Enhanced E-cadherin expression and increased calcium-dependent cell-cell adhesion in human T-cell leukemia virus type I Tax-expressing PC12 cells

1996 ◽  
Vol 109 (3) ◽  
pp. 609-617 ◽  
Author(s):  
I. Kitajima ◽  
K. Kawahara ◽  
N. Hanyu ◽  
H. Shin ◽  
T. Tokioka ◽  
...  

Human T-cell leukemia virus type I (HTLV-I) Tax protein induces the expression of host cellular genes, some of which are crucial in cell proliferation and differentiation. We examined the mechanisms by which HTLV-I Tax protein induces phenotypic changes in PC12 cells. We demonstrated that the HTLV-I Tax gene induces epithelioid changes and increases cell-cell contact in PC12 cells. No change in the expression of the neural cell adhesion molecule was observed between HTLV-I Tax-expressing PC12 cells and PC12 cells transfected with a control plasmid. However, HTLV-I Tax-expressing PC12 cells demonstrated a marked change in the abundance and distribution of E-cadherin, which was concentrated at regions of cellular contact and accompanied by changes in calcium-dependent cell adhesion. Although E-cadherin is expressed at low levels in PC12 and PC12 transfected with a control plasmid cells, the steady state level of E-cadherin in tax-expressing PC12 cells increases significantly, apparently as a result of regulation at the transcriptional level. Diminished expression of Tax protein in Tax-expressing PC12 cells exposed to antisense oligonucleotides for the Tax gene suppresses E-cadherin expression and decreases cell-cell adhesion. These findings imply that HTLV-I Tax protein enhanced E-cadherin expression modulates calcium-dependent cell-cell adhesion mechanisms.

2019 ◽  
Vol 20 (14) ◽  
pp. 3404 ◽  
Author(s):  
Andrea Dalle Vedove ◽  
Federico Falchi ◽  
Stefano Donini ◽  
Aurelie Dobric ◽  
Sebastien Germain ◽  
...  

Cadherins are a large family of transmembrane calcium-dependent cell adhesion proteins that orchestrate adherens junction formation and are crucially involved in tissue morphogenesis. Due to their important role in cancer development and metastasis, cadherins can be considered attractive targets for drug discovery. A recent crystal structure of the complex of a cadherin extracellular portion and a small molecule inhibitor allowed the identification of a druggable interface, thus providing a viable strategy for the design of cadherin dimerization modulators. Here, we report on a structure-based virtual screening approach that led to the identification of efficient and selective modulators of E-cadherin-mediated cell–cell adhesion. Of all the putative inhibitors that were identified and experimentally tested by cell adhesion assays using human pancreatic tumor BxPC-3 cells expressing both E-cadherin and P-cadherin, two compounds turned out to be effective in inhibiting stable cell–cell adhesion at micromolar concentrations. Moreover, at the same concentrations, one of them also showed anti-invasive properties in cell invasion assays. These results will allow further development of novel and selective cadherin-mediated cell–cell adhesion modulators for the treatment of a variety of cadherin-expressing solid tumors and for improving the efficiency of drug delivery across biological barriers.


1992 ◽  
Vol 118 (3) ◽  
pp. 671-679 ◽  
Author(s):  
K A Knudsen ◽  
M J Wheelock

E- and N-cadherin are members of a family of calcium-dependent, cell surface glycoproteins involved in cell-cell adhesion. Extracellularly, the transmembrane cadherins self-associate, while, intracellularly, they interact with the actin-based cytoskeleton. Several intracellular proteins, collectively termed catenins, have been noted to co-immunoprecipitate with E- and N-cadherin and are thought to be involved in linking the cadherins to the cytoskeleton. Two catenins have been identified recently: a 102-kD vinculin-like protein (alpha-catenin) and a 92-kD Drosophila armadillo/plakoglobin-like protein (beta-catenin). Here, we show that plakoglobin, or an 83-kD plakoglobin-like protein, co-immunoprecipitates and colocalizes with both E- and N-cadherin. The 83-kD protein is immunologically distinct from the 92-kD beta-catenin and, because of its molecular mass, likely represents the cadherin-associated protein called gamma-catenin. Thus, two different members of a plakoglobin family associate with N- and E-cadherin and, together with the 102-kD alpha-catenin, appear to participate in linking the cadherins to the actin-based cytoskeleton.


2015 ◽  
Vol 210 (7) ◽  
pp. 1065-1074 ◽  
Author(s):  
Julie M. Bianchini ◽  
Khameeka N. Kitt ◽  
Martijn Gloerich ◽  
Sabine Pokutta ◽  
William I. Weis ◽  
...  

As part of the E-cadherin–β-catenin–αE-catenin complex (CCC), mammalian αE-catenin binds F-actin weakly in the absence of force, whereas cytosolic αE-catenin forms a homodimer that interacts more strongly with F-actin. It has been concluded that cytosolic αE-catenin homodimer is not important for intercellular adhesion because E-cadherin/αE-catenin chimeras thought to mimic the CCC are sufficient to induce cell–cell adhesion. We show that, unlike αE-catenin in the CCC, these chimeras homodimerize, bind F-actin strongly, and inhibit the Arp2/3 complex, all of which are properties of the αE-catenin homodimer. To more accurately mimic the junctional CCC, we designed a constitutively monomeric chimera, and show that E-cadherin–dependent cell adhesion is weaker in cells expressing this chimera compared with cells in which αE-catenin homodimers are present. Our results demonstrate that E-cadherin/αE-catenin chimeras used previously do not mimic αE-catenin in the native CCC, and imply that both CCC-bound monomer and cytosolic homodimer αE-catenin are required for strong cell–cell adhesion.


1994 ◽  
Vol 124 (5) ◽  
pp. 729-741 ◽  
Author(s):  
L Hinck ◽  
WJ Nelson ◽  
J Papkoff

Wnt-1 homologs have been identified in invertebrates and vertebrates and play important roles in cellular differentiation and organization. In Drosophila, the products of the segment polarity genes wingless (the Wnt-1 homolog) and armadillo participate in a signal transduction pathway important for cellular boundary formation in embryonic development, but functional interactions between the proteins are unknown. We have examined Wnt-1 function in mammalian cells in which armadillo (beta-catenin and plakoglobin) is known to bind to and regulate cadherin cell adhesion proteins. We show that Wnt-1 expression results in the accumulation of beta-catenin and plakoglobin. In addition, binding of beta-catenin to the cell adhesion protein, cadherin, is stabilized, resulting in a concomitant increase in the strength of calcium-dependent cell-cell adhesion. Thus, a consequence of the functional interaction between Wnt-1 and armadillo family members is the strengthening of cell-cell adhesion, which may lead to the specification of cellular boundaries.


Virology ◽  
2002 ◽  
Vol 302 (1) ◽  
pp. 132-143 ◽  
Author(s):  
Toshiyuki Takahashi ◽  
Masaya Higuchi ◽  
Masaya Fukushi ◽  
Masayasu Oie ◽  
Masaaki Ito ◽  
...  

1983 ◽  
Vol 97 (3) ◽  
pp. 944-948 ◽  
Author(s):  
S I Ogou ◽  
C Yoshida-Noro ◽  
M Takeichi

The molecules involved in Ca2+-dependent cell-cell adhesion systems (CDS) in mouse hepatocytes were characterized and compared with those in teratocarcinoma cells. Fab fragments of antibody raised against liver tissues (anti-liver) inhibited Ca2+-dependent aggregation of both liver and teratocarcinoma cells. A monoclonal antibody raised against teratocarcinoma CDS (ECCD-1) also inhibited the Ca2+-dependent aggregation of these two cell types equally. These antibodies induced disruption of cell-cell adhesion in monolayers of hepatocytes. Thus, CDS in these two cell types are not immunologically distinctive. Immunochemical analyses with these antibodies showed that CDS in both hepatocytes and teratocarcinoma cells involved at least two classes of cell surface proteins with molecular weights of 124,000 and 104,000. ECCD-1 selectively bound to hepatocytes but not to fibroblastic cells in liver cell cultures. Thus, the molecular constitution of CDS in hepatocytes and teratocarcinoma stem cells is identical. As ECCD-1 reacts with other classes of embryonic and fetal cells, the molecules identified here could have a major role in cell-cell adhesion in various tissues at any developmental stage of animals.


1994 ◽  
Vol 68 (5) ◽  
pp. 3374-3379 ◽  
Author(s):  
T Yamada ◽  
S Yamaoka ◽  
T Goto ◽  
M Nakai ◽  
Y Tsujimoto ◽  
...  

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