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Frolov A, Guzman MA, Hayat G, Martin JR. Two Cases of Sporadic Amyotrophic Lateral Sclerosis With Contrasting Clinical Phenotypes: Genetic Insights. Cureus 2024; 16:e56023. [PMID: 38606235 PMCID: PMC11008550 DOI: 10.7759/cureus.56023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2024] [Indexed: 04/13/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disease that affects individuals of diverse racial and ethnic backgrounds. There is currently no cure for ALS, and the number of efficient disease-modifying drugs for ALS is limited to a few, despite the large number of clinical trials conducted in recent years. The latter could be attributed to the significant heterogeneity of ALS clinical phenotypes even in their familial forms. To address this issue, we conducted postmortem genetic screening of two female patients with sporadic ALS (sALS) and contrasting clinical phenotypes. The results demonstrated that despite their contrasting clinical phenotypes, both patients had rare pathologic/deleterious mutations in five genes: ACSM5, BBS12, HLA-DQB1, MUC20, and OBSCN, with mutations in three of those genes being identical: BBS12, HLA-DQB1, and MUC20. Additional groups of mutated genes linked to ALS, other neurologic disorders, and ALS-related pathologies were also identified. These data are consistent with a hypothesis that an individual could be primed for ALS via mutations in a specific set of genes not directly linked to ALS. The disease could be initiated by a concerted action of several mutated genes linked to ALS and the disease's clinical phenotype will evolve further through accessory gene mutations associated with other neurological disorders and ALS-related pathologies.
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Affiliation(s)
- Andrey Frolov
- Center for Anatomical Science and Education, Saint Louis University School of Medicine, Saint Louis, USA
| | - Miguel A Guzman
- Department of Pathology, Saint Louis University School of Medicine, Saint Louis, USA
| | - Ghazala Hayat
- Department of Neurology, Saint Louis University School of Medicine, Saint Louis, USA
- ALS Center of Excellence, Saint Louis University School of Medicine, Saint Louis, USA
| | - John R Martin
- Center for Anatomical Science and Education, Saint Louis University School of Medicine, Saint Louis, USA
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Kumar Murmu A, Pal A, Debnath M, Chakraborty A, Pal S, Banerjee S, Pal A, Ghosh N, Karmakar U, Samanta R. Role of mucin 2 gene for growth in Anas platyrhynchos: a novel report. Front Vet Sci 2023; 10:1089451. [PMID: 38026626 PMCID: PMC10666069 DOI: 10.3389/fvets.2023.1089451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 07/17/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction The mucin gene is expressed in the mucous membrane of the inner layer of the internal organs. Intestinalmucin 2 (MUC2), amajor gel-formingmucin, represents a primary barrier component of mucus layers. Materials and methods This is the first report on the role of mucin genes in growth traits in animals. In this study, we randomly studied Bengal ducks (Anas platyrhynchos) reared from day old to 10 weeks of age under an organized farm and studied the growth parameters as well as body weight and average daily body weight gain. Result and discussion We characterized the mucin gene for Bengal ducks and observed glycosylation and EGF1 (EGF-like domain signature) as important domains for growth traits in ducks. We observed a better expression profile for the mucin gene in high-growing ducks in comparison to that of low-growing ducks with real-time PCR. Hence, the mucin gene may be employed as a marker for growth traits.
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Affiliation(s)
- Anuj Kumar Murmu
- Department of Livestock Production and Management, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Aruna Pal
- Department of Livestock Farm Complex, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Manti Debnath
- Department of Livestock Farm Complex, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Argha Chakraborty
- Department of Livestock Farm Complex, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Subhamoy Pal
- Department of Animal Science, Visva-Bharati University, Santiniketan, West Bengal, India
| | - Samiddha Banerjee
- Department of Livestock Farm Complex, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Abantika Pal
- Department of Computer Science, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India
- University of California, San Francisco, San Francisco, CA, United States
| | - Nilotpal Ghosh
- Department of Livestock Production and Management, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Utpal Karmakar
- Department of Animal Resource Development, Government of West Bengal, Kolkata, India
| | - Rajarshi Samanta
- Department of Livestock Production and Management, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
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Reffsin S, Miller J, Ayyanathan K, Dunagin MC, Jain N, Schultz DC, Cherry S, Raj A. Single cell susceptibility to SARS-CoV-2 infection is driven by variable cell states. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.06.547955. [PMID: 37461472 PMCID: PMC10350037 DOI: 10.1101/2023.07.06.547955] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
The ability of a virus to infect a cell type is at least in part determined by the presence of host factors required for the viral life cycle. However, even within cell types that express known factors needed for infection, not every cell is equally susceptible, suggesting that our knowledge of the full spectrum of factors that promote infection is incomplete. Profiling the most susceptible subsets of cells within a population may reveal additional factors that promote infection. However, because viral infection dramatically alters the state of the cell, new approaches are needed to reveal the state of these cells prior to infection with virus. Here, we used single-cell clone tracing to retrospectively identify and characterize lung epithelial cells that are highly susceptible to infection with SARS-CoV-2. The transcriptional state of these highly susceptible cells includes markers of retinoic acid signaling and epithelial differentiation. Loss of candidate factors identified by our approach revealed that many of these factors play roles in viral entry. Moreover, a subset of these factors exert control over the infectable cell state itself, regulating the expression of key factors associated with viral infection and entry. Analysis of patient samples revealed the heterogeneous expression of these factors across both cells and patients in vivo. Further, the expression of these factors is upregulated in particular inflammatory pathologies. Altogether, our results show that the variable expression of intrinsic cell states is a major determinant of whether a cell can be infected by SARS-CoV-2.
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Affiliation(s)
- Sam Reffsin
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Jesse Miller
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kasirajan Ayyanathan
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Margaret C. Dunagin
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Naveen Jain
- Genetics and Epigenetics, Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David C. Schultz
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Sara Cherry
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
- Department of Microbiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Arjun Raj
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Xue B, Guo WM, Jia JD, Kadeerhan G, Liu HP, Bai T, Shao Y, Wang DW. MUC20 as a novel prognostic biomarker in ccRCC correlating with tumor immune microenvironment modulation. Am J Cancer Res 2022; 12:695-712. [PMID: 35261796 PMCID: PMC8899979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023] Open
Abstract
Tumor microenvironment (TME) broadly participates in genesis development of clear cell renal cell carcinoma (ccRCC). To recognize the immune and stromal modulation in TME, we screened the differentially expressed TME-related genes generated by the ESTIMATE algorithm in ccRCC specimens. Following the construction of protein-protein interaction (PPI) network and univariate COX regression, mucin 20 (MUC20) was judged to be a predictive factor. Further analysis, including immunohistochemistry (IHC) showed that MUC20 was positively correlated with survival and negatively correlated with the clinicopathologic characteristics (grade, clinical and TNM stages) in ccRCC patients. Gene Set Enrichment Analysis suggested that the low-expression MUC20 group was primarily enriched in immune-related activities, inflammation and epithelial-mesenchymal transition. Based on the CIBERSORT analysis for tumor-infiltrating immune cells (TICs), MUC20 was positively correlated with CD8+ T cells and resting mast cells and negatively correlated with activated CD4+ memory T cells, Treg cells, and plasma cells, implying that MUC20 may contribute to immune component in TME. Additionally, the patients with low MUC20 expression had better response to immune checkpoint blockades (ICBs) and 17 potential anticancer drugs were screened regarding calculating IC50 value. Thus, MUC20 may contain a value of prognosis assessment for ccRCC patients and indicate the immune modulation status of TME, which provided a novel insight for comprehensive immunotherapy.
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Affiliation(s)
- Bo Xue
- Shanxi Medical UniversityTaiyuan 030001, Shanxi, China
| | - Wen-Min Guo
- Department of Urology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhen 518116, Guangdong, China
| | - Jie-Dong Jia
- Department of Urology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhen 518116, Guangdong, China
| | - Gaohaer Kadeerhan
- Department of Urology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhen 518116, Guangdong, China
| | - Hua-Ping Liu
- Department of Urology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhen 518116, Guangdong, China
| | - Tao Bai
- Department of Pathology, First Hospital of Shanxi Medical UniversityTaiyuan 030001, Shanxi, China
| | - Yuan Shao
- Shanxi Medical UniversityTaiyuan 030001, Shanxi, China
| | - Dong-Wen Wang
- Shanxi Medical UniversityTaiyuan 030001, Shanxi, China
- Department of Urology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhen 518116, Guangdong, China
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Wang X, Shirazi F, Yan W, Liu X, Wang H, Orlowski RZ, Wang H. Mucin 20 modulates proteasome capacity through c-Met signalling to increase carfilzomib sensitivity in mantle cell lymphoma. J Cell Mol Med 2021; 25:10164-10174. [PMID: 34651428 PMCID: PMC8572801 DOI: 10.1111/jcmm.16953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 09/08/2021] [Accepted: 09/11/2021] [Indexed: 11/28/2022] Open
Abstract
Mantle cell lymphoma (MCL) is a haematologic malignancy. The proteasome inhibitor (PI) bortezomib has been approved to treat MCL, but resistance has emerged through mechanisms that remain unclear. This study aimed to explore the mechanism of PI resistance in MCL and identify new targets for this patient subgroup. Carfilzomib‐resistant (CR) MCL cell lines and primary samples were used for both in vitro and in vivo experiments to identify gene expression and explore their related signalling pathways. We first identified mucin 20 (MUC20) suppression in carfilzomib‐resistant MCL models. MUC20 overexpression sensitized cells to carfilzomib in vitro and in vivo. MUC20 expression was inversely related to activation of c‐Met and the downstream p44/42 MAPK pathway. c‐Met activation with hepatocyte growth factor (HGF) induced PI resistance, while c‐Met inhibition restored PI sensitivity. Carfilzomib resistance and depressed MUC20 expression were associated with enhanced proteasome activity and higher expression of proteassemblin (POMP), a chaperone for catalytically active proteasome assembly. c‐Met and POMP were associated through binding and induction of MAPK‐regulated ELK1 to the POMP promoter. Our data reveal that c‐Met signalling activation enhanced proteasome capacity as a mechanism of PI resistance, and MUC20 expression may be a useful biomarker for PI therapy.
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Affiliation(s)
- Xiaobin Wang
- The Departments of Hematology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Fazal Shirazi
- The Departments of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Wei Yan
- The Departments of Hematology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Xiaoyu Liu
- The Departments of Hematology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Hua Wang
- The Departments of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Robert Z Orlowski
- The Departments of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Huihan Wang
- The Departments of Hematology, Shengjing Hospital, China Medical University, Shenyang, China
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Martinez-Carrasco R, Argüeso P, Fini ME. Membrane-associated mucins of the human ocular surface in health and disease. Ocul Surf 2021; 21:313-330. [PMID: 33775913 PMCID: PMC8328898 DOI: 10.1016/j.jtos.2021.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/02/2021] [Accepted: 03/08/2021] [Indexed: 02/06/2023]
Abstract
Mucins are a family of high molecular weight, heavily-glycosylated proteins produced by wet epithelial tissues, including the ocular surface epithelia. Densely-packed O-linked glycan chains added post-translationally confer the biophysical properties of hydration, lubrication, anti-adhesion and repulsion. Membrane-associated mucins (MAMs) are the distinguishing components of the mucosal glycocalyx. At the ocular surface, MAMs maintain wetness, lubricate the blink, stabilize the tear film, and create a physical barrier to the outside world. In addition, it is increasingly appreciated that MAMs function as cell surface receptors that transduce information from the outside to the inside of the cell. Recently, our team published a comprehensive review/perspectives article for molecular scientists on ocular surface MAMs, including previously unpublished data and analyses on two new genes MUC21 and MUC22, as well as new MAM functions and biological roles, comparing human and mouse (PMID: 31493487). The current article is a refocus for the audience of The Ocular Surface. First, we update the gene and protein information in a more concise form, and include a new section on glycosylation. Next, we discuss biological roles, with some new sections and further updating from our previous review. Finally, we provide a new chapter on MAM involvement in ocular surface disease. We end this with discussion of an emerging mechanism responsible for damage to the epithelia and their mucosal glycocalyces: the unfolded protein response (UPR). The UPR offers a novel target for therapeutic intervention.
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Affiliation(s)
- Rafael Martinez-Carrasco
- Department of Ophthalmology, Tufts University School of Medicine at New England Eye Center, Tufts Medical Center, Boston, MA, 02111, USA.
| | - Pablo Argüeso
- Department of Ophthalmology, Harvard Medical School at Schepens Eye Research Institute of Mass, Eye and Ear, Boston, MA, 02114, USA.
| | - M Elizabeth Fini
- Department of Ophthalmology, Tufts University School of Medicine at New England Eye Center, Tufts Medical Center: Program in Pharmacology & Drug Development, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, O2111, USA.
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Role of Glycans on Key Cell Surface Receptors That Regulate Cell Proliferation and Cell Death. Cells 2021; 10:cells10051252. [PMID: 34069424 PMCID: PMC8159107 DOI: 10.3390/cells10051252] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Cells undergo proliferation and apoptosis, migration and differentiation via a number of cell surface receptors, most of which are heavily glycosylated. This review discusses receptor glycosylation and the known roles of glycans on the functions of receptors expressed in diverse cell types. We included growth factor receptors that have an intracellular tyrosine kinase domain, growth factor receptors that have a serine/threonine kinase domain, and cell-death-inducing receptors. N- and O-glycans have a wide range of functions including roles in receptor conformation, ligand binding, oligomerization, and activation of signaling cascades. A better understanding of these functions will enable control of cell survival and cell death in diseases such as cancer and in immune responses.
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Identification of oral squamous cell carcinoma markers MUC2 and SPRR1B downstream of TANGO. J Cancer Res Clin Oncol 2021; 147:1659-1672. [PMID: 33620575 DOI: 10.1007/s00432-021-03568-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 02/15/2021] [Indexed: 01/05/2023]
Abstract
PURPOSE Transport and Golgi organization protein 1 (TANGO) promotes angiogenesis and lymphangiogenesis in oral squamous cell carcinoma (OSCC). To elucidate the underlying mechanisms, this study aims to identify and characterize elements downstream of TANGO that mediate its involvement in OSCC. METHODS In this study, microarray analysis compared gene expression between control and TANGO-repressed HSC3 cells. Protein expression in 213 OSCC tissue samples was analyzed immunohistochemically. RESULTS TANGO repression decreased or increased expression of Mucin 20 (MUC20) and small proline-rich protein 1B (SPRR1B), respectively. MUC20 increased the growth and invasiveness of OSCC cells via altered matrix metalloproteinase (MMP)-2 and E-cadherin expression and c-met phosphorylation. MUC20 induced angiogenesis and lymphangiogenesis by activating vascular endothelial growth factors A and C. In well-differentiated OSCC, SPRR1B expression was high (P = 0.0091) and correlated with keratinization markers and promoted proliferation by inducing mitogen-activated protein kinase p38 phosphorylation. MUC20 expression correlated significantly with clinical stage (P = 0.0024), lymph node metastasis (P = 0.0036), and number of blood and lymph vessels (P < 0.0001). MUC20-expressing cases had a significantly worse prognosis than non-expressing cases (P < 0.0001). CONCLUSION MUC20 and SPRR1B located downstream of TANGO may be useful molecular markers for OSCC.
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Yang M, Song B, Liu J, Bing Z, Wang Y, Yu L. Gene signature for prognosis in comparison of pancreatic cancer patients with diabetes and non-diabetes. PeerJ 2020; 8:e10297. [PMID: 33240632 PMCID: PMC7666560 DOI: 10.7717/peerj.10297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/13/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Pancreatic cancer (PC) has much weaker prognosis, which can be divided into diabetes and non-diabetes. PC patients with diabetes mellitus will have more opportunities for physical examination due to diabetes, while pancreatic cancer patients without diabetes tend to have higher risk. Identification of prognostic markers for diabetic and non-diabetic pancreatic cancer can improve the prognosis of patients with both types of pancreatic cancer. METHODS Both types of PC patients perform differently at the clinical and molecular levels. The Cancer Genome Atlas (TCGA) is employed in this study. The gene expression of the PC with diabetes and non-diabetes is used for predicting their prognosis by LASSO (Least Absolute Shrinkage and Selection Operator) Cox regression. Furthermore, the results are validated by exchanging gene biomarker with each other and verified by the independent Gene Expression Omnibus (GEO) and the International Cancer Genome Consortium (ICGC). The prognostic index (PI) is generated by a combination of genetic biomarkers that are used to rank the patient's risk ratio. Survival analysis is applied to test significant difference between high-risk group and low-risk group. RESULTS An integrated gene prognostic biomarker consisted by 14 low-risk genes and six high-risk genes in PC with non-diabetes. Meanwhile, and another integrated gene prognostic biomarker consisted by five low-risk genes and three high-risk genes in PC with diabetes. Therefore, the prognostic value of gene biomarker in PC with non-diabetes and diabetes are all greater than clinical traits (HR = 1.102, P-value < 0.0001; HR = 1.212, P-value < 0.0001). Gene signature in PC with non-diabetes was validated in two independent datasets. CONCLUSIONS The conclusion of this study indicated that the prognostic value of genetic biomarkers in PCs with non-diabetes and diabetes. The gene signature was validated in two independent databases. Therefore, this study is expected to provide a novel gene biomarker for predicting prognosis of PC with non-diabetes and diabetes and improving clinical decision.
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Affiliation(s)
- Mingjun Yang
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, Gansu, China
| | - Boni Song
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, Gansu, China
- Institute of Modern Physics of Chinese Academy of Sciences, Lanzhou, China
| | - Juxiang Liu
- Gansu Key Laboratory of Endocrine and metabolism, Department of Endocrinology, Gansu Provincial People’s Hospital, Lanzhou, Gansu, China
| | - Zhitong Bing
- Institute of Modern Physics of Chinese Academy of Sciences, Lanzhou, China
- Evidence Based Medicine Center, School of Basic Medical Science of Lanzhou University,, Lanzhou, China
| | - Yonggang Wang
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, Gansu, China
| | - Linmiao Yu
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, Gansu, China
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Gan GL, Liu J, Chen WJ, Ye QQ, Xu Y, Wu HT, Li W. The Diverse Roles of the Mucin Gene Cluster Located on Chromosome 11p15.5 in Colorectal Cancer. Front Cell Dev Biol 2020; 8:514. [PMID: 32695780 PMCID: PMC7338833 DOI: 10.3389/fcell.2020.00514] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 05/28/2020] [Indexed: 02/05/2023] Open
Abstract
Colorectal cancer (CRC), the third most common malignant tumor in the world, shows multiple complex and pathologies based on the impaired structure and function of the intestinal mucosal barrier. Goblet cells secrete mucins, which are involved in the formation of the intestinal mucosal barrier and not only lubricate and protect the intestinal mucosa but also participate in the processes of cell adhesion, intercellular signal transduction, and immune regulation. It is accepted that the disordered expression and dysfunction of mucins are associated with the occurrence and development of CRC. This article focuses on the secretory mucins encoded by a gene cluster located on chromosome 11p15.5 and systematically reviews their composition, regulation, function, and role in CRC, to deepen the understanding of the pathogeneses of CRC and to provide a new basis and ideas for the treatment of CRC.
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Affiliation(s)
- Guo-Lian Gan
- Department of General Surgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Jing Liu
- Changjiang Scholar’s Laboratory/Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Breast Cancer, Shantou University Medical College, Shantou, China
- Department of Physiology/Cancer Research Center, Shantou University Medical College, Shantou, China
| | - Wen-Jia Chen
- Changjiang Scholar’s Laboratory/Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Breast Cancer, Shantou University Medical College, Shantou, China
- Department of Physiology/Cancer Research Center, Shantou University Medical College, Shantou, China
| | - Qian-Qian Ye
- Changjiang Scholar’s Laboratory/Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Breast Cancer, Shantou University Medical College, Shantou, China
- Department of Physiology/Cancer Research Center, Shantou University Medical College, Shantou, China
| | - Ya Xu
- Changjiang Scholar’s Laboratory/Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Breast Cancer, Shantou University Medical College, Shantou, China
| | - Hua-Tao Wu
- Department of General Surgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- *Correspondence: Hua-Tao Wu,
| | - Wei Li
- Department of General Surgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- Wei Li,
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Stepanjuk A, Koel M, Pook M, Saare M, Jääger K, Peters M, Krjutškov K, Ingerpuu S, Salumets A. MUC20 expression marks the receptive phase of the human endometrium. Reprod Biomed Online 2019; 39:725-736. [PMID: 31519421 DOI: 10.1016/j.rbmo.2019.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 04/20/2019] [Accepted: 05/08/2019] [Indexed: 11/19/2022]
Abstract
RESEARCH QUESTION How does mucin MUC20 expression change during the menstrual cycle in different cell types of human endometrium? DESIGN Study involved examination of MUC20 expression in two previously published RNA-seq datasets in whole endometrial tissue (n = 10), sorted endometrial epithelial (n = 44) or stromal (n = 42) cell samples. RNA-Seq results were validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in whole tissue (n = 10), sorted epithelial (n = 17) and stromal (n = 17) cell samples. MUC20 protein localization and expression were analysed in human endometrium by immunohistochemical analysis of intact endometrial tissue (n = 6) and also Western blot of cultured stromal and epithelial cells (n = 2). RESULTS MUC20 is differentially expressed in the endometrium between the pre-receptive and receptive phases. We show that MUC20 is predominantly expressed by epithelial cells of the receptive endometrium, both at the mRNA (RNA-Seq, P = 0.005; qRT-PCR, P = 0.039) and protein levels (Western blot; immunohistochemistry, P = 0.029). CONCLUSION Our results indicate MUC20 as a novel marker of mid-secretory endometrial biology. We propose a model of MUC20 function in the hepatocyte growth factor (HGF)-activated mesenchymal-epithelial transition (MET) receptor signalling specifically in the receptive phase. Further investigations should reveal the precise function of MUC20 in human endometrium and the possible connection between MUC20 and HGF-activated MET receptor signalling. MUC20 could potentially be included in the list of endometrial receptivity markers after further clinical validation.
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Affiliation(s)
- Artjom Stepanjuk
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, Tartu 51010, Estonia
| | - Mariann Koel
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, Tartu 51010, Estonia; Competence Centre on Health Technologies, Tiigi 61b, Tartu 50410, Estonia
| | - Martin Pook
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, Tartu 51010, Estonia
| | - Merli Saare
- Competence Centre on Health Technologies, Tiigi 61b, Tartu 50410, Estonia; Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tartu, L. Puusepa 8, Tartu 50406, Estonia
| | - Kersti Jääger
- Competence Centre on Health Technologies, Tiigi 61b, Tartu 50410, Estonia
| | - Maire Peters
- Competence Centre on Health Technologies, Tiigi 61b, Tartu 50410, Estonia; Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tartu, L. Puusepa 8, Tartu 50406, Estonia
| | - Kaarel Krjutškov
- Competence Centre on Health Technologies, Tiigi 61b, Tartu 50410, Estonia; Research Program of Molecular Neurology, Research Programs Unit, University of Helsinki, and Folkhälsan Institute of Genetics, Haartmaninkatu 8, Helsinki 00290, Finland
| | - Sulev Ingerpuu
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, Tartu 51010, Estonia
| | - Andres Salumets
- Competence Centre on Health Technologies, Tiigi 61b, Tartu 50410, Estonia; Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tartu, L. Puusepa 8, Tartu 50406, Estonia; Department of Biomedicine, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, Tartu 50411, Estonia; Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 2, Helsinki 00014, Finland.
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Fini ME, Jeong S, Gong H, Martinez-Carrasco R, Laver NMV, Hijikata M, Keicho N, Argüeso P. Membrane-associated mucins of the ocular surface: New genes, new protein functions and new biological roles in human and mouse. Prog Retin Eye Res 2019; 75:100777. [PMID: 31493487 DOI: 10.1016/j.preteyeres.2019.100777] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/26/2019] [Accepted: 08/31/2019] [Indexed: 01/17/2023]
Abstract
The mucosal glycocalyx of the ocular surface constitutes the point of interaction between the tear film and the apical epithelial cells. Membrane-associated mucins (MAMs) are the defining molecules of the glycocalyx in all mucosal epithelia. Long recognized for their biophysical properties of hydration, lubrication, anti-adhesion and repulsion, MAMs maintain the wet ocular surface, lubricate the blink, stabilize the tear film and create a physical barrier to the outside world. However, it is increasingly appreciated that MAMs also function as cell surface receptors that transduce information from the outside to the inside of the cell. A number of excellent review articles have provided perspective on the field as it has progressed since 1987, when molecular cloning of the first MAM was reported. The current article provides an update for the ocular surface, placing it into the broad context of findings made in other organ systems, and including new genes, new protein functions and new biological roles. We discuss the epithelial tissue-equivalent with mucosal differentiation, the key model system making these advances possible. In addition, we make the first systematic comparison of MAMs in human and mouse, establishing the basis for using knockout mice for investigations with the complexity of an in vivo system. Lastly, we discuss findings from human genetics/genomics, which are providing clues to new MAM roles previously unimagined. Taken together, this information allows us to generate hypotheses for the next stage of investigation to expand our knowledge of MAM function in intracellular signaling and roles unique to the ocular surface.
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Affiliation(s)
- M Elizabeth Fini
- Department of Ophthalmology, Tufts University School of Medicine, at New England Eye Center, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA.
| | - Shinwu Jeong
- USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 1975 Zonal Ave, Los Angeles, CA, 90033, USA.
| | - Haiyan Gong
- Department of Ophthalmology, Boston University School of Medicine, 72 E Concord St, Boston, MA, 02118, USA.
| | - Rafael Martinez-Carrasco
- Department of Ophthalmology, Tufts University School of Medicine, at New England Eye Center, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA.
| | - Nora M V Laver
- Department of Ophthalmology, Tufts University School of Medicine, at New England Eye Center, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA.
| | - Minako Hijikata
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose-shi, Tokyo, 204-8533, Japan.
| | - Naoto Keicho
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose-shi, Tokyo, 204-8533, Japan.
| | - Pablo Argüeso
- Department of Ophthalmology, Harvard Medical School, at Schepens Eye Research Institute of Mass. Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA.
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Chen ST, Kuo TC, Liao YY, Lin MC, Tien YW, Huang MC. Silencing of MUC20 suppresses the malignant character of pancreatic ductal adenocarcinoma cells through inhibition of the HGF/MET pathway. Oncogene 2018; 37:6041-6053. [PMID: 29993037 PMCID: PMC6237765 DOI: 10.1038/s41388-018-0403-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 05/28/2018] [Accepted: 06/14/2018] [Indexed: 12/18/2022]
Abstract
Mucins are heavily glycosylated proteins that play critical roles in the pathogenesis of tumour malignancies. Pancreatic ductal adenocarcinoma (PDAC) is characterised by the aberrant expression of mucins. However, the role of mucin (MUC) 20 in PDAC remains unclear. PDAC is usually surrounded by a dense fibrotic stroma consisting of an extracellular matrix and pancreatic stellate cells (PSCs). The stroma creates a nutrient-deprived, hypoxic, and acidic microenvironment, and promotes the malignant behaviours of PDAC cells. In this study, immunohistochemical staining demonstrated that high MUC20 expression correlated with poor progression-free survival and high local recurrence rate of PDAC patients (n = 61). The expression of MUC20 was induced by serum deprivation, hypoxia, and acidic pH in PDAC cells. MUC20 knockdown with siRNA decreased cell viability, as well as migration and invasion induced by PSCs in HPAC and HPAF-II cells. In intraperitoneal, subcutaneous, and orthotopic injection models, MUC20 knockdown decreased tumour growth in immunodeficient mice. Phospho-RTK array and western blot analysis indicated that MUC20 knockdown decreased HGF-mediated phosphorylation of MET in PDAC cells. Moreover, HGF-induced malignant phenotypes could be suppressed by MUC20 knockdown. Co-immunoprecipitation revealed the physical association of MUC20 and MET. These findings suggest that MUC20 knockdown suppresses the malignant phenotypes of PDAC cells at least partially through the inhibition of the HGF/MET pathway and that MUC20 could act as a potential therapeutic target.
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Affiliation(s)
- Syue-Ting Chen
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ting-Chun Kuo
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Ying-Yu Liao
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Mei-Chun Lin
- Department of Otolaryngology, National Taiwan University Hospital, Hsinchu, Hsinchu, Taiwan
- National Taiwan University Cancer Center, Taipei, Taiwan
| | - Yu-Wen Tien
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
| | - Min-Chuan Huang
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.
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Xia J, Fan H, Chang T, Xu L, Zhang W, Song Y, Zhu B, Zhang L, Gao X, Chen Y, Li J, Gao H. Searching for new loci and candidate genes for economically important traits through gene-based association analysis of Simmental cattle. Sci Rep 2017; 7:42048. [PMID: 28169328 PMCID: PMC5294460 DOI: 10.1038/srep42048] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 01/06/2017] [Indexed: 12/26/2022] Open
Abstract
Single-marker genome-wide association study (GWAS) is a convenient strategy of genetic analysis that has been successful in detecting the association of a number of single-nucleotide polymorphisms (SNPs) with quantitative traits. However, analysis of individual SNPs can only account for a small proportion of genetic variation and offers only limited knowledge of complex traits. This inadequacy may be overcome by employing a gene-based GWAS analytic approach, which can be considered complementary to the single-SNP association analysis. Here we performed an initial single-SNP GWAS for bone weight (BW) and meat pH value with a total of 770,000 SNPs in 1141 Simmental cattle. Additionally, 21836 cattle genes collected from the Ensembl Genes 83 database were analyzed to find supplementary evidence to support the importance of gene-based association study. Results of the single SNP-based association study showed that there were 11 SNPs significantly associated with bone weight (BW) and two SNPs associated with meat pH value. Interestingly, all of these SNPs were located in genes detected by the gene-based association study.
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Affiliation(s)
- Jiangwei Xia
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Huizhong Fan
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Tianpeng Chang
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Lingyang Xu
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Wengang Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Yuxin Song
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Bo Zhu
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Lupei Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Xue Gao
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Yan Chen
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Junya Li
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Huijiang Gao
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
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The properties of the mucus barrier, a unique gel--how can nanoparticles cross it? Ther Deliv 2016; 7:229-44. [PMID: 27010985 DOI: 10.4155/tde-2015-0002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The key criterion for a nanoparticle drug-delivery system is the ability to produce substantial bioavailability without damaging the physiological protective mechanisms. The main area for drug delivery is the aerodigestive tract. All epithelial surfaces have a membrane-bound layer and in the lung this layer is surmounted by a gel layer. In the gastrointestinal tract the membrane-bound mucin layer is covered by a mucus bilayer. The pore sizes of mucus gels are around 100 to 200 nm. Consequently, only nanoparticles in this size range could potentially penetrate without modification of these layers. To study nanoparticle permeation with results that pertain to in vivo conditions, native mucus mucin preparations must be used. Strategies to increase pores in mucus gels are discussed herein.
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Uchino Y, Woodward AM, Argüeso P. Differential effect of rebamipide on transmembrane mucin biosynthesis in stratified ocular surface epithelial cells. Exp Eye Res 2016; 153:1-7. [PMID: 27725198 DOI: 10.1016/j.exer.2016.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 09/29/2016] [Accepted: 10/06/2016] [Indexed: 10/20/2022]
Abstract
Mucins are a group of highly glycosylated glycoproteins responsible for the protection of wet-surfaced epithelia. Recent data indicate that transmembrane mucins differ in their contribution to the protective function of the ocular surface, with MUC16 being the most effective barrier on the apical surface glycocalyx. Here, we investigated the role of the mucoprotective drug rebamipide in the regulation of transmembrane mucin biosynthesis using stratified cultures of human corneal and conjunctival epithelial cells. We find that the addition of rebamipide to corneal, but not conjunctival, epithelial cells increased MUC16 protein biosynthesis. Rebamipide did not affect the levels of MUC1, 4 and 20 compared to control. In these experiments, rebamipide had no effect on the expression levels of Notch intracellular domains, suggesting that the rebamipide-induced increase in MUC16 biosynthesis in differentiated corneal cultures is not regulated by Notch signaling. Overall these findings indicate that rebamipide induces the differential upregulation of MUC16 in stratified cultures of human corneal epithelial cells, which may have implications to the proper restoration of barrier function in ocular surface disease.
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Affiliation(s)
- Yuichi Uchino
- Schepens Eye Research Institute and Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Ashley M Woodward
- Schepens Eye Research Institute and Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Pablo Argüeso
- Schepens Eye Research Institute and Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
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Chen CH, Shyu MK, Wang SW, Chou CH, Huang MJ, Lin TC, Chen ST, Lin HH, Huang MC. MUC20 promotes aggressive phenotypes of epithelial ovarian cancer cells via activation of the integrin β1 pathway. Gynecol Oncol 2015; 140:131-7. [PMID: 26616226 DOI: 10.1016/j.ygyno.2015.11.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Mucin (MUC) 20 has recently been implicated to play a role in human carcinogenesis. However, the role of MUC20 in epithelial ovarian cancer (EOC) remains to be elucidated. METHODS MUC20 expression was assessed in tissue microarray and tumor specimens of EOC patients by immunohistochemistry. Effects of MUC20 on cell viability, adhesion, migration, and invasion were analyzed in MUC20 overexpressing or knockdown EOC cells. Western blotting was performed to analyze signaling pathways modulated by MUC20. RESULTS MUC20 was overexpressed in EOC samples compared with benign tissues. High MUC20 expression was significantly associated with poor overall survival in patients with advanced-stage disease. MUC20 overexpression significantly enhanced EOC cell migration and invasion, but not viability. Mechanistic investigations showed that MUC20 increased cell adhesion to extracellular matrix (ECM) proteins and enhanced activation of integrin β1 and phosphorylation of focal adhesion kinase (FAK). The enhancement of cell motility and the integrin β1 signaling by MUC20 was significantly suppressed by integrin β1 blocking antibody. Furthermore, these effects of MUC20 on EOC cells were also demonstrated in MUC20 knockdown cells. CONCLUSIONS Our results suggest that MUC20 enhances aggressive behaviors of EOC cells by activating integrin β1 signaling and provide novel insights into the role of MUC20 in ovarian cancer metastasis.
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Affiliation(s)
- Chi-Hau Chen
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Ming-Kwang Shyu
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan
| | - Shu-Wei Wang
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chih-Hsing Chou
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Miao-Juei Huang
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Tzu-Chi Lin
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Syue-Ting Chen
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Ho-Hsiung Lin
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan
| | - Min-Chuan Huang
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan; Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan.
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18
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Mao S, Zhang J. The emerging role of hepatocyte growth factor in renal diseases. J Recept Signal Transduct Res 2015; 36:303-9. [DOI: 10.3109/10799893.2015.1080275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Exploring the role and diversity of mucins in health and disease with special insight into non-communicable diseases. Glycoconj J 2015; 32:575-613. [PMID: 26239922 DOI: 10.1007/s10719-015-9606-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/18/2015] [Indexed: 12/11/2022]
Abstract
Mucins are major glycoprotein components of the mucus that coats the surfaces of cells lining the respiratory, digestive, gastrointestinal and urogenital tracts. They function to protect epithelial cells from infection, dehydration and physical or chemical injury, as well as to aid the passage of materials through a tract i.e., lubrication. They are also implicated in the pathogenesis of benign and malignant diseases of secretory epithelial cells. In Human there are two types of mucins, membrane-bound and secreted that are originated from mucous producing goblet cells localized in the epithelial cell layer or in mucous producing glands and encoded by MUC gene. Mucins belong to a heterogeneous family of high molecular weight proteins composed of a long peptidic chain with a large number of tandem repeats that form the so-called mucin domain. The molecular weight is generally high, ranging between 0.2 and 10 million Dalton and all mucins contain one or more domains which are highly glycosylated. The size and number of repeats vary between mucins and the genetic polymorphism represents number of repeats (VNTR polymorphisms), which means the size of individual mucins can differ substantially between individuals which can be used as markers. In human it is only MUC1 and MUC7 that have mucin domains with less than 40% serine and threonine which in turn could reduce number of PTS domains. Mucins can be considered as powerful two-edged sword, as its normal function protects from unwanted substances and organisms at an arm's length while, malfunction of mucus may be an important factor in human diseases. In this review we have unearthed the current status of different mucin proteins in understanding its role and function in various non-communicable diseases in human with special reference to its organ specific locations. The findings described in this review may be of direct relevance to the major research area in biomedicine with reference to mucin and mucin associated diseases.
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Viticchiè G, Muller PAJ. c-Met and Other Cell Surface Molecules: Interaction, Activation and Functional Consequences. Biomedicines 2015; 3:46-70. [PMID: 28536399 PMCID: PMC5344229 DOI: 10.3390/biomedicines3010046] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 01/08/2015] [Indexed: 12/18/2022] Open
Abstract
The c-Met receptor, also known as the HGF receptor, is one of the most studied tyrosine kinase receptors, yet its biological functions and activation mechanisms are still not fully understood. c-Met has been implicated in embryonic development and organogenesis, in tissue remodelling homeostasis and repair and in cancer metastasis. These functions are indicative of the many cellular processes in which the receptor plays a role, including cell motility, scattering, survival and proliferation. In the context of malignancy, sustained activation of c-Met leads to a signalling cascade involving a multitude of kinases that initiate an invasive and metastatic program. Many proteins can affect the activation of c-Met, including a variety of other cell surface and membrane-spanning molecules or receptors. Some cell surface molecules share structural homology with the c-Met extracellular domain and can activate c-Met via clustering through this domain (e.g., plexins), whereas other receptor tyrosine kinases can enhance c-Met activation and signalling through intracellular signalling cascades (e.g., EGFR). In this review, we provide an overview of c-Met interactions and crosstalk with partner molecules and the functional consequences of these interactions on c-Met activation and downstream signalling, c-Met intracellular localization/recycling and c-Met degradation.
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Affiliation(s)
- Giuditta Viticchiè
- MRC (Medical Research Council) Toxicology Unit, Lancaster Road, Leicester LE1 9HN, UK.
| | - Patricia A J Muller
- MRC (Medical Research Council) Toxicology Unit, Lancaster Road, Leicester LE1 9HN, UK.
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21
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Woodward AM, Argüeso P. Expression analysis of the transmembrane mucin MUC20 in human corneal and conjunctival epithelia. Invest Ophthalmol Vis Sci 2014; 55:6132-8. [PMID: 25168902 DOI: 10.1167/iovs.14-15269] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE Cell surface mucins are a group of highly O-glycosylated transmembrane glycoproteins responsible for the protection of epithelial cells on mucosal surfaces. The aim of this study was to investigate the localization and regulation of mucin 20 (MUC20) at the ocular surface. METHODS Localization of MUC20 in human corneal and conjunctival epithelia was evaluated by immunofluorescence microscopy. Immortalized corneal (HCLE) and conjunctival (HCjE) cell lines were grown at different stages of differentiation and subjected to quantitative PCR and Western blot analyses. Cell surface proteins on apical cell membranes were biotinylated and isolated by neutravidin chromatography. RESULTS The MUC20 was detected throughout the entire human ocular surface epithelia, predominantly in cell membranes within intermediate cell layers. In conjunctiva, MUC20 also was observed in the cytoplasm of apical cells within the stratified squamous epithelium, but not in goblet cells. Quantitative PCR and immunoblotting demonstrated expression of MUC20 in HCLE and HCjE cells. Induction of differentiation with serum-containing medium resulted in upregulation of MUC20 mRNA and protein. Biotin labeling of the surface of stratified cultures revealed low levels of MUC20 protein on apical glycocalyces. Further, MUC20 was not detected in the cell culture media or in human tears, suggesting that the extracellular domain of MUC20 is not released from the ocular surface as described previously for other cell surface mucins. CONCLUSIONS Our results indicate that MUC20 is a novel transmembrane mucin expressed by the human corneal and conjunctival epithelia, and suggest that differential expression of MUC20 during differentiation has a role in maintaining ocular surface homeostasis.
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Affiliation(s)
- Ashley M Woodward
- Schepens Eye Research Institute and Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Pablo Argüeso
- Schepens Eye Research Institute and Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
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Wang RY, Chen L, Chen HY, Hu L, Li L, Sun HY, Jiang F, Zhao J, Liu GMY, Tang J, Chen CY, Yang YC, Chang YX, Liu H, Zhang J, Yang Y, Huang G, Shen F, Wu MC, Zhou WP, Wang HY. MUC15 inhibits dimerization of EGFR and PI3K-AKT signaling and is associated with aggressive hepatocellular carcinomas in patients. Gastroenterology 2013; 145:1436-48.e1-12. [PMID: 23933603 DOI: 10.1053/j.gastro.2013.08.009] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Revised: 07/30/2013] [Accepted: 08/04/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Aberrant expression of MUC15 correlates with development of colorectal adenocarcinoma, and MUC15 has been reported to prevent trophoblast invasion of human placenta. However, little is known about the role of MUC15 in pathogenesis of hepatocellular carcinoma (HCC). METHODS We analyzed HCC samples and matched nontumor liver tissues (controls) collected from 313 patients who underwent hepatectomy in Shanghai, China, from January 2006 through September 2009. Levels of messenger RNAs and proteins were determined by immunohistochemical, quantitative reverse transcription polymerase chain reaction, and immunoblot analyses. Statistical analyses were used to associate levels of MUC15 with tumor features and patient outcomes. RESULTS Levels of MUC15 messenger RNA and protein were reduced in a greater percentage of HCC samples than control tissues. Tumors with reduced levels of MUC15 were more likely to have aggressive characteristics (eg, high levels of α-fetoprotein, vascular invasion, lack of encapsulation, and poor differentiation) than those with low levels. Patients whose tumors had reduced levels of MUC15 had shorter overall survival times (24 months vs 46 months for patients with tumors with high levels of MUC15) and time to disease recurrence. Stable expression of MUC15 in HCC cell lines (SMMC-7721 and HCC-LM3) reduced their proliferation and invasive features in vitro, and ability to form metastatic tumors in mice. MUC15 reduced transcription of the matrix metalloproteinases 2 and 7 increased expression of tissue inhibitor of metalloproteinase-2, which required phosphoinositide 3-kinase-v-akt murine thymoma viral oncogene homolog signaling. Physical interaction between MUC15 and epidermal growth factor receptor led to its relocation and degradation within early endosomes and was required for inactivation of phosphoinositide 3-kinase-v-akt murine thymoma viral oncogene homolog signaling. CONCLUSIONS Reduced levels of MUC15 in HCCs are associated with shorter survival times of patients and reduced time to disease recurrence. Expression of MUC15 in HCC cells reduces their aggressive behavior in vitro and in mice by inducing dimerization of epidermal growth factor receptor and decreasing phosphoinositide 3-kinase signaling via v-akt murine thymoma viral oncogene homolog.
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Affiliation(s)
- Ruo-Yu Wang
- International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Shanghai, China; The Department of Hepatic Surgery, Eastern Hepatobiliary Surgery Hospital, Shanghai, China
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Xiao X, Wang L, Wei P, Chi Y, Li D, Wang Q, Ni S, Tan C, Sheng W, Sun M, Zhou X, Du X. Role of MUC20 overexpression as a predictor of recurrence and poor outcome in colorectal cancer. J Transl Med 2013; 11:151. [PMID: 23787019 PMCID: PMC3702436 DOI: 10.1186/1479-5876-11-151] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 06/13/2013] [Indexed: 01/17/2023] Open
Abstract
Background Colorectal cancer (CRC) remains one of the most common cancers worldwide. We observed that MUC20 was significantly up-regulated in CRC patients with poor prognosis based on the microarray analysis. However, little is known about the role of MUC20 in CRC. Methods Microarray experiments were performed on the Affymetrix U133 plus 2.0 GeneChip Array. The protein and mRNA levels of MUC20 were examined by immunohistochemistry (IHC) and Real-Time quantitative PCR (RT-qPCR) in CRC tissues and adjacent noncancerous tissues (ANCT). ShRNA and overexpression plasmids were used to regulate MUC20 expression in CRC cell lines in vitro; wound healing, Transwell migration assays, and Western blotting were used to detect migration and invasion changes. Results MUC20 was one of the up-regulated genes in CRC patients with poor prognosis by microarray. Using IHC and RT-qPCR, we showed that MUC20 expression was significantly higher in CRC tissues than in ANCT (P < 0.05). We further showed that MUC20 overexpression was correlated with recurrence and poor outcome (P < 0.05). The Kaplan-Meier survival curves indicated that disease-free survival (DFS) and overall survival (OS) were significantly worse in CRC patients with MUC20 overexpression. The Cox multivariate analysis revealed that MUC20 overexpression and TNM stage were independent prognostic factors. Elevated expression of MUC20 in cells promoted migration and invasion, whereas ShRNA-mediated knockdown inhibited these processes. In addition, Western blotting demonstrated that MUC20-induced invasion was associated with MMP-2, MMP-3, and E-cadherin. Conclusions Cumulatively, MUC20 may serve as an important predictor of recurrence and poor outcome for CRC patients. MUC20 overexpression could enhance migration and invasion abilities of CRC cells. Translation of its roles into clinical practice will need further investigation and additional test validation.
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Affiliation(s)
- Xiuying Xiao
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai 200032, China
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Chen CH, Wang SW, Chen CW, Huang MR, Hung JS, Huang HC, Lin HH, Chen RJ, Shyu MK, Huang MC. MUC20 overexpression predicts poor prognosis and enhances EGF-induced malignant phenotypes via activation of the EGFR-STAT3 pathway in endometrial cancer. Gynecol Oncol 2012; 128:560-7. [PMID: 23262208 DOI: 10.1016/j.ygyno.2012.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 12/07/2012] [Accepted: 12/08/2012] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Mucins play a critical role in the malignancy of various tumors and have been identified as diagnostic markers and as attractive therapeutic targets. However, the role of mucin (MUC) 20 in endometrial cancer (EC) is still unknown. METHODS The relationship between MUC20 expression and clinical characteristics of EC was analyzed in 97 EC tumors and 16 normal tissues by immunohistochemistry. Effects of MUC20 on EC cells, HEC-1A and RL95-2, were examined by in vitro cell growth, migration, and invasion assays, as well as in vivo tumor growth in SCID mouse model. Western blotting was performed to analyze signaling pathways modulated by MUC20. RESULTS MUC20 expression was significantly higher in EC tumors compared with the normal tissue. High levels of MUC20 expression in EC tumors were correlated with an unfavorable histologic subtype. Furthermore, MUC20 was an independent prognostic factor for poor survival as evaluated by multivariate analyses. Overexpression of MUC20 in EC cells significantly enhanced cell growth, migration, and invasion, as well as tumor growth in vivo. The MUC20-enhanced invasive behavior was significantly blocked by erlotinib, an EGFR inhibitor. Moreover, MUC20 overexpression enhanced EGF-mediated migration and invasion, suggesting a critical role of EGFR in MUC20-mediated effects. We found that MUC20 overexpression could enhance EGF-induced phosphorylation of EGFR and STAT3. Inhibition of the STAT3 activity by its inhibitor Stattic significantly suppressed the MUC20-enhanced invasive behavior. CONCLUSIONS MUC20 is novel prognostic factor for EC and its overexpression enhances EGF-triggered invasive behavior through activation of EGFR-STAT3 pathway.
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Affiliation(s)
- Chi-Hau Chen
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan
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Phorbol 12-Myristate 13-Acetate Induces MUC16 Expression via PKCδ and p38 in Human Airway Epithelial Cells. Clin Exp Otorhinolaryngol 2012; 5:161-9. [PMID: 22977714 PMCID: PMC3437418 DOI: 10.3342/ceo.2012.5.3.161] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 02/09/2012] [Accepted: 02/17/2012] [Indexed: 11/13/2022] Open
Abstract
Objectives Phorbol 12-myristate 13-acetate (PMA) is widely used as a protein kinase C (PKC) activator, PKC is involved in the secretion of mucins. MUC16, one of the membrane-bound mucins, is produced in human airway epithelial cells. However, the effect and signaling pathway of PMA on MUC16 expression in human airway epithelial cells has not been reported. Therefore, the effect and brief signaling pathway of PMA on MUC16 expression were investigated in human airway epithelial cells in this study. Methods In the mucin-producing human NCI-H292 airway epithelial cells and the primary cultures of normal nasal epithelial cells, the effect and signaling pathway of PMA on MUC16 expression were investigated using reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR, enzyme immunoassay, and immunoblot analysis with several specific inhibitors and small interfering RNA (siRNA) for p38 mitogen-activated protein kinase (MAPK). Results PMA increased MUC16 expression, and activated phosphorylation of p38 MAPK. However, it did not activate phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). SB203580 (p38 MAPK inhibitor) inhibited PMA-induced MUC16 expression, while U0126 (ERK1/2 inhibitor) did not. In addition, the knockdown of p38 MAPK by p38 MAPK siRNA significantly blocked PMA-induced MUC16 mRNA expression. Rottlerin (PKCδ inhibitor) inhibited PMA-induced MUC16 expression, and also inhibited the phosphorylation of activated p38 MAPK by PMA. Conclusion These results show for the first time that PMA-induced MUC16 expression is regulated by activation of the PKCδ and p38 MAPK signaling pathway in human airway epithelial cells.
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Yamada N, Kitamoto S, Yokoyama S, Hamada T, Goto M, Tsutsumida H, Higashi M, Yonezawa S. Epigenetic regulation of mucin genes in human cancers. Clin Epigenetics 2011; 2:85-96. [PMID: 22704331 PMCID: PMC3365379 DOI: 10.1007/s13148-011-0037-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 04/18/2011] [Indexed: 12/16/2022] Open
Abstract
Mucins are high molecular weight glycoproteins that play important roles in diagnostic and prognostic prediction and in carcinogenesis and tumor invasion. Regulation of expression of mucin genes has been studied extensively, and signaling pathways, transcriptional regulators, and epigenetic modification in promoter regions have been described. Detection of the epigenetic status of cancer-related mucin genes is important for early diagnosis of cancer and for monitoring of tumor behavior and response to targeted therapy. Effects of micro-RNAs on mucin gene expression have also started to emerge. In this review, we discuss the current views on epigenetic mechanisms of regulation of mucin genes (MUC1, MUC2, MUC3A, MUC4, MUC5AC, MUC5B, MUC6, MUC16, and MUC17) and the possible clinical applications of this epigenetic information.
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Bafna S, Kaur S, Batra SK. Membrane-bound mucins: the mechanistic basis for alterations in the growth and survival of cancer cells. Oncogene 2010; 29:2893-904. [PMID: 20348949 DOI: 10.1038/onc.2010.87] [Citation(s) in RCA: 285] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mucins (MUC) are high molecular weight O-linked glycoproteins whose primary functions are to hydrate, protect, and lubricate the epithelial luminal surfaces of the ducts within the human body. The MUC family is comprised of large secreted gel forming and transmembrane (TM) mucins. MUC1, MUC4, and MUC16 are the well-characterized TM mucins and have been shown to be aberrantly overexpressed in various malignancies including cystic fibrosis, asthma, and cancer. Recent studies have uncovered the unique roles of these mucins in the pathogenesis of cancer. These mucins possess specific domains that can make complex associations with various signaling pathways, impacting cell survival through alterations of cell growth, proliferation, death, and autophagy. The cytoplasmic domain of MUC1 serves as a scaffold for interaction with various signaling proteins. On the other hand, MUC4 mediates its effect by stabilizing and enhancing the activity of growth factor receptor ErbB2. MUC16, previously known as CA125, is a well-known serum marker for the diagnosis of ovarian cancer and has a key role in stimulation and dissemination of ovarian cancer cells by interacting with mesothelin and galectin. Therefore, herein we discuss the function and divergent mechanisms of MUC1, MUC4, and MUC16 in carcinogenesis in the context of alteration in cell growth and survival.
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Affiliation(s)
- S Bafna
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA
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Senapati S, Das S, Batra SK. Mucin-interacting proteins: from function to therapeutics. Trends Biochem Sci 2009; 35:236-45. [PMID: 19913432 DOI: 10.1016/j.tibs.2009.10.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 10/14/2009] [Accepted: 10/16/2009] [Indexed: 12/12/2022]
Abstract
Mucins are high molecular weight glycoproteins that are involved in regulating diverse cellular activities both in normal and pathological conditions. Mucin activity and localization is mediated by several molecular mechanisms, including discrete interactions with other proteins. An understanding of the biochemistry behind the known interactions between mucins and other proteins, coupled with an appreciation of their pathophysiological significance, can lend insight into the development of novel therapeutic agents. Indeed, a recent study demonstrated that a cell permeable inhibitor, PMIP, that disrupts the MUC1-EGFR interaction, is effective in killing breast cancer cells in vitro and in tumor models.
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Affiliation(s)
- Shantibhusan Senapati
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Singh PK, Behrens ME, Eggers JP, Cerny RL, Bailey JM, Shanmugam K, Gendler SJ, Bennett EP, Hollingsworth MA. Phosphorylation of MUC1 by Met modulates interaction with p53 and MMP1 expression. J Biol Chem 2008; 283:26985-95. [PMID: 18625714 DOI: 10.1074/jbc.m805036200] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
MUC1, a transmembrane mucin, is a key modulator of several signaling pathways that affect oncogenesis, motility, and cell morphology. The interaction of MUC1 cytoplasmic tail (MUC1CT) with signal transducers and its nuclear translocation and subsequent biological responses are believed to be regulated by phosphorylation status, but the precise mechanisms by which this occurs remain poorly defined. We detected a novel association between the Met receptor tyrosine kinase and the MUC1CT. Met catalyzed phosphorylation of tyrosine at YHPM in the MUC1CT. Stimulation of S2-013.MUC1F pancreatic cancer cells with hepatocyte growth factor facilitated nuclear localization of MUC1CT, as determined by real time confocal imaging analysis. MUC1 overexpression also facilitated faster turnover of Met. Phosphorylation of MUC1CT by Met enhanced its interaction with p53, which led to suppression of AP1 transcription factor activity through interactions at the MMP1 promoter, ultimately leading to reduced transcription of MMP1. This correlated with a decrease in hepatocyte growth factor-induced invasiveness when MUC1 was overexpressed. The results demonstrate that MUC1 modulates Met-mediated oncogenic signaling in cancer.
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Affiliation(s)
- Pankaj K Singh
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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Blalock TD, Spurr-Michaud SJ, Tisdale AS, Gipson IK. Release of membrane-associated mucins from ocular surface epithelia. Invest Ophthalmol Vis Sci 2008; 49:1864-71. [PMID: 18436821 DOI: 10.1167/iovs.07-1081] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Three membrane-associated mucins (MAMs)--MUC1, MUC4, and MUC16--are expressed at the ocular surface epithelium. Soluble forms of MAMs are detected in human tears, but the mechanisms of their release from the apical cells are unknown. The purpose of this study was to identify physiologic agents that induce ocular surface MAM release. METHODS An immortalized human corneal-limbal epithelial cell line (HCLE) expressing the same MAMs as native tissue was used. An antibody specific to the MUC16 cytoplasmic tail was developed to confirm that only the extracellular domain is released into the tear fluid or culture media. Effects of agents that have been shown to be present in tears or are implicated in the release or shedding of MAMs in other epithelia (neutrophil elastase, tumor necrosis factor [TNF]), TNF-alpha-converting enzyme, and matrix metalloproteinase-7 and -9) were assessed on HCLE cells. HCLE cell surface proteins were biotinylated to measure the efficiency of induced MAM release and surface restoration. Effects of induced release on surface barrier function were measured by rose bengal dye penetrance. RESULTS MUC16 in tears and in HCLE-conditioned medium lacked the cytoplasmic tail. TNF induced the release of MUC1, MUC4, and MUC16 from the HCLE surface. Matrix metalloproteinase-7 and neutrophil elastase induced the release of MUC16 but not of MUC1 or MUC4. Neutrophil elastase removed 68% of MUC16, 78% of which was restored to the HCLE cell surface 24 hours after release. Neutrophil elastase-treated HCLE cells showed significantly reduced rose bengal dye exclusion. CONCLUSIONS Results suggest that the extracellular domains of MUC1, MUC4, and MUC16 can be released from the ocular surface by agents in tears. Neutrophil elastase and TNF, present in higher amounts in the tears of patients with dry eye, may cause MAM release, allowing rose bengal staining.
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Affiliation(s)
- Timothy D Blalock
- Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
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Carraway KL, Funes M, Workman HC, Sweeney C. Contribution of membrane mucins to tumor progression through modulation of cellular growth signaling pathways. Curr Top Dev Biol 2007; 78:1-22. [PMID: 17338913 DOI: 10.1016/s0070-2153(06)78001-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mucins are large, heavily O-glycosylated proteins expressed by epithelial tissues. The canonical function of membrane mucins is to provide protection to vulnerable epithelia by forming a steric barrier against assault, and by contributing to the formation of protective extracellular mucin gels. The aberrant overexpression of mucins is thought to contribute to tumor progression by allowing tumor cells to evade immune recognition, and by aiding in the breakdown of cell-cell and cell-matrix contacts to facilitate migration and metastasis. Recent evidence suggests that we should now modify our thinking about mucin function by considering their roles in signaling pathways leading to cellular growth control. Here we review the markedly divergent mechanisms by which membrane mucins, specifically MUC1 and MUC4, influence pathways contributing to cellular proliferation and survival. The cytoplasmic domain of MUC1 serves as a scaffold for the assembly of a variety of signaling proteins, while MUC4 influences the trafficking and localization of growth factor receptors, and hence their responses to external stimuli. We also discuss how tumor cells exploit these mechanisms to promote their own growth and metastasis.
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Lang T, Hansson GC, Samuelsson T. An inventory of mucin genes in the chicken genome shows that the mucin domain of Muc13 is encoded by multiple exons and that ovomucin is part of a locus of related gel-forming mucins. BMC Genomics 2006; 7:197. [PMID: 16887038 PMCID: PMC1552070 DOI: 10.1186/1471-2164-7-197] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Accepted: 08/03/2006] [Indexed: 01/31/2023] Open
Abstract
Background Mucins are large glycoproteins that cover epithelial surfaces of the body. All mucins contain at least one PTS domain, a region rich in proline, threonine and serine. Mucins are also characterized by von Willebrand D (VWD) domains or SEA domains. We have developed computational methods to identify mucin genes and proteins based on these properties of the proteins. Using such methods we are able to characterize different organisms where genome sequence is available with respect to their mucin repertoire. Results We have here made a comprehensive analysis of potential mucins encoded by the chicken (Gallus gallus) genome. Three transmembrane mucins (Muc4, Muc13, and Muc16) and four gel-forming mucins (Muc6, Muc2, Muc5ac, and Muc5b) were identified. The gel-forming mucins are encoded within a locus similar to the corresponding human mucins. However, the chicken has an additional gene inserted between Muc2 and Muc5ac that encodes the the α-subunit of ovomucin, a protein similar to Muc2, but it is lacking a PTS domain. We also show that the β-subunit of ovomucin is the orthologue of human MUC6. The transmembrane Muc13 gene is in chicken as well as in mammals adjacent to the HEG (heart of glass) gene. HEG has PTS, EGF and transmembrane domains like Muc13, suggesting that these two proteins are evolutionary related. Unlike previously known mucins, the PTS domain of Muc13 is encoded by multiple exons, where each exon encodes a repeat unit of the PTS domain. Conclusion We report new mucin homologues in chicken and this information will aid in understanding the evolution of mucins in vertebrates. The fact that ovomucin, a protein not found in mammals, was located in the same locus as other gel-forming mucins provides strong support that these proteins are evolutionary related. Furthermore, a relationship of HEG and the transmembrane Muc13 is suggested on the basis of their biochemical properties and their presence in the same locus. Finally, our finding that the chicken Muc13 is distributed between multiple exons raises the interesting possibility that the length of the PTS domain could be controlled by alternative splicing.
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Affiliation(s)
- Tiange Lang
- Department of Medical Biochemistry, Goteborg University, Goteborg, Sweden
| | - Gunnar C Hansson
- Department of Medical Biochemistry, Goteborg University, Goteborg, Sweden
| | - Tore Samuelsson
- Department of Medical Biochemistry, Goteborg University, Goteborg, Sweden
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Malmberg EK, Noaksson KA, Phillipson M, Johansson MEV, Hinojosa-Kurtzberg M, Holm L, Gendler SJ, Hansson GC. Increased levels of mucins in the cystic fibrosis mouse small intestine, and modulator effects of the Muc1 mucin expression. Am J Physiol Gastrointest Liver Physiol 2006; 291:G203-10. [PMID: 16500918 DOI: 10.1152/ajpgi.00491.2005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mouse model (Cftr(tm1UNC)/Cftr(tm1UNC)) for cystic fibrosis (CF) shows mucus accumulation and increased Muc1 mucin mRNA levels due to altered splicing (Hinojosa-Kurtzberg AM, Johansson MEV, Madsen CS, Hansson GC, and Gendler SJ. Am J Physiol Gastrointest Liver Physiol 284: G853-G862, 2003). However, it is not known whether Muc1 is a major mucin contributing to the increased mucus and why CF/Muc1-/- mice show lower mucus accumulation. To address this, we have purified mucins from the small intestine of CF mice using guanidinium chloride extraction, ultracentrifugation, and gel filtration and analyzed them by slot blot, gel electrophoresis, proteomics, and immunoblotting. Normal and CF mice with wild-type (WT) Muc1 or Muc1-/- or that are transgenic for human MUC1 (MUC1.Tg, on a Muc1-/- background) were analyzed. The total amount of mucins, both soluble and insoluble in guanidinium chloride, increased up to 10-fold in the CF mice compared with non-CF animals, whereas the CF mice lacking Muc1 showed intermediate levels between the CF and non-CF mice. However, the levels of Muc3 (orthologue of human MUC17) were increased in the CF/Muc1-/- mice compared with the CF/MUC1.Tg animals. The amount of MUC1 mucin was increased several magnitudes in the CF mice, but MUC1 did still not appear to be a major mucin. The amount of insoluble mucus of the large intestine was also increased in the CF mice, an effect that was partially restored in the CF/Muc1-/- mice. The thickness of the firmly adherent mucus layer of colon in the Muc1-/- mice was significantly lower than that of WT mice. The results suggest that MUC1 is not a major component in the accumulated mucus of CF mice and that MUC1 can influence the amount of other mucins in a still unknown way.
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Affiliation(s)
- Emily K Malmberg
- Department of Medical Biochemistry, Göteborg University, Gothenburg, Sweden
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Funes M, Miller JK, Lai C, Carraway KL, Sweeney C. The mucin Muc4 potentiates neuregulin signaling by increasing the cell-surface populations of ErbB2 and ErbB3. J Biol Chem 2006; 281:19310-9. [PMID: 16690615 DOI: 10.1074/jbc.m603225200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mucins provide a protective barrier for epithelial surfaces, and their overexpression in tumors has been implicated in malignancy. We have previously demonstrated that Muc4, a transmembrane mucin that promotes tumor growth and metastasis, physically interacts with the ErbB2 receptor tyrosine kinase and augments receptor tyrosine phosphorylation in response to the neuregulin-1beta (NRG1beta) growth factor. In the present study we demonstrate that Muc4 expression in A375 human melanoma cells, as well as MCF7 and T47D human breast cancer cells, enhances NRG1beta signaling through the phosphatidylinositol 3-kinase pathway. In examining the mechanism underlying Muc4-potentiated ErbB2 signaling, we found that Muc4 expression markedly augments NRG1beta binding to A375 cells without altering the total quantity of receptors expressed by the cells. Cell-surface protein biotinylation experiments and immunofluorescence studies suggest that Muc4 induces the relocalization of the ErbB2 and ErbB3 receptors from intracellular compartments to the plasma membrane. Moreover, Muc4 interferes with the accumulation of surface receptors within internal compartments following NRG1beta treatment by suppressing the efficiency of receptor internalization. These observations suggest that transmembrane mucins can modulate receptor tyrosine kinase signaling by influencing receptor localization and trafficking and contribute to our understanding of the mechanisms by which mucins contribute to tumor growth and progression.
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Affiliation(s)
- Melanie Funes
- University of California-Davis Cancer Center, Sacramento, California 95817, USA
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