scholarly journals A mechanism for inhibition of E-cadherin-mediated cell-cell adhesion by the membrane-associated mucin episialin/MUC1.

1996 ◽  
Vol 7 (4) ◽  
pp. 565-577 ◽  
Author(s):  
J Wesseling ◽  
S W van der Valk ◽  
J Hilkens

Episialin (MUC1, PEM, EMA, CA15-3 antigen) is a sialylated, membrane-associated glycoprotein with an extended mucin-like ectodomain. This domain mainly consists of 30-90 homologous 20-amino acid repeats that are rich in O-glycosylation sites (serines and threonines). It is likely that this part forms a polyproline beta-turn helix. As a result, the ectodomain can protrude more than 200 nm above the cell surface, whereas most cell surface molecules do not exceed a length of 35 nm. Normally, episialin is present at the apical side of glandular epithelial cells. On carcinoma cells, however, it can be strongly overexpressed and it is often present over the entire cell surface. We have previously shown that episialin, if it is interspersed between adhesion molecules, nonspecifically reduces cell-cell and cell-extracellular matrix interactions in vitro and in vivo, presumably by steric hindrance caused by the extreme length and high density of the episialin molecules at the cell surface. To analyze the molecular mechanism for this anti-adhesion effect in more detail, we have now deleted an increasing number of repeats in the episialin cDNA and transfected the resulting mutants into murine L929 cells expressing the homophilic adhesion molecule E-cadherin. Here we show that the length of episialin is the dominant factor that determines the inhibition of E-cadherin-mediated cell-cell interactions. For the anti-adhesive effect mediated by the full length episialin, charge repulsion by negatively charged sialylated O-linked glycans is far less important.

1998 ◽  
Vol 111 (9) ◽  
pp. 1305-1318 ◽  
Author(s):  
S.M. Norvell ◽  
K.J. Green

The integrity of cell-cell junctions in epithelial cells depends on functional interactions of both extracellular and intracellular domains of cadherins with other junction proteins. To examine the roles of the different domains of E-cadherin and desmoglein in epithelial junctions, we stably expressed full length desmoglein 1 and chimeras of E-cadherin and desmoglein 1 in A431 epithelial cells. Full length desmoglein 1 was able to incorporate into or disrupt endogenous desmosomes depending on expression level. Each of the chimeric cadherin molecules exhibited distinct localization patterns at the cell surface. A chimera of the desmoglein 1 extracellular domain and the E-cadherin intracellular domain was distributed diffusely at the cell surface while the reverse chimera, comprising the E-cadherin extracellular domain and the desmoglein 1 intracellular domain, localized in large, sometimes contiguous patches at cell-cell interfaces. Nevertheless, both constructs disrupted desmosome assembly. Expression of constructs containing the desmoglein 1 cytoplasmic domain resulted in approximately a 3-fold decrease in E-cadherin bound to plakoglobin and a 5- to 10-fold reduction in the steady-state levels of the endogenous desmosomal cadherins, desmoglein 2 and desmocollin 2, possibly contributing to the dominant negative effect of the desmoglein 1 tail. In addition, biochemical analysis of protein complexes in the stable lines revealed novel in vivo protein interactions. Complexes containing beta-catenin and desmoglein 1 were identified in cells expressing constructs containing the desmoglein 1 tail. Furthermore, interactions were identified between endogenous E-cadherin and the chimera containing the E-cadherin extracellular domain and the desmoglein 1 intracellular domain providing in vivo evidence for previously predicted lateral interactions of E-cadherin extracellular domains.


2000 ◽  
Vol 349 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Yutaka SHIMOYAMA ◽  
Gozoh TSUJIMOTO ◽  
Masaki KITAJIMA ◽  
Michiya NATORI

We identified three novel human type-II classic cadherins, cadherin-7, -9 and -10, by cDNA cloning and sequencing, and confirmed that they interact with catenins and function in cell-cell adhesion as do other classic cadherins. Cell-cell binding activities of the eight human type-II classic cadherins, including the three new molecules, were evaluated by long-term cell-aggregation experiments using mouse L fibroblast clones transfected with the individual cadherins. The experiments indicated that all the type-II cadherins appeared to possess similar binding strength, which was virtually equivalent to that of E-cadherin. We next examined the binding specificities of the type-II cadherins using the mixed cell-aggregation assay. Although all of the type-II cadherins exhibited binding specificities distinct from that of E-cadherin, heterophilic interactions ranging from incomplete to complete were frequently observed among them. The combinations of cadherin-6 and -9, cadherin-7 and -14, cadherin-8 and -11, and cadherin-9 and -10 interacted in a complete manner, and in particular cadherin-7 and -14, and cadherin-8 and -11 showed an indistinguishable binding specificity against other cadherin subclasses, at least in this assay system. Although these data were obtained from an in vitro study, they should be useful for understanding cadherin-mediated mechanisms of development, morphogenesis and cell-cell interactions in vivo.


1998 ◽  
Vol 9 (11) ◽  
pp. 3161-3177 ◽  
Author(s):  
Peter A. Piepenhagen ◽  
W. James Nelson

Organization of proteins into structurally and functionally distinct plasma membrane domains is an essential characteristic of polarized epithelial cells. Based on studies with cultured kidney cells, we have hypothesized that a mechanism for restricting Na/K-ATPase to the basal-lateral membrane involves E-cadherin–mediated cell–cell adhesion and integration of Na/K-ATPase into the Triton X-100–insoluble ankyrin- and spectrin-based membrane cytoskeleton. In this study, we examined the relevance of these in vitro observations to the generation of epithelial cell polarity in vivo during mouse kidney development. Using differential detergent extraction, immunoblotting, and immunofluorescence histochemistry, we demonstrate the following. First, expression of the 220-kDa splice variant of ankyrin-3 correlates with the development of resistance to Triton X-100 extraction for Na/K-ATPase, E-cadherin, and catenins and precedes maximal accumulation of Na/K-ATPase. Second, expression of the 190-kDa slice variant of ankyrin-3 correlates with maximal accumulation of Na/K-ATPase. Third, Na/K-ATPase, ankyrin-3, and fodrin specifically colocalize at the basal-lateral plasma membrane of all epithelial cells in which they are expressed and during all stages of nephrogenesis. Fourth, the relative immunofluorescence staining intensities of Na/K-ATPase, ankyrin-3, and fodrin become more similar during development until they are essentially identical in adult kidney. Thus, renal epithelial cells in vivo regulate the accumulation of E-cadherin–mediated adherens junctions, the membrane cytoskeleton, and Na/K-ATPase through sequential protein expression and assembly on the basal-lateral membrane. These results are consistent with a mechanism in which generation and maintenance of polarized distributions of these proteins in vivo and in vitro involve cell–cell adhesion, assembly of the membrane cytoskeleton complex, and concomitant integration and retention of Na/K-ATPase in this complex.


Blood ◽  
2003 ◽  
Vol 102 (6) ◽  
pp. 2173-2179 ◽  
Author(s):  
Martha J. James ◽  
Lavina Belaramani ◽  
Kanella Prodromidou ◽  
Arpita Datta ◽  
Sussan Nourshargh ◽  
...  

Abstract Due to their ability to inhibit antigen-induced T-cell activation in vitro and in vivo, anergic T cells can be considered part of the spectrum of immunoregulatory T lymphocytes. Here we report that both murine and human anergic T cells can impair the ability of parenchymal cells (including endothelial and epithelial cells) to establish cell-cell interactions necessary to sustain leukocyte migration in vitro and tissue infiltration in vivo. The inhibition is reversible and cell-contact dependent but does not require cognate recognition of the parenchymal cells to occur. Instrumental to this effect is the increased cell surface expression and enzymatic activity of molecules such as CD26 (dipeptidyl-peptidase IV), which may act by metabolizing chemoattractants bound to the endothelial/epithelial cell surface. These results describe a previously unknown antigen-independent anti-inflammatory activity by locally generated anergic T cells and define a novel mechanism for the long-known immunoregulatory properties of these cells.


1994 ◽  
Vol 125 (2) ◽  
pp. 313-320 ◽  
Author(s):  
T Crepaldi ◽  
A L Pollack ◽  
M Prat ◽  
A Zborek ◽  
K Mostov ◽  
...  

Scatter Factor, also known as Hepatocyte Growth Factor (SF/HGF), has pleiotropic functions including direct control of cell-cell and cell-substrate adhesion in epithelia. The subcellular localization of the SF/HGF receptor is controversial. In this work, the cell surface distribution of the SF/HGF receptor was studied in vivo in epithelial tissues and in vitro in polarized MDCK monolayers. A panel of monoclonal antibodies against the beta chain of the SF/HGF receptor stained the basolateral but not the apical surface of epithelia lining the lumen of human organs. Radiolabeled or fluorescent-tagged anti-receptor antibodies selectively bound the basolateral cell surface of MDCK cells, which form a polarized monolayer sealed by intercellular junctions, when grown on polycarbonate filters in a two-chamber culture system. The receptor was concentrated around the cell-cell contact zone, showing a distribution pattern overlapping with that of the cell adhesion molecule E-cadherin. The basolateral localization of the SF/HGF receptor was confirmed by immunoprecipitation after domain selective cell surface biotinylation. When cells were fully polarized the SF/HGF receptor became resistant to non-ionic detergents, indicating interaction with insoluble component(s). In pulse-chase labeling and surface biotinylation experiments, the newly synthesized receptor was found exclusively at the basolateral surface. We conclude that the SF/HGF receptor is selectively exposed at the basolateral plasma membrane domain of polarized epithelial cells and is targeted after synthesis to that surface by direct delivery from the trans-Golgi network.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Chun Cheng ◽  
Jun Yang ◽  
Si-Wei Li ◽  
Guofu Huang ◽  
Chenxi Li ◽  
...  

AbstractHistone deacetylases (HDACs) are involved in tumor progression, and some have been successfully targeted for cancer therapy. The expression of histone deacetylase 4 (HDAC4), a class IIa HDAC, was upregulated in our previous microarray screen. However, the role of HDAC4 dysregulation and mechanisms underlying tumor growth and metastasis in nasopharyngeal carcinoma (NPC) remain elusive. Here, we first confirmed that the HDAC4 levels in primary and metastatic NPC tissues were significantly increased compared with those in normal nasopharyngeal epithelial tissues and found that high HDAC4 expression predicted a poor overall survival (OS) and progression-free survival (PFS). Functionally, HDAC4 accelerated cell cycle G1/S transition and induced the epithelial-to-mesenchymal transition to promote NPC cell proliferation, migration, and invasion in vitro, as well as tumor growth and lung metastasis in vivo. Intriguingly, knockdown of N-CoR abolished the effects of HDAC4 on the invasion and migration abilities of NPC cells. Mechanistically, HDAC3/4 binds to the E-cadherin promoter to repress E-cadherin transcription. We also showed that the HDAC4 inhibitor tasquinimod suppresses tumor growth in NPC. Thus, HDAC4 may be a potential diagnostic marker and therapeutic target in patients with NPC.


2021 ◽  
Vol 15 (1) ◽  
pp. 1-17
Author(s):  
Sarah Alsharif ◽  
Pooja Sharma ◽  
Karina Bursch ◽  
Rachel Milliken ◽  
Van Lam ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji-wen Cheng ◽  
Li-xia Duan ◽  
Yang Yu ◽  
Pu Wang ◽  
Jia-le Feng ◽  
...  

Abstract Background Mesenchymal stem cells (MSCs) play a crucial role in cancer development and tumor resistance to therapy in prostate cancer, but the influence of MSCs on the stemness potential of PCa cells by cell–cell contact remains unclear. In this study, we investigated the effect of direct contact of PCa cells with MSCs on the stemness of PCa and its mechanisms. Methods First, the flow cytometry, colony formation, and sphere formation were performed to determine the stemness of PCaMSCs, and the expression of stemness-related molecules (Sox2, Oct4, and Nanog) was investigated by western blot analysis. Then, we used western blot and qPCR to determine the activity levels of two candidate pathways and their downstream stemness-associated pathway. Finally, we verified the role of the significantly changed pathway by assessing the key factors in this pathway via in vitro and in vivo experiments. Results We established that MSCs promoted the stemness of PCa cells by cell–cell contact. We here established that the enhanced stemness of PCaMSCs was independent of the CCL5/CCR5 pathway. We also found that PCaMSCs up-regulated the expression of Notch signaling-related genes, and inhibition of Jagged1-Notch1 signaling in PCaMSCs cells significantly inhibited MSCs-induced stemness and tumorigenesis in vitro and in vivo. Conclusions Our results reveal a novel interaction between MSCs and PCa cells in promoting tumorigenesis through activation of the Jagged1/Notch1 pathway, providing a new therapeutic target for the treatment of PCa.


2002 ◽  
Vol 1 (5) ◽  
pp. 319-327 ◽  
Author(s):  
M. P. Rols ◽  
M. Golzio ◽  
B. Gabriel ◽  
J. Teissié

Electric field pulses are a new approach for drug and gene delivery for cancer therapy. They induce a localized structural alteration of cell membranes. The associated physical mechanisms are well explained and can be safely controlled. A position dependent modulation of the membrane potential difference is induced when an electric field is applied to a cell. Electric field pulses with an overcritical intensity evoke a local membrane alteration. A free exchange of hydrophilic low molecular weight molecules takes place across the membrane. A leakage of cytosolic metabolites and a loading of polar drugs into the cytoplasm are obtained. The fraction of the cell surface which is competent for exchange is a function of the field intensity. The level of local exchange is strongly controlled by the pulse duration and the number of successive pulses. The permeabilised state is long lived. Its lifetime is under the control of the cumulated pulse duration. Cell viability can be preserved. Gene transfer is obtained but its mechanism is not a free diffusion. Plasmids are electrophoretically accumulated against the permeabilised cell surface and form aggregates due to the field effect. After the pulses, several steps follow: translocation to the cytoplasm, traffic to the nucleus and expression. Molecular structural and metabolic changes in cells remain mostly poorly understood. Nevertheless, while most studies were established on cells in culture ( in vitro), recent experiments show that similar effects are obtained on tissue ( in vivo). Transfer remains controlled by the physical parameters of the electrical treatment.


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