Calcium-dependent Cell Adhesion Molecules Research Articles

Study of single nucleotide polymorphisms and serum level of E-cadherin and their relation to psoriasis severity

Backgroundpsoriasis is a persistent autoimmune-mediated systemic inflammatory illness that affects the skin and several organ systems. A family of calcium-dependent cell adhesion molecules called cadherins (CDH) works through homophilic contacts to keep cells attached to one another. In comparison to normal skin, several investigations found that the expression of E-cadherin was downregulated in the granular and basal layers of psoriasis lesional skin. ObjectivesThis study aimed to relate the serum level of E-cadherin and its genes (rs17715799 and rs13689) SNPs with the severity of psoriasis. MethodsIn the current study, 120 participants were divided into two groups: 60 patients with plaque psoriasis were in group I, and 60 healthy controls were in group II. The serum level of E-cadherin protein was measured using an enzyme linked immunosorbent assay (ELISA), and SNPs in the E-cadherin gene (rs17715799 and rs13689) were identified using real-time polymerase chain reaction (RT-PCR) technology. ResultsIn our study group I had a considerably higher serum level of the protein E-cadherin. It was confirmed that the E cadherin (rs13689) genotype frequency distribution revealed a significant difference between the two studied groups. The frequency of the CC genotype was higher in group I. While there was no significant variation in the genotype frequency distribution of E-cadherin (rs17715799) between the two study groups under the dominant, over-dominant, and recessive modes of inheritance (p 0.204) conclusion: patients with psoriasis had considerably higher serum levels of E-cadherin. The E-cadherin gene rs13689 polymorphism affects the chance of developing psoriasis. However, the E-cadherin gene rs17715799 polymorphism has no impact on the onset of psoriasis. As a result, the E-cadherin gene rs13689 but not rs17715799 might be considered as a marker for the risk of developing psoriasis.

Clinicopathological significance and prognostic value of E-cadherin expression in non-small cell lung cancer: A protocol for systematic review and meta-analysis.

Background:E-cadherin, a calcium-dependent cell adhesion molecule, as an important mediator of adhesion and signaling pathway, plays a key role in maintaining tissue integrity. However, the association of E-cadherin expression with clinicopathological features and prognostic value in non-small cell lung cancer (NSCLC) is still controversial. Therefore, the purpose of the study is to explore the clinicopathological features and prognostic value of E-cadherin expression in non-small cell lung cancer by meta-analysis.Methods:PubMed, EMBASE, Cochrane Library, and Web of Science were searched to collect the studies about expression of E-cadherin and clinicopathological features and prognosis of non-small cell lung cancer. The last search time was May 2020. Stata 15.0 software was used for statistical analysis.Results:A total of 35 studies were included, of which the results showed that high expression of E-cadherin compared with its low expression, for overall survival, HR = 0.68 (95% CI:0.64–0.73, P < .05); for disease-free survival or progression-free survival, HR = 0.54 (95% CI: 0.44–0.67); low differentiation of lung cancer compared with moderate and high differentiation, OR = 0.40 (95% CI: 0.27–0.58, P < .05); Advanced lung cancer compared with early stage, OR = 0.54 (95% CI: 0.44–0.66, P < .05); lymph node metastasis compared with non-lymph node metastasis, OR = 0.49 (95% CI: 0.31∼0.77).Conclusion:Low expression of E-cadherin is closely related to poor prognosis of patients with NSCLC, promoting tumor staging and lymph node metastasis, inhibiting tumor differentiation as well.

Immunohistochemical Expression of E-cadherin in Invasive Duct Carcinoma of the Breast

Breast cancer is the most frequent malignant tumor in women worldwide. E-Cadherin is a calcium-dependent epithelial cell adhesion molecule that is expressed at adherens junctions. Its loss may result in a poorly differentiated tumorphenotype. Cells with mutated E-cadherin demonstrate increased motility, altered organization of their actin cytoskeletonand associated with metastases, thereby providing evidence for its role as an invasion suppressor.Objectives: Assess the prognostic value of E-cadherin expression in invasive duct carcinoma (IDC) of the breastand to evaluate its correlations with other prognostic parameters.Materials and Methods: Immunohistochemical (IHC) E-Cadherin expression was studied in 60 IDC and the results were correlated with the clinico-pathological parameters.Results: E-cadherin was positive in 46/60 (76.7%) of IDC; 15/60 (25%) showed strong membranous staining. A significant inverse correlation was found between E-cadherin expression and number of lymph node metastasis.Conclusions: Loss of E-cadherin expression is a predictive of invasion and metastasis in IDC.

Cell Migration Guided by Cell-Cell Contacts in Innate Immunity.

The directed migration of leukocytes to sites of damage or infection is necessary for a productive immune response. There is substantial evidence supporting a key role for chemoattractants in directed migration, however, less is known about how cell-cell contacts affect the migratory behavior of leukocytes in innate immunity. Here, we explore how cell-cell contacts can affect the directed migration of innate immune cells, including their role in attracting, repelling, or stopping cell motility. Further investigation of cell contact dynamics as guidance cues may yield new insights into the regulation of innate immunity.

Quantitative MRI-Based Analysis Identifies Developmental Limbic Abnormalities in PCDH19 Encephalopathy.

Protocadherin-19 (PCDH19) is a calcium dependent cell-adhesion molecule involved in neuronal circuit formation with prevalent expression in the limbic structures. PCDH19-gene mutations cause a developmental encephalopathy with prominent infantile onset focal seizures, variably associated with intellectual disability and autistic features. Diagnostic neuroimaging is usually unrevealing. We used quantitative MRI to investigate the cortex and white matter in a group of 20 PCDH19-mutated patients. By a statistical comparison between quantitative features in PCDH19 brains and in a group of age and sex matched controls, we found that patients exhibited bilateral reductions of local gyrification index (lGI) in limbic cortical areas, including the parahippocampal and entorhinal cortex and the fusiform and lingual gyri, and altered diffusivity features in the underlying white matter. In patients with an earlier onset of seizures, worse psychiatric manifestations and cognitive impairment, reductions of lGI and diffusivity abnormalities in the limbic areas were more pronounced. Developmental abnormalities involving the limbic structures likely represent a measurable anatomic counterpart of the reduced contribution of the PCDH19 protein to local cortical folding and white matter organization and are functionally reflected in the phenotypic features involving cognitive and communicative skills as well as local epileptogenesis.

Farelerde erken embriyo gelişiminde e-kadherin ekspresyonu

E-cadherin is a member of the cadherin superfamily of calcium-dependent cell adhesion molecules, and has critical roles in cell adhesion during early embryo development. To determine the expression and distribution of E-cadherin, we applied immunofluorescent staining on late 8 cell, morula and blastocyst stage embryos during the experiments. Firstly, we superovulated the females and sacrificed them to isolate oviducts. We flushed 2 cell embryos by using FHM HEPES-buffered medium from the CD1 female mouse oviducts and cultured them in KSOM medium until the blastocyst stage. Embryos were fixed and immunostained with E-cadherin, then images were assessed using a fluorescence microscope. We demonstrate that E-cadherin is expressed throughout the late 8 cell to fully expanded blastocysts. We observed that E-cadherin is present only in the cell-cell contact sites and not in the apical sites of the membrane of late 8 cell stage embryo. In morula, E-cadherin localized on the surface of blastomeres and cell-cell junctions. In blastocyst stage, embryos showed membrane staining in cell-cell contact regions in trophectoderm cells while localized on the surface of inner cell mass. Our results indicate that E-cadherin mediated cell adhesion has major roles on compaction, trophectoderm epithelial differentation and implantation.

A study combining whole-exome sequencing and structural neuroimaging analysis for major depressive disorder

BackgroundGenetic variations associated with major depressive disorder (MDD) may affect the structural aspects of neural networks mediated by the molecular pathways involved in neuronal survival and synaptic plasticity. However, few studies have applied a novel approach such as whole-exome sequencing (WES) analysis to investigate the genetic contribution to the neurostructural changes in MDD. MethodsIn the first part of the study, we investigated rare variants of selected genes from previous WES studies using a WES analysis in 184 patients with MDD and 82 healthy controls. In the second part of the study, we explored the association between the common genetic variants from the WES analysis and cortical thickness in 91 patients with MDD and 75 healthy controls. The gray-matter thickness of each cortical region was measured using FreeSurfer. ResultsWe identified recurrent non-silent variants in 24 MDD-related genes including FASN, MYH13, UNC13D, LILRA1, CACNA1B, TRIO, HOMER3, and BCAR3, and observed eleven recurrently altered copy number alternations where a gain on 15q11.2 and losses on 7q34 and 15q11.1-q11.2 in MDD genomes. We also found that rs11592462 in CDH23, a calcium-dependent cell-adhesion molecule encoding gene, was significantly associated with thinning in the right anterior cingulate cortex. LimitationThe small sample size may lead our findings to be underpowered regarding rare variants. Conclusion: The present study identified that non-synonymous rare variants were significantly associated with risk of MDD and found that genetic contributions to the development of MDD may be mediated by alterations in cortical thickness of emotion-processing neural circuits.

Early-life stress impairs developmental programming in Cadherin 13 (CDH13)-deficient mice

ObjectiveCadherin-13 (CDH13), a member of the calcium-dependent cell adhesion molecule family, has been linked to neurodevelopmental disorders, including autism spectrum (ASD) and attention-deficit/hyperactivity (ADHD) disorders, but also to depression. In the adult brain, CDH13 expression is restricted e.g. to the presynaptic compartment of inhibitory GABAergic synapses in the hippocampus and Cdh13 knockout mice show an increased inhibitory drive onto hippocampal CA1 pyramidal neurons, leading to a shift in excitatory/inhibitory balance. CDH13 is also moderating migration of serotonergic neurons in the dorsal raphe nucleus, establishing projections preferentially to the thalamus and cerebellum during brain development. Furthermore, CDH13 is upregulated by chronic stress as well as in depression, suggesting a role in early-life adaptation to stressful experience. Here, we therefore investigated the interaction between Cdh13 variation and neonatal maternal separation (MS) in mice. MethodsMale and female wild-type (Cdh13+/+), heterozygous (Cdh13+/−) and homozygous (Cdh13−/−) knockout mice exposed to MS, or daily handling as control, were subjected to a battery of behavioural tests to assess motor activity, learning and memory as well as anxiety-like behaviour. A transcriptome analysis of the hippocampus was performed in an independent cohort of mice which was exposed to MS or handling, but remained naïve for behavioural testing. ResultsMS lead to increased anxiety-like behaviour in Cdh13−/− mice compared to the other two MS groups. Cdh13−/− mice showed a context-dependent effect on stress- and anxiety-related behaviour, impaired extinction learning following contextual fear conditioning and decreased impulsivity, as well as a mild decrease in errors in the Barnes maze and reduced risk-taking in the light-dark transition test after MS. We also show sex differences, with increased locomotor activity in female Cdh13−/− mice, but unaltered impulsivity and activity in male Cdh13−/− mice. Transcriptome analysis revealed several pathways associated with cell surface/adhesion molecules to be altered following Cdh13 deficiency, together with an influence on endoplasmic reticulum function. ConclusionMS resulted in increased stress resilience, increased exploration and an overall anxiolytic behavioural phenotype in male Cdh13+/+ and Cdh13+/− mice. Cdh13 deficiency, however, obliterated most of the effects caused by early-life stress, with Cdh13−/− mice exhibiting delayed habituation, no reduction of anxiety-like behaviour and decreased fear extinction. Our behavioural findings indicate a role of CDH13 in the programming of and adaptation to early-life stress. Finally, our transcriptomic data support the view of CDH13 as a neuroprotective factor as well as a mediator in cell-cell interactions, with an impact on synaptic plasticity.

Expression profile of N-cadherin and protocadherin-19 in postnatal mouse limbic structures.

Cadherins are a superfamily of calcium-dependent cell adhesion molecules that are involved in brain development and organization. Previous genetic studies revealed that mutations in protocadherin-19 (Pcdh19) lead to an epilepsy syndrome with a variable degree of cognitive disability. Seizure origins are located in the frontotemporal and limbic structures. Expression studies of Pcdh19 in mouse confirmed a widespread presence during brain development while the function and the pathogenesis of Pcdh19 are still unknown in mammals. The neuronal cadherin (N-cadherin; Ncdh) is known for its important role in neurulation, brain development and regulation of synaptic function. Studies in zebrafish revealed that both cadherins can interact with each other in cell adhesion. We investigated the expression pattern of Pcdh19 and Ncdh in limbic structures at four postnatal stages of C57BL/6J mice by using double-label in situ hybridization. Results confirm a strong expression of both, Ncdh and Pcdh19, in structures of the limbic system with overlapping expression patterns particularly within regions of the amygdala, the hippocampus and the ventral hypothalamus. A detailed analysis of the limbic system highlight clear expression boundaries between several nuclei and reveal the fine regulation of Pcdh19 and Ncdh expression during the first postnatal week. Most expression patterns of both cadherins remain constant with a few exceptions particularly between P2 and P5.

Bacterial uracil modulates Drosophila DUOX-dependent gut immunity via Hedgehog-induced signaling endosomes.

Genetic studies in Drosophila have demonstrated that generation of microbicidal reactive oxygen species (ROS) through the NADPH dual oxidase (DUOX) is a first line of defense in the gut epithelia. Bacterial uracil acts as DUOX-activating ligand through poorly understood mechanisms. Here, we show that the Hedgehog (Hh) signaling pathway modulates uracil-induced DUOX activation. Uracil-induced Hh signaling is required for intestinal expression of the calcium-dependent cell adhesion molecule Cadherin 99C (Cad99C) and subsequent Cad99C-dependent formation of endosomes. These endosomes play essential roles in uracil-induced ROS production by acting as signaling platforms for PLCβ/PKC/Ca2+-dependent DUOX activation. Animals with impaired Hh signaling exhibit abolished Cad99C-dependent endosome formation and reduced DUOX activity, resulting in high mortality during enteric infection. Importantly, endosome formation, DUOX activation, and normal host survival are restored by genetic reintroduction of Cad99C into enterocytes, demonstrating the important role for Hh signaling in host resistance to enteric infection.

E-cadherin Immunohistochemistry Stain and Acute Erythroid Leukemia, the Emerging Story

E-Cadherin is calcium-dependent cell adhesion molecule encoded by CDH1 gene at chromosome 16q22.1. Ecadherin regulates cell-cell adhesions and controls mobility and proliferation of epithelial cells. Recently, the role of E-cadherin in erythroid maturation has been elucidated. It is selectively expressed in immature erythroblasts and gradually down regulated as erythroid precursors mature. Acute erythroid leukemia is neoplastic proliferation of immature erythroid precursors in bone marrow with or without significant myeloblasts component. In the recent years E-cadherin has emerged as the most sensitive and specific marker for immature erythroblasts. Moreover, combination of E-cadherin with glycophorin A in immunohistochemistry staining can effectively separate immature vs. mature erythroid precursors in bone marrow biopsy. In this short review I will shed light on the key points related to the nature of relationship between E-cadherin and acute erythroid leukemia.

Myo10 is required for neurogenic cell adhesion and migration.

Myosin X (Myo10), an untraditional member of myosin superfamily, is characterized as an actin-based molecular motor, which plays a critical role in diverse cellular motile events. Previous research by our group has found that Myo10 influenced neuronal radial migration in developing neocortex, but the underlying mechanism is still largely unknown. In this study, we found that knockdown of endogenous Myo10 in a normal gonadotropin-releasing hormone (GnRH) neuronal cell line transfected with the large T antigen (NLT) induced the impairment of cell motility and orientation. In the wound healing assay, with the Golgi complex staining to display cell polarity, Myo10 knockdown cells were randomly oriented compared to the control. Furthermore, suppressing the expression of Myo10 decreased the ability of cell-matrix adhesion. N-cadherin, a calcium-dependent classical cell adhesion molecule, rescued the migration deficiency caused by Myo10 knockdown in cell aggregates and collagen gel assay. These results suggest that Myo10 is required for neurogenic cell migration through N-cadherin mediated cell adhesion.

Vangl2 regulates E-cadherin in epithelial cells.

E-cadherin belongs to the classic cadherin subfamily of calcium-dependent cell adhesion molecules and is crucial for the formation and function of epithelial adherens junctions. In this study, we demonstrate that Vangl2, a vertebrate regulator of planar cell polarity (PCP), controls E-cadherin in epithelial cells. E-cadherin co-immunoprecipitates with Vangl2 from embryonic kidney extracts, and this association is also observed in transfected fibroblasts. Vangl2 enhances the internalization of E-cadherin when overexpressed. Conversely, the quantitative ratio of E-cadherin exposed to the cell surface is increased in cultured renal epithelial cells derived from Vangl2Lpt/+ mutant mice. Interestingly, Vangl2 is also internalized through protein traffic involving Rab5- and Dynamin-dependent endocytosis. Taken together with recent reports regarding the transport of Frizzled3, MMP14 and nephrin, these results suggest that one of the molecular functions of Vangl2 is to enhance the internalization of specific plasma membrane proteins with broad selectivity. This function may be involved in the control of intercellular PCP signalling or in the PCP-related rearrangement of cell adhesions.

Regulation of Desmocollin3 Expression by Promoter Hypermethylation is Associated with Advanced Esophageal Adenocarcinomas.

BACKGROUND: Desmocollin3 (DSC3) is a member of the cadherin superfamily of calcium-dependent cell adhesion molecules and plays an important role in tumor invasion and metastasis. In this study, we investigated the epigenetic mechanism that regulates DSC3 expression in esophageal adenocarcinomas (EACs). METHODS: Expression of DSC3 was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The promoter DNA methylation level of DSC3 was examined using quantitative bisulfite pyrosequencing. RESULTS: The qRT-PCR analysis demonstrated significant down-regulation of the DSC3 mRNA levels in human EAC cell lines and tissue samples (P<.001). In addition, the EAC cell lines and tumor samples have aberrant promoter hypermethylation as compared to normal esophageal samples (P<.001). DSC3 promoter hypermethylation (>10% methylation level) was detected in 97.5% (39/40) of EAC samples whereas none of the normal tissue samples showed hypermethylation (P<.0001). There was a significant inverse correlation between promoter DNA methylation levels and mRNA expression folds for DSC3 (coefficient r=-0.685, P<.0001). Treatment of FLO-1 and SKGT4 EAC cells with 5-Aza-deoxytidine led to a significant reduction in the promoter DNA methylation levels with restoration of the DSC3 expression, suggesting that promoter DNA methylation is a key epigenetic mechanism regulating DSC3 expression. High DSC3 promoter DNA methylation levels were significantly correlated with advanced tumor stage (P<.001) and lymph node metastasis (P<.001). CONCLUSION: Taken together, our results demonstrate that epigenetic silencing of DSC3 is a frequent finding in EAC that is possibly associated with advanced stages.

Protocadherins in neurological diseases.

Cadherins were originally isolated as calcium-dependent cell adhesion molecules and are characterized by their cadherin motifs in the extracellular domain. In vertebrates, including humans, there are more than 100 different cadherin-related genes, which constitute the cadherin superfamily. The protocadherin (Pcdh) family comprises a large subgroup within the cadherin superfamily. The Pcdhs are divided into clustered and non-clustered Pcdhs, based on their genomic structure. Almost all the Pcdh genes are expressed widely in the brain and play important roles in brain development and in the regulation of brain function. This chapter presents an overview of Pcdh family members with regard to their functions, knockout mouse phenotypes, and association with neurological diseases and tumors.

Collective cell streams in epithelial monolayers depend on cell adhesion

We report spontaneously emerging, randomly oriented, collective streaming behavior within a monolayer culture of a human keratinocyte cell line, and explore the effect of modulating cell adhesions by perturbing the function of calcium-dependent cell adhesion molecules. We demonstrate that decreasing cell adhesion induces narrower and more anisotropic cell streams, reminiscent of decreasing the Taylor scale of turbulent liquids. To explain our empirical findings, we propose a cell-based model that represents the dual nature of cell–cell adhesions. Spring-like connections provide mechanical stability, while a cellular Potts model formalism represents surface-tension driven attachment. By changing the relevance and persistence of mechanical links between cells, we are able to explain the experimentally observed changes in emergent flow patterns.

Cadherins and Wnt signalling: a functional link controlling bone formation

Cadherins are calcium-dependent cell adhesion molecules that have a major role in morphogenesis and tissue formation. In bone, cadherins control osteoblast differentiation by mediating cell-cell adhesion and signals that promote phenotypic osteoblast gene expression. Furthermore, cadherins can interact with Wnt signalling to modulate osteoblastogenesis. One mechanism involves the interaction of N-cadherin with β-catenin at the cell membrane, resulting in β-catenin sequestration, reduction of the cytosolic β-catenin pool and inhibition of Wnt signalling. In addition to modulating the β-catenin pool, N-cadherin can regulate osteoblasts by interacting with the Wnt coreceptors LRP5 or LRP6. We showed that the functional interaction between N-cadherin and LRP5/6 in osteoblasts promotes β-catenin degradation and reduces canonical Wnt signalling. This crosstalk between N-cadherin and Wnt signalling has a negative impact on osteoblast proliferation, differentiation and survival, independently of cell-cell adhesion, which results in decreased bone formation and delayed bone accrual in mice. The identification of this crosstalk between N-cadherin and Wnt signalling may have therapeutic implications, as a disruption of the N-cadherin-LRP5/6 interaction using a competitor peptide can increase Wnt/β-catenin signalling without affecting cell-cell adhesion, and this effect results in increased osteoblastogenesis and bone tissue formation in vivo. In this review, we summarize our current knowledge of the key crosstalks between cadherins and Wnt signalling that impact osteoblast function, bone formation and bone mass, and the possible therapeutic implications of such interactions for promoting osteoblastogenesis, bone formation and bone mass.

E-Cadherin Protects Primary Hepatocyte Spheroids from Cell Death by a Caspase-Independent Mechanism

Cultivation of primary hepatocytes as spheroids creates an efficient three-dimensional model system for hepatic studies in vitro and as a cell source for a spheroid reservoir bioartificial liver. The mechanism of spheroid formation is poorly understood, as is an explanation for why normal, anchorage-dependent hepatocytes remain viable and do not undergo detachment-induced apoptosis, known as anoikis, when placed in suspension spheroid culture. The purpose of this study was to investigate the role of E-cadherin, a calcium-dependent cell adhesion molecule, in the formation and maintenance of hepatocyte spheroids. Hepatocyte spheroids were formed by a novel rocker technique and cultured in suspension for up to 24 h. The dependence of spheroid formation on E-cadherin and calcium was established using an E-cadherin blocking antibody and a calcium chelator. We found that inhibiting E-cadherin prevented cell-cell attachment and spheroid formation, and, surprisingly, E-cadherin inhibition led to hepatocyte death through a caspase-independent mechanism. In conclusion, E-cadherin is required for hepatocyte spheroid formation and may be responsible for protecting hepatocytes from a novel form of caspase-independent cell death.

Self-Recognition and Ca2+-Dependent Carbohydrate-Carbohydrate Cell Adhesion Provide Clues to the Cambrian Explosion

The Cambrian explosion of life was a relatively short period approximately 540 Ma that marked a generalized acceleration in the evolution of most animal phyla, but the trigger of this key biological event remains elusive. Sponges are the oldest extant Precambrian metazoan phylum and thus a valid model to study factors that could have unleashed the rise of multicellular animals. One such factor is the advent of self-/non-self-recognition systems, which would be evolutionarily beneficial to organisms to prevent germ-cell parasitism or the introduction of deleterious mutations resulting from fusion with genetically different individuals. However, the molecules responsible for allorecognition probably evolved gradually before the Cambrian period, and some other (external) factor remains to be identified as the missing triggering event. Sponge cells associate through calcium-dependent, multivalent carbohydrate-carbohydrate interactions of the g200 glycan found on extracellular proteoglycans. Single molecule force spectroscopy analysis of g200-g200 binding indicates that calcium affects the lifetime (+Ca/-Ca: 680 s/3 s) and bond reaction length (+Ca/-Ca: 3.47 A/2.27 A). Calculation of mean g200 dissociation times in low and high calcium within the theoretical framework of a cooperative binding model indicates the nonlinear and divergent characteristics leading to either disaggregated cells or stable multicellular assemblies, respectively. This fundamental phenomenon can explain a switch from weak to strong adhesion between primitive metazoan cells caused by the well-documented rise in ocean calcium levels at the end of Precambrian time. We propose that stronger cell adhesion allowed the integrity of genetically uniform animals composed only of "self" cells, facilitating genetic constitutions to remain within the metazoan individual and be passed down inheritance lines. The Cambrian explosion might have been triggered by the coincidence in time of primitive animals endowed with self-/non-self-recognition and of a surge in seawater calcium that increased the binding forces between their calcium-dependent cell adhesion molecules.

Identification of a novel dual E- and N-cadherin antagonist

E- and N-cadherin are related calcium-dependent cell adhesion molecules that exert an influence over multiple biological and disease processes. Antagonists of these cadherins can therefore be envisaged as therapeutically useful drugs. We have used phage display technology to discover such antagonists. A peptide phage library was screened against a chimeric protein composed of the human E-cadherin ectodomain fused to the Fc fragment of human immunoglobulin G1 (E-cad/Fc). All of the phage clones that were isolated also bound a chimeric protein composed of the human N-cadherin ectodomain fused to the Fc fragment of human immunoglobulin G1 (N-cad/Fc). A peptide displayed by several of the isolated phage clones was synthesized (H-SWELYYPLRANL-NH 2) and found to bind both E- and N-cad/Fc chimeric proteins with affinities ( K D) of 9.4 μM and 323 nM, respectively, as judged by surface plasmon resonance spectroscopy. This peptide was also capable of blocking the aggregation of E- and N-cad/Fc chimeric protein-coated beads, as well as the aggregation of MCF-7 and MDA-MB435 human breast cancer cells (these cells express E- and N-cadherin, respectively). Finally, we showed that the peptide disrupted MCF-7 and MDA-MB435 cell monolayers. The peptide, H-SWELYYPLRANL-NH 2 thus proved to be a biologically active, dual E- and N-cadherin antagonist. Such an antagonist has application in a wide variety of biological contexts.