scholarly journals Early Events in Actin Cytoskeleton Dynamics and E-Cadherin-Mediated Cell-Cell Adhesion during Epithelial-Mesenchymal Transition

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 578 ◽  
Author(s):  
Irina Y. Zhitnyak ◽  
Svetlana N. Rubtsova ◽  
Nikita I. Litovka ◽  
Natalya A. Gloushankova
Keyword(s):  
Cell Adhesion ◽  
Epithelial Mesenchymal Transition ◽  
Immunofluorescent Staining ◽  
Actin Binding ◽  
Mesenchymal Transition ◽  
Actin Bundle ◽  
Cell Contacts ◽  
The Stability ◽  
E Cadherin ◽  
Cell Cell

Epithelial-mesenchymal transition (EMT) plays an important role in development and also in initiation of metastasis during cancer. Disruption of cell-cell contacts during EMT allowing cells to detach from and migrate away from their neighbors remains poorly understood. Using immunofluorescent staining and live-cell imaging, we analyzed early events during EMT induced by epidermal growth factor (EGF) in IAR-20 normal epithelial cells. Control cells demonstrated stable adherens junctions (AJs) and robust contact paralysis, whereas addition of EGF caused rapid dynamic changes at the cell-cell boundaries: fragmentation of the circumferential actin bundle, assembly of actin network in lamellipodia, and retrograde flow. Simultaneously, an actin-binding protein EPLIN was phosphorylated, which may have decreased the stability of the circumferential actin bundle. Addition of EGF caused gradual replacement of linear E-cadherin–based AJs with dynamic and unstable punctate AJs, which, unlike linear AJs, colocalized with the mechanosensitive protein zyxin, confirming generation of centripetal force at the sites of cell-cell contacts during EMT. Our data show that early EMT promotes heightened dynamics at the cell-cell boundaries—replacement of stable AJs and actin structures with dynamic ones—which results in overall weakening of cell-cell adhesion, thus priming the cells for front-rear polarization and eventual migration.

scholarly journals INDUCTION OF EPITHELIAL-TO-MESENCHYMAL TRANSITION IN MCF-7-SNAI1 CELLS LEADS TO REORGANIZATION OF ADHERENS JUNCTIONS AND ACQUISITION OF MIGRATORY ACTIVITY

2018 ◽  
Vol 17 (4) ◽  
pp. 24-29
Author(s):  
I. Y. Zhitnyak ◽  
N. I. Litovka ◽  
S. N. Rubtsova ◽  
N. A. Gloushankova
Keyword(s):  
Cell Adhesion ◽  
Culture Medium ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Mesenchymal Phenotype ◽  
Mesenchymal Transition ◽  
Migratory Activity ◽  
Mcf 7 ◽  
E Cadherin ◽  
Cell Cell

Using DIC and confocal microscopy, changes in morphology, migratory characteristics and adherence junctions (AJs) were analyzed in the mammary carcinoma cell line MCF-7-SNAI1  after activation of the EMT transcription factor SNAI1. Western Blot analysis showed that  after removal of tetracycline from the cell culture medium expression of SNAI1 reached its  peak in 24 hours and then plateaued for 7 days. During the 7 days the cells continued to  express E-cadherin; however, tangential AJs typical for cells with stable cell-cell adhesion,  changed into radial AJs. The radial AJs continued to accumulate E-cadherin during 24‑72  hours after tetracycline removal. As a result of SNAI1 activation, the cells underwent  epithelial-mesenchymal transition (EMT) and became migratory. On a two-dimensional  substrate, cells exhibited both individual and collective migration. As the tetracycline  washout period progressed, the fraction of the cells capable of migrating through migration chamber membranes increased; on the contrary, cells’ ability to invade an epithelial  monolayer decreased. These results demonstrate that retaining a hybrid epithelial/mesenchymal  phenotype and accumulation of E-cadherin in AJs during early stages of EMT do not impede  disruption of stable cell-cell adhesion and cells’ acquisition of migratory activity.

scholarly journals Role of Cadherins in Cancer—A Review

2020 ◽  
Vol 21 (20) ◽  
pp. 7624
Author(s):  
Ilona Kaszak ◽  
Olga Witkowska-Piłaszewicz ◽  
Zuzanna Niewiadomska ◽  
Bożena Dworecka-Kaszak ◽  
Felix Ngosa Toka ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Tumor Progression ◽  
Signaling Pathways ◽  
Rho Gtpases ◽  
Epithelial Mesenchymal Transition ◽  
Clinical Importance ◽  
Mesenchymal Transition ◽  
E Cadherin ◽  
Cell Cell

Cadherins play an important role in tissue homeostasis, as they are responsible for cell-cell adhesion during embryogenesis, tissue morphogenesis, differentiation and carcinogenesis. Cadherins are inseparably connected with catenins, forming cadherin-catenin complexes, which are crucial for cell-to-cell adherence. Any dysfunction or destabilization of cadherin-catenin complex may result in tumor progression. Epithelial mesenchymal transition (EMT) is a mechanism in which epithelial cadherin (E-cadherin) expression is lost during tumor progression. However, during tumorigenesis, many processes take place, and downregulation of E-cadherin, nuclear β-catenin and p120 catenin (p120) signaling are among the most critical. Additional signaling pathways, such as Receptor tyrosine kinase (RTK), Rho GTPases, phosphoinositide 3-kinase (PI3K) and Hippo affect cadherin cell-cell adhesion and also contribute to tumor progression and metastasis. Many signaling pathways may be activated during tumorigenesis; thus, cadherin-targeting drugs seem to limit the progression of malignant tumor. This review discusses the role of cadherins in selected signaling mechanisms involved in tumor growth. The clinical importance of cadherin will be discussed in cases of human and animal cancers.

scholarly journals E-cadherin represses anchorage-independent growth in sarcomas through both signaling and mechanical mechanisms

2018 ◽  
Author(s):  
Mohit Kumar Jolly ◽  
Kathryn E Ware ◽  
Shengnan Xu ◽  
Shivee Gilja ◽  
Samantha Shetler ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Intracellular Signaling ◽  
Epithelial Mesenchymal Transition ◽  
Migration And Invasion ◽  
Specific Cell ◽  
Mesenchymal Transition ◽  
Anchorage Independent Growth ◽  
Sarcoma Cells ◽  
E Cadherin ◽  
Cell Cell

E-cadherin, an epithelial-specific cell-cell adhesion molecule, plays multiple roles in maintaining adherens junctions, regulating migration and invasion, and mediating intracellular signaling. Downregulation of E-cadherin is a hallmark of epithelial-mesenchymal transition (EMT) and correlates with poor prognosis in multiple carcinomas. Conversely, upregulation of E-cadherin is prognostic for improved survival in sarcomas. Yet, despite the prognostic benefit of E-cadherin expression in sarcoma, the mechanistic significance of E-cadherin in sarcomas remains poorly understood. Here, by combining mathematical models with wet-bench experiments, we identify the core regulatory networks mediated by E-cadherin in sarcomas, and decipher their functional consequences. Unlike in carcinomas, E-cadherin overexpression in sarcomas does not induce a mesenchymal-epithelial transition (MET). However, E-cadherin acts to reduce both anchorage-independent growth and spheroid formation of sarcoma cells. Ectopic E-cadherin expression acts to downregulate phosphorylated CREB (p-CREB) and the transcription factor, TBX2, to inhibit anchorage-independent growth. RNAi-mediated knockdown of TBX2 phenocopies the effect of E-cadherin on p-CREB levels and restores sensitivity to anchorage-independent growth in sarcoma cells. Beyond its signaling role, E-cadherin expression in sarcoma cells can also strengthen cell-cell adhesion and restricts spheroid growth through mechanical action. Together, our results demonstrate that E-cadherin inhibits sarcoma aggressiveness by preventing anchorage-independent growth.

scholarly journals A molecular mechanism directly linking E-cadherin adhesion to initiation of epithelial cell surface polarity

2007 ◽  
Vol 178 (2) ◽  
pp. 323-335 ◽  
Author(s):  
Lene N. Nejsum ◽  
W. James Nelson
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cell ◽  
Cell Surface ◽  
Basolateral Membrane ◽  
Surface Polarity ◽  
Cell Contacts ◽  
Protein Receptors ◽  
Epithelial Cell Surface ◽  
E Cadherin ◽  
Cell Cell

Mechanisms involved in maintaining plasma membrane domains in fully polarized epithelial cells are known, but when and how directed protein sorting and trafficking occur to initiate cell surface polarity are not. We tested whether establishment of the basolateral membrane domain and E-cadherin–mediated epithelial cell–cell adhesion are mechanistically linked. We show that the basolateral membrane aquaporin (AQP)-3, but not the equivalent apical membrane AQP5, is delivered in post-Golgi structures directly to forming cell–cell contacts where it co-accumulates precisely with E-cadherin. Functional disruption of individual components of a putative lateral targeting patch (e.g., microtubules, the exocyst, and soluble N-ethylmaleimide–sensitive factor attachment protein receptors) did not inhibit cell–cell adhesion or colocalization of the other components with E-cadherin, but each blocked AQP3 delivery to forming cell–cell contacts. Thus, components of the lateral targeting patch localize independently of each other to cell–cell contacts but collectively function as a holocomplex to specify basolateral vesicle delivery to nascent cell–cell contacts and immediately initiate cell surface polarity.

Aquaporin-5 regulation of cell-cell adhesion proteins: an elusive "tail" story

2020 ◽  
Author(s):  
Frédéric H. Login ◽  
Johan Palmfeldt ◽  
Joleen Cheah ◽  
Soichiro Yamada ◽  
Lene N. Nejsum
Keyword(s):  
Cell Adhesion ◽  
Water Transport ◽  
Epithelial Mesenchymal Transition ◽  
Tail Domain ◽  
Aquaporin 5 ◽  
Mesenchymal Transition ◽  
Cancer Spread ◽  
Aqp5 Expression ◽  
Migration Capacity ◽  
Cell Cell

Aquaporins (AQPs) are water channels that facilitate transport of water across cellular membranes. AQPs are overexpressed in several cancers. Especially in breast cancer, AQP5 overexpression correlates with spread to lymph nodes and poor prognosis. Previously, we showed that AQP5 expression reduced cell-cell adhesion by reducing levels of adherens and tight junction proteins (e.g., ZO1, plakoglobin and β-catenin) at the actual junctions. Here, we show that when targeted to the plasma membrane, the AQP5 C-terminal tail domain regulated junctional proteins. Moreover, that AQP5 interacted with ZO1, plakoglobin, β-catenin and desmoglein-2, which were all reduced at junctions upon AQP5 overexpression. Thus, our data suggest that AQP5 mediates the effect on cell-cell adhesion via interactions with junctional protein independently of AQP5 mediated water transport. AQP5 overexpression in cancers may thus contribute to carcinogenesis and cancer spread by two independent mechanisms: reduced cell-cell adhesion, a characteristic of epithelial-mesenchymal transition, and increased cell migration capacity via water transport.

scholarly journals Dual roles of myocardin-related transcription factors in epithelial–mesenchymal transition via slug induction and actin remodeling

2007 ◽  
Vol 179 (5) ◽  
pp. 1027-1042 ◽  
Author(s):  
Tsuyoshi Morita ◽  
Taira Mayanagi ◽  
Kenji Sobue
Keyword(s):  
Transcription Factors ◽  
Actin Cytoskeleton ◽  
Nuclear Translocation ◽  
Epithelial Mesenchymal Transition ◽  
Ectopic Expression ◽  
Cytoskeletal Proteins ◽  
Mesenchymal Transition ◽  
Cell Contacts ◽  
Tgf Β1 ◽  
Cell Cell

Epithelial–mesenchymal transition (EMT) is a critical process occurring during embryonic development and in fibrosis and tumor progression. Dissociation of cell–cell contacts and remodeling of the actin cytoskeleton are major events of the EMT. Here, we show that myocardin-related transcription factors (MRTFs; also known as MAL and MKL) are critical mediators of transforming growth factor β (TGF-β) 1–induced EMT. In all epithelial cell lines examined here, TGF-β1 triggers the nuclear translocation of MRTFs. Ectopic expression of constitutive-active MRTF-A induces EMT, whereas dominant-negative MRTF-A or knockdown of MRTF-A and -B prevents the TGF-β1–induced EMT. MRTFs form complexes with Smad3. Via Smad3, the MRTF–Smad3 complexes bind to a newly identified cis-element GCCG-like motif in the promoter region of Canis familiaris and the human slug gene, which activates slug transcription and thereby dissociation of cell–cell contacts. MRTFs also increase the expression levels of actin cytoskeletal proteins via serum response factor, thereby triggering reorganization of the actin cytoskeleton. Thus, MRTFs are important mediators of TGF-β1–induced EMT.

scholarly journals Immediate and Delayed Effects of E-Cadherin Inhibition on Gene Regulation and Cell Motility in Human Epidermoid Carcinoma Cells

2005 ◽  
Vol 25 (20) ◽  
pp. 9138-9150 ◽  
Author(s):  
Henriette Andersen ◽  
Jakob Mejlvang ◽  
Shaukat Mahmood ◽  
Irina Gromova ◽  
Pavel Gromov ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Motility ◽  
Family Members ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Short Term ◽  
Mesenchymal Transition ◽  
Negative Mutant ◽  
E Cadherin ◽  
Cell Cell

ABSTRACT The invasion suppressor protein, E-cadherin, plays a central role in epithelial cell-cell adhesion. Loss of E-cadherin expression or function in various tumors of epithelial origin is associated with a more invasive phenotype. In this study, by expressing a dominant-negative mutant of E-cadherin (Ec1WVM) in A431 cells, we demonstrated that specific inhibition of E-cadherin-dependent cell-cell adhesion led to the genetic reprogramming of tumor cells. In particular, prolonged inhibition of cell-cell adhesion activated expression of vimentin and repressed cytokeratins, suggesting that the effects of Ec1WVM can be classified as epithelial-mesenchymal transition. Both short-term and prolonged expression of Ec1WVM resulted in morphological transformation and increased cell migration though to different extents. Short-term expression of Ec1WVM up-regulated two AP-1 family members, c-jun and fra-1, but was insufficient to induce complete mesenchymal transition. AP-1 activity induced by the short-term expression of Ec1WVM was required for transcriptional up-regulation of AP-1 family members and down-regulation of two other Ec1WVM-responsive genes, S100A4 and igfbp-3. Using a dominant-negative mutant of c-Jun (TAM67) and RNA interference-mediated silencing of c-Jun and Fra-1, we demonstrated that AP-1 was required for cell motility stimulated by the expression of Ec1WVM. In contrast, Ec1WVM-mediated changes in cell morphology were AP-1-independent. Our data suggest that mesenchymal transition induced by prolonged functional inhibition of E-cadherin is a slow and gradual process. At the initial step of this process, Ec1WVM triggers a positive autoregulatory mechanism that increases AP-1 activity. Activated AP-1 in turn contributes to Ec1WVM-mediated effects on gene expression and tumor cell motility. These data provide novel insight into the tumor suppressor function of E-cadherin.

scholarly journals RAC1 Regulates Adherens Junctions through Endocytosis of E-Cadherin

2001 ◽  
Vol 12 (4) ◽  
pp. 847-862 ◽  
Author(s):  
Nasreen Akhtar ◽  
Neil A. Hotchin
Keyword(s):  
Cell Adhesion ◽  
Fluorescent Protein ◽  
Adherens Junctions ◽  
Expression Vectors ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Cell Contacts ◽  
Green Fluorescent ◽  
E Cadherin ◽  
Cell Cell

The establishment of cadherin-dependent cell–cell contacts in human epidermal keratinocytes are known to be regulated by the Rac1 small GTP-binding protein, although the mechanisms by which Rac1 participates in the assembly or disruption of cell–cell adhesion are not well understood. In this study we utilized green fluorescent protein (GFP)-tagged Rac1 expression vectors to examine the subcellular distribution of Rac1 and its effects on E-cadherin–mediated cell–cell adhesion. Microinjection of keratinocytes with constitutively active Rac1 resulted in cell spreading and disruption of cell–cell contacts. The ability of Rac1 to disrupt cell–cell adhesion was dependent on colony size, with large established colonies being resistant to the effects of active Rac1. Disruption of cell–cell contacts in small preconfluent colonies was achieved through the selective recruitment of E-cadherin–catenin complexes to the perimeter of multiple large intracellular vesicles, which were bounded by GFP-tagged L61Rac1. Similar vesicles were observed in noninjected keratinocytes when cell–cell adhesion was disrupted by removal of extracellular calcium or with the use of an E-cadherin blocking antibody. Moreover, formation of these structures in noninjected keratinocytes was dependent on endogenous Rac1 activity. Expression of GFP-tagged effector mutants of Rac1 in keratinocytes demonstrated that reorganization of the actin cytoskeleton was important for vesicle formation. Characterization of these Rac1-induced vesicles revealed that they were endosomal in nature and tightly colocalized with the transferrin receptor, a marker for recycling endosomes. Expression of GFP-L61Rac1 inhibited uptake of transferrin-biotin, suggesting that the endocytosis of E-cadherin was a clathrin-independent mechanism. This was supported by the observation that caveolin, but not clathrin, localized around these structures. Furthermore, an inhibitory form of dynamin, known to inhibit internalization of caveolae, inhibited formation of cadherin vesicles. Our data suggest that Rac1 regulates adherens junctions via clathrin independent endocytosis of E-cadherin.

scholarly journals Claudins and Gastric Cancer: An Overview

Cancers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 290
Author(s):  
Itaru Hashimoto ◽  
Takashi Oshima
Keyword(s):  
Gastric Cancer ◽  
Cell Adhesion ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Treatment Strategies ◽  
The Cancer Genome Atlas ◽  
Therapeutic Drug ◽  
Mesenchymal Transition ◽  
New Treatment ◽  
Cell Cell

Despite recent improvements in diagnostic ability and treatment strategies, advanced gastric cancer (GC) has a high frequency of recurrence and metastasis, with poor prognosis. To improve the treatment results of GC, the search for new treatment targets from proteins related to epithelial–mesenchymal transition (EMT) and cell–cell adhesion is currently being conducted. EMT plays an important role in cancer metastasis and is initiated by the loss of cell–cell adhesion, such as tight junctions (TJs), adherens junctions, desmosomes, and gap junctions. Among these, claudins (CLDNs) are highly expressed in some cancers, including GC. Abnormal expression of CLDN1, CLDN2, CLDN3, CLDN4, CLDN6, CLDN7, CLDN10, CLDN11, CLDN14, CLDN17, CLDN18, and CLDN23 have been reported. Among these, CLDN18 is of particular interest. In The Cancer Genome Atlas, GC was classified into four new molecular subtypes, and CLDN18–ARHGAP fusion was observed in the genomically stable type. An anti-CLDN18.2 antibody drug was recently developed as a therapeutic drug for GC, and the results of clinical trials are highly predictable. Thus, CLDNs are highly expressed in GC as TJs and are expected targets for new antibody drugs. Herein, we review the literature on CLDNs, focusing on CLDN18 in GC.

scholarly journals Glycosyltransferase POMGNT1 deficiency affects N-cadherin-mediated cell-cell adhesion

2020 ◽  
Author(s):  
Sina Ibne Noor ◽  
Marcus Hoffmann ◽  
Natalie Rinis ◽  
Markus F. Bartels ◽  
Patrick Winterhalter ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Adhesion ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Clinical Symptoms ◽  
Adhesion Properties ◽  
Knock Out ◽  
Mesenchymal Transition ◽  
Transcriptional Changes ◽  
Cell Cell

AbstractDefects in protein O-mannosylation lead to severe congenital muscular dystrophies known as α-dystroglycanopathy. A hallmark of these diseases is the loss of the O-mannose-bound matriglycan on α-dystroglycan, which leads to a reduction in cell adhesion to the extracellular matrix. Mutations in protein O-mannose β1,2-N-acetylglucosaminyltransferase 1 (POMGNT1), which is crucial for the elongation of O-mannosyl glycans, are mainly associated with muscle-eye-brain (MEB) disease. In addition to defects in cell-extracellular matrix adhesion, aberrant cell-cell adhesion has occasionally been observed in response to defects in POMGNT1. However, direct molecular mechanisms are largely unknown. We used POMGNT1 knock-out HEK293T cells and fibroblasts from a MEB patient to gain a deeper insight into the molecular changes in POMGNT1 deficiency. A combination of biochemical and molecular biological techniques with proteomics, glycoproteomics and glycomics revealed that a lack of POMGNT1 activity strengthens cell-cell adhesion. We demonstrate that the altered intrinsic adhesion properties are due to an increased abundance of N-cadherin (N-Cdh). In addition, site-specific changes in the N-glycan structures in the extracellular domain of N-Cdh were detected, which positively impact on homotypic interactions. We found that in POMGNT1 deficient cells ERK1/2 and p38 signaling pathways are activated and transcriptional changes that are comparable to the epithelial-mesenchymal transition (EMT) are triggered, defining a possible molecular mechanism underlying the observed phenotype. Our study indicates that changes in cadherin-mediated cell-cell adhesion and other EMT-related processes may contribute to the complex clinical symptoms of MEB or α-dystroglycanopathy in general, and suggests a previously underestimated impact of changes in O-mannosylation on N-glycosylation.

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