scholarly journals The tumor-associated EpCAM regulates morphogenetic movements through intracellular signaling

2010 ◽  
Vol 191 (3) ◽  
pp. 645-659 ◽  
Author(s):  
Nadim Maghzal ◽  
Emily Vogt ◽  
Wolfgang Reintsch ◽  
James S. Fraser ◽  
François Fagotto
Keyword(s):  
Embryonic Development ◽  
Intracellular Signaling ◽  
Cell Adhesion Molecule ◽  
Potential Role ◽  
Surface Protein ◽  
Normal Function ◽  
Cell Surface Protein ◽  
Epithelial Cell Adhesion Molecule ◽  
Signaling Function ◽  
Abnormal Tissue

Epithelial cell adhesion molecule (EpCAM) is best known as a tumor-associated protein highly expressed in carcinomas. The function of this cell surface protein during embryonic development and its potential role in cancer are still poorly understood. We identified EpCAM in a gain-of-function screen for inducers of abnormal tissue mixing during gastrulation. Elevated EpCAM levels in either the ectoderm or the mesoderm confer “invasive” properties to cells in both populations. We found that this phenotype represents an “overstimulation” of an essential activity of EpCAM in controlling cell movements during embryonic development. Surprisingly, this property is independent of the putative adhesive function of EpCAM, and rather relies on a novel signaling function that operates through down-regulation of PKC activity. We show that inhibition of novel PKCs accounts entirely for the invasive phenotype induced by abnormally high levels of EpCAM as well as for its normal function in regulating cell rearrangement during early development.

Zebrafish paraxial protocadherin is a downstream target of spadetail involved in morphogenesis of gastrula mesoderm

Development ◽  
1998 ◽  
Vol 125 (17) ◽  
pp. 3389-3397 ◽  
Author(s):  
A. Yamamoto ◽  
S.L. Amacher ◽  
S.H. Kim ◽  
D. Geissert ◽  
C.B. Kimmel ◽  
...  
Keyword(s):  
Cell Adhesion Molecule ◽  
Homeobox Gene ◽  
Surface Protein ◽  
Dominant Negative ◽  
Paraxial Mesoderm ◽  
Cell Surface Protein ◽  
Gene Encoding ◽  
Genetic Studies ◽  
Structural Cell ◽  
Downstream Target

Zebrafish paraxial protocadherin (papc) encodes a transmembrane cell adhesion molecule (PAPC) expressed in trunk mesoderm undergoing morphogenesis. Microinjection studies with a dominant-negative secreted construct suggest that papc is required for proper dorsal convergence movements during gastrulation. Genetic studies show that papc is a close downstream target of spadetail, gene encoding a transcription factor required for mesodermal morphogenetic movements. Further, we show that the floating head homeobox gene is required in axial mesoderm to repress the expression of both spadetail and papc, promoting notochord and blocking differentiation of paraxial mesoderm. The PAPC structural cell-surface protein may provide a link between regulatory transcription factors and the actual cell biological behaviors that execute morphogenesis during gastrulation.

scholarly journals Expression and function of epithelial cell adhesion molecule EpCAM: where are we after 40 years?

2020 ◽  
Vol 39 (3) ◽  
pp. 969-987 ◽  
Author(s):  
Olivier Gires ◽  
Min Pan ◽  
Henrik Schinke ◽  
Martin Canis ◽  
Patrick A. Baeuerle
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cell ◽  
Tumor Cells ◽  
Prognostic Marker ◽  
Adhesion Molecule ◽  
Intracellular Signaling ◽  
Cell Adhesion Molecule ◽  
Metastatic Cancer ◽  
Epithelial Cell Adhesion Molecule ◽  
Mesenchymal Transition

Abstract EpCAM (epithelial cell adhesion molecule) was discovered four decades ago as a tumor antigen on colorectal carcinomas. Owing to its frequent and high expression on carcinomas and their metastases, EpCAM serves as a prognostic marker, a therapeutic target, and an anchor molecule on circulating and disseminated tumor cells (CTCs/DTCs), which are considered the major source for metastatic cancer cells. Today, EpCAM is reckoned as a multi-functional transmembrane protein involved in the regulation of cell adhesion, proliferation, migration, stemness, and epithelial-to-mesenchymal transition (EMT) of carcinoma cells. To fulfill these functions, EpCAM is instrumental in intra- and intercellular signaling as a full-length molecule and following regulated intramembrane proteolysis, generating functionally active extra- and intracellular fragments. Intact EpCAM and its proteolytic fragments interact with claudins, CD44, E-cadherin, epidermal growth factor receptor (EGFR), and intracellular signaling components of the WNT and Ras/Raf pathways, respectively. This plethora of functions contributes to shaping intratumor heterogeneity and partial EMT, which are major determinants of the clinical outcome of carcinoma patients. EpCAM represents a marker for the epithelial status of primary and systemic tumor cells and emerges as a measure for the metastatic capacity of CTCs. Consequentially, EpCAM has reclaimed potential as a prognostic marker and target on primary and systemic tumor cells.

Immunogold and immunoblot studies on a cell surface protein found in primary mesenchyme cells and in the cortical secretory vesicles of the sea urchin egg

1987 ◽  
Vol 45 ◽  
pp. 832-833
Author(s):  
G.L. Decker ◽  
M.C. Valdizan
Keyword(s):  
Cell Surface ◽  
Sea Urchin ◽  
Surface Protein ◽  
Egg Cell ◽  
Secretory Vesicles ◽  
Cell Surface Protein ◽  
Surface Complexes ◽  
Mesenchyme Cells ◽  
Lowicryl K4m ◽  
Primary Mesenchyme Cells

A monoclonal antibody designated MAb 1223 has been used to show that primary mesenchyme cells of the sea urchin embryo express a 130-kDa cell surface protein that may be directly involved in Ca2+ uptake required for growth of skeletal spicules. Other studies from this laboratory have shown that the 1223 antigen, although in relatively low abundance, is also expressed on the cell surfaces of unfertilized eggs and on the majority of blastomeres formed prior to differentiation of the primary mesenchyme cells.We have studied the distribution of 1223 antigen in S. purpuratus eggs and embryos and in isolated egg cell surface complexes that contain the cortical secretory vesicles. Specimens were fixed in 1.0% paraformaldehyde and 1.0% glutaraldehyde and embedded in Lowicryl K4M as previously reported. Colloidal gold (8nm diameter) was prepared by the method of Mulpfordt.

scholarly journals Solubility assessment of single-chain antibody fragment against epithelial cell adhesion molecule extracellular domain in four Escherichia coli strains

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Fatemeh Sadat Javadian ◽  
Majid Basafa ◽  
Aidin Behravan ◽  
Atieh Hashemi
Keyword(s):  
Escherichia Coli ◽  
Cell Adhesion ◽  
Epithelial Cell ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Extracellular Domain ◽  
Epithelial Cell Adhesion Molecule ◽  
Single Chain ◽  
E Coli ◽  
The Impact

Abstract Background Overexpression of the EpCAM (epithelial cell adhesion molecule) in malignancies makes it an attractive target for passive immunotherapy in a wide range of carcinomas. In comparison with full-length antibodies, due to the small size, the scFvs (single-chain variable fragments) are more suitable for recombinant expression in E. coli (Escherichia coli). However, the proteins expressed in large amounts in E. coli tend to form inclusion bodies that need to be refolded which may result in poor recovery of bioactive proteins. Various engineered strains were shown to be able to alleviate the insolubility problem. Here, we studied the impact of four E. coli strains on the soluble level of anti-EpEX-scFv (anti-EpCAM extracellular domain-scFv) protein. Results Although results showed that the amount of soluble anti-EpEX-scFv obtained in BL21TM (DE3) (114.22 ± 3.47 mg/L) was significantly higher to those produced in the same condition in E. coli RosettaTM (DE3) (71.39 ± 0.31 mg/L), and OrigamiTM T7 (58.99 ± 0.44 mg/L) strains, it was not significantly different from that produced by E. coli SHuffleTM T7 (108.87 ± 2.71 mg/L). Furthermore, the highest volumetric productivity of protein reached 318.29 ± 26.38 mg/L in BL21TM (DE3). Conclusions Although BL21TM (DE3) can be a suitable strain for high-level production of anti-EpEX-scFv protein, due to higher solubility yield (about 55%), E. coli SHuffleTM T7 seems to be better candidate for soluble production of scfv compared to BL21TM (DE3) (solubility yield of about 30%).

scholarly journals Monomer–dimer dynamics and distribution of GPI-anchored uPAR are determined by cell surface protein assemblies

2007 ◽  
Vol 179 (5) ◽  
pp. 1067-1082 ◽  
Author(s):  
Valeria R. Caiolfa ◽  
Moreno Zamai ◽  
Gabriele Malengo ◽  
Annapaola Andolfo ◽  
Chris D. Madsen ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Cell Surface ◽  
Plasminogen Activator ◽  
Fluorescent Protein ◽  
Surface Protein ◽  
Basal Membrane ◽  
Membrane Dynamics ◽  
Live Cells ◽  
Cell Surface Protein ◽  
Protein Assemblies

To search for functional links between glycosylphosphatidylinositol (GPI) protein monomer–oligomer exchange and membrane dynamics and confinement, we studied urokinase plasminogen activator (uPA) receptor (uPAR), a GPI receptor involved in the regulation of cell adhesion, migration, and proliferation. Using a functionally active fluorescent protein–uPAR in live cells, we analyzed the effect that extracellular matrix proteins and uPAR ligands have on uPAR dynamics and dimerization at the cell membrane. Vitronectin directs the recruitment of dimers and slows down the diffusion of the receptors at the basal membrane. The commitment to uPA–plasminogen activator inhibitor type 1–mediated endocytosis and recycling modifies uPAR diffusion and induces an exchange between uPAR monomers and dimers. This exchange is fully reversible. The data demonstrate that cell surface protein assemblies are important in regulating the dynamics and localization of uPAR at the cell membrane and the exchange of monomers and dimers. These results also provide a strong rationale for dynamic studies of GPI-anchored molecules in live cells at steady state and in the absence of cross-linker/clustering agents.

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