, Martin B, Rose M. Cloning and analysis of cDNA encoding a major airway glycoprotein, human tracheobronchial mucin (MUC5). J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)99965-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
36
|
Walsh MD, Hohn BG, Thong W, Devine PL, Gardiner RA, Samaratunga ML, McGuckin MA. Mucin expression by transitional cell carcinomas of the bladder. BRITISH JOURNAL OF UROLOGY 1994; 73:256-62. [PMID: 8162502 DOI: 10.1111/j.1464-410x.1994.tb07514.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To examine the presence of a membrane-associated and secreted mucin (MUC1) and a secreted gel-forming mucin (MUC2) in normal and malignant urothelium. MATERIALS AND METHODS Sections were obtained from archival paraffin blocks from 11 patients with nonmalignant urological conditions and 89 patients with transitional cell carcinomas (TCC). Mucin expression was examined by immunohistochemistry using monoclonal antibodies BC2 and 4F1, reactive with epitopes on the protein core of MUC1 and MUC2 respectively. RESULTS In normal urothelium MUC1 was limited predominantly to the apical membranes of the umbrella cell layer. MUC1 was present in all cases of TCC, and the pattern of expression divided into three categories: luminal membrane staining only, luminal plus cytoplasmic staining of intermediate +/- basal layers, or staining of only isolated cells or cell groups. These staining patterns were significantly associated with both tumour grade and stage (P < 0.001), with cytoplasmic staining more prevalent in higher grade and stage tumours. MUC2 was not detected in normal urothelium, and was present in 40% of cases of TCC, characterized by intense granular cytoplasmic staining. No association between MUC2 expression and either tumour grade or stage was demonstrated. CONCLUSION MUC1 mucin was expressed by both normal and malignant urothelium, with increased expression characteristic of higher grade and stage tumours. MUC2 expression was found in 40% of tumours but not in normal urothelium. The role of these mucins in the biology of the bladder requires further investigation.
Collapse
Affiliation(s)
- M D Walsh
- Department of Surgery, University of Queensland, Royal Brisbane Hospital, Herston, Australia
| | | | | | | | | | | | | |
Collapse
|
37
|
Durrant LG, Jacobs E, Price MR. Production of monoclonal antibodies recognising the peptide core of MUC2 intestinal mucin. Eur J Cancer 1994; 30A:355-63. [PMID: 8204359 DOI: 10.1016/0959-8049(94)90256-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A peptide based on the tandem repeat sequence of MUC2 mucin was used to produce a series of monoclonal antibodies (MAb). The fine specificity of these antibodies and their implications for MUC2 expression are presented. Three of the MAbs, 996/1, 996/7 and 995/25, were specific to the MUC2p and failed to bind to peptides based on the MUC1,3,4 tandem repeat sequences whereas three others, 994/152, 994/91 and 996/36, cross reacted with the MUC2p and the MUC3 tandem repeat peptide but not the MUC1 and MUC4 peptides. An antigen, affinity purified from a colorectal tumour on one of the MUC2p-specific MAbs, 996/1, was shown to be a high molecular weight polydisperse, mucin-like antigen. Two of the MAbs, 996/1 and 994/152, recognised MUC2 in tissue sections, although the fine specificity varied between the two MAbs, with 994/152 strongly staining gastric, ileum and kidney epithelia, and MAb 996/1 intensely staining colon, liver and prostate tissues. These antibodies also stained a colorectal cell line, and MAb 994/152 also stained a gastric and an ovarian cell line. Six of the MAbs were used to stain colorectal tumour and adjacent 'normal' colonic mucosa sections. All six stained normal mucosa, but only two of the MAbs, 996/1 and 994/91, stained tumour tissue. The staining probably reflects exposure of cryptic epitopes due to varying levels of glycosylation in different tissues. These anti-MUC2p MAbs may help in determining the normal role of MUC2 mucin and how it is subverted in malignancy.
Collapse
Affiliation(s)
- L G Durrant
- Department of Surgery, University of Nottingham, U.K
| | | | | |
Collapse
|
38
|
Gum J, Hicks J, Toribara N, Siddiki B, Kim Y. Molecular cloning of human intestinal mucin (MUC2) cDNA. Identification of the amino terminus and overall sequence similarity to prepro-von Willebrand factor. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)41965-x] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
39
|
Lesuffleur T, Porchet N, Aubert JP, Swallow D, Gum JR, Kim YS, Real FX, Zweibaum A. Differential expression of the human mucin genes MUC1 to MUC5 in relation to growth and differentiation of different mucus-secreting HT-29 cell subpopulations. J Cell Sci 1993; 106 ( Pt 3):771-83. [PMID: 8308060 DOI: 10.1242/jcs.106.3.771] [Citation(s) in RCA: 188] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mucin expression was analysed, in relation to cell growth, in parental HT-29 cells and in two populations of mucus-secreting HT-29 cells selected by adaptation to methotrexate (HT29-MTX) or 5-fluorouracil (HT29-FU). These two populations express mature mucins that differ in their immunoreactivity to antibodies against gastric (HT29-MTX) or colonic mucins (HT29-FU). In the parental population, at late confluency, only very few cells produce mucins or the MUC1 glycoprotein, this being consistent with the low level of expression of the mRNAs corresponding to the MUC1 to MUC5C mucin genes. In the HT29-MTX and HT29-FU populations, the appearance of mucus droplets, as shown by histochemistry and immunofluorescence, starts a few days after confluency, progressively involving a greater proportion of cells and reaching a steady state at late confluency. The MUC1 glycoprotein appears earlier, already being detectable in preconfluent cells. Its distribution is restricted to the apical surface of the cells and is distinct from that of the mucus droplets. In both populations the growth-related levels of MUC1 mRNA are concordant with the apparent levels of expression of the MUC1 glycoprotein. The levels of MUC2, MUC3, MUC4 and MUC5C mRNAs differ from one population to another and, within each population, according to the stage of the culture. The highest levels of MUC2 and MUC4 mRNAs are found in the HT29-FU cells, whereas the highest levels of MUC3 and MUC5C are found in the HT29-MTX cells, suggesting that the differences observed in the mature mucins expressed by either population may be related to which MUC genes are expressed. In both populations significant or even high levels of MUC mRNAs are already present in early cultures, i.e. at a stage when the mature mucins are not yet detectable, suggesting that mucin maturation is a later event.
Collapse
|
40
|
Khatri IA, Forstner GG, Forstner JF. Suggestive evidence for two different mucin genes in rat intestine. Biochem J 1993; 294 ( Pt 2):391-9. [PMID: 8373354 PMCID: PMC1134467 DOI: 10.1042/bj2940391] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In the present report we describe the isolation and sequence of a partial cDNA (M2-798) for a rat intestinal mucin designated M2. A rat intestinal lambda ZAP II cDNA library was screened using a polyclonal antiserum which was prepared against deglycosylated high-molecular-mass glycopeptides of the purified mucin. Mucin cDNA clones were found to contain tandem repeats of 18 nt which encoded a threonine- and proline-rich peptide having a consensus sequence of TTTPDV. This is the same sequence reported recently by Gum, Hicks, Lagace, Byrd, Toribara, Siddiki, Fearney, Lamport and Kim [(1991) J. Biol. Chem. 266, 22733-22738] for a rat intestinal cDNA called RMUC 176. A novel feature present in the cDNA M2-798 is a 246 nt unique region at the 3' end which encodes a hydrophobic sequence of 82 amino acids. RNA blots probed with M2-798 cDNA produced a single hybridization band between 7.5 and 9.0 kb in rat small intestine and colon. An identical hybridization pattern was obtained with a PCR-generated cDNA probe corresponding solely to the unique hydrophobic region of M2-798, demonstrating that this region is encoded by the authentic M2 mRNA. Our data suggest that the unique region of M2 has the potential to be either a transmembrane region, or a domain which mediates hydrophobic interactions of the mucin with other molecules. Since we have previously reported another rat intestinal cDNA which encodes the C-terminus of a mucin-like peptide (MLP) [Xu, Wang, Huan, Cutz, Forstner and Forstner (1992) Biochem. J. 286, 335-338], we wished to discover whether M2 was encoded by the same gene. RNA blotting experiments with probes specific for M2 and MLP showed different mRNAs for each. The message for M2 (7.5-8.5 kb) was smaller than that for MLP (> 9.5 kb) and, unlike MLP, gave no signal in human colonic LS174T cells. The results of DNA blots probed with M2-798 and an MLP-probe suggest that M2 and MLP are likely to be single-copy genes. It would appear therefore that normal rat intestine, like human intestine, may express two different mucin genes.
Collapse
Affiliation(s)
- I A Khatri
- Department of Biochemistry, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | |
Collapse
|
41
|
Curran M, Atkinson D, Timothy K, Vincent GM, Moss AJ, Leppert M, Keating M. Locus heterogeneity of autosomal dominant long QT syndrome. J Clin Invest 1993; 92:799-803. [PMID: 8102381 PMCID: PMC294917 DOI: 10.1172/jci116653] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Autosomal dominant long QT syndrome (LQT) is an inherited disorder that causes syncope and sudden death from cardiac arrhythmias. In genetic linkage studies of seven unrelated families we mapped a gene for LQT to the short arm of chromosome 11 (11p15.5), near the Harvey ras-1 gene (H ras-1). To determine if the same locus was responsible for LQT in additional families, we performed linkage studies with DNA markers from this region (H ras-1 and MUC2). Pairwise linkage analyses resulted in logarithm of odds scores of -2.64 and -5.54 for kindreds 1977 and 1756, respectively. To exclude the possibility that rare recombination events might account for these results, we performed multipoint linkage analyses using additional markers from chromosome 11p15.5 (tyrosine hydroxylase and D11S860). Multipoint analyses excluded approximately 25.5 centiMorgans of chromosome 11p15.5 in K1756 and approximately 13 centiMorgans in K1977. These data demonstrate that the LQT gene in these kindreds is not linked to H ras-1 and suggest that mutations in at least two genes can cause LQT. While the identification of locus heterogeneity of LQT will complicate genetic diagnosis, characterization of additional LQT loci will enhance our understanding of this disorder.
Collapse
Affiliation(s)
- M Curran
- Division of Cardiology, University of Utah Health Sciences Center, Salt Lake City 84112
| | | | | | | | | | | | | |
Collapse
|
42
|
Pilbrow SJ, Hertzog PJ, Pinczower GD, Linnane AW. Expression of large intestinal mucin antigen (LIMA) epitopes in the normal and neoplastic gastrointestinal tract. J Pathol 1993; 169:361-73. [PMID: 7684076 DOI: 10.1002/path.1711690314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This study has identified the expression in normal and neoplastic gastrointestinal (GI) tract of epitopes on the colonic mucin LIMA (large intestinal mucin antigen), which are unique markers of normal colonic differentiation. Six anti-LIMA monoclonal antibodies (MAbs) (22D4, 9B5, 2C3, 23B2, 46A2, and 10B3) were studied immunohistochemically in normal GI tract, colorectal adenomas, and colorectal and gastric cancers. All MAbs showed specificities consistent with distinct epitopes, five of which were neuraminidase-resistant and four periodate-sensitive. Each reacted with mucin in 60-100 per cent normal colons--MAbs 10B3 and 23B2 also with small intestinal mucin--but none with gastric mucin. Five MAbs showed crypt and regional gradients in normal colon, MAbs, 22D4, 9B5, and 2C3 showing a hierarchy of reactivities in the crypt. Individual adenomas showed decreasing goblet cell (GC) LIMA expression with increasing size. However, 30 per cent of familial adenomatous polyposis (FAP) patients had generalized background losses of 9B5 and 2C3 GC reactivity, retaining 22D4, whilst 44 per cent of non-FAP patients lost 22D4 GC reactivity, regaining 9B5 and 2C3--evidence for polymorphism of mucin expression. All colorectal cancers expressed LIMA epitopes (frequently weaker than normal), and three MAbs (22D4, 9B5, and 2C3) showed deeper than normal staining in adjacent crypts. Eighty-five per cent of gastric cancers also expressed LIMA epitopes.
Collapse
Affiliation(s)
- S J Pilbrow
- Biochemistry Department, Monash University, Clayton, Victoria, Australia
| | | | | | | |
Collapse
|
43
|
Toribara N, Roberton A, Ho S, Kuo W, Gum E, Hicks J, Gum J, Byrd J, Siddiki B, Kim Y. Human gastric mucin. Identification of a unique species by expression cloning. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53402-5] [Citation(s) in RCA: 238] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
44
|
Structure and chromosomal localization of the murine gene encoding GLYCAM 1. A mucin-like endothelial ligand for L selectin. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53641-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
45
|
Gambús G, de Bolós C, Andreu D, Francí C, Egea G, Real FX. Detection of the MUC2 apomucin tandem repeat with a mouse monoclonal antibody. Gastroenterology 1993; 104:93-102. [PMID: 7678241 DOI: 10.1016/0016-5085(93)90840-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND The MUC2 intestinal mucin gene contains tandem repeats of 23 amino acid length that are rich in threonine. METHODS Mouse monoclonal antibody LDQ10 was raised against chemically deglycosylated mucin isolated from LS174T colon cancer nude mouse xenografts. RESULTS LDQ10 reacts with deglycosylated colon cancer mucin and with a synthetic peptide encompassing the MUC2 tandem repeat sequence. In immunohistochemical assays, strong reactivity with goblet cells in colon, small bowel, and stomach is observed; weaker reactivity with mucin-producing cells in other epithelial tissues is shown. The epitope recognized by LDQ10 is localized in the rough endoplasmic reticulum of normal colonic goblet cells. LDQ10 also shows strong reactivity with colorectal and stomach cancers and weaker reactivity with pancreas, breast, and bladder cancers. CONCLUSIONS Antibody LDQ10 detects a peptide epitope of MUC2 that becomes cryptic on glycosylation. Altered synthesis of the MUC2 apomucin takes place in a variety of epithelial cancers.
Collapse
Affiliation(s)
- G Gambús
- Institut Municipal d'Investigació Mèdica, Barcelona, Spain
| | | | | | | | | | | |
Collapse
|
46
|
Shankar V, Tan S, Gilmore MS, Sachdev GP. Molecular cloning of the carboxy terminus of a canine tracheobronchial mucin. Biochem Biophys Res Commun 1992; 189:958-64. [PMID: 1282002 DOI: 10.1016/0006-291x(92)92297-b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A cDNA library constructed from canine tracheal mRNA was screened with polyclonal antiserum specific to canine tracheal apomucin (CTM-A). Eight antibody reactive clones were isolated and purified to clonality. One of the clones, designated pCTM-A, had a 1.7 kb insert and included a single open reading frame with a poly (A)+ tail. The amino acid composition of the encoded protein was consistent with that expected for CTM-A. The fusion protein produced by cloning the 1.7 kb insert in the pMALc expression vector reacted with the purified anti-apomucin CTM-A antibody. Also, polyclonal antibodies raised to the purified protein product encoded by pCTM-A reacted with deglycosylated CTM-A confirming that this clone does indeed code for apomucin CTM-A. This is the first report of a cDNA encoding the C-terminus of a canine tracheal mucin.
Collapse
Affiliation(s)
- V Shankar
- College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City 73190
| | | | | | | |
Collapse
|
47
|
Gum JR. Mucin genes and the proteins they encode: structure, diversity, and regulation. Am J Respir Cell Mol Biol 1992; 7:557-64. [PMID: 1449803 DOI: 10.1165/ajrcmb/7.6.557] [Citation(s) in RCA: 166] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mucins are the structural components of the mucus gels that protect the respiratory, gastrointestinal, and reproductive tracts. These polydisperse glycoproteins (250,000 to 20,000,000 D) are approximately 80% carbohydrate on a mass basis and have a high intrinsic viscosity due to their large size and extreme hydrophilicity. Mucin oligosaccharides, the structures responsible for this hydrophilicity, are heterogeneous in size and structure but are chiefly O-linked, i.e., they initiate from N-acetylgalactosamine residues attached to threonine and serine residues of the polypeptide backbone. Our understanding of the structure of mucins has advanced rapidly in the last few years with the isolation and sequencing of cDNA clones that encode mucin polypeptide backbones. All currently well-characterized mucins have been found to contain extended arrays of tandemly repeated peptides rich in potential O-glycosylation sites. Less is known about the unique sequences that flank the tandem repeat arrays of secretory mucins, but currently available information indicates that these flanking regions contain cysteine-rich stretches that participate in mucin oligomer formation. Thus, secretory mucins appear to consist of oligomers containing heavily glycosylated domains flanked by unique sequences required for polymerization. Progress has also been made in characterizing the genes that encode mucins. At least four human mucin genes are known at present, although many others may remain to be discovered. Moreover, much work remains before we gain an understanding of the mechanisms involved in the expression of mucin genes and their tissue-specific regulation.
Collapse
Affiliation(s)
- J R Gum
- Gastrointestinal Research Laboratory, Department of Veterans Affairs Medical Center, San Francisco, California
| |
Collapse
|
48
|
Gum J, Hicks J, Toribara N, Rothe E, Lagace R, Kim Y. The human MUC2 intestinal mucin has cysteine-rich subdomains located both upstream and downstream of its central repetitive region. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)36620-7] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
49
|
Fox MF, Lahbib F, Pratt W, Attwood J, Gum J, Kim Y, Swallow DM. Regional localization of the intestinal mucin gene MUC3 to chromosome 7q22. Ann Hum Genet 1992; 56:281-7. [PMID: 1362870 DOI: 10.1111/j.1469-1809.1992.tb01154.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The gene MUC3 which codes for a mucin expressed in intestine (Gum et al. 1990) has previously been mapped, using somatic cell hybrids, to chromosome 7. We describe here the regional localization of MUC3 to chromosome 7q22 by in situ hybridization. Preliminary linkage analysis using CEPH (Centre d'Etude du Polymorphisme Humain) families supports this assignment and places MUC3 in the same linkage group as COL1A2 and CFTR.
Collapse
Affiliation(s)
- M F Fox
- MRC Human Biochemical Genetics Unit, Galton Laboratory, University College London, UK
| | | | | | | | | | | | | |
Collapse
|
50
|
Xu G, Huan L, Khatri I, Sajjan US, McCool D, Wang D, Jones C, Forstner G, Forstner J. Human intestinal mucin-like protein (MLP) is homologous with rat MLP in the C-terminal region, and is encoded by a gene on chromosome 11 p 15.5. Biochem Biophys Res Commun 1992; 183:821-8. [PMID: 1550588 DOI: 10.1016/0006-291x(92)90557-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A cDNA specific for a human intestinal mucin (MLP) was amplified by PCR from cDNA of cultured human colonic adenocarcinoma cells, LS174T. The human cDNA shared high sequence homology with a corresponding rat intestinal mucin (MLP) cDNA in the 3' terminal region, and hybridized to the same mRNA (approximately 9.0 Kb) that was recognized by a probe for the MUC-2 human intestinal mucin gene. The gene encoding our human mucin peptide also mapped to chromosome 11 p 15.5, the known locus of MUC-2. Our findings suggest that human MLP and MUC-2 are encoded by the same gene and that rat and human intestinal mucin share a common C-terminal amino acid structure.
Collapse
Affiliation(s)
- G Xu
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|