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Luo Q, Li X, Xie K. Plakophilin 1 in carcinogenesis. Mol Carcinog 2024. [PMID: 38888207 DOI: 10.1002/mc.23779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/11/2024] [Accepted: 06/06/2024] [Indexed: 06/20/2024]
Abstract
Plakophilin 1 (PKP1) belongs to the desmosome family as an anchoring junction protein in cellular junctions. It localizes at the interface of the cell membrane and cytoplasm. Although PKP1 is a non-transmembrane protein, it may become associated with the cell membrane via transmembrane proteins such as desmocollins and desmogleins. Homozygous deletion of PKP1 results in ectodermal dysplasia-skin fragility syndrome (EDSF) and complete knockout of PKP1 in mice produces comparable symptoms to EDSF in humans, although mice do not survive more than 24 h. PKP1 is not limited to expression in desmosomal structures, but is rather widely expressed in cytoplasm and nucleus, where it assumes important cellular functions. This review will summarize distinct roles of PKP1 in the cell membrane, cytoplasm, and nucleus with an overview of relevant studies on its function in diverse types of cancer.
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Affiliation(s)
- Qiang Luo
- Center for Pancreatic Cancer Research, The South China University of Technology School of Medicine, Guangzhou, Guangdong, China
| | - Xiaojia Li
- Center for Pancreatic Cancer Research, The South China University of Technology School of Medicine, Guangzhou, Guangdong, China
| | - Keping Xie
- Center for Pancreatic Cancer Research, The South China University of Technology School of Medicine, Guangzhou, Guangdong, China
- The Second Affiliated Hospital and Guangzhou First People's Hospital, South China University of Technology School of Medicine, Guangzhou, Guangdong, China
- The South China University of Technology Comprehensive Cancer Center, Guangzhou, Guangdong, China
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2
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3
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Quinlan RA, Schwarz N, Windoffer R, Richardson C, Hawkins T, Broussard JA, Green KJ, Leube RE. A rim-and-spoke hypothesis to explain the biomechanical roles for cytoplasmic intermediate filament networks. J Cell Sci 2018; 130:3437-3445. [PMID: 29032358 DOI: 10.1242/jcs.202168] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 08/02/2017] [Indexed: 12/17/2022] Open
Abstract
Textbook images of keratin intermediate filament (IF) networks in epithelial cells and the functional compromization of the epidermis by keratin mutations promulgate a mechanical role for this important cytoskeletal component. In stratified epithelia, keratin filaments form prominent radial spokes that are focused onto cell-cell contact sites, i.e. the desmosomes. In this Hypothesis, we draw attention to a subset of keratin filaments that are apposed to the plasma membrane. They form a rim of filaments interconnecting the desmosomes in a circumferential network. We hypothesize that they are part of a rim-and-spoke arrangement of IFs in epithelia. From our review of the literature, we extend this functional role for the subplasmalemmal rim of IFs to any cell, in which plasma membrane support is required, provided these filaments connect directly or indirectly to the plasma membrane. Furthermore, cytoplasmic IF networks physically link the outer nuclear and plasma membranes, but their participation in mechanotransduction processes remain largely unconsidered. Therefore, we also discuss the potential biomechanical and mechanosensory role(s) of the cytoplasmic IF network in terms of such a rim (i.e. subplasmalemmal)-and-spoke arrangement for cytoplasmic IF networks.
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Affiliation(s)
- Roy A Quinlan
- Department of Biosciences, University of Durham, Upper Mountjoy, Stockton Road, Durham DH1 3LE, UK .,Biophysical Sciences Institute, University of Durham, Upper Mountjoy, Stockton Road, Durham DH1 3LE, UK
| | - Nicole Schwarz
- RWTH Aachen University, Institute of Molecular and Cellular Anatomy, Wendlingweg 2, 52074 Aachen, Germany
| | - Reinhard Windoffer
- RWTH Aachen University, Institute of Molecular and Cellular Anatomy, Wendlingweg 2, 52074 Aachen, Germany
| | - Christine Richardson
- Department of Biosciences, University of Durham, Upper Mountjoy, Stockton Road, Durham DH1 3LE, UK
| | - Tim Hawkins
- Department of Biosciences, University of Durham, Upper Mountjoy, Stockton Road, Durham DH1 3LE, UK
| | - Joshua A Broussard
- Dept. of Pathology W127, Tarry Bldg, Room 3-735, Northwestern University, Feinberg School of Medicine, 303 E. Chicago Ave., Chicago, IL 60611, USA
| | - Kathleen J Green
- Dept. of Pathology W127, Tarry Bldg, Room 3-735, Northwestern University, Feinberg School of Medicine, 303 E. Chicago Ave., Chicago, IL 60611, USA
| | - Rudolf E Leube
- RWTH Aachen University, Institute of Molecular and Cellular Anatomy, Wendlingweg 2, 52074 Aachen, Germany
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4
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Rietscher K, Wolf A, Hause G, Rother A, Keil R, Magin TM, Glass M, Niessen CM, Hatzfeld M. Growth Retardation, Loss of Desmosomal Adhesion, and Impaired Tight Junction Function Identify a Unique Role of Plakophilin 1 In Vivo. J Invest Dermatol 2016; 136:1471-1478. [DOI: 10.1016/j.jid.2016.03.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 12/12/2022]
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5
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Kashyap S, Shanker V, Sharma N. Ectodermal Dysplasia-Skin Fragility Syndrome: A Rare Case Report. Indian J Dermatol 2015; 60:421. [PMID: 26288439 PMCID: PMC4533569 DOI: 10.4103/0019-5154.160525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Ectodermal dysplasia/skin fragility syndrome (ED-SFS) is a newly described autosomal recessive disorder characterized by skin fragility and blistering, palmoplantar keratoderma, abnormal hair growth, nail dystrophy, and occasionally defective sweating. It results from mutations in the PKP1 gene encoding plakophilin 1 (PKP1), which is an important component of stratifying epithelial desmosomes and a nuclear component of many cell types. Only 12 cases of this rare genodermatosis have been reported so far. We present an unusual case of ED-SFS in a 12-year boy who was normal at birth but subsequently developed skin fragility, hair and nail deformities, abnormal dentition, palmoplantar keratoderma, and abnormal sweating but no systemic abnormality.
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Affiliation(s)
- Subhash Kashyap
- Department of Dermatology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
| | - Vinay Shanker
- Department of Dermatology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
| | - Neelam Sharma
- Department of Pathology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
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6
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Yang C, Fischer-Kešo R, Schlechter T, Ströbel P, Marx A, Hofmann I. Plakophilin 1-deficient cells upregulate SPOCK1: implications for prostate cancer progression. Tumour Biol 2015; 36:9567-77. [DOI: 10.1007/s13277-015-3628-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/31/2015] [Indexed: 12/19/2022] Open
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7
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Mehrian-Shai R, Freedman S, Shams S, Doherty J, Slattery W, Hsu NYH, Reichardt JKV, Andalibi A, Toren A. Schwannomas exhibit distinct size-dependent gene-expression patterns. Future Oncol 2015; 11:1751-8. [PMID: 26075443 DOI: 10.2217/fon.15.72] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Neurofibromatosis type 2 (NF2)-associated vestibular schwannomas have variable size at presentation which presents a unique challenge in NF2 patient management. Therefore, we investigated the molecular signature characteristic of the differences in size for improved individualized precise therapy. MATERIALS & METHODS RNA expression analysis was performed on 15 small and 27 large NF2-associated vestibular schwannoma tumors using a microarray analyzing over 47,000 transcripts. RESULTS A signature of 11 genes was found to be correlated with NF2 tumor size. CONCLUSION We have identified the genetic hallmark that differentiates large NF2-associated tumors from smaller tumors. This is the first time that these genes have been shown to be the hallmark for NF2 tumor size.
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Affiliation(s)
- Ruty Mehrian-Shai
- Department of Pediatric Hemato-Oncology, The Cancer Research Center, Sheba Medical Center, 2 Sheba Road, Ramat Gan, 52621, Israel
| | - Shany Freedman
- Department of Pediatric Hemato-Oncology, The Cancer Research Center, Sheba Medical Center, 2 Sheba Road, Ramat Gan, 52621, Israel
| | - Soheil Shams
- BioDiscovery, 5155 W Rosecrans Ave # 310, Hawthorne, CA 90250, USA
| | - Joni Doherty
- Head & Neck Surgery, University of California, San Diego School of Medicine, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - William Slattery
- Department of Clinical Studies, House Ear Institute, 2100 W 3rd St #500, Los Angeles, CA 90057, USA
| | | | - Juergen K V Reichardt
- Division of Tropical Health & Medicine, James Cook University, Townsville, QLD, Australia
| | - Ali Andalibi
- Stony Brook University, Stony Brook, NY 11794, USA
| | - Amos Toren
- Department of Pediatric Hemato-Oncology, The Cancer Research Center, Sheba Medical Center, 2 Sheba Road, Ramat Gan, 52621, Israel
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8
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Viñuela-Prieto JM, Sánchez-Quevedo MC, Alfonso-Rodríguez CA, Oliveira AC, Scionti G, Martín-Piedra MA, Moreu G, Campos A, Alaminos M, Garzón I. Sequential keratinocytic differentiation and maturation in a three-dimensional model of human artificial oral mucosa. J Periodontal Res 2014; 50:658-65. [PMID: 25470318 DOI: 10.1111/jre.12247] [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] [Accepted: 10/21/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND OBJECTIVE Oral mucosa shortage may limit or condition some clinical approaches in maxillofacial, periodontal and implant treatment. The availability of a human oral mucosa model generated by tissue engineering could help clinicians to address the lack of oral mucosa. In this work, we carried out a sequential maturation and differentiation study of the epithelial cell layer of an artificial human oral mucosa substitute based on fibrin-agarose biomaterials with fibroblasts and keratinocytes. MATERIAL AND METHODS Histological, immunohistochemical and gene expression analyses were carried out in artificial human oral mucosa models developed and cultured for 1, 2 and 3 wk. RESULTS Artificial oral mucosa models showed expression of tight junction proteins and cytokeratins from the first week of in vitro development. Mature samples of 3 wk of development subjected to air-liquid conditions showed signs of epithelial differentiation and expressed specific RNAs and proteins corresponding to adherent and gap junctions and basement lamina. Moreover, these mature samples overexpressed some desmosomal and tight junction transcripts, with gap junction components being downregulated. CONCLUSION These results suggest that bioengineered human oral mucosa substitutes form a well-developed epithelial layer that was very similar to human native tissues. In consequence, the epithelial layer could be fully functional in these oral mucosa substitutes, thus implying that these tissues may have clinical usefulness.
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Affiliation(s)
- J M Viñuela-Prieto
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain.,PhD Programme in Biomedicine, University of Granada, Granada, Spain
| | - M C Sánchez-Quevedo
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
| | - C A Alfonso-Rodríguez
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
| | - A C Oliveira
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
| | - G Scionti
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
| | - M A Martín-Piedra
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
| | - G Moreu
- Department of Stomatology, Faculty of Dentistry, University of Granada, Granada, Spain
| | - A Campos
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
| | - M Alaminos
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
| | - I Garzón
- Department of Histology (Tissue Engineering Group), Faculty of Medicine, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria ibs, Granada, Spain
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9
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Todorovic V, Koetsier JL, Godsel LM, Green KJ. Plakophilin 3 mediates Rap1-dependent desmosome assembly and adherens junction maturation. Mol Biol Cell 2014; 25:3749-64. [PMID: 25208567 PMCID: PMC4230782 DOI: 10.1091/mbc.e14-05-0968] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Desmosomal Armadillo family member Pkp3 is established as a coordinator of desmosome and adherens junction assembly and maturation through its physical and functional association with Rap1. It thus functions in a manner distinct from the closely related Pkp2. The pathways driving desmosome and adherens junction assembly are temporally and spatially coordinated, but how they are functionally coupled is poorly understood. Here we show that the Armadillo protein plakophilin 3 (Pkp3) mediates both desmosome assembly and E-cadherin maturation through Rap1 GTPase, thus functioning in a manner distinct from the closely related plakophilin 2 (Pkp2). Whereas Pkp2 and Pkp3 share the ability to mediate the initial phase of desmoplakin (DP) accumulation at sites of cell–cell contact, they play distinct roles in later steps: Pkp3 is required for assembly of a cytoplasmic population of DP-enriched junction precursors, whereas Pkp2 is required for transfer of the precursors to the membrane. Moreover, Pkp3 forms a complex with Rap1 GTPase, promoting its activation and facilitating desmosome assembly. We show further that Pkp3 deficiency causes disruption of an E-cadherin/Rap1 complex required for adherens junction sealing. These findings reveal Pkp3 as a coordinator of desmosome and adherens junction assembly and maturation through its functional association with Rap1.
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Affiliation(s)
- Viktor Todorovic
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Jennifer L Koetsier
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Lisa M Godsel
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Kathleen J Green
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 R.H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
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10
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Abstract
Desmosomes are morphologically and biochemically defined cell-cell junctions that are required for maintaining the mechanical integrity of skin and the heart in adult mammals. Furthermore, since mice with null mutations in desmosomal plaque proteins (plakoglobin and desmoplakin) die in utero, it is also evident that desmosomes are indispensable for normal embryonic development. This review focuses on the role of desmosomes in vivo. We will summarize the effects of mutations in desmosomal genes on pre- and post-embryonic development of mouse and man and discuss recent findings relating to the specific role of desmosomal cadherins in skin differentiation and homeostasis.
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Affiliation(s)
- Xing Cheng
- Department of Dermatology, Baylor College of Medicine, Houston, TX 77030, USA
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11
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Genetic skin diseases related to desmosomes and corneodesmosomes. J Dermatol Sci 2014; 74:99-105. [PMID: 24636350 DOI: 10.1016/j.jdermsci.2014.02.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 02/15/2014] [Accepted: 02/20/2014] [Indexed: 12/17/2022]
Abstract
The integrity of the epidermis depends on the cohesion between keratinocytes, and desmosomes are the main adhesion structures. When cells become cornified, desmosomes are modified and transformed into corneodesmosomes. Mutations in the genes encoding desmosomal components underlie several skin diseases including palmoplantar keratoderma and forms of epidermolysis bullosa, indicating the importance of desmosomes as mechanical stress-bearing structures. Other types of genetic defects in a desmosome component (desmoglein 1), a corneodesmosome component (corneodesmosin), and an inhibitor for proteases involved in corneodesmosome degradation (LEKTI) result in three clinically overlapping conditions: SAM syndrome, an inflammatory type of peeling skin disease, and Netherton syndrome. All three result in allergies to multiple allergens due to severe barrier impairment. Conversely, impaired corneodesmosomal degradation due to matriptase mutations could lead to ichthyosis. By discovering the diverse clinical phenotypes of these diseases, we can enrich our understanding of the multifunctional roles of desmosomes and corneodesmosomes in skin biology.
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12
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An alternative promoter of the human plakophilin-3 gene controls the expression of the new isoform PKP3b. Cell Tissue Res 2013; 355:143-62. [DOI: 10.1007/s00441-013-1736-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/13/2013] [Indexed: 01/24/2023]
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13
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Plakophilin-associated RNA-binding proteins in prostate cancer and their implications in tumor progression and metastasis. Virchows Arch 2013; 463:379-90. [PMID: 23881279 DOI: 10.1007/s00428-013-1452-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 07/01/2013] [Accepted: 07/08/2013] [Indexed: 01/04/2023]
Abstract
Both plakophilins (PKP) 1 and 3 play a role in the progression of prostate cancer. The RNA-binding proteins (RBPs) GAP-SH3-binding protein (G3BP), fragile-X-related protein 1 (FXR1), poly(A)-binding protein, cytoplasmic 1 (PABPC1), and up-frameshift factor 1 (UPF1) are associated with PKP3. All these RBPs have an impact on RNA metabolism. Until recently, the PKP-associated RBPs have not been analyzed in prostate cancer. In the current study, we showed by affinity purification that the PKP3-associated RBPs were also binding partners of PKP1. We examined the expression of PKP1/3-associated RBPs and PKP1/3 in prostate cell lines, tumor-free prostate, and 136 prostatic adenocarcinomas by immunofluorescence and immunoblot. All four RBPs G3BP, FXR1, UPF1, and PABPC1 were expressed in the glandular epithelium of the normal prostate. PKP1 and FXR1 were strongly reduced in tumor tissues with Gleason score >7 and diminished expression of PKP1 and FXR1 also appeared to be associated with a metastatic phenotype. Additionally, the predominant nuclear localization of UPF1 in normal glandular cells and low grade tumors was switched to a more cytoplasmic pattern in carcinomas with Gleason score >7. Our findings suggest that PKP1 and FXR1 may have a tumor-suppressive function and are downregulated in more aggressive tumors. Collectively, PKP1/3-associated RBPs FXR1 and UPF1 may have a functional role in prostate cancer progression and metastasis and highlight the potential importance of posttranscriptional regulation of gene expression and nonsense-mediated decay in cancer.
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14
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Gómez-Morales M, Cámara-Pulido M, Miranda-León MT, Sánchez-Palencia A, Boyero L, Gómez-Capilla JA, Fárez-Vidal ME. Differential immunohistochemical localization of desmosomal plaque-related proteins in non-small-cell lung cancer. Histopathology 2013; 63:103-13. [DOI: 10.1111/his.12126] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 03/06/2013] [Indexed: 01/01/2023]
Affiliation(s)
| | - Miguel Cámara-Pulido
- Department of Pathology; School of Medicine; University of Granada; Granada; Spain
| | - María Teresa Miranda-León
- Department of Statistics and Operative Research; School of Medicine; University of Granada; Granada; Spain
| | - Abel Sánchez-Palencia
- Department of Thoracic Surgery; Virgen de las Nieves University Hospital; Granada; Spain
| | - Laura Boyero
- Department of Biochemistry and Molecular Biology; School of Medicine; University of Granada; Granada; Spain
| | - José Antonio Gómez-Capilla
- Department of Biochemistry and Molecular Biology; School of Medicine; University of Granada; Granada; Spain
| | - María Esther Fárez-Vidal
- Department of Biochemistry and Molecular Biology; School of Medicine; University of Granada; Granada; Spain
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15
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Abstract
Desmosomes are intercellular adhesive junctions that are particularly prominent in tissues experiencing mechanical stress, such as the heart and epidermis. Whereas the related adherens junction links actin to calcium-dependent adhesion molecules known as classical cadherins, desmosomes link intermediate filaments (IF) to the related subfamily of desmosomal cadherins. By tethering these stress-bearing cytoskeletal filaments to the plasma membrane, desmosomes serve as integrators of the IF cytoskeleton throughout a tissue. Recent evidence suggests that IF attachment in turn strengthens desmosomal adhesion. This collaborative arrangement results in formation of a supracellular network, which is critical for imparting mechanical integrity to tissues. Diseases and animal models targeting desmosomal components highlight the importance of desmosomes in development and tissue integrity, while the downregulation of individual protein components in cancer metastasis and wound healing suggests their importance in cell homeostasis. This chapter will provide an update on desmosome composition, function, and regulation, and will also discuss recent work which raises the possibility that desmosome proteins do more than play a structural role in tissues where they reside.
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16
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Rickelt S. Plakophilin-2: a cell-cell adhesion plaque molecule of selective and fundamental importance in cardiac functions and tumor cell growth. Cell Tissue Res 2012; 348:281-94. [PMID: 22281687 PMCID: PMC3349858 DOI: 10.1007/s00441-011-1314-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 12/16/2011] [Indexed: 01/23/2023]
Abstract
Within the characteristic ensemble of desmosomal plaque proteins, the armadillo protein plakophilin-2 (Pkp2) is known as a particularly important regulatory component in the cytoplasmic plaques of various other cell-cell junctions, such as the composite junctions (areae compositae) of the myocardiac intercalated disks and in the variously-sized and -shaped complex junctions of permanent cell culture lines derived therefrom. In addition, Pkp2 has been detected in certain protein complexes in the nucleoplasm of diverse kinds of cells. Using a novel set of highly sensitive and specific antibodies, both kinds of Pkp2, the junctional plaque-bound and the nuclear ones, can also be localized to the cytoplasmic plaques of diverse non-desmosomal cell-cell junction structures. These are not only the puncta adhaerentia and the fasciae adhaerentes connecting various types of highly proliferative non-epithelial cells growing in culture but also some very proliferative states of cardiac interstitial cells and cardiac myxomata, including tumors growing in situ as well as fetal stages of heart development and cultures of valvular interstitial cells. Possible functions and assembly mechanisms of such Pkp2-positive cell-cell junctions as well as medical consequences are discussed.
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Affiliation(s)
- Steffen Rickelt
- Helmholtz Group for Cell Biology, German Cancer Research Center, Heidelberg, Germany.
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17
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Kaz AM, Luo Y, Dzieciatkowski S, Chak A, Willis JE, Upton MP, Leidner RS, Grady WM. Aberrantly methylated PKP1 in the progression of Barrett's esophagus to esophageal adenocarcinoma. Genes Chromosomes Cancer 2012; 51:384-93. [PMID: 22170739 PMCID: PMC3292431 DOI: 10.1002/gcc.21923] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 10/04/2011] [Accepted: 11/16/2011] [Indexed: 11/07/2022] Open
Abstract
The aberrant DNA methylation of tumor suppressor genes occurs frequently in Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) and likely affects the initiation and progression of BE to EAC. In the present study, we discovered PKP1 as a novel methylated gene in EAC and then investigated the role of loss of PKP1, a constituent of the desmosome complex found in stratified epithelial layers, on the behavior of Barrett's esophagus and esophageal adenocarcinoma cells. By using primary esophageal tissue samples we determined that PKP1 was rarely methylated in normal squamous esophagus (5/55; 9.1%) and BE (5/39; 12.8%) and more frequently methylated in Barrett's esophagus with high-grade dysplasia (HGD) or EAC (20/60; 33.3%; P < 0.05). Furthermore, PKP1 levels were decreased in BE and HGD/EAC cases compared to normal squamous esophagus cases. Knockdown of PKP1 in the BE cell lines CP-A and CP-D (both normally express PKP1) resulted in increased cell motility. Thus, PKP1 loss secondary to promoter methylation, as well as other mechanisms, may promote the progression of BE to EAC in a subset of patients via decreased desmosome assembly and increased cell motility.
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Affiliation(s)
- Andrew M Kaz
- Division of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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18
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Roberts BJ, Pashaj A, Johnson KR, Wahl JK. Desmosome dynamics in migrating epithelial cells requires the actin cytoskeleton. Exp Cell Res 2011; 317:2814-22. [PMID: 21945137 DOI: 10.1016/j.yexcr.2011.09.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 08/22/2011] [Accepted: 09/08/2011] [Indexed: 10/17/2022]
Abstract
Re-modeling of epithelial tissues requires that the cells in the tissue rearrange their adhesive contacts in order to allow cells to migrate relative to neighboring cells. Desmosomes are prominent adhesive structures found in a variety of epithelial tissues that are believed to inhibit cell migration and invasion. Mechanisms regulating desmosome assembly and stability in migrating cells are largely unknown. In this study we established a cell culture model to examine the fate of desmosomal components during scratch wound migration. Desmosomes are rapidly assembled between epithelial cells at the lateral edges of migrating cells and structures are transported in a retrograde fashion while the structures become larger and mature. Desmosome assembly and dynamics in this system are dependent on the actin cytoskeleton prior to being associated with the keratin intermediate filament cytoskeleton. These studies extend our understanding of desmosome assembly and provide a system to examine desmosome assembly and dynamics during epithelial cell migration.
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Affiliation(s)
- Brett J Roberts
- The University of Nebraska Medical Center College of Dentistry, Lincoln, NE 68583, USA
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19
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Demirag GG, Sullu Y, Gurgenyatagi D, Okumus NO, Yucel I. Expression of plakophilins (PKP1, PKP2, and PKP3) in gastric cancers. Diagn Pathol 2011; 6:1. [PMID: 21194493 PMCID: PMC3025932 DOI: 10.1186/1746-1596-6-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Accepted: 01/02/2011] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The importance of cell-cell junction proteins (including armadillo proteins) in tumor biology is known, but limited with regard to plakophilins. We explored the relationship between plakophilins (PKP1, PKP2, PKP3) to gastric cancer via immunohistochemical techniques. METHODS We compared the immunohistochemistry of PKPs in 34 gastric adenocarcinomas and 20 normal gastric tissues. RESULTS In gastric cancer, PKP1 expression was unchanged but PKP2 and PKP3 were significantly decreased as compared to normal controls. There was no observable clinical association with PKP1 or PKP2 expression; however, low PKP3 level and poor prognosis appeared to correlate with regards to node number and tumor stage. The mean disease-free survival (DFS) was 38 ± 3 months (range: 32 - 44) and mean overall survival (OS) 42 ± 4 months (range: 38 - 50). Decreased PKP2 appeared to negatively impact DFS. CONCLUSION Decreased PKP2 and PKP3 may be early prognostic markers and loss of PKP3 expression during gastric carcinoma progression may indicate an invasive phenotype.
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Affiliation(s)
- Guzin G Demirag
- Ondokuz Mayis University, Faculty of Medicine, Department of Pathology, Samsun, Turkey
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20
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Berretta R, Moscato P. Cancer biomarker discovery: the entropic hallmark. PLoS One 2010; 5:e12262. [PMID: 20805891 PMCID: PMC2923618 DOI: 10.1371/journal.pone.0012262] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2009] [Accepted: 06/26/2010] [Indexed: 12/29/2022] Open
Abstract
Background It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-througput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases.
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Affiliation(s)
- Regina Berretta
- Centre for Bioinformatics, Biomarker Discovery and Information-Based Medicine, The University of Newcastle, Callaghan, New South Wales, Australia
- Information Based Medicine Program, Hunter Medical Research Institute, John Hunter Hospital, New Lambton Heights, New South Wales, Australia
| | - Pablo Moscato
- Centre for Bioinformatics, Biomarker Discovery and Information-Based Medicine, The University of Newcastle, Callaghan, New South Wales, Australia
- Information Based Medicine Program, Hunter Medical Research Institute, John Hunter Hospital, New Lambton Heights, New South Wales, Australia
- Australian Research Council Centre of Excellence in Bioinformatics, Callaghan, New South Wales, Australia
- * E-mail:
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21
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Sobolik-Delmaire T, Reddy R, Pashaj A, Roberts BJ, Wahl JK. Plakophilin-1 localizes to the nucleus and interacts with single-stranded DNA. J Invest Dermatol 2010; 130:2638-46. [PMID: 20613778 DOI: 10.1038/jid.2010.191] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Plakophilins (Pkp-1, -2, and -3) comprise a family of armadillo repeat-containing proteins first identified as desmosomal plaque components, in which they link desmoplakin to the desmosomal cadherins. In addition to their role in desmosomal cell-cell adhesion, Pkps also localize to the nucleus, where they perform unknown functions. Of the three Pkps, Pkp-1 is most readily detected in the nucleus, where it is localized to the nucleoplasm. Pkp chimeras containing the Pkp-1 head domain and Pkp-3 armadillo repeat domain were localized to the nucleus in A431 cells, whereas Pkp chimeras containing the Pkp-3 head domain and Pkp-1 armadillo repeat domain localized to the desmosome and the cytosol. DNAse I digestion of chromatin in cultured cells results in loss of nuclear Pkp-1, suggesting that Pkp-1 associates specifically with nuclear components. In addition, in vitro assays revealed that the amino-terminal head domains of Pkps-1 and -2 were sufficient to bind single-stranded DNA. Induction of DNA damage induced a partial redistribution of Pkp-1 protein to the nucleolus, and depletion of Pkp-1 resulted in increased survival in response to DNA damage. These data suggest that in addition to mediating desmosome assembly, the nuclear pool of Pkp can influence cell survival by interactions with DNA.
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Affiliation(s)
- Tammy Sobolik-Delmaire
- Department of Oral Biology, UNMC College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583-0740, USA
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22
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The desmosomal plaque proteins of the plakophilin family. Dermatol Res Pract 2010; 2010:101452. [PMID: 20585595 PMCID: PMC2879962 DOI: 10.1155/2010/101452] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 01/26/2010] [Indexed: 11/18/2022] Open
Abstract
Three related proteins of the plakophilin family (PKP1_3) have been identified as junctional proteins that are essential for the formation and stabilization of desmosomal cell contacts. Failure of PKP expression can have fatal effects on desmosomal adhesion, leading to abnormal tissue and organ development. Thus, loss of functional PKP 1 in humans leads to ectodermal dysplasia/skin fragility (EDSF) syndrome, a genodermatosis with severe blistering of the epidermis as well as abnormal keratinocytes differentiation. Mutations in the human PKP 2 gene have been linked to severe heart abnormalities that lead to arrhythmogenic right ventricular cardiomyopathy (ARVC). In the past few years it has been shown that junctional adhesion is not the only function of PKPs. These proteins have been implicated in cell signaling, organization of the cytoskeleton, and control of protein biosynthesis under specific cellular circumstances. Clearly, PKPs are more than just cell adhesion proteins. In this paper we will give an overview of our current knowledge on the very distinct roles of plakophilins in the cell.
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23
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Breuninger S, Reidenbach S, Sauer CG, Ströbel P, Pfitzenmaier J, Trojan L, Hofmann I. Desmosomal plakophilins in the prostate and prostatic adenocarcinomas: implications for diagnosis and tumor progression. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:2509-19. [PMID: 20348237 DOI: 10.2353/ajpath.2010.090737] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The plakophilins, members of the armadillo-repeat family, consist of three different proteins (PKP1-3) that are specifically recruited to desmosomal plaques in a highly cell type-specific manner. Using immunofluorescence, immunoelectron microscopy, and immunoblot, we found that all three plakophilins occurred in luminal and basal cells of the pseudostratified prostate epithelium. The analysis of 135 cases of prostatic adenocarcinomas grouped into tumors with low (Gleason score < or = 6), intermediate (Gleason score 7), and high Gleason score (8 < or = Gleason score < or = 10) showed that the expression of PKP1 was reduced or lost in adenocarcinomas with high Gleason scores. The expression of PKP2 was unchanged in all prostatic adenocarcinomas analyzed. In contrast, PKP3 expression was increased in carcinomas with high Gleason scores in comparison with carcinomas with low Gleason scores. In DU 145 cell lines with either overexpression or knockdown of PKP3, both imbalances resulted in fewer desmosomal cell contacts. In addition, overexpression of PKP3 in DU 145 cells led to an augmentation in proliferation rate. Our data imply that both loss of PKP1 and up-regulation of PKP3 expression are biologically important events in prostate cancer and are associated with a more aggressive phenotype.
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Affiliation(s)
- Sonja Breuninger
- Joint Research Division Vascular Biology of the Medical Faculty Mannheim, Heidelberg University, and the German Cancer Research Center (DKFZ-ZMBH-Alliance), Center for Biomedicine and Medical Technology Mannheim (CBTM), Mannheim, Germany
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24
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Narayana N, Gist J, Smith T, Tylka D, Trogdon G, Wahl JK. Desmosomal component expression in normal, dysplastic, and oral squamous cell carcinoma. Dermatol Res Pract 2010; 2010:649731. [PMID: 20585603 PMCID: PMC2879963 DOI: 10.1155/2010/649731] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2009] [Revised: 01/03/2010] [Accepted: 01/27/2010] [Indexed: 12/01/2022] Open
Abstract
Squamous cell carcinoma (oral SCC) is the most common oral cancer in the U.S., affecting nearly 30,000 Americans each year. Despite recent advances in detection and treatment, there has been little improvement in the five-year survival rate for this devastating disease. Oral cancer may be preceded by premalignant disease that appears histologically as dysplasia. Identification of molecular markers for cellular change would assist in determining the risk of dysplasia progressing to oral squamous cell carcinoma. The goal of this study was to determine if any correlation exists between histological diagnosed dysplasia and OSCC lesions and altered expression of desmosomal cell-cell adhesion molecules in the oral epithelium. Our data showed that oral SCC tissue samples showed decreased immunoreactivity of both desmoplakin and plakophilin-1 proteins compared to normal oral epithelium. Furthermore, significant decrease in desmoplakin immunoreactivity was observed in dysplastic tissue compared to normal oral epithelium. In contrast, the level of desmoglein-1 staining was unchanged between samples however desmoglein-1 was found localized to cell borders in oral SCC samples. These data suggest that changes in expression of desmoplakin and plakophilin-1 may prove to be a useful marker for changes in tissue morphology and provide a tool for identifying pre-neoplastic lesions of the oral cavity.
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Affiliation(s)
- Nagamani Narayana
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry, 40th and Holdrege, Lincoln, NE 68583, USA
| | - Julie Gist
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry, 40th and Holdrege, Lincoln, NE 68583, USA
| | - Tyler Smith
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry, 40th and Holdrege, Lincoln, NE 68583, USA
| | - Daniel Tylka
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry, 40th and Holdrege, Lincoln, NE 68583, USA
| | - Gavin Trogdon
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry, 40th and Holdrege, Lincoln, NE 68583, USA
| | - James K. Wahl
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry, 40th and Holdrege, Lincoln, NE 68583, USA
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25
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Bass-Zubek AE, Godsel LM, Delmar M, Green KJ. Plakophilins: multifunctional scaffolds for adhesion and signaling. Curr Opin Cell Biol 2009; 21:708-16. [PMID: 19674883 DOI: 10.1016/j.ceb.2009.07.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 06/28/2009] [Accepted: 07/06/2009] [Indexed: 11/26/2022]
Abstract
Armadillo family proteins known as plakophilins have been characterized as structural components of desmosomes that stabilize and strengthen adhesion by enhancing attachments with the intermediate filament cytoskeleton. However, plakophilins and their close relatives are emerging as versatile scaffolds for multiple signaling and metabolic processes that not only facilitate junction dynamics but also more globally regulate diverse cellular activities. While perturbation of plakophilin functions contribute to inherited diseases and cancer pathogenesis, the functional significance of the multiple PKP isoforms and the mechanisms by which their behaviors are regulated remain to be elucidated.
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Affiliation(s)
- Amanda E Bass-Zubek
- Department of Pathology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Chicago, IL 60611, USA
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26
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Sobolik-Delmaire T, Katafiasz D, Keim SA, Mahoney MG, Wahl JK. Decreased Plakophilin-1 Expression Promotes Increased Motility in Head and Neck Squamous Cell Carcinoma Cells. ACTA ACUST UNITED AC 2009; 14:99-109. [PMID: 17668353 DOI: 10.1080/15419060701463082] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Desmosomes are prominent cell-cell adhesive junctions found in a variety of epithelial tissues, including the oral epithelium. The transmembrane core of the desmosome is composed of the desmosomal cadherins that interact extracellularly to mediate cell-cell adhesion. The cytoplasmic domain of desmosomal cadherins interact with plaque proteins that in turn interact with the keratin intermediate filament cytoskeleton. Plakophilin 1 is a major desmosomal plaque component that functions to recruit intermediate filaments to sites of cell-cell contact via interactions with desmoplakin. Decreased assembly of desmosomes has been reported in several epithelial cancers. We examined plakophilin-1 expression in an esophageal squamous cell carcinoma tissue microarray and found that plakophilin-1 expression inversely correlates with tumor grade. In addition, we sought to investigate the effect of plakophilin-1 expression on desmosome assembly and cell motility in oral squamous cell carcinoma cell lines. Cell lines expressing altered levels of plakophilin-1 were generated and the ability of these cells to recruit desmoplakin to sites of cell-cell contact was examined. Our results show that decreased expression of plakophilin-1 results in decreased desmosome assembly and increased cell motility and invasion. These data lead us to propose that loss of plakophilin-1 expression during head and neck squamous cell carcinoma (HNSCC) progression may contribute to an invasive phenotype.
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Affiliation(s)
- Tammy Sobolik-Delmaire
- Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska, USA
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27
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Obrigkeit DH, Jugert FK, Beermann T, Baron JM, Frank J, Merk HF, Bickers DR, Abuzahra F. Effects of Photodynamic Therapy Evaluated in a Novel Three-dimensional Squamous Cell Carcinoma Organ Construct of the Skin. Photochem Photobiol 2009; 85:272-8. [DOI: 10.1111/j.1751-1097.2008.00432.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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Rickelt S, Franke WW, Doerflinger Y, Goerdt S, Brandner JM, Peitsch WK. Subtypes of melanocytes and melanoma cells distinguished by their intercellular contacts: heterotypic adherens junctions, adhesive associations, and dispersed desmoglein 2 glycoproteins. Cell Tissue Res 2008; 334:401-22. [PMID: 18975006 DOI: 10.1007/s00441-008-0704-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 09/17/2008] [Indexed: 12/11/2022]
Abstract
In the tissue integration of melanocytes and melanoma cells, an important role is attributed to cell adhesion molecules, notably the cadherins. In cultured melanoma cells, we have previously described a more heterogeneous repertoire of cadherins than normal, including some melanoma subtypes synthesizing the desmosomal cadherin, desmoglein 2, out of the desmosomal context. Using biochemical and immunological characterization of junctional molecules, confocal laser scanning, and electron and immunoelectron microscopy, we now demonstrate homo- and heterotypic cell-cell adhesions of normal epidermal melanocytes. In human epidermis, both in situ and in cell culture, melanocytes and keratinocytes are connected by closely aligned membranes that are interspersed by small puncta adhaerentia containing heterotypic complexes of E- and P-cadherin. Moreover, melanocytes growing in culture often begin to synthesize desmoglein 2, which is dispersed over extended areas of intimate adhesive cell-cell associations. As desmoglein 2 is not found in melanocytes in situ, we hypothesize that its synthesis is correlated with cell proliferation. Indeed, in tissue microarrays, desmoglein 2 has been demonstrated in a sizable subset of nevi and primary melanomas. The biological meanings of these cell-cell adhesion molecule arrangements, the possible diagnostic and prognostic significance of these findings, and the implications of the heterogeneity types of melanomas are discussed.
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Affiliation(s)
- Steffen Rickelt
- Helmholtz Group for Cell Biology, German Cancer Research Center, Heidelberg, Germany
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29
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Holthöfer B, Windoffer R, Troyanovsky S, Leube RE. Structure and function of desmosomes. ACTA ACUST UNITED AC 2007; 264:65-163. [PMID: 17964922 DOI: 10.1016/s0074-7696(07)64003-0] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Desmosomes are prominent adhesion sites that are tightly associated with the cytoplasmic intermediate filament cytoskeleton providing mechanical stability in epithelia and also in several nonepithelial tissues such as cardiac muscle and meninges. They are unique in terms of ultrastructural appearance and molecular composition with cell type-specific variations. The dynamic assembly properties of desmosomes are important prerequisites for the acquisition and maintenance of tissue homeostasis. Disturbance of this equilibrium therefore not only compromises mechanical resilience but also affects many other tissue functions as becomes evident in various experimental scenarios and multiple diseases.
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Affiliation(s)
- Bastian Holthöfer
- Department of Anatomy and Cell Biology, Johannes Gutenberg University, 55128 Mainz, Germany
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30
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Schmitt-Graeff A, Koeninger A, Olschewski M, Haxelmans S, Nitschke R, Bochaton-Piallat ML, Lifschitz-Mercer B, Gabbiani G, Langbein L, Czernobilsky B. The Ki67+ proliferation index correlates with increased cellular retinol-binding protein-1 and the coordinated loss of plakophilin-1 and desmoplakin during progression of cervical squamous lesions. Histopathology 2007; 51:87-97. [PMID: 17593084 DOI: 10.1111/j.1365-2559.2007.02724.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
AIMS To investigate the modulation of cellular retinol-binding protein (CRBP)-1 and the desmosomal plaque proteins plakophilin (PKP)-1 and desmoplakin (DP) in correlation with the Ki67+ proliferation index (PI) during the progression of cervical squamous intraepithelial lesions (SIL) to squamous cell carcinoma (SCC). METHODS Using in situ imaging by brightfield and confocal laser scanning microscopy, the expression of CRBP-1 protein and transcripts, PKP-1, DP and the Ki67 PI were analysed in 38 low-grade (L) SIL, 56 high-grade (H) SIL, 49 SCC, 30 control cervices and 10 human papillomavirus-positive condylomatous lesions. RESULTS CRBP-1+ cells increased from 11.4% in the normal cervix to 80.3% in LSILs, 92.3% in HSILs and slightly decreased to 78.3% in invasive SCCs (P = 0.0001) in close association with the Ki67 PI (r =0.41; P < 0.0001). PKP-1+ and DP+ cells were correlated (0.32; P < 0.0001) and decreased from normal (81% versus 92.3%) to LSIL (53.1% versus 85.3%), to HSIL (46.4% versus 67.5%) and SCC (35.1% versus 35.9%). The Ki67+ PI was inversely correlated with DP (-0.20, P = 0.0014) and PKP-1 (-0.19, P = 0.015). Condylomata retained low CRBP-1 and high expression of PKP-1 and DP. CONCLUSIONS The gain of CRBP-1 and the loss of desmosomal proteins occur early in cervical carcinogenesis.
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31
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Goossens S, Janssens B, Bonné S, De Rycke R, Braet F, van Hengel J, van Roy F. A unique and specific interaction between alphaT-catenin and plakophilin-2 in the area composita, the mixed-type junctional structure of cardiac intercalated discs. J Cell Sci 2007; 120:2126-36. [PMID: 17535849 DOI: 10.1242/jcs.004713] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Alpha-catenins play key functional roles in cadherin-catenin cell-cell adhesion complexes. We previously reported on alphaT-catenin, a novel member of the alpha-catenin protein family. alphaT-catenin is expressed predominantly in cardiomyocytes, where it colocalizes with alphaE-catenin at the intercalated discs. Whether alphaT- and alphaE-catenin have specific or synergistic functions remains unknown. In this study we used the yeast two-hybrid approach to identify specific functions of alphaT-catenin. An interaction between alphaT-catenin and plakophilins was observed and subsequently confirmed by co-immunoprecipitation and colocalization. Interaction with the amino-terminal part of plakophilins appeared to be specific for the central ;adhesion-modulation' domain of alphaT-catenin. In addition, we showed, by immuno-electron microscopy, that desmosomal proteins in the heart localize not only to the desmosomes in the intercalated discs but also at adhering junctions with hybrid composition. We found that in the latter junctions, endogenous plakophilin-2 colocalizes with alphaT-catenin. By providing an extra link between the cadherin-catenin complex and intermediate filaments, the binding of alphaT-catenin to plakophilin-2 is proposed to be a means of modulating and strengthening cell-cell adhesion between cardiac muscle cells. This could explain the devastating effect of plakophilin-2 mutations on cell junction stability in intercalated discs, which lead to cardiac muscle malfunction.
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Affiliation(s)
- Steven Goossens
- Department for Molecular Biomedical Research, VIB, Ghent University, B-9052 Ghent, Belgium
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32
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Kottke MD, Delva E, Kowalczyk AP. The desmosome: cell science lessons from human diseases. J Cell Sci 2006; 119:797-806. [PMID: 16495480 DOI: 10.1242/jcs.02888] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Human skin diseases have revealed fundamental mechanisms by which cytoskeletal proteins contribute to tissue architecture and function. In particular, the analysis of epidermal blistering disorders and the role of keratin gene mutations in these diseases has led to significant increases in our understanding of intermediate filament biology. The major cell-surface attachment site for intermediate filament networks is the desmosome, an adhesive intercellular junction prominent in the epidermis and the heart. During the past decade, substantial progress has been made in understanding the molecular basis of a variety of epidermal autoimmune diseases, skin fragility syndromes, and disorders that involve a combination of heart and skin defects caused by perturbations in desmosome structure and function. These human diseases reveal key roles for desmosomes in maintaining tissue integrity, but also suggest functions for desmosomal components in signal transduction pathways and epidermal organization.
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Affiliation(s)
- Margaret D Kottke
- Department of Dermatology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
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Ersoy-Evans S, Erkin G, Fassihi H, Chan I, Paller AS, Sürücü S, McGrath JA. Ectodermal dysplasia–skin fragility syndrome resulting from a new homozygous mutation, 888delC, in the desmosomal protein plakophilin 1. J Am Acad Dermatol 2006; 55:157-61. [PMID: 16781314 DOI: 10.1016/j.jaad.2005.10.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 09/30/2005] [Accepted: 10/01/2005] [Indexed: 11/30/2022]
Abstract
We report an unusual case of an inherited disorder of the desmosomal protein plakophilin 1, resulting in ectodermal dysplasia-skin fragility syndrome. The affected 6-year-old boy had red skin at birth and subsequently developed skin fragility, progressive plantar keratoderma, nail dystrophy, and alopecia. Skin biopsy revealed widening of intercellular spaces in the epidermis and a reduced number of small, poorly formed desmosomes. Mutation analysis of the plakophilin 1 gene PKP1 revealed a homozygous deletion of C at nucleotide 888 within exon 5. This mutation differs from the PKP1 gene pathology reported in 8 previously published individuals with this rare genodermatosis. However, all cases show similar clinical features, highlighting the importance of functional plakophilin 1 in maintaining desmosomal adhesion in skin, as well as the role of this protein in aspects of ectodermal development.
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Affiliation(s)
- Sibel Ersoy-Evans
- Hacettepe University Faculty of Medicine, Department of Dermatology, Sihhiye, Ankara, 06100, Turkey.
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Schwarz J, Ayim A, Schmidt A, Jäger S, Koch S, Baumann R, Dünne AA, Moll R. Differential expression of desmosomal plakophilins in various types of carcinomas: correlation with cell type and differentiation. Hum Pathol 2006; 37:613-22. [PMID: 16647960 DOI: 10.1016/j.humpath.2006.01.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 01/06/2006] [Accepted: 01/11/2006] [Indexed: 12/12/2022]
Abstract
Plakophilins (PKPs) are a set of 3 constitutive armadillo repeat proteins of the desmosomal plaque, termed PKP 1, PKP 2, and PKP 3, which have been shown to be functionally relevant for desmosomal adhesion. We have performed a systematic immunohistochemical study of the 3 PKPs in oral and pharyngeal squamous cell carcinomas (SqCCs; n = 40); colorectal, pancreatic, and prostate adenocarcinomas (n = 31), and hepatocellular carcinomas (HCCs; n = 8). In SqCCs, PKP 1 and PKP 3 revealed common desmosome-type immunostaining, their expression level being inversely correlated with the degree of malignancy. Instead, staining for PKP 2 was limited. In contrast, all adenocarcinomas contained PKP 2 and-often abundantly-PKP 3 in desmosome-typical pattern, whereas PKP 1 was expressed only in prostate tumors. The presence of PKP 3 in adenocarcinomas was confirmed by immunoblotting. In HCCs, only PKP 2 was detected. Under certain staining conditions, focal nuclear immunoreactivity for PKP 1 was observed in some SqCCs and HCCs. Our results, which are inconsistent with previously published data to some extent, indicate a principal preservation of the cell type and differentiation-related expression patterns of PKPs in normal epithelia. For PKP 1, a suppressor function of malignant behavior seems conceivable, whereas the putative functional significance of its occurrence in tumor cell nuclei requires further studies.
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Affiliation(s)
- Juliane Schwarz
- Department of Pathology, Philipps-University of Marburg Medical School, D-35033 Marburg, Germany
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35
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Sobolik-Delmaire T, Katafiasz D, Wahl JK. Carboxyl Terminus of Plakophilin-1 Recruits It to Plasma Membrane, whereas Amino Terminus Recruits Desmoplakin and Promotes Desmosome Assembly. J Biol Chem 2006; 281:16962-16970. [PMID: 16632867 DOI: 10.1074/jbc.m600570200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plakophilins are armadillo repeat-containing proteins, initially identified as desmosomal plaque proteins that have subsequently been shown to also localize to the nucleus. Loss of plakophilin-1 is the underlying cause of ectodermal dysplasia/skin fragility syndrome, and skin from these patients exhibits desmosomes that are reduced in size and number. Thus, it has been suggested that plakophilin-1 plays an important role in desmosome stability and/or assembly. In this study, we used a cell culture system (A431DE cells) that expresses all of the proteins necessary to assemble a desmosome, except plakophilin-1. Using this cell line, we sought to determine the role of plakophilin-1 in de novo desmosome assembly. When exogenous plakophilin-1 was expressed in these cells, desmosomes were assembled, as assessed by electron microscopy and immunofluorescence localization of desmoplakin, into punctate structures. Deletion mutagenesis experiments revealed that amino acids 686-726 in the carboxyl terminus of plakophilin-1 are required for its localization to the plasma membrane. In addition, we showed that amino acids 1-34 in the amino terminus were necessary for subsequent recruitment of desmoplakin to the membrane and desmosome assembly.
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Affiliation(s)
- Tammy Sobolik-Delmaire
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry and Nebraska Center for Cellular Signaling, Omaha, Nebraska 68138
| | - Dawn Katafiasz
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry and Nebraska Center for Cellular Signaling, Omaha, Nebraska 68138
| | - James K Wahl
- Department of Oral Biology, University of Nebraska Medical Center College of Dentistry and Nebraska Center for Cellular Signaling, Omaha, Nebraska 68138.
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Abstract
Desmosomes are highly organized intercellular junctions that provide mechanical integrity to tissues by anchoring intermediate filaments to sites of strong adhesion. These cell-cell adhesion junctions are found in skin, heart, lymph nodes and meninges. Over the last 8 years, several naturally occurring human gene mutations in structural components of desmosomes have been reported. These comprise autosomal dominant or recessive mutations in plakophilin 1, plakophilin 2, desmoplakin, plakoglobin, desmoglein 1, desmoglein 4 and corneodesmosin. These discoveries have often highlighted novel or unusual phenotypes, including abnormal skin fragility and differentiation, and developmental anomalies of various ectodermal appendages, especially hair. Some desmosomal gene mutations may also result in cardiac disease, notably cardiomyopathy. This article describes the spectrum of clinical features that may be found in the inherited disorders of desmosomes and highlights the key functions of several of the desmosomal proteins in tissue adhesion and cell biology.
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Affiliation(s)
- John A McGrath
- Genetic Skin Disease Group, St John's Institute of Dermatology, The Guy's, King's College and St Thomas' Hospitals' Medical School, London, UK.
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Peitsch WK, Hofmann I, Bulkescher J, Hergt M, Spring H, Bleyl U, Goerdt S, Franke WW. Drebrin, an Actin-Binding, Cell-Type Characteristic Protein: Induction and Localization in Epithelial Skin Tumors and Cultured Keratinocytes. J Invest Dermatol 2005; 125:761-74. [PMID: 16185277 DOI: 10.1111/j.0022-202x.2005.23793.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Isoform E2 of drebrin, an actin-binding protein originally identified in neuronal cells, has recently been identified in diverse non-neuronal cells, mostly in association with cell processes and intercellular junctions. Here, we report on the presence of drebrin in normal human skin, epithelial skin cancers, and cultured keratinocytes. Keratinocytes of normal epidermis contain almost no drebrin but the protein is readily seen in hair follicles. By immunohistochemistry and immunoblot, basal cell carcinomas (BCC) are rich in drebrin, and confocal laser scanning and immunoelectron microscopy show accumulation at adhering junctions, in co-localization with actin and partially with plaque proteins. In squamous cell carcinomas, keratoacanthomas, and in epidermal precancers, drebrin is heterogeneously distributed, appearing as mosaics. Primary keratinocyte cultures contain significant amounts of drebrin enriched at adhering junctions. When epithelium-derived cells devoid of drebrin are transfected with drebrin-enhanced green fluorescent protein, constructs accumulate in the cell periphery, and immunoprecipitation shows complexes with actin. During epidermal growth factor induced formation of cell processes, drebrin retains this junction association, as observed by live cell microscopy. Our results suggest novel functions of drebrin such as an involvement in cell-cell adhesion and tumorigenesis and a potential value in diagnosis of BCC.
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Affiliation(s)
- Wiebke K Peitsch
- Department of Dermatology, Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
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McGrath JA, Wessagowit V. Human hair abnormalities resulting from inherited desmosome gene mutations. Keio J Med 2005; 54:72-9. [PMID: 16077256 DOI: 10.2302/kjm.54.72] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over the last eight years, several naturally occurring human gene mutations in structural components of desmosomes, cell-cell adhesion junctions found in skin, heart and meninges, have been reported. These comprise dominant or recessive mutations in plakophilin 1, plakophilin 2, desmoplakin, desmoglein 1, desmoglein 4, plakoglobin and corneodesmosin. Of note, as well as compromising tissue integrity, many of the resulting phenotypes have been associated with visible changes in hair. This article describes the particular hair abnormalities resulting from these desmosome gene mutations. Collectively, the data demonstrate the surprising effects inherited desmosome gene/protein pathology may have on hair growth and development. Further analysis of these and other desmosome genes is likely to resolve more hair disease mysteries and provides several further intriguing new discoveries in years to come.
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Affiliation(s)
- John A McGrath
- Genetic Skin Disease Group, St John's Institute of Dermatology, The Guy's, King's College and St Thomas' Hospitals' Medical School, London, UK
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39
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Abstract
The linkage of the different types of cytoskeletal proteins to cell adhesion structures at the cytoplasmic membrane and the connection of these contact sites to corresponding sites of adjacent cells is a prerequisite for integrity and stability of cells and tissues. The structurally most prominent types of such cell-cell adhesion complexes are the desmosomes (maculae adhaerentes), which are found in all epithelia and certain non-epithelial tissues. As an element of the cytoskeleton, intermediate filaments are connected to the adhesive desmosomal transmembrane proteins by the cytoplasmic desmosomal plaque proteins. At least three different types of proteins are found in the desmosomal plaque, one of which is represented by the plakophilins, a recently described sub-family of sequence-related armadillo-repeat proteins. Consisting of three isoforms, plakophilins (plakophilin 1 to 3, PKP 1 to 3) are located in all desmosomes in a differentiation-dependent manner. While PKP 2 and PKP 3 are part of almost all desmosome-bearing cell types (PKP 2 except for differentiated cells of stratified epithelia and PKP 3 for hepatocytes and cardiomyocytes), PKP 1 is restricted to desmosomes of cells of stratified and complex epithelia. Besides the architectural function that plakophilins seem to fulfill in the desmosomes, at least PKP 1 and 2 are also localized in the nucleus independently of any differentiation-related processes and with an up to now enigmatic function in this compartment. In the following article we want to summarize the current knowledge concerning structure, function and regulation of the plakophilins that has been achieved during the last decade.
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Affiliation(s)
- Ansgar Schmidt
- Philipp University of Marburg Medical School, Institute of Pathology, Baldingerstrasse, Marburg D-35033, Germany.
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Abstract
Plakophilins (pkp-1, -2, and -3) comprise a family of armadillo-repeat containing proteins that are found in the desmosomal plaque and in the nucleus. Plakophilin-1 is most highly expressed in the suprabasal layers of the epidermis and loss of plakophilin-1 expression results in skin fragility-ectodermal dysplasia syndrome, which is characterized by a reduction in the number and size of desmosomes in the epithelia of affected individuals. To investigate the role of plakophilin-1 during desmosome formation, we fused plakophilin-1 to the hormone-binding domain of the estrogen receptor to create a fusion protein (plakophilin-1/ER) that can be activated in cell culture by the addition of 4-hydroxytamoxifen. When plakophilin-1/ER was expressed in A431 cells it was incorporated into endogenous desmosomes and did not disrupt desmosome formation. A derivative of A431 cells (A431D) do not form desmosomes, even though they express all the components believed to be necessary for desmosome assembly. Expression and activation of plakophilin-1/ER in A431D cells resulted in punctate desmoplakin staining on the cell surface. Co-expression of a classical cadherin (N-cadherin) and plakophilin-1/ER in A431D cells resulted in punctate desmoplakin staining at cell-cell borders. These data suggest that plakophilin-1 can induce assembly of desmosomal components in A431D cells in the absence of a classical cadherin; however a classical cadherin (N-cadherin) is required to direct assembly of desmosomes between adjacent cells. The activatable plakophilin-1/ER system provides a unique culture system to study the assembly of the desmosomal plaque in culture.
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Affiliation(s)
- James K Wahl
- University of Nebraska Medical Center, College of Dentistry, Department of Oral Biology and Nebraska Center for Cellular Signaling, Omaha, Nebraska 68198, USA.
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Kurzen H, Münzing I, Hartschuh W. Expression of desmosomal proteins in squamous cell carcinomas of the skin. J Cutan Pathol 2004; 30:621-30. [PMID: 14744087 DOI: 10.1034/j.1600-0560.2003.00122.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Desmosomal proteins are well established markers of epithelial differentiation. Down-regulation of desmosomal proteins has been suggested to be a sign of reduced adhesiveness in metastasizing cells. METHODS We examined actinic keratoses, Bowen's disease, and squamous cell carcinoma (SCC) of the skin for the expression of desmosomal proteins using isoform-specific antibodies on paraffin-embedded sections. Evaluation was performed qualitatively in comparison to the epidermis and semiquantitatively using an area-intensity-score. RESULTS We found no qualitative correlation of desmoplakin or plakoglobin expression with risk of metastasis. Plakophilin 1, desmoglein 1, and the desmocollins 1-3 were found to be heterogeneously expressed in all neoplasms without significant correlation to aggressive tumor behavior. Plakophilin 2 was not expressed in any of the neoplasms examined. As most striking finding, desmoglein 2 was up-regulated qualitatively in half of all neoplasms examined and showed a significant higher proportion of positive cells in high-risk SCC than in low-risk SCC. CONCLUSIONS Desmosomal proteins are highly regulated in cutaneous SCC. Only desmoglein 2 expression correlates with risk of metastasis. Desmosomes may still be functional in metastasizing tumor cells.
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Affiliation(s)
- Hjalmar Kurzen
- Department of Dermatology, University of Heidelberg, Heidelberg, Germany.
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Sprecher E, Molho-Pessach V, Ingber A, Sagi E, Indelman M, Bergman R. Homozygous splice site mutations in PKP1 result in loss of epidermal plakophilin 1 expression and underlie ectodermal dysplasia/skin fragility syndrome in two consanguineous families. J Invest Dermatol 2004; 122:647-51. [PMID: 15086548 DOI: 10.1111/j.0022-202x.2004.22335.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
During the last years, a growing number of inherited skin disorders have been recognized to be caused by abnormal function of desmosomal proteins. In the present study, we describe the first female individuals affected with the ectodermal dysplasia/skin fragility syndrome (MIM604536), a rare autosomal recessive disease due to mutations in the PKP1 gene encoding plakophilin 1, a critical component of desmosomal plaque. One patient was shown to carry a homozygous splice site mutation in intron 4. The second patient displayed a homozygous recurrent mutation affecting the acceptor splice site of intron 1. Both mutations were associated with intraepidermal separation, widening of intercellular spaces, and abnormal desmosome ultrastructure, and were found to result in the absence of immunoreactive plakophilin 1 in the epidermis of the affected individuals. These two cases emphasize the role of molecular genetics in the assessment of congenital blistering in newborns and illustrate the importance of proper desmosomal activity for normal epidermis development and function.
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Affiliation(s)
- Eli Sprecher
- Department of Dermatology and Laboratory of Molecular Dermatology, Rambam Medical Center, Haifa, Israel.
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Wan H, Dopping-Hepenstal PJC, Gratian MJ, Stone MG, McGrath JA, Eady RAJ. Desmosomes exhibit site-specific features in human palm skin. Exp Dermatol 2003; 12:378-88. [PMID: 12930293 DOI: 10.1034/j.1600-0625.2002.120404.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Hereditary skin disorders resulting from desmosome gene pathology may preferentially involve the palms and soles. Why this is so is not clear. Moreover, even in normal control skin it is unknown whether there are differences in desmosome number, size or structural organization in palmoplantar sites compared with skin from other body regions. Therefore, we sought evidence for such differences by examining desmosome expression in relation to epidermal differentiation in both epidermis and cultured keratinocytes from normal human palm and breast skin samples. Confocal microscopy of skin biopsy material showed relative differences in the expression profiles of several desmosomal proteins (desmogleins, desmocollins, desmoplakin, plakoglobin and plakophilin 1) between the two sites. Western blotting revealed a higher expression level of all five proteins in palm compared with breastcultured keratinocytes. Staining for the differentiation-associated component, involucrin, suggested an earlier onset of synthesis of this protein in palm epidermis, and a suspension-induced differentiation assay showed that involucrin synthesis began earlier in palm keratinocytes than in breast cells. At 4-8 h, the number of involucrin-positive cells in palm keratinocytes was almost twice that in breast. Morphometric analysis showed that, overall, desmosomes were larger but of similar population density in the palm compared with breast skin. These findings demonstrate differences in desmosome structure and protein expression between the two sites, possibly reflecting the needs of palms and soles to withstand constant mechanical stress. They may also help to explain the preferential involvement of this region in certain hereditary disorders (palmoplantar keratodermas), associated with mutations in desmoplakin or desmoglein 1.
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Affiliation(s)
- Hong Wan
- Department of Cell and Molecular Pathology, St John's Institute of Dermatology, London, UK
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44
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McMillan JR, Haftek M, Akiyama M, South AP, Perrot H, McGrath JA, Eady RAJ, Shimizu H. Alterations in desmosome size and number coincide with the loss of keratinocyte cohesion in skin with homozygous and heterozygous defects in the desmosomal protein plakophilin 1. J Invest Dermatol 2003; 121:96-103. [PMID: 12839569 DOI: 10.1046/j.1523-1747.2003.12324.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Recessive mutations in the desmosomal plaque protein plakophilin 1 (PkP1) underlie ectodermal dysplasia/skin fragility syndrome (MIM 604536). We undertook an immunohistochemical and quantitative electron microscopic examination of suprabasal desmosomes from 4 skin samples from 3 PkP1 deficient patients, an unaffected carrier with a PKP1 heterozygous acceptor splice site mutation and 5 healthy control subjects. Desmosomal plaque size (>50 desmosomes per individual) and frequency (>20 high power fields, HPF) were assessed. Compared with controls, desmosomes were reduced dramatically both in size (49%) and frequency (61%) in the lower suprabasal layers (LSB) in PkP1 null patients (P<0.01). In the LSB compartment of the heterozygous carrier, corresponding reductions were 37% and 20%, respectively (P<0.01). Surprisingly, the PkP1 null patient's upper suprabasal layer, (USB), desmosome size was larger (59%, P<0.01) than the control value, and showed increased desmoglein 1 and PkP2 USB staining. The USB desmosome frequency in PKP1 null patients was similar to the LSB compartment (but reduced by 43% compared to USB controls). The carrier showed no difference in the USB desmosome size and frequency compared with the controls (P>0.05). The PKP1 null patients showed poorly developed inner and outer desmosomal plaques. Thus, both the patients and unaffected carrier showed reductions in the LSB desmosome size and number; despite only PkP1 null patients exhibiting any phenotype. These findings attest to the molecular recruiting and stabilizing roles of PkP1 in desmosome formation, particularly in the LSB compartment.
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Affiliation(s)
- James R McMillan
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
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45
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Papagerakis S, Shabana AH, Depondt J, Gehanno P, Forest N. Immunohistochemical localization of plakophilins (PKP1, PKP2, PKP3, and p0071) in primary oropharyngeal tumors: correlation with clinical parameters. Hum Pathol 2003; 34:565-72. [PMID: 12827610 DOI: 10.1016/s0046-8177(03)00174-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Plakophilins (PKPs) are members of the armadillo multigene family. Armadillo-related proteins function in both cell adhesion and signal transduction, and also play a central role in tumorigenesis. Here we report the immunohistochemical localization of PKPs in 37 cases of human primary squamous cell carcinoma of the oropharynx lacking overt distant metastases that were followed clinically for 3 years. Immunoreactivity for the PKPs PKP1, PKP2, PKP3, and p0071 (also known as PKP4) was assessed on frozen unfixed sections using a semiquantitative scoring system. Results were correlated with tumor grade, clinicopathologic parameters, and patient survival. Only p0071 was associated with tumor growth, demonstrating an inverse correlation with tumor size. PKP1 and PKP3 immunoreactivity was inversely correlated with tumor histological grade and was observed only in tumors that did not metastasize. In contrast, strong PKP2 immunoreactivity was observed in 85.7% of metastatic tumors. Interestingly, patients with tumors in which PKP1 and PKP3 immunoreactivity was reduced or absent exhibited local recurrences or metastases, or both, as well as poor survival. Correlation of the subcellular localization of PKPs with routine histological and clinical parameters suggests that these proteins may serve as useful markers for predicting the clinical outcome of the disease. Although the 4 PKPs displayed different levels and patterns of subcellular distribution in tumors, there was a positive correlation between immunoreactivity for PKP2 and PKP3, as well as for PKP2 and p0071, suggesting possible functional similarities associated with differentiation, tumor growth, and disease prognosis. Nevertheless, the mechanisms involved in altering the subcellular localization in tumors compared with normal epithelium are unknown, and further investigation is needed to determine whether PKPs are causative factors for oral carcinogenesis or are merely characteristic of the phenotype.
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Chen X, Bonne S, Hatzfeld M, van Roy F, Green KJ. Protein binding and functional characterization of plakophilin 2. Evidence for its diverse roles in desmosomes and beta -catenin signaling. J Biol Chem 2002; 277:10512-22. [PMID: 11790773 DOI: 10.1074/jbc.m108765200] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plakophilins are a subfamily of p120-related arm-repeat proteins that can be found in both desmosomes and the nucleus. Among the three known plakophilin members, plakophilin 1 has been linked to a genetic skin disorder and shown to play important roles in desmosome assembly and organization. However, little is known about the binding partners and functions of the most widely expressed member, plakophilin 2. To better understand the cellular functions of plakophilin 2, we have examined its protein interactions with other junctional molecules using co-immunoprecipitation and yeast two-hybrid assays. Here we show that plakophilin 2 can interact directly with several desmosomal components, including desmoplakin, plakoglobin, desmoglein 1 and 2, and desmocollin 1a and 2a. The head domain of plakophilin 2 is critical for most of these interactions and is sufficient to direct plakophilin 2 to cell borders. In addition, plakophilin 2 is less efficient than plakophilin 1 in localizing to the nucleus and enhancing the recruitment of excess desmoplakin to cell borders in transiently transfected COS cells. Furthermore, plakophilin 2 is able to associate with beta-catenin through its head domain, and the expression of plakophilin 2 in SW480 cells up-regulates the endogenous beta-catenin/T cell factor-signaling activity. This up-regulation by plakophilin 2 is abolished by ectopic expression of E-cadherin, suggesting that these proteins compete for the same pool of signaling active beta-catenin. Our results demonstrate that plakophilin 2 interacts with a broader repertoire of desmosomal components than plakophilin 1 and provide new insight into the possible roles of plakophilin 2 in regulating the signaling activity of beta-catenin.
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Affiliation(s)
- Xinyu Chen
- Department of Pathology, Northwestern University Medical School, Chicago, Illinois 60611, USA
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Valéry C, Grob JJ, Verrando P. Identification by cDNA microarray technology of genes modulated by artificial ultraviolet radiation in normal human melanocytes: relation to melanocarcinogenesis. J Invest Dermatol 2001; 117:1471-82. [PMID: 11886511 DOI: 10.1046/j.0022-202x.2001.01607.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Target genes of ultraviolet stress response in cutaneous melanocytes, potentially associated with solar-induced melanocarcinogenesis, were characterized by cDNA microarray technology. In cultured normal human melanocytes, 198 genes out of approximately 9000 arrayed were found modulated > or = 1.9 times following artificial ultraviolet minus sign mainly ultraviolet-B minus sign irradiation (100 mJ per cm(2)). Among them, 159 corresponded to known sequences, the encoded proteins being mostly involved in DNA or RNA binding/synthesis/modification, or ribosomal proteins. The others were transcription factors, receptors, tumor suppressors, and (proto)oncogenes. Members of these families have already been linked to melanoma. In addition, some of the modulated genes were borne by chromosomes harboring candidate melanoma loci. Comparisons with genes modified in melanoma samples reported in previous studies with similar microarray platform showed that 59% of the known genes sensitive to ultraviolet were modulated in the same way. Furthermore, 39 expressed sequence tags were modulated, and preliminary experiments showed that two expressed sequence tags displayed differential expressions both in melanoma cell lines and in melanoma tumors. These results provide a basis for further studies on the role of modulated genes in ultraviolet-induced melanoma. Because some of these genes are potential markers of the disease, they might help for developing new molecular-based strategies for risk prediction in patients.
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Affiliation(s)
- C Valéry
- Laboratoire d'Investigation des Maladies de la Peau, LIMP -- Université de la Méditerranée, Marseille, France
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48
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Abstract
The ectodermal dysplasias (EDs) are a large and complex nosological group of diseases, first described by Thurnam in 1848. In the last 10 years more than 170 different pathological clinical conditions have been recognised and defined as EDs, all sharing in common anomalies of the hair, teeth, nails, and sweat glands. Many are associated with anomalies in other organs and systems and, in some conditions, with mental retardation.The anomalies affecting the epidermis and epidermal appendages are extremely variable and clinical overlap is present among the majority of EDs. Most EDs are defined by particular clinical signs (for example, eyelid adhesion in AEC syndrome, ectrodactyly in EEC). To date, few causative genes have been identified for these diseases. We recently reviewed genes known to be responsible for EDs in light of their molecular and biological function and proposed a new approach to EDs, integrating both molecular-genetic data and corresponding clinical findings. Based on our previous report, we now propose a clinical-genetic classification of EDs, expand it to other entities in which no causative genes have been identified based on the phenotype, and speculate on possible candidate genes suggested by associated "non-ectodermal" features.
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Affiliation(s)
- M Priolo
- Operative Unit of Medical Genetics, Azienda Ospedaliera Bianchi-Melacrino- Morelli, Via Melacrino, 89100 Reggio Calabria, Italy.
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49
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Affiliation(s)
- E Cozzani
- Institute of Dermatology, University of Genoa, Genoa, Italy
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50
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Shi Y, Simmons MN, Seki T, Oh SP, Sugrue SP. Change in gene expression subsequent to induction of Pnn/DRS/memA: increase in p21(cip1/waf1). Oncogene 2001; 20:4007-18. [PMID: 11494129 DOI: 10.1038/sj.onc.1204507] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2000] [Revised: 03/29/2001] [Accepted: 04/04/2001] [Indexed: 12/26/2022]
Abstract
Pnn (PNN) is a nuclear and cell adhesion-related protein. Previous work has suggested that Pnn/DRS/memA is a potential tumor suppressor involved in the regulation of cell adhesion and cell migration. Using the ecdysone-inducible mammalian expression system, a stable inducible GFP-tagged human Pnn gene (PNNGFP) expressing 293 cell line was created (EcR293-PNNGFP). Cells induced to express PNNGFP not only exhibited increased cell-cell adhesion but also exhibited changes in cell growth and cell cycle progression. cDNA array analyses, together with real time PCR, revealed that the effects of exogenously expressed Pnn on cellular behavior may be linked to the regulation of the expression of specific subset genes. This subset includes cell cycle-related genes such as p21(cip1/waf1), CDK4, CPR2; cell migration and invasion regulatory genes such as RhoA, CDK5, TIMP-1, MMP-7, and EMMPRIN; and MIC-1. Concordant with previous observations of Pnn-induced phenotype changes, genes coding for epithelial associated processes and cell division controls were elevated, while those coding for increased cell motility and cellular reorganizations were downregulated. We utilized p21 promoter-luciferase reporter constructs and demonstrated that a marked stimulation of p21 promoter activity in 293 cells correlated with increased Pnn expression. Taken together, these data indicate that Pnn may participate in the regulation of gene expression, thereby, positively promoting cell-cell adhesion, and negatively affecting cell migration and cell proliferation.
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Affiliation(s)
- Y Shi
- Department of Anatomy and Cell Biology, University of Florida College of Medicine, Archer Road, Gainesville, Florida, FL 32610-0235, USA
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