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Galogre M, Rodin D, Pyatnitskiy M, Mackelprang M, Koman I. "A Review of HER2 overexpression and somatic mutations in cancers". Crit Rev Oncol Hematol 2023; 186:103997. [PMID: 37062337 DOI: 10.1016/j.critrevonc.2023.103997] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/14/2023] [Accepted: 04/13/2023] [Indexed: 04/18/2023] Open
Abstract
The Human Epidermal Growth Factor Receptor (HER) proteins family, which includes HER2, are membrane-bound receptors that activate many intracellular pathways associated with growth and development. When there are mutations in HER2, or when it becomes overexpressed, it can cause oncogenesis and offer differential prognosis and treatment across almost all cancer types. Both mutations in HER2 and its overexpression have distinct mechanisms by which they can cause these effects in cancers. This review outlines how HER2's normal pathway is altered in both overexpression and mutation and compiles all the well-known mechanisms by which HER2 can cause oncogenesis. Finally, this review briefly outlines how HER2 mutants and HER2 overexpression is detected, and how their detection can lead to different prognosis and treatment in cancers.
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Affiliation(s)
| | - Dmitry Rodin
- Institute of Personalised and Translational Medicine, Ariel University, Ariel, Israel Kiryat Hamada
| | - Mikhail Pyatnitskiy
- Institute of Biomedical Chemistry RAMS, Solianka st.,14, 109544, Moscow, Russia
| | | | - Igor Koman
- SmartOmica, Tērbatas iela 36 - 4, Latvia Rīga, LV-1011; Institute of Personalised and Translational Medicine, Ariel University, Ariel, Israel Kiryat Hamada
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Fu R, Jiang X, Li G, Zhu Y, Zhang H. Junctional complexes in epithelial cells: sentinels for extracellular insults and intracellular homeostasis. FEBS J 2022; 289:7314-7333. [PMID: 34453866 DOI: 10.1111/febs.16174] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/13/2021] [Accepted: 08/27/2021] [Indexed: 01/13/2023]
Abstract
The cell-cell and cell-ECM junctions within the epithelial tissues are crucial anchoring structures that provide architectural stability, mechanical resistance, and permeability control. Their indispensable role as signaling hubs orchestrating cell shape-related changes such as proliferation, differentiation, migration, and apoptosis has also been well recognized. However, growing amount of evidence now suggests that the multitasking nature of epithelial junctions extends well beyond anchorage-dependent or cell shape change-related biological processes. In this review, we discuss the emerging roles of junctional complexes in regulating innate immune defense, stress resistance, and intracellular proteostasis of the epithelial cells, with emphasis on the upstream regulation of epithelial junctions on various aspects of the epithelial barrier.
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Affiliation(s)
- Rong Fu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, China
| | - Xiaowan Jiang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, China
| | - Gang Li
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, China
| | - Yi Zhu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, China
| | - Huimin Zhang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, China
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Peng L, Li Y, Gu H, Xiang L, Xiong Y, Wang R, Zhou H, Wang J. Mucin 4 mutation is associated with tumor mutation burden and promotes antitumor immunity in colon cancer patients. Aging (Albany NY) 2021; 13:9043-9055. [PMID: 33714943 PMCID: PMC8034916 DOI: 10.18632/aging.202756] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/27/2021] [Indexed: 12/14/2022]
Abstract
At present, immunotherapy is widely used for different mismatch repair (dMMR) or highly microsatellite instability (MSI-H) colorectal cancer patients, and tumor mutation burden (TMB) is a valuable independent predictor of response to immunotherapy. However, specific gene mutations and their relationship with TMB and tumor-infiltrating immune cells in colon cancer remains unclear. In the present study, we analyzed somatic mutation data of colon cancer from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) datasets, and found that 17 frequently mutated genes were occurred in both cohorts, including APC, TP53, TNN, KRAS, MUC16, MUC4 (mucin 4), SYNE1, FLG, FAT4, OBSCN, FAT3, RYR2, PIK3CA, FBXW7, DNAH11, MUC5B and ZFHX4. Interestingly, only MUC4 mutation was associated with higher TMB and patient clinical prognosis among the 17 mutated genes. Moreover, according to gene set enrichment analysis (GSEA) and the CIBERSORT algorithm, we revealed that MUC4 mutation activated signaling pathways involved in the immune system and enhanced the antitumor immune response. In conclusion, MUC4 may have important clinical implications for immune therapy of colon cancer.
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Affiliation(s)
- Linglong Peng
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Yang Li
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Haitao Gu
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Ling Xiang
- Department of Clinical Nutrition, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Yongfu Xiong
- Department of Hepatobiliary Surgery, The Affiliated Hospital of North Sichuan Medical College, Sichuan 637000, China
| | - Rong Wang
- Department of Oncology, The Cancer Center of the Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, China
| | - He Zhou
- Department of Gastrointestinal Surgery, The Affiliated Hospital of North Sichuan Medical College, Sichuan 637000, China
| | - Jijian Wang
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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Liberelle M, Jonckheere N, Melnyk P, Van Seuningen I, Lebègue N. EGF-Containing Membrane-Bound Mucins: A Hidden ErbB2 Targeting Pathway? J Med Chem 2020; 63:5074-5088. [PMID: 32027502 DOI: 10.1021/acs.jmedchem.9b02001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Membrane-bound mucins belong to a heterogeneous family of large O-glycoproteins involved in numerous cancers and inflammatory diseases of the epithelium. Some of them are also involved in protein-protein interactions, with receptor tyrosine kinase ErbB2, and fundamental and clinical data showed that these complexes have a detrimental impact on cancer outcome, thus raising interest in therapeutic targeting. This paper aims to demonstrate that MUC3, MUC4, MUC12, MUC13, and MUC17 have a common evolutionary origin and share a common structural organization with EGF-like and SEA domains. Theoretical structure-function relationship analysis of the conserved domains indicated that the studied membrane-bound mucins share common biological properties along with potential specific functions. Finally, the potential druggability of these complexes is discussed, revealing ErbB2-related pathways of cell signaling to be targeted.
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Affiliation(s)
- Maxime Liberelle
- Univ. Lille, Inserm CHU Lille, UMR-S1172-JPArc-Centre de Recherche Jean-Pierre Aubert Neurosciences et Cancer, F-59000 Lille, France.,Univ. Lille, Inserm, CHU Lille, UMR-S 1172-LiNC-Lille Neuroscience & Cognition, F-59000 Lille, France
| | - Nicolas Jonckheere
- Univ. Lille, Inserm CHU Lille, UMR-S1172-JPArc-Centre de Recherche Jean-Pierre Aubert Neurosciences et Cancer, F-59000 Lille, France.,Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-UMR-S 1277-Canther-Cancer Heterogeneity, Plasticity and Resistance to Therapies, F-59000 Lille, France
| | - Patricia Melnyk
- Univ. Lille, Inserm CHU Lille, UMR-S1172-JPArc-Centre de Recherche Jean-Pierre Aubert Neurosciences et Cancer, F-59000 Lille, France.,Univ. Lille, Inserm, CHU Lille, UMR-S 1172-LiNC-Lille Neuroscience & Cognition, F-59000 Lille, France
| | - Isabelle Van Seuningen
- Univ. Lille, Inserm CHU Lille, UMR-S1172-JPArc-Centre de Recherche Jean-Pierre Aubert Neurosciences et Cancer, F-59000 Lille, France.,Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-UMR-S 1277-Canther-Cancer Heterogeneity, Plasticity and Resistance to Therapies, F-59000 Lille, France
| | - Nicolas Lebègue
- Univ. Lille, Inserm CHU Lille, UMR-S1172-JPArc-Centre de Recherche Jean-Pierre Aubert Neurosciences et Cancer, F-59000 Lille, France.,Univ. Lille, Inserm, CHU Lille, UMR-S 1172-LiNC-Lille Neuroscience & Cognition, F-59000 Lille, France
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5
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Walls ZF, Schwengels M, Palau V. Intracellular sequestration of HER2 via targeted subcellular peptide delivery. J Drug Target 2018. [DOI: 10.1080/1061186x.2018.1450411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Zachary F. Walls
- Department of Pharmaceutical Sciences, Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN, USA
- Center of Excellence for Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, USA
| | | | - Victoria Palau
- Department of Pharmaceutical Sciences, Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN, USA
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Rokutan-Kurata M, Yoshizawa A, Sumiyoshi S, Sonobe M, Menju T, Momose M, Koyama M, Shigeto S, Fujimoto M, Zhang M, Morita S, Date H, Haga H. Lung Adenocarcinoma With MUC4 Expression Is Associated With Smoking Status, HER2 Protein Expression, and Poor Prognosis: Clinicopathologic Analysis of 338 Cases. Clin Lung Cancer 2017; 18:e273-e281. [DOI: 10.1016/j.cllc.2016.11.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/14/2016] [Accepted: 11/22/2016] [Indexed: 10/20/2022]
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Dong H, Ma L, Gan J, Lin W, Chen C, Yao Z, Du L, Zheng L, Ke C, Huang X, Song H, Kumar R, Yeung SC, Zhang H. PTPRO represses ERBB2-driven breast oncogenesis by dephosphorylation and endosomal internalization of ERBB2. Oncogene 2017; 36:410-422. [PMID: 27345410 PMCID: PMC5269534 DOI: 10.1038/onc.2016.213] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 05/05/2016] [Accepted: 05/08/2016] [Indexed: 02/05/2023]
Abstract
The plasma membrane-associated tyrosine phosphatase PTPRO is frequently transcriptionally repressed in cancers and signifies poor prognosis of breast cancer patients. In this study, deletion of Ptpro in MMTV-Erbb2 transgenic mice dramatically shortened the mammary tumor latency and accelerated tumor growth due to loss of Ptpro within the breast cancer cells but not in surrounding tissue as confirmed by hetero-transplantation studies. Both in vitro and in vivo data demonstrated that the phosphatase activity was required for the inactivation of ERBB2 and its downstream signaling. PTPRO regulated the phosphorylation status of ERBB2 at Y1248. Co-immunoprecipitation and proximity ligation assay (Duolink) indicated that PTPRO directly physically interacted with ERBB2. Moreover, PTPRO phosphatase activity shortened the half-life of ERBB2 by increasing endocytotic degradation. PTPRO reexpression by demethylation treatment using 5-azacytidine reduced the proliferation and colony formation potential in ERBB2-positive breast cancer cells. Taken together, PTPRO inhibited ERBB2-driven breast cancer through dephosphorylation leading to dual effects of ERBB2 signaling suppression and endosomal internalization of ERBB2, Therefore, reexpression of PTPRO may be a potential therapy for ERBB2-overexpressing breast cancer.
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Affiliation(s)
- H Dong
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - L Ma
- Department of Gastroenterology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - J Gan
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - W Lin
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - C Chen
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - Z Yao
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - L Du
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - L Zheng
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - C Ke
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - X Huang
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center of Nanjing University, Nanjing, China
| | - H Song
- Department of Cell Biology, Xi'an Jiaotong University Suzhou Academy, Suzhou, China
| | - R Kumar
- Department of Biochemistry and Molecular Medicine, School of Medicine and Health Sciences, George Washington University, Washington DC, USA
| | - S C Yeung
- Cancer Research Center, Shantou University Medical College, Shantou, China
- Department of Emergency Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. E-mail:
| | - H Zhang
- Cancer Research Center, Shantou University Medical College, Shantou, China
- Department of Biotherapy, Affiliated Cancer Hospital of Shantou University Medical College, Shantou, China
- Cancer Research Center, Shantou University Medical College, Xinling Road No. 22, Shantou 515041, ChinaE-mail:
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Milara J, Morell A, Ballester B, Armengot M, Morcillo E, Cortijo J. MUC4 impairs the anti-inflammatory effects of corticosteroids in patients with chronic rhinosinusitis with nasal polyps. J Allergy Clin Immunol 2016; 139:855-862.e13. [PMID: 27639937 DOI: 10.1016/j.jaci.2016.06.064] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/18/2016] [Accepted: 06/02/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Current evidence suggests that membrane-tethered mucins could mediate corticosteroid efficacy, interacting with glucocorticoid receptor (GR) in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Mucin 4 (MUC4)-tethered mucin is expressed in nasal polyp (NP) epithelial cells and upregulated under inflammatory conditions. Moreover, MUC4β has the capacity to interact with other intracellular proteins. We hypothesized that MUC4 modulates corticosteroid efficacy of patients with CRSwNP. OBJECTIVE We sought to analyze the role of MUC4 in corticosteroid effectiveness in different cohorts of patients with CRSwNP and elucidate the possible mechanisms involved. METHODS Eighty-one patients with CRSwNP took oral corticosteroids for 15 days. Corticosteroid resistance was evaluated by using nasal endoscopy. Expression of MUC4 and MUC4β was evaluated by means of real-time PCR, Western blotting, and immunohistochemistry. BEAS-2B knockdown with RNA interference for MUC4 (small interfering RNA [siRNA]-MUC4) was used to analyze the role of MUC4 in the anti-inflammatory effects of dexamethasone. RESULTS Twenty-two patients had NPs resistant to oral corticosteroids. MUC4 expression was upregulated in these patients. In siRNA-MUC4 BEAS-2B airway epithelial cells dexamethasone produced higher anti-inflammatory effects, increased inhibition of phospho-extracellular signal-regulated kinase 1/2, increased mitogen-activated protein kinase phosphatase 1 expression, and increased glucocorticoid response element activation. Immunoprecipitation and immunofluorescence experiments revealed that MUC4β forms a complex with GRα in the nuclei of NP epithelial cells from corticosteroid-resistant patients. CONCLUSION MUC4β participates in the corticosteroid resistance process, inhibiting normal GRα nuclear function. The high expression of MUC4 in patients with CRSwNP might participate in corticosteroid resistance.
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Affiliation(s)
- Javier Milara
- Department of Pharmacy, University Hospital Consortium, Valencia, Spain; Department of Pharmacology, Faculty of Medicine, Jaume I University, Castellon, Spain; Department of Pharmacology, Faculty of Medicine, University of Valencia, Valencia, Spain; CIBERES, Health Institute Carlos III, Valencia, Spain.
| | - Anselm Morell
- Department of Pharmacology, Faculty of Medicine, University of Valencia, Valencia, Spain; CIBERES, Health Institute Carlos III, Valencia, Spain
| | | | - Miguel Armengot
- Rhinology Unit, University Hospital Consortium, Valencia, Spain; Department of Medicine, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Esteban Morcillo
- Department of Pharmacology, Faculty of Medicine, University of Valencia, Valencia, Spain; CIBERES, Health Institute Carlos III, Valencia, Spain; Instituto de Investigación Sanitaria INCLIVA, Valencia, Spain
| | - Julio Cortijo
- Department of Pharmacology, Faculty of Medicine, University of Valencia, Valencia, Spain; CIBERES, Health Institute Carlos III, Valencia, Spain; Research and Teaching Unit, University Hospital Consortium, Valencia, Spain
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Epithelial MUC1 promotes cell migration, reduces apoptosis and affects levels of mucosal modulators during acetylsalicylic acid (aspirin)-induced gastropathy. Biochem J 2015; 465:423-31. [DOI: 10.1042/bj20140617] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
MUC1, a transmembrane mucin highly expressed in the stomach, is up-regulated after acetylsalicylic acid (ASA) intake in humans and mice. Epithelial Muc1/MUC1 facilitates mucosal wound healing by enhancing cell migration and proliferation, protecting against apoptosis and mediating expression of mucosal modulators.
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10
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Pathogenesis of human enterovirulent bacteria: lessons from cultured, fully differentiated human colon cancer cell lines. Microbiol Mol Biol Rev 2014; 77:380-439. [PMID: 24006470 DOI: 10.1128/mmbr.00064-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hosts are protected from attack by potentially harmful enteric microorganisms, viruses, and parasites by the polarized fully differentiated epithelial cells that make up the epithelium, providing a physical and functional barrier. Enterovirulent bacteria interact with the epithelial polarized cells lining the intestinal barrier, and some invade the cells. A better understanding of the cross talk between enterovirulent bacteria and the polarized intestinal cells has resulted in the identification of essential enterovirulent bacterial structures and virulence gene products playing pivotal roles in pathogenesis. Cultured animal cell lines and cultured human nonintestinal, undifferentiated epithelial cells have been extensively used for understanding the mechanisms by which some human enterovirulent bacteria induce intestinal disorders. Human colon carcinoma cell lines which are able to express in culture the functional and structural characteristics of mature enterocytes and goblet cells have been established, mimicking structurally and functionally an intestinal epithelial barrier. Moreover, Caco-2-derived M-like cells have been established, mimicking the bacterial capture property of M cells of Peyer's patches. This review intends to analyze the cellular and molecular mechanisms of pathogenesis of human enterovirulent bacteria observed in infected cultured human colon carcinoma enterocyte-like HT-29 subpopulations, enterocyte-like Caco-2 and clone cells, the colonic T84 cell line, HT-29 mucus-secreting cell subpopulations, and Caco-2-derived M-like cells, including cell association, cell entry, intracellular lifestyle, structural lesions at the brush border, functional lesions in enterocytes and goblet cells, functional and structural lesions at the junctional domain, and host cellular defense responses.
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Zhou L, Yang H, Okoro EU, Guo Z. Up-regulation of cholesterol absorption is a mechanism for cholecystokinin-induced hypercholesterolemia. J Biol Chem 2014; 289:12989-99. [PMID: 24692543 DOI: 10.1074/jbc.m113.534388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Excessive absorption of intestinal cholesterol is a risk factor for atherosclerosis. This report examines the effect of cholecystokinin (CCK) on plasma cholesterol level and intestinal cholesterol absorption using the in vivo models of C57BL/6 wild-type and low density lipoprotein receptor knock-out (LDLR(-/-)) mice. These data were supported by in vitro studies involving mouse primary intestinal epithelial cells and human Caco-2 cells; both express CCK receptor 1 and 2 (CCK1R and CCK2R). We found that intravenous injection of [Thr(28),Nle(31)]CCK increased plasma cholesterol levels and intestinal cholesterol absorption in both wild-type and LDLR(-/-) mice. Treatment of mouse primary intestinal epithelial cells with [Thr(28),Nle(31)]CCK increased cholesterol absorption, whereas selective inhibition of CCK1R and CCK2R with antagonists attenuated CCK-induced cholesterol absorption. In Caco-2 cells, CCK enhanced CCK1R/CCK2R heterodimerization. Knockdown of both CCK1R and CCK2 or either one of them diminished CCK-induced cholesterol absorption to the same extent. CCK also increased cell surface-associated NPC1L1 (Niemann-Pick C1-like 1) transporters but did not alter their total protein expression. Inhibition or knockdown of NPC1L1 attenuated CCK-induced cholesterol absorption. CCK enhanced phosphatidylinositide 3-kinase (PI3K) and Akt phosphorylation and augmented the interaction between NPC1L1 and Rab11a (Rab-GTPase-11a), whereas knockdown of CCK receptors or inhibition of G protein βγ dimer (Gβγ) diminished CCK-induced PI3K and Akt phosphorylation. Inhibition of PI3K and Akt or knockdown of PI3K diminished CCK-induced NPC1L1-Rab11a interaction and cholesterol absorption. Knockdown of Rab11a suppressed CCK-induced NPC1L1 translocation and cholesterol absorption. These data imply that CCK enhances cholesterol absorption by activation of a pathway involving CCK1R/CCK2R, Gβγ, PI3K, Akt, Rab11a, and NPC1L.
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Affiliation(s)
- LiChun Zhou
- From the Department of Physiology, Meharry Medical College, Nashville, Tennessee 37208
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MUC4 modulates human glioblastoma cell proliferation and invasion by upregulating EGFR expression. Neurosci Lett 2014; 566:82-7. [PMID: 24582898 DOI: 10.1016/j.neulet.2014.02.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 02/09/2014] [Accepted: 02/18/2014] [Indexed: 01/03/2023]
Abstract
Glioblastoma (GBM), the most common primary brain tumor, is the leading cause of deaths related to tumors in the central nervous system. The prognosis of GBM patients is currently poor, and the mechanisms underlying GBM genesis remain unclear. The expression of MUC4, a high-molecular-weight and highly glycosylated protein, has been studied in many cancers. However, information on MUC4 expression in GBM is limited. In this study, we found that MUC4 was overexpressed in GBM cell lines and tissues. The proliferation and invasive potential of GBM cells were significantly increased by the ectopic expression of MUC4. By contrast, RNA interference targeting MUC4 in GBM cells significantly decreased the proliferation and invasive potential of GBM cells. We also found that the expression of epidermal growth factor receptor (EGFR) was modulated by MUC4. EGFR inhibition by siRNA reversed the MUC4-induced proliferation and invasion. These results indicated that MUC4 expression in GBM was important in GBM cell proliferation and invasion, which may be partly associated with EGFR overexpression.
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Firth JD, Ekuni D, Irie K, Tomofuji T, Morita M, Putnins EE. Lipopolysaccharide induces a stromal-epithelial signalling axis in a rat model of chronic periodontitis. J Clin Periodontol 2012; 40:8-17. [PMID: 23167849 DOI: 10.1111/jcpe.12023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 09/10/2012] [Accepted: 09/16/2012] [Indexed: 11/29/2022]
Abstract
AIM Lipopolysaccharide is a bacterial virulence factor implicated in chronic periodontitis, which may penetrate the junctional epithelial barrier and basement membrane to insult underlying stroma. We sought to identify lipopolysaccharide-induced global gene expression changes responsible for signalling between stroma and epithelium during disease onset. MATERIALS AND METHODS Using a rat lipopolysaccharide periodontitis model, junctional epithelium and underlying stromal tissue were separately collected from healthy and diseased animals by laser-capture microdissection and subject to gene expression microarray analysis. Key gene products identified were validated in gingival epithelial and fibroblast cell cultures. RESULTS Global gene expression patterns distinguishing health versus disease were found in and between both tissue types. In stroma, the most significantly altered gene ontology function group (Z ≥ 4.00) was cytokines, containing most significantly (±2-fold; p < 0.05) upregulated genes amphiregulin, IL1-β and Fas ligand, all positive, diffusible modulators of the epithelial growth factor receptor pathway. In epithelium, the most significant changes were in downregulated FOS-related antigen-1 gene, somatostatin receptor-2 gene and mucin-4 gene, all negative modulators of the epithelial growth factor receptor pathway. CONCLUSION These results establish a periodontitis model for studying gene product interactions and suggests that the onset of junctional epithelial disease hyperproliferation involves a concerted stromal-epithelial signalling axis.
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Affiliation(s)
- James D Firth
- Department of Oral Biological & Medical Sciences, University of British Columbia, Vancouver, BC, Canada
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Jonckheere N, Skrypek N, Merlin J, Dessein AF, Dumont P, Leteurtre E, Harris A, Desseyn JL, Susini C, Frénois F, Van Seuningen I. The mucin MUC4 and its membrane partner ErbB2 regulate biological properties of human CAPAN-2 pancreatic cancer cells via different signalling pathways. PLoS One 2012; 7:e32232. [PMID: 22393391 PMCID: PMC3290552 DOI: 10.1371/journal.pone.0032232] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 01/24/2012] [Indexed: 01/19/2023] Open
Abstract
The mucin MUC4 and its membrane partner the ErbB2 oncogenic receptor are potential interacting partners in human pancreatic tumour development. However, the way they function is still largely unknown. In this work, we aimed to identify the cellular mechanisms and the intracellular signalling pathways under the control of both ErbB2 and MUC4 in a human pancreatic adenocarcinomatous cell line. Using co-immunoprecipitation and GST pull-down, we show that MUC4 and ErbB2 interact in the human pancreatic adenocarcinomatous cell line CAPAN-2 via the EGF domains of MUC4. Stable cell clones were generated in which either MUC4 or ErbB2 were knocked down (KD) by a shRNA approach. Biological properties of these cells were then studied in vitro and in vivo. Our results show that ErbB2-KD cells are more apoptotic and less proliferative (decreased cyclin D1 and increased p27kip1 expression) while migration and invasive properties were not altered. MUC4-KD clones were less proliferative with decreased cyclin D1 expression, G1 cell cycle arrest and altered ErbB2/ErbB3 expression. Their migration properties were reduced whereas invasive properties were increased. Importantly, inhibition of ErbB2 and MUC4 expression did not impair the same signalling pathways (inhibition of MUC4 expression affected the JNK pathway whereas that of ErbB2 altered the MAPK pathway). Finally, ErbB2-KD and MUC4-KD cells showed impaired tumour growth in vivo. Our results show that ErbB2 and MUC4, which interact physically, activate different intracellular signalling pathways to regulate biological properties of CAPAN-2 pancreatic cancer cells.
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Affiliation(s)
- Nicolas Jonckheere
- Inserm, UMR837, Jean Pierre Aubert Research Center, Team #5 Mucins, epithelial differentiation and carcinogenesis, Lille, France.
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Pfister AB, Wood RC, Salas PJI, Zea DL, Ramsauer VP. Early response to ErbB2 over-expression in polarized Caco-2 cells involves partial segregation from ErbB3 by relocalization to the apical surface and initiation of survival signaling. J Cell Biochem 2011; 111:643-52. [PMID: 20589763 DOI: 10.1002/jcb.22754] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In several human cancers, ErbB2 over-expression facilitates the formation of constitutively active homodimers resistant to internalization which results in progressive signal amplification from the receptor, conducive to cell survival, proliferation, or metastasis. Here we report on studies of the influence of ErbB2 over-expression on localization and signaling in polarized Caco-2 and MDCK cells, two established models to study molecular trafficking. In these cells, ErbB2 is not over-expressed and shares basolateral localization with ErbB3. Over-expression of ErbB2 by transient transfection resulted in partial separation of the receptors by relocalization of ErbB2, but not ErbB3, to the apical surface, as shown by biotinylation of the apical or basolateral surfaces. These results were confirmed by immunofluorescence and confocal microscopy. Polarity controls indicated that the relocalization of ErbB2 is not the result of depolarization of the cells. Biotinylation and confocal microscopy also showed that apical, but not basolateral ErbB2 is activated at tyrosine 1139. This phosphotyrosine binds adaptor protein Grb2, as confirmed by immunoprecipitation. However, we found that it does not initiate the canonical Grb2-Ras-Raf-Erk pathway. Instead, our data supports the activation of a survival pathway via Bcl-2. The effects of ErbB2 over-expression were abrogated by the humanized anti-ErbB2 monoclonal antibody Herceptin added only from the apical side. The ability of apical ErbB2 to initiate an altered downstream cascade suggests that subcellular localization of the receptor plays an important role in regulating ErbB2 signaling in polarized epithelia.
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Affiliation(s)
- Amber B Pfister
- Department of Pharmaceutical Sciences, Bill Gatton College of Pharmacy, East Tennessee State University, Johnson City, Tennessee 37614, USA
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16
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Maker AV, Katabi N, Gonen M, DeMatteo RP, D'Angelica MI, Fong Y, Jarnagin WR, Brennan MF, Allen PJ. Pancreatic cyst fluid and serum mucin levels predict dysplasia in intraductal papillary mucinous neoplasms of the pancreas. Ann Surg Oncol 2011; 18:199-206. [PMID: 20717734 PMCID: PMC4241376 DOI: 10.1245/s10434-010-1225-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Indexed: 02/06/2023]
Abstract
INTRODUCTION There are no reliable markers of dysplasia in patients with incidentally discovered intraductal papillary mucinous neoplasms of the pancreas (IPMN). IPMN dysplasia may be associated with mucin protein (MUC) expression and histopathologic subtype. We hypothesize that MUC expression in cyst fluid and serum can identify lesions with high risk of malignancy. METHODS Cyst fluid and serum were collected from 40 patients during pancreatectomy for IPMN between 2005 and 2009. Samples were grouped into low-risk (low-grade or moderate dysplasia, n = 21) and high-risk groups (high-grade dysplasia or carcinoma, n = 19). Mucin expression (MUC1, MUC2, MUC4, and MUC5AC) was assessed utilizing enzyme-linked immunosorbent assays. RESULTS MUC2 and MUC4 cyst fluid concentrations were elevated in high-risk versus low-risk groups (10 ± 3.0 ng/ml vs. 4.4 ± 1.2 ng/ml, p = 0.03; 20.6 ± 10.6 ng/ml vs. 4.5 ± 1.4 ng/ml, p = 0.03, respectively). Corresponding serum samples revealed higher levels of MUC5AC in high-risk compared with low-risk patients (19.9 ± 9.3 ng/ml vs. 2.2 ± 1.1 ng/ml, p = 0.04). Histopathologic subtype was significantly associated with grade of dysplasia, and the intestinal subtype displayed increased MUC2 cyst fluid concentrations (13.8 ± 6.5 ng/ml vs. 4.1 ± 0.9 ng/ml, p = 0.02). CONCLUSIONS In this study, high-risk IPMN showed elevated cyst fluid concentrations of MUC2 and MUC4, and increased serum levels of MUC5AC. High-risk IPMN also displayed a distinct mucin expression profile in specific histologic subtypes. These data, if validated, may allow surgeons to more appropriately select patients for operative resection.
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MESH Headings
- Adenocarcinoma, Mucinous/diagnosis
- Adenocarcinoma, Mucinous/metabolism
- Adenocarcinoma, Mucinous/surgery
- Biomarkers, Tumor/blood
- Biomarkers, Tumor/metabolism
- Carcinoma, Pancreatic Ductal/diagnosis
- Carcinoma, Pancreatic Ductal/metabolism
- Carcinoma, Pancreatic Ductal/surgery
- Carcinoma, Papillary/diagnosis
- Carcinoma, Papillary/metabolism
- Carcinoma, Papillary/surgery
- Cysts/chemistry
- Enzyme-Linked Immunosorbent Assay
- Female
- Humans
- Immunoenzyme Techniques
- Male
- Mucin 5AC/metabolism
- Mucin-1/metabolism
- Mucin-2/metabolism
- Mucin-4/metabolism
- Pancreatectomy
- Pancreatic Juice/metabolism
- Pancreatic Neoplasms/diagnosis
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/surgery
- Prognosis
- Prospective Studies
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Affiliation(s)
- Ajay V Maker
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
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Rogers RL, Van Seuningen I, Gould J, Hertzog PJ, Naylor MJ, Pritchard MA. Transcript profiling of Elf5+/- mammary glands during pregnancy identifies novel targets of Elf5. PLoS One 2010; 5:e13150. [PMID: 20949099 PMCID: PMC2951341 DOI: 10.1371/journal.pone.0013150] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 08/25/2010] [Indexed: 01/05/2023] Open
Abstract
Background Elf5, an epithelial specific Ets transcription factor, plays a crucial role in the pregnancy-associated development of the mouse mammary gland. Elf5−/− embryos do not survive, however the Elf5+/− mammary gland displays a severe pregnancy-associated developmental defect. While it is known that Elf5 is crucial for correct mammary development and lactation, the molecular mechanisms employed by Elf5 to exert its effects on the mammary gland are largely unknown. Principal Findings Transcript profiling was used to investigate the transcriptional changes that occur as a result of Elf5 haploinsufficiency in the Elf5+/− mouse model. We show that the development of the mouse Elf5+/− mammary gland is delayed at a transcriptional and morphological level, due to the delayed increase in Elf5 protein in these glands. We also identify a number of potential Elf5 target genes, including Mucin 4, whose expression, is directly regulated by the binding of Elf5 to an Ets binding site within its promoter. Conclusion We identify novel transcriptional targets of Elf5 and show that Muc4 is a direct target of Elf5, further elucidating the mechanisms through which Elf5 regulates proliferation and differentiation in the mammary gland.
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Affiliation(s)
- Renee L. Rogers
- Centre for Functional Genomics and Human Disease, Monash Institute of Medical Research, Clayton, Victoria, Australia
- * E-mail: (MAP); (RLR)
| | | | - Jodee Gould
- Centre for Functional Genomics and Human Disease, Monash Institute of Medical Research, Clayton, Victoria, Australia
| | - Paul J. Hertzog
- Centre for Functional Genomics and Human Disease, Monash Institute of Medical Research, Clayton, Victoria, Australia
| | - Matthew J. Naylor
- Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- St. Vincent's Hospital Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Melanie A. Pritchard
- Centre for Functional Genomics and Human Disease, Monash Institute of Medical Research, Clayton, Victoria, Australia
- * E-mail: (MAP); (RLR)
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Abstract
Background: Breast cancer anti-oestrogen resistance 4 (BCAR4) was identified in a search for genes involved in anti-oestrogen resistance in breast cancer. We explored whether BCAR4 is predictive for tamoxifen resistance and prognostic for tumour aggressiveness, and studied its function. Methods: BCAR4 mRNA levels were measured in primary breast tumours, and evaluated for association with progression-free survival (PFS) and clinical benefit in patients with oestrogen receptor (ERα)-positive tumours receiving tamoxifen as first-line monotherapy for advanced disease. In a separate cohort of patients with lymph node-negative, ERα-positive cancer, and not receiving systemic adjuvant therapy, BCAR4 levels were evaluated for association with distant metastasis-free survival (MFS). The function of BCAR4 was studied with immunoblotting and RNA interference in a cell model. Results: Multivariate analyses established high BCAR4 mRNA levels as an independent predictive factor for poor PFS after start of tamoxifen therapy for recurrent disease. High BCAR4 mRNA levels were associated with poor MFS and overall survival, reflecting tumour aggressiveness. In BCAR4-expressing cells, phosphorylation of v-erb-b2 erythroblastic leukaemia viral oncogene homolog (ERBB)2, ERBB3, and their downstream mediators extracellular signal-regulated kinase 1/2 and v-akt murine thymoma viral oncogene homolog (AKT) 1/2, was increased. Selective knockdown of ERBB2 or ERBB3 inhibited proliferation, confirming their role in BCAR4-induced tamoxifen resistance. Conclusion: BCAR4 may have clinical relevance for tumour aggressiveness and tamoxifen resistance. Our cell model suggests that BCAR4-positive breast tumours are driven by ERBB2/ERBB3 signalling. Patients with such tumours may benefit from ERBB-targeted therapy.
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Kozloski GA, Carraway CAC, Carraway KL. Mechanistic and signaling analysis of Muc4-ErbB2 signaling module: new insights into the mechanism of ligand-independent ErbB2 activity. J Cell Physiol 2010; 224:649-57. [PMID: 20432461 DOI: 10.1002/jcp.22163] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The membrane mucin Muc4 is aberrantly expressed in numerous epithelial carcinomas and is currently used as a cancer diagnostic and prognostic tool. Muc4 can also potentiate signal transduction by modulating differential ErbB2 phosphorylation in the absence and in the presence of the ErbB3 soluble ligand heregulin (HRG-beta1). These features of Muc4 suggest that Muc4 is not merely a cancer marker, but an oncogenic factor with a unique-binding/activation relationship with the receptor ErbB2. In the present study, we examined the signaling mechanisms that are associated with the Muc4-ErbB2 module by analyzing ErbB2 differential signaling in response to Muc4 expression. Our study was carried out in the A375 human melanoma and BT-474 breast cancer cell lines as our model systems. Quantitative and comparative signaling modulations were evaluated by immunoblot using phospho-specific antibodies, and densitometry analysis. Signaling complex components were identified by chemical cross-linking, fractionation by gel filtration, immunoprecipitation, and immunoblotting. Activated downstream signaling pathways were analyzed by an antibody microarray screen and immunoblot analyses. Our results indicate that Muc4 modulates ErbB2 signaling potential significantly by stabilizing and directly interacting with the ErbB2-ErbB3 heterodimer. Further analyses indicate that Muc4 promotes ErbB2 autocatalysis, but it has no effect on ErbB3 phosphorylation, although the chemical cross-linking data indicated that the signaling module is composed of Muc4, ErbB2, and ErbB3. Our microarray analysis indicates that Muc4 expression promotes cell migration by increasing the phosphorylation of the focal adhesion kinase and also through an increase in the levels of beta-catenin.
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Affiliation(s)
- Goldi A Kozloski
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida 33101, USA
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20
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Lomako J, Lomako WM, Carothers Carraway CA, Carraway KL. Regulation of the membrane mucin Muc4 in corneal epithelial cells by proteosomal degradation and TGF-beta. J Cell Physiol 2010; 223:209-14. [PMID: 20054827 DOI: 10.1002/jcp.22028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
MUC4 is a heterodimeric membrane mucin, composed of a mucin subunit ASGP-1 (MUC4alpha) and a transmembrane subunit ASGP-2 (MUC4beta), which has been implicated in the protection of epithelial cell surfaces. In the rat stratified corneal epithelium Muc4 is found predominantly in the most superficial cell layers. Since previous studies in other tissues have shown that Muc4 is regulated by TGF-beta via a proteosomal degradation mechanism, we investigated the regulation of corneal Muc4 in stratified cultures of corneal epithelial cells. Application of proteosome or processing inhibitors led to increases in levels of Muc4, particularly in the basal and intermediate levels of the stratified cultures. These changes were accompanied by increases in Muc4 ubiquitination, chaperone association and incorporation into intracellular aggresomes. In contrast, treatment with TGF-beta resulted in reduced levels of Muc4, which were reversed by proteosome inhibition. The results support a model in which Muc4 precursor is synthesized in all layers of the corneal epithelium, but Muc4 is degraded in basal and intermediate layers by a proteosomal mechanism at least partly dependent on TGF-beta inhibition of Muc4 processing.
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Affiliation(s)
- Joseph Lomako
- Department of Cell Biology and Anatomy, School of Medicine, University of Miami, Miami, Florida 33136, USA
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21
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Carraway KL, Theodoropoulos G, Kozloski GA, Carothers Carraway CA. Muc4/MUC4 functions and regulation in cancer. Future Oncol 2010; 5:1631-40. [PMID: 20001800 DOI: 10.2217/fon.09.125] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The membrane mucin MUC4 (human) is abundantly expressed in many epithelia, where it is proposed to play a protective role, and is overexpressed in some epithelial tumors. Studies on the rat homologue, Muc4, indicate that it acts through anti-adhesive or signaling mechanisms. In particular, Muc4/MUC4 can serve as a ligand/modulator of the receptor tyrosine kinase ErbB2, regulating its phosphorylation and the phosphorylation of its partner ErbB3, with or without the involvement of the ErbB3 ligand neuregulin. Muc4/MUC4 can also modulate cell apoptosis via multiple mechanisms, both ErbB2 dependent and independent. Muc4/MUC4 expression is regulated by multiple mechanisms, ranging from transcriptional to post-translational. The roles of MUC4 in tumors suggest that it may be valuable as a tumor marker or target for therapy.
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Affiliation(s)
- Kermit L Carraway
- Department of Cell Biology and Anatomy, University of Miami School of Medicine, Miami, FL 33136, USA.
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22
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Milanezi F, Leitão D, Ricardo S, Augusto I, Schmitt F. Evaluation of HER2 in breast cancer: reality and expectations. ACTA ACUST UNITED AC 2009; 3:607-20. [PMID: 23496046 DOI: 10.1517/17530050903222221] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND The introduction of drugs, whose mechanisms of action are directed against specific molecules involved in cancer initiation and/or progression, has changed the daily workup of breast cancer patients. At present, HER2 expression and/or amplification should be evaluated in every primary invasive breast cancer either at the time of diagnosis or at the time of recurrence, mostly to guide selection of trastuzumab in the adjuvant and/or metastatic setting. The adequate selection of patients is an essential step for indication of anti-HER2 therapy. OBJECTIVE This review focuses on the state of the art for HER2 evaluation in breast cancer, as well as expectations regarding future molecular assays based on mechanisms of resistance to HER2-driven therapy. METHODS Data were obtained by searching the PubMed database, including the terms 'HER2', 'in situ hybridisation', 'immunohistochemistry', 'trastuzumab', 'breast cancer', 'therapy', 'resistance' and 'tyrosine-kinase inhibitors', with a preference for updated publications. CONCLUSION Pathologists have a central role in the selection of patients who will benefit from anti-HER-based therapies, with a responsibility to obtain the most reliable results for immunohistochemistry and in situ hybridisation techniques. Pre-analytical variables, such as type of fixative and time of fixation, are critical to guarantee consistent and quality assays, as well as to facilitate interpretation and decrease interobserver variability. Rigorous quality control and centralisation of techniques/interpretation of results are recommended to guarantee consistent assays.
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Affiliation(s)
- Fernanda Milanezi
- Institute of Molecular Pathology and Immunology of Porto University, Rua Roberto Frias, s/n, 4200-465, Porto, Portugal +351 225570700 ; +351 225570799 ;
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23
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Theodoropoulos G, Carraway CAC, Carraway KL. MUC4 involvement in ErbB2/ErbB3 phosphorylation and signaling in response to airway cell mechanical injury. J Cell Biochem 2009; 107:112-22. [PMID: 19288496 DOI: 10.1002/jcb.22106] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The receptor tyrosine kinases ErbB2 and ErbB3 are phosphorylated in response to injury of the airway epithelium. Since we have shown that the membrane mucin MUC4 can act as a ligand/modulator for ErbB2, affecting its localization in polarized epithelial cells and its phosphorylation, we questioned whether Muc4 was involved, along with ErbB2 and ErbB3, in the damage response of airway epithelia. To test this hypothesis, we first examined the localization of MUC4 in human airway samples. Both immunocytochemistry and immunofluorescence showed a co-localization of MUC4 and ErbB2 at the airway luminal surface. Sequential immunoprecipitation and immunoblotting from airway cells demonstrated that the MUC4 and ErbB2 are present as a complex in airway epithelial cells. To assess the participation of MUC4 in the damage response, cultures of NCI-H292 or airway cells were scratch-wounded, then analyzed for association of phospho-ErbB2 and -ErbB3 with MUC4 by sequential immunoprecipitation and immunoblotting. Wounded cultures exhibited increased phosphorylation of both receptors in complex with MUC4. Scratch wounding also increased activation of the downstream pathway through Akt, as predicted from our previous studies on Muc4 effects on ErbB2 and ErbB3. The participation of MUC4 in the phosphorylation response was also indicated by siRNA repression of MUC4 expression, which resulted in diminution of the phosphorylation of ErbB2 and ErbB3. These studies provide a new model for the airway epithelial damage response, in which the MUC4-ErbB2 complex is a key element in the sensor mechanism and phosphorylation of the receptors.
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Affiliation(s)
- George Theodoropoulos
- Department of Cell Biology, University of Miami School of Medicine, Miami, Florida 33101, USA
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24
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Jin Q, Esteva FJ. Cross-talk between the ErbB/HER family and the type I insulin-like growth factor receptor signaling pathway in breast cancer. J Mammary Gland Biol Neoplasia 2008; 13:485-98. [PMID: 19034632 DOI: 10.1007/s10911-008-9107-3] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Accepted: 11/13/2008] [Indexed: 12/15/2022] Open
Abstract
Understanding the molecular mechanisms involved in tumorigenesis and their influence on clinical outcome is providing specific molecular markers for targeted therapy. Activation of tyrosine kinase receptors from the human epidermal growth factor receptor family (EGFR, HER2, HER3, HER4) and the insulin-like growth factor receptor I (IGF-IR) plays a key role in the initiation and progression of breast cancer. HER2 overexpression is a validated therapeutic target, as shown by the clinical efficacy of trastuzumab and lapatinib. However, only 25-30% of patients with HER2-overexpressing tumors respond to single-agent trastuzumab or lapatinib, and resistance develops even in responding patients. Therefore, to optimize therapeutic efficacy, it is urgent to elucidate the complex network of signaling pathways that develop in breast cancer cells. Signaling interactions have been reported between ErbB/HER family members and IGF-IR. As increased IGF-IR signaling has been implicated in trastuzumab resistance, agents targeting HER2, and IGF-IR could be potential therapeutic tools in breast cancers that develop resistance to HER2-directed therapy.
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Affiliation(s)
- Quanri Jin
- Departments of Breast Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA
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25
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Abstract
The mucin MUC4 is a high molecular weight transmembrane glycoprotein. It consists of a mucin-type subunit (MUC4alpha) and a transmembrane growth factor-like subunit (MUC4beta). The mucin MUC4 is overexpressed in many epithelial malignancies including ovarian cancer, suggesting a possible role in the pathogenesis of these cancers. In this study, we investigated the functional role of MUC4 in the human ovarian cancer cell line SKOV3. The mucin MUC4 was ectopically expressed by stable transfection, and its expression was examined by western blot and confocal microscopy analyses. The in vitro studies demonstrated an enhanced motility of MUC4-expressing SKOV3 cells compared with the vector-transfected cells. The mucin MUC4 expression was associated with apparent changes in actin organisation, leading to the formation of microspike, lammelopodia and filopodia-like cellular projections. An enhanced protein expression and activation of HER2, a receptor tyrosine kinase, was also seen, although no significant change was observed in HER-2 transcript levels in the MUC4-transfected SKOV3 cells. Reciprocal co-immunoprecipitation revealed an interaction of MUC4 with HER2. Further, the MUC4-overexpressing SKOV3 cells exhibited an increase in the phosphorylation of focal adhesion kinase (FAK), Akt and ERK, downstream effectors of HER2. Taken together, our findings demonstrate that MUC4 plays a role in ovarian cancer cell motility, in part, by altering actin arrangement and potentiating HER2 downstream signalling in these cells.
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Milanezi F, Carvalho S, Schmitt FC. EGFR/HER2 in breast cancer: a biological approach for molecular diagnosis and therapy. Expert Rev Mol Diagn 2008; 8:417-34. [PMID: 18598224 DOI: 10.1586/14737159.8.4.417] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Novel cancer therapies have focused on specific molecular markers present in malignant tumors. The rationale of targeted therapy relies on the knowledge of molecular mechanisms involved in carcinogenesis and their influence in clinical outcome allied to a more specific and less toxic treatment. Activation of EGF receptor and HER2 is an important factor for initiation and progression of malignancies, including breast cancer where the status of HER2 is an essential step in the diagnostic workup; EGFR overexpression has been associated to the so-called basal-like breast carcinomas, which opens a new avenue for diagnosis and therapeutic approach in these tumors. This review will focus on mechanisms of HER2 and EGF receptor upregulation, the targeted therapies that are currently in use for these receptors, possible combined therapies, as well as the approach for molecular diagnosis from the pathologist's point of view.
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Affiliation(s)
- Fernanda Milanezi
- Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal.
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Abstract
Cell surface mucins are large transmembrane glycoproteins involved in diverse functions ranging from shielding the airway epithelium against pathogenic infection to regulating cellular signaling and transcription. Although hampered by the relatively recent characterization of cell surface mucins and the difficulties inherent in working with molecules of their size, numerous studies have placed the tethered mucins in the thick of normal and diseased lung physiology. This review focuses on the three best-characterized cell surface mucins expressed in the respiratory tract: MUC1, MUC4, and MUC16.
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Affiliation(s)
- Christine L Hattrup
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Mayo Clinic Arizona, Scottsdale, AR 85259, USA
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28
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Chaturvedi P, Singh AP, Batra SK. Structure, evolution, and biology of the MUC4 mucin. FASEB J 2007; 22:966-81. [PMID: 18024835 DOI: 10.1096/fj.07-9673rev] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Mucins are high-molecular-weight glycoproteins and are implicated in diverse biological functions. MUC4, a member of transmembrane mucin family, is expressed in airway epithelial cells and body fluids like saliva, tear film, ear fluid, and breast milk. In addition to its normal expression, an aberrant expression of MUC4 has been reported in a variety of carcinomas. Among various potential domains of MUC4, epidermal growth factor (EGF) -like domains are hypothesized to interact with and activate the ErbB2 receptors, suggesting an intramembrane-growth factor function for MUC4. The heavily glycosylated tandem repeat domain provides the structural rigidity to the extended extracellular region. MUC4, by virtue of its extended structure, serves as a barrier for some cell-cell and cell-extracellular matrix interactions and as a potential reservoir for certain growth factors. An intricate relationship between MUC4 and growth factor signaling is also reflected in the transcriptional regulation of MUC4. The MUC4 promoter has binding sites for different transcription factors, which are responsible for the regulation of its expression in different tissues. The interferon-gamma, retinoic acid, and transforming growth factor-beta signaling pathways regulate MUC4 expression in a partially interdependent manner. Taken together, all of these features of MUC4 strongly support its role as a potential candidate for diagnostic and therapeutic applications in cancer and other diseases.
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Affiliation(s)
- Pallavi Chaturvedi
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA
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Singh PK, Wen Y, Swanson BJ, Shanmugam K, Kazlauskas A, Cerny RL, Gendler SJ, Hollingsworth MA. Platelet-derived growth factor receptor beta-mediated phosphorylation of MUC1 enhances invasiveness in pancreatic adenocarcinoma cells. Cancer Res 2007; 67:5201-10. [PMID: 17545600 DOI: 10.1158/0008-5472.can-06-4647] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
MUC1 is a heterodimeric transmembrane glycoprotein that is overexpressed and aberrantly glycosylated in ductal adenocarcinomas. Differential phosphorylation of the MUC1 cytoplasmic tail (MUC1CT) has been associated with signaling events that influence the proliferation and metastasis of cancer cells. We identified a novel tyrosine phosphorylation site (HGRYVPP) in the MUC1CT by mass spectrometric analysis of MUC1 from human pancreatic adenocarcinoma cell lines. Analyses in vitro and in vivo showed that platelet-derived growth factor receptor beta (PDGFRbeta) catalyzed phosphorylation of this site and of tyrosine in the RDTYHPM site. Stimulation of S2-013.MUC1F cells with PDGF-BB increased nuclear colocalization of MUC1CT and beta-catenin. PDGF-BB stimulation had no significant effect on cell proliferation rate; however, it enhanced invasion in vitro through Matrigel and in vivo tumor growth and metastases. Invasive properties of the cells were significantly altered on expression of phosphorylation-abrogating or phosphorylation-mimicking mutations at these sites. We propose that interactions of MUC1 and PDGFRbeta induce signal transduction events that influence the metastatic properties of pancreatic adenocarcinoma.
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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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Croce MV, Isla-Larrain M, Rabassa ME, Demichelis S, Colussi AG, Crespo M, Lacunza E, Segal-Eiras A. Lewis x is highly expressed in normal tissues: a comparative immunohistochemical study and literature revision. Pathol Oncol Res 2007; 13:130-8. [PMID: 17607374 DOI: 10.1007/bf02893488] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Accepted: 05/10/2007] [Indexed: 01/22/2023]
Abstract
An immunohistochemical analysis was employed to determine the expression of carbohydrate antigens associated to mucins in normal epithelia. Tissue samples were obtained as biopsies from normal breast (18), colon (35) and oral cavity mucosa (8). The following carbohydrate epitopes were studied: sialyl-Lewis x, Lewis x, Lewis y, Tn hapten, sialyl-Tn and Thomsen-Friedenreich antigen. Mucins were also studied employing antibodies against MUC1, MUC2, MUC4, MUC5AC, MUC6 and also normal colonic glycolipid. Statistical analysis was performed and Kendall correlations were obtained. Lewis x showed an apical pattern mainly at plasma membrane, although cytoplasmic staining was also found in most samples. TF, Tn and sTn haptens were detected in few specimens, while sLewis x was found in oral mucosa and breast tissue. Also, normal breast expressed MUC1 at a high percentage, whereas MUC4 was observed in a small number of samples. Colon specimens mainly expressed MUC2 and MUC1, while most oral mucosa samples expressed MUC4 and MUC1. A positive correlation between MUC1VNTR and TF epitope (r=0.396) was found in breast samples, while in colon specimens MUC2 and colonic glycolipid versus Lewis x were statistically significantly correlated (r=0.28 and r=0.29, respectively). As a conclusion, a defined carbohydrate epitope expression is not exclusive of normal tissue or a determined localization, and it is possible to assume that different glycoproteins and glycolipids may be carriers of carbohydrate antigens depending on the tissue localization considered.
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Affiliation(s)
- María V Croce
- Centre of Basic and Applied Immunological Research (CINIBA), Faculty of Medical Sciences, UNLP, La Plata, Argentina
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Nagata K, Horinouchi M, Saitou M, Higashi M, Nomoto M, Goto M, Yonezawa S. Mucin expression profile in pancreatic cancer and the precursor lesions. ACTA ACUST UNITED AC 2007; 14:243-54. [PMID: 17520199 DOI: 10.1007/s00534-006-1169-2] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Accepted: 04/11/2006] [Indexed: 12/17/2022]
Abstract
In this review article, we demonstrate the mucin expression profile in normal tissue, invasive ductal carcinoma (IDC), two subtypes of intraductal papillary-mucinous neoplasm (IPMN dark cell type and IPMN clear cell type), pancreatic intraepithelial neoplasia (PanIN), and mucinous cystic neoplasm (MCN) of the pancreas. In MUC1, there are various glycoforms, such as poorly glycosylated MUC1, sialylated MUC1, and fully glycosylated MUC1. IDCs showed high expression of all the glycoforms of MUC1. IPMNs dark cell type showed no expression or low expression of all the glycoforms of MUC1. IPMNs clear cell type showed low expression of poorly glycosylated MUC1, but expression of sialylated MUC1 and fully glycosylated MUC1. Expression of MUC2 was negative in IDCs, high in IPMNs dark cell type and low in IPMNs clear cell type. MUC5AC was highly expressed in IDCs, IPMNs dark cell type, and IPMNs clear cell type. MUC6 expression was higher in IPMNs clear cell type than in IDCs and IPMNs dark cell type. Our recent study demonstrated that high expression of MUC4 in IDCs is correlated with a poor outcome for patients. In PanINs, expression of both MUC5AC and MUC6 are an early event, whereas up-regulation of MUC1 is a late event. MCNs do not look as if they will show a specific mucin expression profile according to the literature review.
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Affiliation(s)
- Kohji Nagata
- Department of Human Pathology, Field of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan
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Ginestier C, Adélaïde J, Gonçalvès A, Repellini L, Sircoulomb F, Letessier A, Finetti P, Geneix J, Charafe-Jauffret E, Bertucci F, Jacquemier J, Viens P, Birnbaum D. ERBB2 phosphorylation and trastuzumab sensitivity of breast cancer cell lines. Oncogene 2007; 26:7163-9. [PMID: 17525746 DOI: 10.1038/sj.onc.1210528] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Breast cancers that overexpress the ERBB2 tyrosine kinase receptor may be treated with the recombinant humanized monoclonal anti-ERBB2 antibody trastuzumab (herceptin). However, resistance to this targeted therapy is frequent. We have determined the response of 18 breast tumor cell lines to trastuzumab and compared it with the ERBB2 phosphorylation status using antibodies directed against tyrosine residue 1248. We show that sensitivity to trastuzumab is frequently associated with the expression of a phosphorylated ERBB2 protein.
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Affiliation(s)
- C Ginestier
- UMR599 Inserm, Institut Paoli-Calmettes, Centre de Recherche en Cancérologie de Marseille, Département d'Oncologie Moléculaire, Marseille, France
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Moasser MM. The oncogene HER2: its signaling and transforming functions and its role in human cancer pathogenesis. Oncogene 2007; 26:6469-87. [PMID: 17471238 PMCID: PMC3021475 DOI: 10.1038/sj.onc.1210477] [Citation(s) in RCA: 767] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The year 2007 marks exactly two decades since Human Epidermal Growth Factor Receptor-2 (HER2) was functionally implicated in the pathogenesis of human breast cancer. This finding established the HER2 oncogene hypothesis for the development of some human cancers. The subsequent two decades have brought about an explosion of information about the biology of HER2 and the HER family. An abundance of experimental evidence now solidly supports the HER2 oncogene hypothesis and etiologically links amplification of the HER2 gene locus with human cancer pathogenesis. The molecular mechanisms underlying HER2 tumorigenesis appear to be complex and a unified mechanistic model of HER2-induced transformation has not emerged. Numerous hypotheses implicating diverse transforming pathways have been proposed and are individually supported by experimental models and HER2 may indeed induce cell transformation through multiple mechanisms. Here I review the evidence supporting the oncogenic function of HER2, the mechanisms that are felt to mediate its oncogenic functions, and the evidence that links the experimental evidence with human cancer pathogenesis.
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Affiliation(s)
- M M Moasser
- Department of Medicine and Comprehensive Cancer Center, University of California, San Francisco, CA 94143-0875, USA.
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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.
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Affiliation(s)
- Motoko Sasaki
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Takaramachi 13-1, Kanazawa 920-8640, Japan.
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Carraway CAC, Carraway KL. Sequestration and segregation of receptor kinases in epithelial cells: implications for ErbB2 oncogenesis. ACTA ACUST UNITED AC 2007; 2007:re3. [PMID: 17426346 DOI: 10.1126/stke.3812007re3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Cell behaviors are regulated by signaling pathways triggered by the activation of cell surface receptors. A key aspect of receptor signaling is the location of these receptors relative to their ligands and to other receptors, particularly in epithelia, whose cells are polarized by tight junction barriers into apical and basolateral membrane regions. In polarized epithelia, the co-receptor ErbB2 is often localized to the apical surface by its intramembrane ligand Muc4, thus segregating it from its partner ErbB3, which is sequestered at the lateral surface, co-localized with cadherin junctions. The ErbB2-ErbB3 receptor heterodimer, when activated, is a potent stimulator of cell proliferation; thus, the segregation mechanism helps maintain these cells in a differentiated state. Similarly, epidermal growth factor, the ligand for ErbB1, which is present in the apical fluid of some epithelia, is segregated from its receptor by the tight junction barrier. Loss of cell polarity and the tight junction barrier facilitates the interaction of ErbB2 with the hemidesmosome integrin alpha(6)beta(4). This integrin acts as a docking site for signaling pathways to promote cell proliferation and further disruption of cell junctions. The ultimate dissolution of tight junctions may result from activation of transforming growth factor-beta receptors, one subunit of which is directly associated with the junction. This activation triggers degradation of critical tight junction components. These sequestration and segregation phenomena provide a model by which overexpression of the ErbB2 receptor kinase may trigger oncogenesis by initiating junction breakdown. Equally important, these mechanisms may act as a sensor for epithelial damage that can activate repair mechanisms.
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Zhang J, Carraway CAC, Carraway KL. Muc4 expression during blood vessel formation in damaged rat cornea. Curr Eye Res 2007; 31:1011-4. [PMID: 17169838 DOI: 10.1080/02713680601052155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To determine the timing of Muc4 expression during the association of endothelial cells to form blood vessels in the rat corneal stroma after corneal wounding. METHODS Corneal damage was inflicted using brief cauterization with silver nitrite. Contralateral and wounded corneas were examined at time periods after wounding by immunohistochemistry and immunofluorescence for Muc4 and for the blood vessel endothelial cell marker von Willebrand Factor. RESULTS Blood vessels and von Willebrand Factor-stained cells were very sparse in corneal stroma from unwounded corneas. In contrast, aggregates of von Willebrand Factor-stained cells were prevalent in wounded corneas at days 4-5 and 7-10. Muc4 expression was limited at days 4-5, but extensive at days 7-10. CONCLUSION Muc4 expression develops in endothelial cells during the mid-stages of cell aggregation and blood vessel formation.
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Affiliation(s)
- Jin Zhang
- Department of Cell Biology and Anatomy, University of Miami School of Medicine, Miami, FL 33101, 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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38
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Theodoropoulos G, Carraway KL. Molecular signaling in the regulation of mucins. J Cell Biochem 2007; 102:1103-16. [DOI: 10.1002/jcb.21539] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Tsutsumida H, Goto M, Kitajima S, Kubota I, Hirotsu Y, Wakimoto J, Batra SK, Imai K, Yonezawa S. MUC4 expression correlates with poor prognosis in small-sized lung adenocarcinoma. Lung Cancer 2006; 55:195-203. [PMID: 17126950 DOI: 10.1016/j.lungcan.2006.10.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 09/01/2006] [Accepted: 10/10/2006] [Indexed: 11/25/2022]
Abstract
The mortality of lung cancer remains high, despite improved diagnostic techniques that allow small lung tumors to be detected. In this study, we evaluated the prognostic significance of the tracheal mucin MUC4 by immunohistochemical investigation of the expression profiles of MUC4, ErbB2, p27 and MUC1 in lung adenocarcinoma specimens (non-bronchiolo-alveolar type, < or =3cm) from 185 patients. MUC4 is a membrane mucin, similarly to MUC1, and in addition MUC4 functions as an intra-membrane ligand for receptor tyrosine kinase ErbB2 and is associated with regulation of p27. However, MUC4 expression was found to be unrelated to expression of MUC1, ErbB2 and p27 in small-sized lung adenocarcinomas. The disease-free interval (DFI) and survival rate of 25 patients with high MUC4 expression (> or =25% of neoplastic cells stained) were significantly lower than those of 160 patients with low MUC4 expression (<25% of neoplastic cells stained) (P<0.05), whereas ErbB2 and p27 expression showed no significant correlation with DFI and survival. Univariate analysis showed that high MUC4 and p27 expression correlated with blood vessel invasion (P=0.0004), and MUC4 expression was frequently detected in regions of stromal invasion. In addition, the survival rate of stage IA patients with high MUC4 expression was significantly lower than that of stage IA patients with low MUC4 expression (P<0.05). In conclusion, high MUC4 expression in small-sized lung adenocarcinomas correlates with a short DFI and a poor survival rate. Therefore, MUC4 expression might be a new independent factor for prediction of outcome and indication of poor prognosis in lung adenocarcinoma.
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Affiliation(s)
- Hideaki Tsutsumida
- Department of Human Pathology, Field of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan
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40
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Stein RA, Staros JV. Insights into the evolution of the ErbB receptor family and their ligands from sequence analysis. BMC Evol Biol 2006; 6:79. [PMID: 17026767 PMCID: PMC1618406 DOI: 10.1186/1471-2148-6-79] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 10/06/2006] [Indexed: 11/21/2022] Open
Abstract
Background In the time since we presented the first molecular evolutionary study of the ErbB family of receptors and the EGF family of ligands, there has been a dramatic increase in genomic sequences available. We have utilized this greatly expanded data set in this study of the ErbB family of receptors and their ligands. Results In our previous analysis we postulated that EGF family ligands could be characterized by the presence of a splice site in the coding region between the fourth and fifth cysteines of the EGF module and the placement of that module near the transmembrane domain. The recent identification of several new ligands for the ErbB receptors supports this characterization of an ErbB ligand; further, applying this characterization to available sequences suggests additional potential ligands for these receptors, the EGF modules from previously identified proteins: interphotoreceptor matrix proteoglycan-2, the alpha and beta subunit of meprin A, and mucins 3, 4, 12, and 17. The newly available sequences have caused some reorganizations of relationships among the ErbB ligand family, but they add support to the previous conclusion that three gene duplication events gave rise to the present family of four ErbB receptors among the tetrapods. Conclusion This study provides strong support for the hypothesis that the presence of an easily identifiable sequence motif can distinguish EGF family ligands from other EGF-like modules and reveals several potential new EGF family ligands. It also raises interesting questions about the evolution of ErbB2 and ErbB3: Does ErbB2 in teleosts function differently from ErbB2 in tetrapods in terms of ligand binding and intramolecular tethering? When did ErbB3 lose kinase activity, and what is the functional significance of the divergence of its kinase domain among teleosts?
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Affiliation(s)
- Richard A Stein
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - James V Staros
- Dept. of Biochemistry and Cell Biology, SUNY-Stony Brook, Stony Brook, NY 11794, USA, and Dept. of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA
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41
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Pino V, Ramsauer VP, Salas P, Carothers Carraway CA, Carraway KL. Membrane Mucin Muc4 Induces Density-dependent Changes in ERK Activation in Mammary Epithelial and Tumor Cells. J Biol Chem 2006; 281:29411-20. [PMID: 16891313 DOI: 10.1074/jbc.m604858200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The membrane mucin Muc4 has been shown to alter cellular behavior through both anti-adhesive effects on cell-cell and cell-extracellular matrix interactions and its ability to act as an intramembrane ligand for the receptor tyrosine kinase ErbB2. The ERK pathway is regulated by both cell-matrix and cell-cell adhesion. An analysis of the effects of Muc4 expression on ERK phosphorylation in mammary tumor and epithelial cells, which exhibit both adhesion-dependent growth and contact inhibition of growth, showed that the effects are density dependent, with opposing effects on proliferating cells and contact-inhibited cells. In these cells, cell-matrix interactions through integrins are required for activation of the ERK mitogenesis pathway. However, cell-cell interactions via cadherins inhibit the ERK pathway. Expression of Muc4 reverses both of these effects. In contact-inhibited cells, Muc4 appears to activate the ERK pathway at the level of Raf-1; this activation does not depend on Ras activation. The increase in ERK activity correlates with an increase in cyclin D(1) expression in these cells. This abrogation of contact inhibition is dependent on the number of mucin repeats in the mucin subunit of Muc4, indicative of an anti-adhesive effect. The mechanism by which Muc4 disrupts contact inhibition involves a Muc4-induced relocalization of E-cadherin from adherens junctions at the lateral membrane of the cells to the apical membrane. Muc4-induced abrogation of contact inhibition may be an important mechanism by which tumors progress from an early, more benign state to invasiveness.
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Affiliation(s)
- Vanessa Pino
- Departments of Cell Biology and Anatomy and Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida 33101, USA
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Abstract
Colonic mucus is a key element of colonic barrier as it is located at the frontier between luminal microflora and colonic mucosa itself. Colonic mucus is mainly composed of high molecular weight glycoproteins called mucins that can be either secreted or membrane-linked. The expression of various colonic mucins is altered in colorectal cancers or inflammations. The aim of this review is to highlight the crucial role played by colonic mucins in the maintenance of colonic barrier integrity, both because they are part of the protective mucus layer, and because they individually exert specific functions involved in epithelial barrier, like cell growth and differentiation, immunomodulation, signal transduction or cell adhesion.
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Affiliation(s)
- Estelle Gaudier
- UMR, Physiologie des Adaptations Nutrionnelles, Centre de recherche en Nutrition Humaine, INRA, 44316 Nantes
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43
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Karg A, Dinç ZA, Başok O, Uçvet A. MUC4 expression and its relation to ErbB2 expression, apoptosis, proliferation, differentiation, and tumor stage in non-small cell lung cancer (NSCLC). Pathol Res Pract 2006; 202:577-83. [PMID: 16814944 DOI: 10.1016/j.prp.2006.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Accepted: 04/06/2006] [Indexed: 11/15/2022]
Abstract
There is a peptide sequence homology between the gene product of human MUC4 and rat Muc4/sialomucin complex (SMC). Each contains a transmembrane subunit with two epidermal growth factor (EGF)-like domains that act as ligand for ErbB2. MUC4 and ErbB2 mediate intracellular signaling pathways that are linked to repression of apoptosis and either to proliferation or to differentiation of tumor cells. This study investigates the expression of human MUC4 in neoplastic and corresponding non-neoplastic tissues, and the relation of MUC4 expression in neoplastic tissues to ErbB2 expression, apoptosis, proliferation, differentiation, and tumor stage in a series of 100 non-small cell lung carcinomas (NSCLCs). MUC4 and ErbB2 expressions and cell proliferation (PCNA) were shown using immunohistochemistry. Apoptotic index (AI) and tumor differentiation were determined by morphologic criteria. All the non-neoplastic bronchial tissues and 85% of NSCLCs showed MUC4 expression. MUC4 expression was found to be higher in neoplastic than in non-neoplastic tissues (Yates correction p: 0.0006). MUC4 expression was inversely correlated with AI (p=0.0002) and was correlated with ErbB2 expression (p=0.022), but not with PCNA counts and tumor stage. Our results indirectly suggest that MUC4, in association with ErbB-2, might be involved in the repression of apoptosis and differentiation rather than proliferation in tumor cells of NSCLCs.
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Affiliation(s)
- Aydanur Karg
- Department of Pathology, School of Medicine, Dokuz Eylül University, Inciralti, Izmir, Turkey
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44
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Abstract
The three-dimensional organization of the tear film, which is produced and drained by the different structures of the ocular adnexa, is essential for maintainance and protection of the ocular surface. This is facilitated by a class of large, highly glycosylated, hydrophilic glycoproteins, the mucins, which are usually expressed in association with a class of peptides having a well-defined, structurally conserved trefoil domain, the mammalian trefoil factor family (TFF) peptides. In this review, the latest information regarding mucin and TFF peptide function and regulation in the human lacrimal system, the tear film and the ocular surface is summarized with regard to mucous epithelia integrity, rheological and antimicrobial properties of the tear film and tear outflow, age-related changes and certain disease states such as dry eye, dacryostenosis and dacryolith formation.
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Affiliation(s)
- Friedrich P Paulsen
- Department of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Grosse Steinstr. 52 06097 Halle (Saale), Germany.
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45
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Ramsauer VP, Pino V, Farooq A, Carothers Carraway CA, Salas PJ, Carraway KL. Muc4-ErbB2 complex formation and signaling in polarized CACO-2 epithelial cells indicate that Muc4 acts as an unorthodox ligand for ErbB2. Mol Biol Cell 2006; 17:2931-41. [PMID: 16624867 PMCID: PMC1483030 DOI: 10.1091/mbc.e05-09-0895] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Muc4 serves as an intramembrane ligand for the receptor tyrosine kinase ErbB2. The time to complex formation and the stoichiometry of the complex were determined to be <15 min and 1:1 by analyses of Muc4 and ErbB2 coexpressed in insect cells and A375 tumor cells. In polarized CACO-2 cells, Muc4 expression causes relocalization of ErbB2, but not its heterodimerization partner ErbB3, to the apical cell surface, effectively segregating the two receptors. The apically located ErbB2 is phosphorylated on tyrosines 1139 and 1248. The phosphorylated ErbB2 in CACO-2 cells recruits the cytoplasmic adaptor protein Grb2, consistent with previous studies showing phosphotyrosine 1139 to be a Grb2 binding site. To address the issue of downstream signaling from apical ErbB2, we analyzed the three MAPK pathways of mammalian cells, Erk, p38, and JNK. Consistent with the more differentiated phenotype of the CACO-2 cells, p38 phosphorylation was robustly increased by Muc4 expression, with a consequent activation of Akt. In contrast, Erk and JNK phosphorylation was not changed. The ability of Muc4 to segregate ErbB2 and other ErbB receptors and to alter downstream signaling cascades in polarized epithelial cells suggests that it has a role in regulating ErbB2 in differentiated epithelia.
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Affiliation(s)
| | - Vanessa Pino
- Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, FL 33101
| | - Amjad Farooq
- Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, FL 33101
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46
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Damera G, Xia B, Sachdev GP. IL-4 induced MUC4 enhancement in respiratory epithelial cells in vitro is mediated through JAK-3 selective signaling. Respir Res 2006; 7:39. [PMID: 16551361 PMCID: PMC1435893 DOI: 10.1186/1465-9921-7-39] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2005] [Accepted: 03/21/2006] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Recent studies have identified MUC4 mucin as a ligand for activation of ErbB2, a receptor tyrosine kinase that modulates epithelial cell proliferation following epithelial damage in airways of asthmatics. In this study, we investigated the potential role of IL-4, one of the Th2 inflammatory cytokines persistent in asthmatic airways, in regulating MUC4 expression using a cell line NCI-H650. METHODS Real time PCR analysis was performed to determine concentration and time dependent effects of IL-4 upon MUC4 expression. Nuclear run on experiments were carried out to explore potential transcriptional modulation. Western blotting experiments using a monoclonal antibody specific to ASGP-2 domain of MUC4 were performed to analyze MUC4 glycoprotein levels in plasma membrane fractions. To analyze potential signal transduction cascades, IL-4 treated confluent cultures were co-incubated, separately with a pan-JAK inhibitor, a JAK-3 selective inhibitor or a MEK-1, 2 (MAPK) inhibitor at various concentrations before MUC4 transcript analysis. Corresponding transcription factor activation was tested by western blotting using a monoclonal p-STAT-6 antibody. RESULTS MUC4 levels increased in a concentration and time specific fashion reaching peak expression at 2.5 ng/ml and 8 h. Nuclear run on experiments revealed transcriptional enhancement. Corresponding increases in MUC4 glycoprotein levels were observed in plasma membrane fractions. Pan-JAK inhibitor revealed marked reduction in IL-4 stimulated MUC4 levels and JAK3 selective inhibitor down-regulated MUC4 mRNA expression in a concentration-dependent fashion. In accordance with the above observations, STAT-6 activation was detected within 5 minutes of IL-4 stimulus. No effect in MUC4 levels was observed on using a MAPK inhibitor. CONCLUSION These observations signify a potential role for IL-4 in MUC4 up-regulation in airway epithelia.
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Affiliation(s)
- Gautam Damera
- College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK – 73190, USA
| | - Baoyun Xia
- College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK – 73190, USA
| | - Goverdhan P Sachdev
- College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK – 73190, USA
- The Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK – 73104, USA
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47
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Carraway KL, Ramsauer VP, Carraway CAC. Glycoprotein contributions to mammary gland and mammary tumor structure and function: roles of adherens junctions, ErbBs and membrane MUCs. J Cell Biochem 2006; 96:914-26. [PMID: 16167329 DOI: 10.1002/jcb.20612] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mammary function is dependent on its three-dimensional organization, which is established and maintained by cell adhesive junctions linked through the membrane to the cell cytoskeleton. These junctions serve not only as structural elements, but also function as initiators and integrators of cell signals. In this review we discuss three types of glycoproteins whose interactions impinge on the function of mammary cell-cell junctions, cadherins, ErbB receptor tyrosine kinases and membrane mucins, as a microcosm of events regulating mammary cell behaviors. Actions of these components are integrated by the critical signaling element beta-catenin. When functioning properly, these glycoproteins, beta-catenin and associated signaling pathways mesh into a highly structured program for development and function of the gland. However, disruption or dysfunction of these glycoproteins or the signaling elements can lead to disorganization of the epithelia and ultimately to neoplasia.
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Affiliation(s)
- Kermit L Carraway
- Department of Cell Biology and Anatomy, University of Miami School of Medicine, Miami, Florida 33101, USA.
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48
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Voynow JA, Fischer BM, Roberts BC, Proia AD. Basal-like Cells Constitute the Proliferating Cell Population in Cystic Fibrosis Airways. Am J Respir Crit Care Med 2005; 172:1013-8. [PMID: 16020799 DOI: 10.1164/rccm.200410-1398oc] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Cystic fibrosis airways are recurrently exposed to noxious stimuli, leading to epithelial injury. Previous reports suggest that cystic fibrosis airway epithelia may respond to injury by increasing proliferation. OBJECTIVES We sought to determine the characteristics of the proliferating cell population in cystic fibrosis airways. METHODS Six cystic fibrosis and six normal lung sections from lung transplant recipients or lung surgery were obtained from the Duke Hospital pathology archives. Sections containing bronchi were evaluated for epithelial cell proliferation using immunohistochemistry for a nuclear proliferation antigen, Ki-67, and image analysis; immunohistochemistry for basal cells using a cytokeratin 5/14 antibody; and immunohistochemistry for the epidermal growth factor receptor and ErbB2, two receptor tyrosine kinases implicated in epithelial proliferation and differentiation. RESULTS Overall, cystic fibrosis sections had a greater proliferation index than control sections with 25.1 +/- 2.1% positively staining nuclei/total nuclei compared with control sections, 4.6 +/- 0.9% (p = 0.002). In cystic fibrosis sections only, there were areas of hyperplastic cuboidal cells adjacent to normal pseudostratified columnar epithelial sections; in these areas of epithelial hyperplasia, there was uniform Ki-67 staining, indicating a zone of proliferating cells. The proliferating cell population also expressed the basal cell cytokeratins 5/14 and epidermal growth factor receptor. Expression of ErbB2 was diminished in the proliferating cells. CONCLUSIONS Our results suggest that basal-like cells, expressing the epidermal growth factor receptor, constitute the proliferating cell population in cystic fibrosis airways.
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Affiliation(s)
- Judith A Voynow
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA.
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Saitou M, Goto M, Horinouchi M, Tamada S, Nagata K, Hamada T, Osako M, Takao S, Batra SK, Aikou T, Imai K, Yonezawa S. MUC4 expression is a novel prognostic factor in patients with invasive ductal carcinoma of the pancreas. J Clin Pathol 2005; 58:845-52. [PMID: 16049287 PMCID: PMC1770880 DOI: 10.1136/jcp.2004.023572] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Many patients with invasive ductal carcinoma of the pancreas (IDC) have a poor outcome. MUC4 expression has been implicated as a marker for diagnosis and progression of IDC, but there are no studies of the relation between MUC4 expression and patient prognosis in IDC. AIMS To investigate the prognostic significance of MUC4 expression in IDC. METHODS The expression profiles of MUC4, ErbB2, p27, and MUC1 were investigated in IDC tissues from 135 patients by means of immunohistochemistry. RESULTS MUC4 was expressed in 43 of the 135 patients with IDC (31.9%). The survival of 21 patients with high MUC4 expression (>20% of neoplastic cells stained) was significantly worse than that of the 114 patients with low MUC4 expression (<20% of neoplastic cells stained) (p = 0.0043). Univariate analysis showed that high MUC4 expression (p = 0.0061), large primary tumour status (>T2) (p = 0.0436), distant metastasis (p = 0.0383), lymphatic invasion (p = 0.0243), and surgical margins (p = 0.0333) were significant risk factors affecting the outcome of patients with IDC. Backward stepwise multivariate analysis showed that MUC4 expression (p = 0.0121), lymph node metastasis (p = 0.0245), and lymphatic invasion (p = 0.0239) were significant independent risk factors. ErbB2, p27, and MUC1 were not independent risk factors. CONCLUSIONS This study shows that MUC4 expression in IDC is a new independent factor for poor prognosis and predicts the outcome of patients with IDC.
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Affiliation(s)
- M Saitou
- Department of Human Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
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Fauquette V, Perrais M, Cerulis S, Jonckheere N, Ducourouble MP, Aubert JP, Pigny P, Seuningen I. The antagonistic regulation of human MUC4 and ErbB-2 genes by the Ets protein PEA3 in pancreatic cancer cells: implications for the proliferation/differentiation balance in the cells. Biochem J 2005; 386:35-45. [PMID: 15461591 PMCID: PMC1134764 DOI: 10.1042/bj20040706] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The human transmembrane mucin MUC4 is aberrantly expressed in 75% of pancreatic ductal adenocarcinomas, whereas no expression is found in normal pancreas. Therefore MUC4 appears as a useful biological marker for the diagnosis of ductal adenocarcinomas. Since rat Muc4 was shown to interact with ErbB-2 tyrosine kinase receptor and to either promote cell survival and differentiation or cell proliferation, it is postulated that MUC4 may also participate in pancreatic carcinogenesis. Our aim was to investigate in parallel the role of the Ets factor PEA3 in MUC4 and ErbB-2 transcriptional regulation in pancreatic cancer cells. Two MUC4-expressing WD (well-differentiated) (CAPAN-1 and -2) and one MUC4-non-expressing poorly differentiated (PANC-1) cell lines were used. The three cell lines express ErbB-2 at different levels. By co-transfection and site-directed mutagenesis, we show that PEA3 is a transactivator of the MUC4 promoter and that the -216 and -2368 PEA3 binding sites of the MUC4 promoter are essential. We also demonstrate that PEA3 acts in synergy with c-Jun and specificity protein 1 to transactivate the proximal region of the MUC4 promoter and increase MUC4 mRNA levels in WD cells. These results suggest that MUC4 is a new target gene of the Ets factor PEA3 in pancreatic cancer cells. In contrast, PEA3 represses the transcriptional activity of two fragments of the ErbB-2 promoter in a dose-dependent manner and decreases the endogenous ErbB-2 mRNA levels in WD cell lines. Thus, PEA3, by its capacity to up-regulate the epithelial marker MUC4 and to down-regulate the ErbB-2 oncogene, appears as a key regulator of the differentiation/proliferation balance in pancreatic cancer cells.
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MESH Headings
- Binding Sites
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/metabolism
- Carcinoma, Pancreatic Ductal/pathology
- Cell Differentiation
- Cell Line, Tumor/metabolism
- Down-Regulation
- Gene Expression Regulation, Neoplastic/physiology
- Genes, erbB-2
- Humans
- Mucin-4
- Mucins
- Mutagenesis, Site-Directed
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Promoter Regions, Genetic
- Protein Interaction Mapping
- Proto-Oncogene Proteins c-jun/physiology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptor, ErbB-2
- Sp1 Transcription Factor/physiology
- Structure-Activity Relationship
- Transcription Factors
- Transcriptional Activation
- Up-Regulation
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Affiliation(s)
| | - Michael Perrais
- *Unité INSERM 560, Place de Verdun, 59045 Lille cedex, France
| | - Sylvain Cerulis
- *Unité INSERM 560, Place de Verdun, 59045 Lille cedex, France
| | | | | | | | - Pascal Pigny
- *Unité INSERM 560, Place de Verdun, 59045 Lille cedex, France
- †Université de Lille 2, Faculté de Médecine, 59045 Lille cedex, France
- To whom correspondence should be addressed (email .)
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