Transformation of cell adhesion properties by exogenously introduced E-cadherin cDNA

Tight junction membrane proteins regulate the mechanical resistance of the apical junctional complex

Epithelia must be able to resist mechanical force to preserve tissue integrity. While intercellular junctions are known to be important for the mechanical resistance of epithelia, the roles of tight junctions (TJs) remain to be established. We previously demonstrated that epithelial cells devoid of the TJ membrane proteins claudins and JAM-A completely lack TJs and exhibit focal breakages of their apical junctions. Here, we demonstrate that apical junctions fracture when claudin/JAM-A-deficient cells undergo spontaneous cell stretching. The junction fracture was accompanied by actin disorganization, and actin polymerization was required for apical junction integrity in the claudin/JAM-A-deficient cells. Further deletion of CAR resulted in the disruption of ZO-1 molecule ordering at cell junctions, accompanied by severe defects in apical junction integrity. These results demonstrate that TJ membrane proteins regulate the mechanical resistance of the apical junctional complex in epithelial cells.

Molecular characterization of plasmacytoid urothelial carcinoma and the impact on treatment implications

Bladder cancer researchers and clinicians have increasingly viewed tumor biology through the lens of genomic and molecular alterations, drastically improving our knowledge of the underlying disease biology. This understanding has led to significant advances in treatment options that allow implementation of a personalized approach to cancer treatment. Large-scale genomic studies initially focused on the most common forms of bladder cancer. However, as genomic and molecular technologies become more widespread and are applied to less common variant histologies, we are gaining additional insight into the unique molecular and genomic characteristics driving the biology of variant histologies of bladder cancer. In this review, we summarize the current state of knowledge of molecular alterations underlying the distinct tumor biology of plasmacytoid urothelial carcinoma and how these alterations may impact treatment options.

Evolutionary reversion in tumorigenesis

Cells forming malignant tumors are distinguished from those forming normal tissues based on several features: accelerated/dysregulated cell division, disruption of physiologic apoptosis, maturation/differentiation arrest, loss of polarity, and invasive potential. Among them, accelerated cell division and differentiation arrest make tumor cells similar to stem/progenitor cells, and this is why tumorigenesis is often regarded as developmental reversion. Here, in addition to developmental reversion, we propose another insight into tumorigenesis from a phylogeny viewpoint. Based on the finding that tumor cells also share some features with unicellular organisms, we propose that tumorigenesis can be regarded as "evolutionary reversion". Recent advances in sequencing technologies and the ability to identify gene homologous have made it possible to perform comprehensive cross-species transcriptome comparisons and, in our recent study, we found that leukemic cells resulting from a polycomb dysfunction transcriptionally resemble unicellular organisms. Analyzing tumorigenesis from the viewpoint of phylogeny should reveal new aspects of tumorigenesis in the near future, and contribute to overcoming malignant tumors by developing new therapies.

Clinically conserved genomic subtypes of gastric adenocarcinoma

Gastric adenocarcinoma (GAC) is a lethal disease characterized by genomic and clinical heterogeneity. By integrating 8 previously established genomic signatures for GAC subtypes, we identified 6 clinically and molecularly distinct genomic consensus subtypes (CGSs). CGS1 have the poorest prognosis, very high stem cell characteristics, and high IGF1 expression, but low genomic alterations. CGS2 is enriched with canonical epithelial gene expression. CGS3 and CGS4 have high copy number alterations and low immune reactivity. However, CGS3 and CGS4 differ in that CGS3 has high HER2 activation, while CGS4 has high SALL4 and KRAS activation. CGS5 has the high mutation burden and moderately high immune reactivity that are characteristic of microsatellite instable tumors. Most CGS6 tumors are positive for Epstein Barr virus and show extremely high levels of methylation and high immune reactivity. In a systematic analysis of genomic and proteomic data, we estimated the potential response rate of each consensus subtype to standard and experimental treatments such as radiation therapy, targeted therapy, and immunotherapy. Interestingly, CGS3 was significantly associated with a benefit from chemoradiation therapy owing to its high basal level of ferroptosis. In addition, we also identified potential therapeutic targets for each consensus subtype. Thus, the consensus subtypes produced a robust classification and provide for additional characterizations for subtype-based customized interventions.

Antiparallel dimer structure of CELSR cadherin in solution revealed by high-speed atomic force microscopy

Cadherin EGF LAG seven-pass G-type receptors (CELSR) cadherins, members of the cadherin superfamily, and adhesion G-protein-coupled receptors, play a vital role in cell-cell adhesion. The mutual binding of the extracellular domains (ectodomains) of CELSR cadherins between cells is crucial for tissue formation, including the establishment of planar cell polarity, which directs the proper patterning of cells. CELSR cadherins possess nine cadherin ectodomains (EC1-EC9) and noncadherin ectodomains. However, the structural and functional mechanisms of the binding mode of CELSR cadherins have not been determined. In this study, we investigated the binding mode of CELSR cadherins using single-molecule fluorescence microscopy, high-speed atomic force microscopy (HS-AFM), and bead aggregation assay. The fluorescence microscopy analysis results indicated that the trans-dimer of the CELSR cadherin constitutes the essential adhesive unit between cells. HS-AFM analysis and bead aggregation assay results demonstrated that EC1-EC8 entirely overlap and twist to form antiparallel dimer conformations and that the binding of EC1-EC4 is sufficient to sustain bead aggregation. The interaction mechanism of CELSR cadherin may elucidate the variation of the binding mechanism within the cadherin superfamily and physiological role of CELSR cadherins in relation to planar cell polarity.

Overexpression of E-Cadherin Is a Favorable Prognostic Biomarker in Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Oral squamous cell carcinoma (OSCC) is characterized by poor survival, mostly due to local invasion, loco-regional recurrence, and metastasis. Given that the weakening of cell-to-cell adhesion is a feature associated with the migration and invasion of cancer cells, different studies have explored the prognostic utility of cell adhesion molecules such as E-cadherin (E-cad). This study aims to summarize current evidence in a meta-analysis, focusing on the prognostic role of E-cad in OSCC. To find studies meeting inclusion criteria, Scopus, Web of Science, EMBASE, Medline, and OpenGrey databases were systematically assessed and screened. The selection process led to 25 studies, which were considered eligible for inclusion in the meta-analysis, representing a sample of 2553 patients. E-cad overexpression was strongly associated with longer overall survival (OS) with Hazard Ratio (HR)  = 0.41 95% confidence interval (95% CI) (0.32-0.54); p < 0.001 and disease-free survival with HR 0.47 95% CI (0.37-0.61); p < 0.001. In terms of OS, patients with tongue cancer experienced better survivability when expressing E-cad with HR 0.28 95% CI (0.19-0.43); p < 0.001. Globally, our findings indicate the prognostic role of the immunohistochemical assessment of E-cad in OSCC and its expression might acquire a different role based on the oral cavity subsites.

Prognostic factor identification by screening changes in differentially expressed genes in oral squamous cell carcinoma

OBJECTIVE

This study was designed to identify changes in the expression of proteins occurring during the progression of oral squamous cell carcinoma (OSCC) and to validate their impact on patient prognosis.

MATERIALS AND METHODS

The human OSCC cell line UPCI-SCC-040 was treated in vitro with TGF-β1, and transcriptome analysis of differentially expressed genes (DEGs) revealed putative candidates relative to untreated cells. The respective protein expression levels of the most important genes were immunohistochemically validated on a tissue microarray (TMA) containing tissue samples from 39 patients with OSCC and were correlated with disease-free survival (DFS) as the primary clinical endpoint.

RESULTS

Our univariate Cox proportional hazard regression (CR) analysis revealed significant correlations among positive N stage (local lymph node metastasis, p = .04), stearoyl-CoA desaturase-1 (p < .01), sclerostin (p = .01), and CD137L expression (p = .04) and DFS. Stearoyl-CoA desaturase-1 and sclerostin remained the main prognostic factors (p < .01) in the multiple CR model.

CONCLUSION

We identified changes in differentially expressed genes during OSCC progression in vitro and translated the impact of the most deregulated genes on patient prognosis. Stearoyl-CoA desaturase-1 and sclerostin acted as independent prognostic factors in OSCC and could also be interesting candidates for new cancer targeted therapeutic approaches.

Cell-adhesion Molecules as Key Mechanisms of Tumor Invasion: The Case of Breast Cancer

Cancer is a major health problem worldwide and the second leading cause of death following cardiovascular diseases. Breast cancer is the leading cause of mortality and morbidity among women and one of the most common malignant neoplasms prompt to metastatic disease. In the present review, the mechanisms of the major cell adhesion molecules involved in tumor invasion are discussed, focusing on the case of breast cancer. A non-systematic updated revision of the literature was performed in order to assemble information regarding the expression of the adhesion cell molecules associated with metastasis.

Modulating the expression of tumor suppressor genes using activating oligonucleotide technologies as a therapeutic approach in cancer

Tumor suppressor genes (TSGs) are frequently downregulated in cancer, leading to dysregulation of the pathways that they control. The continuum model of tumor suppression suggests that even subtle changes in TSG expression, for example, driven by epigenetic modifications or copy number alterations, can lead to a loss of gene function and a phenotypic effect. This approach to exploring tumor suppression provides opportunities for alternative therapies that may be able to restore TSG expression toward normal levels, such as oligonucleotide therapies. Oligonucleotide therapies involve the administration of exogenous nucleic acids to modulate the expression of specific endogenous genes. This review focuses on two types of activating oligonucleotide therapies, small-activating RNAs and synthetic mRNAs, as novel methods to increase the expression of TSGs in cancer.

Multiple dimeric structures and strand-swap dimerization of E-cadherin in solution visualized by high-speed atomic force microscopy

Classical cadherins play key roles in cell-cell adhesion. The adhesion process is thought to comprise mainly two steps: X-dimer and strand-swap (SS-) dimer formation of the extracellular domains (ectodomains) of cadherins. The dimerization mechanism of this two-step process has been investigated for type I cadherins, including E-cadherin, of classical cadherins, whereas other binding states also have been proposed, raising the possibility of additional binding processes required for the cadherin dimerization. However, technical limitations in observing single-molecule structures and their dynamics have precluded the investigation of the dynamic binding process of cadherin. Here, we used high-speed atomic force microscopy (HS-AFM) to observe full-length ectodomains of E-cadherin in solution and identified multiple dimeric structures that had not been reported previously. HS-AFM revealed that almost half of the cadherin dimers showed S- (or reverse S-) shaped conformations, which had more dynamic properties than the SS- and X-like dimers. The combined HS-AFM, mutational, and molecular modeling analyses showed that the S-shaped dimer was formed by membrane-distal ectodomains, while the binding interface was different from that of SS- and X-dimers. Furthermore, the formation of the SS-dimer from the S-shaped and X-like dimers was directly visualized, suggesting the processes of SS-dimer formation from S-shaped and X-dimers during cadherin dimerization.

Neural crest cell-placodal neuron interactions are mediated by Cadherin-7 and N-cadherin during early chick trigeminal ganglion assembly

Background: Arising at distinct positions in the head, the cranial ganglia are crucial for integrating various sensory inputs. The largest of these ganglia is the trigeminal ganglion, which relays pain, touch and temperature information through its three primary nerve branches to the central nervous system. The trigeminal ganglion and its nerves are composed of derivatives of two critical embryonic cell types, neural crest cells and placode cells, that migrate from different anatomical locations, coalesce together, and differentiate to form trigeminal sensory neurons and supporting glia. While the dual cellular origin of the trigeminal ganglion has been known for over 60 years, molecules expressed by neural crest cells and placode cells that regulate initial ganglion assembly remain obscure. Prior studies revealed the importance of cell surface cadherin proteins during early trigeminal gangliogenesis, with Cadherin-7 and neural cadherin (N-cadherin) expressed in neural crest cells and placode cells, respectively. Although cadherins typically interact in a homophilic ( i.e., like) fashion, the presence of different cadherins on these intermingling cell populations raises the question as to whether heterophilic cadherin interactions may also be occurring during initial trigeminal ganglion formation, which was the aim of this study. Methods: To assess potential interactions between Cadherin-7 and N-cadherin, we used biochemistry and innovative imaging assays conducted in vitro and in vivo, including in the forming chick trigeminal ganglion. Results: Our data revealed a physical interaction between Cadherin-7 and N-cadherin. Conclusions: These studies identify a new molecular basis by which neural crest cells and placode cells can aggregate in vivo to build the trigeminal ganglion during embryogenesis.

Neural crest cell-placodal neuron interactions are mediated by Cadherin-7 and N-cadherin during early chick trigeminal ganglion assembly

Background: Arising at distinct positions in the head, the cranial ganglia are crucial for integrating various sensory inputs. The largest of these ganglia is the trigeminal ganglion, which relays pain, touch and temperature information through its three primary nerve branches to the central nervous system. The trigeminal ganglion and its nerves are composed of derivatives of two critical embryonic cell types, neural crest cells and placode cells, that migrate from different anatomical locations, coalesce together, and differentiate to form trigeminal sensory neurons and supporting glia. While the dual cellular origin of the trigeminal ganglion has been known for over 60 years, molecules expressed by neural crest cells and placode cells that regulate initial ganglion assembly remain obscure. Prior studies revealed the importance of cell surface cadherin proteins during early trigeminal gangliogenesis, with Cadherin-7 and neural cadherin (N-cadherin) expressed in neural crest cells and placode cells, respectively. Although cadherins typically interact in a homophilic ( i.e., like) fashion, the presence of different cadherins on these intermingling cell populations raises the question as to whether heterophilic cadherin interactions may also be occurring during initial trigeminal ganglion formation, which was the aim of this study. Methods: To assess potential interactions between Cadherin-7 and N-cadherin, we used biochemistry and innovative imaging assays conducted in vitro and in vivo, including in the forming chick trigeminal ganglion. Results: Our data revealed a physical interaction between Cadherin-7 and N-cadherin. Conclusions: These studies identify a new molecular basis by which neural crest cells and placode cells can aggregate in vivo to build the trigeminal ganglion during embryogenesis.

Neural crest cell-placodal neuron interactions are mediated by Cadherin-7 and N-cadherin during early chick trigeminal ganglion assembly

Background: Arising at distinct positions in the head, the cranial ganglia are crucial for integrating various sensory inputs. The largest of these ganglia is the trigeminal ganglion, which relays pain, touch and temperature information through its three primary nerve branches to the central nervous system. The trigeminal ganglion and its nerves are composed of derivatives of two critical embryonic cell types, neural crest cells and placode cells, that migrate from different anatomical locations, coalesce together, and differentiate to form trigeminal sensory neurons and supporting glia. While the dual cellular origin of the trigeminal ganglion has been known for over 60 years, molecules expressed by neural crest cells and placode cells that regulate initial ganglion assembly remain obscure. Prior studies revealed the importance of cell surface cadherin proteins during early trigeminal gangliogenesis, with Cadherin-7 and neural cadherin (N-cadherin) expressed in neural crest cells and placode cells, respectively. Although cadherins typically interact in a homophilic ( i.e., like) fashion, the presence of different cadherins expressed in neural crest cells and placode cells raises the question as to whether heterophilic cadherin interactions may also be occurring. Given this, the aim of the study was to understand whether Cadherin-7 and N-cadherin were interacting during initial trigeminal ganglion formation. Methods: To assess potential interactions between Cadherin-7 and N-cadherin, we used biochemistry and innovative imaging assays conducted in vitro and in vivo, including in the forming chick trigeminal ganglion. Results: Our data revealed a physical interaction between Cadherin-7 and N-cadherin. Conclusions: These studies identify a new molecular basis by which neural crest cells and placode cells can aggregate in vivo to build the trigeminal ganglion during embryogenesis.

Live imaging-based assay for visualising species-specific interactions in gamete adhesion molecules

Successful gamete fusion requires species-specific membrane adhesion. However, the interaction of adhesion molecules in gametes is difficult to study in real time through low-throughput microscopic observation. Therefore, we developed a live imaging-based adhesion molecule (LIAM) assay to study gamete adhesion molecule interactions in cultured cells. First, we modified a fusion assay previously established for fusogens introduced into cultured cells, and confirmed that our live imaging technique could visualise cell-cell fusion in the modified fusion assay. Next, instead of fusogen, we introduced adhesion molecules including a mammalian gamete adhesion molecule pair, IZUMO1 and JUNO, and detected their temporal accumulation at the contact interfaces of adjacent cells. Accumulated IZUMO1 or JUNO was partly translocated to the opposite cells as discrete spots; the mutation in amino acids required for their interaction impaired accumulation and translocation. By using the LIAM assay, we investigated the species specificity of IZUMO1 and JUNO of mouse, human, hamster, and pig in all combinations. IZUMO1 and JUNO accumulation and translocation were observed in conspecific, and some interspecific, combinations, suggesting potentially interchangeable combinations of IZUMO1 and JUNO from different species.

Varied solutions to multicellularity: The biophysical and evolutionary consequences of diverse intercellular bonds

The diversity of multicellular organisms is, in large part, due to the fact that multicellularity has independently evolved many times. Nonetheless, multicellular organisms all share a universal biophysical trait: cells are attached to each other. All mechanisms of cellular attachment belong to one of two broad classes; intercellular bonds are either reformable or they are not. Both classes of multicellular assembly are common in nature, having independently evolved dozens of times. In this review, we detail these varied mechanisms as they exist in multicellular organisms. We also discuss the evolutionary implications of different intercellular attachment mechanisms on nascent multicellular organisms. The type of intercellular bond present during early steps in the transition to multicellularity constrains future evolutionary and biophysical dynamics for the lineage, affecting the origin of multicellular life cycles, cell-cell communication, cellular differentiation, and multicellular morphogenesis. The types of intercellular bonds used by multicellular organisms may thus result in some of the most impactful historical constraints on the evolution of multicellularity.

All-in-one rheometry and nonlinear rheology of multicellular aggregates

Tissues are generally subjected to external stresses, a potential stimulus for their differentiation or remodeling. While single-cell rheology has been extensively studied leading to controversial results about nonlinear response, mechanical tissue behavior under external stress is still poorly understood, in particular, the way individual cell properties translate at the tissue level. Herein, using magnetic cells we were able to form perfectly monitored cellular aggregates (magnetic molding) and to deform them under controlled applied stresses over a wide range of timescales and amplitudes (magnetic rheometer). We explore the rheology of these minimal tissue models using both standard assays (creep and oscillatory response) as well as an innovative broad spectrum solicitation coupled with inference analysis thus being able to determine in a single experiment the best rheological model. We find that multicellular aggregates exhibit a power-law response with nonlinearities leading to tissue stiffening at high stress. Moreover, we reveal the contribution of intracellular (actin network) and intercellular components (cell-cell adhesions) in this aggregate rheology.

Muscle transcriptomics shows overexpression of cadherin 1 in inclusion body myositis

Objective

This study aimed to elucidate the molecular features of inclusion body myositis (IBM).

Methods

We performed RNA sequencing analysis of muscle biopsy samples from 67 participants, consisting of 58 myositis patients with the pathological finding of CD8‐positive T cells invading non‐necrotic muscle fibers expressing major histocompatibility complex class I (43 IBM, 6 polymyositis, and 9 unclassifiable myositis), and 9 controls.

Results

Cluster analysis, principal component analysis, and pathway analysis showed that differentially expressed genes and pathways identified in IBM and polymyositis were mostly comparable. However, pathways related to cell adhesion molecules were upregulated in IBM as compared with polymyositis and controls (p < 0.01). Notably, CDH1, which encodes the epidermal cell junction protein cadherin 1, was overexpressed in the muscles of IBM, which was validated by another RNA sequencing dataset from previous publications. Western blotting confirmed the presence of mature cadherin 1 protein in the muscles of IBM. Immunohistochemical staining confirmed the positivity for anti‐cadherin 1 antibody in the muscles of IBM, whereas there was no muscle fiber positive for anti‐cadherin 1 antibody in immune‐mediated necrotizing myopathy, antisynthetase syndrome, and controls. The fibers stained with anti‐cadherin 1 antibody did not have rimmed vacuoles or abnormal protein accumulation. Experimental skeletal muscle regeneration and differentiation systems showed that CDH1 is expressed during skeletal muscle regeneration and differentiation.

Interpretation

CDH1 was detected as a differentially expressed gene, and immunohistochemistry showed that cadherin 1 exists in the muscles of IBM, whereas it was rarely seen in those of other idiopathic inflammatory myopathies. Cadherin 1 upregulation in muscle could provide a valuable clue to the pathological mechanisms of IBM. ANN NEUROL 2022;91:317–328

Cooperation of membrane-translocated syntaxin4 and basement membrane for dynamic mammary epithelial morphogenesis

Mammary epithelia undergo dramatic morphogenesis after puberty. During pregnancy, luminal epithelial cells in ductal trees are arranged to form well-polarized cystic structures surrounded by a myoepithelial cell layer, an active supplier of the basement membrane (BM). Here, we identified a novel regulatory mechanism involved in this process by using a reconstituted BM-based three-dimensional culture and aggregates of a model mouse cell line, EpH4, that had either been manipulated for inducible expression of the t-SNARE protein syntaxin4 in intact or signal peptide-connected forms, or that were genetically deficient in syntaxin4. We found that cells extruded syntaxin4 upon stimulation with the lactogenic hormone prolactin, which in turn accelerated the turnover of E-cadherin. In response to extracellular expression of syntaxin4, cell populations that were less affected by the BM actively migrated and integrated into the cell layer facing the BM. Concurrently, the BM-facing cells, which were simultaneously stimulated with syntaxin4 and BM, acquired unique epithelial characteristics to undergo dramatic cellular arrangement for cyst formation. These results highlight the importance of the concerted action of extracellular syntaxin4 extruded in response to the lactogenic hormone and BM components in epithelial morphogenesis.

Hypoxia‑induced lactate dehydrogenase A protects cells from apoptosis in endometriosis

The pathological expression and function of lactate dehydrogenase A (LDHA), a key enzyme that converts pyruvate into lactic acid during glycolysis, remains unknown in endometriosis. In the present study, LDHA expression in tissue samples was determined by immunohistochemistry. To examine whether LDHA was induced by hypoxia, primary cultured endometrial stromal cells (ESCs) and glandular epithelial Ishikawa cells were exposed to 1% O₂ (hypoxia) or 21% O₂ (normoxia). Cellular functions were assessed by flow cytometry, Transwell and Cell Counting Kit-8 assays in LDHA-silenced ESCs and Ishikawa cells. Mitochondrial functions were evaluated using mitochondrial membrane potential JC-1 staining, reactive oxygen species flow cytometric analysis and ATP detection. Additionally, lactic acid production was examined and western blotting was used to evaluate the expression levels of proteins associated with apoptosis, cell cycle and glycolysis, as well as regulatory proteins involved in epithelial-mesenchymal transformation and glycolytic pathways. LDHA was localized to endometrial glandular cells and stromal cells. However, LDHA protein expression was higher in endometriotic lesions compared with that in normal and eutopic endometria. LDHA expression levels in ectopic glandular cells were higher during the proliferative stage compared with during the secretory stage. Hypoxia treatment of Ishikawa cells and ESCs markedly induced the mRNA and protein expression of LDHA. Silencing of LDHA expression in Ishikawa cells and THESC cells significantly promoted impaired mitochondrial function and apoptosis while inhibiting migration and glycolysis. However, it had no obvious effect on proliferation. In conclusion, the present study revealed that LDHA was highly expressed in endometriotic tissues, where it may serve a notable role in the occurrence and development of endometriosis.

In vitro investigation of the cell compatibility and antibacterial properties of titanium treated with calcium and ozone

The purpose of this study was to evaluate the surface modification of calcium ions on roughened titanium as a surface treatment of dental implants for cell attachment, growth, and initial bacterial adhesion. When a surface-roughened, pure titanium disk was immersed in a calcium chloride solution (100 mM) containing 20 ppm ozone for 24 h at 25ºC, calcium was detected on the surface by X-ray photoelectron spectroscopy. The calcium-modified, roughened titanium disk had a significantly greater concentration of the initially adhered cells as well as cells cultured over 7 days compared with titanium disks without surface modification. Furthermore, the initial bacterial adhesion on the calcium-ozone treated titanium disk was statistically less than on a pure titanium disk or titanium disk treated without ozone. Dissolved ozone was useful for modifying the surface of roughened titanium with calcium ions and the surface modification may be applicable for dental implants.

Mesenchymal-to-Epithelial Transitions in Development and Cancer

The evolutionary emergence of the mesenchymal phenotype greatly increased the complexity of tissue architecture and composition in early Metazoan species. At the molecular level, an epithelial-to-mesenchymal transition (EMT) was permitted by the innovation of specific transcription factors whose expression is sufficient to repress the epithelial transcriptional program. The reverse process, mesenchymal-to-epithelial transition (MET), involves direct inhibition of EMT transcription factors by numerous mechanisms including tissue-specific MET-inducing transcription factors (MET-TFs), micro-RNAs, and changes to cell and tissue architecture, thus providing an elegant solution to the need for tight temporal and spatial control over EMT and MET events during development and adult tissue homeostasis.

Hereditary diffuse gastric cancer therapeutic roadmap: current and novel approaches in a nutshell

Hereditary diffuse gastric cancer (HDGC) is a rare malignancy characterized by autosomal dominant inheritance of pathological variants of the CDH1 gene encoding E-cadherin, which is involved in cell–cell adhesion, maintenance of epithelial architecture, tumor suppression, and regulation of intracellular signaling pathways. Late-stage recognition of HDGC is typically associated with a poor clinical outcome due to its metastatic potential and risk of lobular breast cancer (LBC) development. The American College of Gastroenterology issued guidelines to evaluate HDGC, test for CDH1 genetic variants, and recommend prophylactic gastrectomy for carriers of CDH1 mutations. If surgery is not pursued, endoscopy is a surveillance alternative, although it carries a limited ability to detect malignant foci. As part of clinical research efforts, novel endoscopy advances are currently studied, and a center of excellence for HDGC was created for a comprehensive multidisciplinary team approach. Within this review, we cover current conventional treatment modalities such as gastrectomy and chemotherapy, as the mainstay treatments, in addition to Pembrolizumab, an immune checkpoint inhibitor, as the last therapeutic resort. We also shed light on novel and promising approaches with emphasis on immunotherapy to treat HDGC. We further break down the therapeutic paradigms to utilize molecular tools, antibodies against checkpoint inhibitors, TGF-β and tyrosine kinase inhibitors, cell-based adoptive therapies, and oncolytic viral therapies. We aim to expand the understanding on how to modulate the tumor microenvironment to tip the balance towards an anti-tumor phenotype, prevent metastasis of the primary disease, and potentially alter the therapeutic landscape for HDGC.

LY75 Suppression in Mesenchymal Epithelial Ovarian Cancer Cells Generates a Stable Hybrid EOC Cellular Phenotype, Associated with Enhanced Tumor Initiation, Spreading and Resistance to Treatment in Orthotopic Xenograft Mouse Model

The implications of the epithelial-mesenchymal transition (EMT) mechanisms in the initiation and progression of epithelial ovarian cancer (EOC) remain poorly understood. We have previously shown that suppression of the antigen receptor LY75 directs mesenchymal-epithelial transition (MET) in EOC cell lines with the mesenchymal phenotype, associated with the loss of Wnt/β-catenin signaling activity. In the present study, we used the LY75-mediated modulation of EMT in EOC cells as a model in order to investigate in vivo the specific role of EOC cells, with an epithelial (E), mesenchymal (M) or mixed epithelial plus mesenchymal (E+M) phenotype, in EOC initiation, dissemination and treatment response, following intra-bursal (IB) injections of SKOV3-M (control), SKOV3-E (Ly75KD) and a mixed population of SKOV3-E+M cells, into severe combined immunodeficiency (SCID) mice. We found that the IB-injected SKOV3-E cells displayed considerably higher metastatic potential and resistance to treatment as compared to the SKOV3-M cells, due to the acquisition of a Ly75KD-mediated hybrid phenotype and stemness characteristics. We also confirmed in vivo that the LY75 depletion directs suppression of the Wnt/β-catenin pathway in EOC cells, suggestive of a protective role of this pathway in EOC etiology. Moreover, our data raise concerns regarding the use of LY75-targeted vaccines for dendritic-cell EOC immunotherapy, due to the possible occurrence of undesirable side effects.

From Orai to E-Cadherin: Subversion of Calcium Trafficking in Cancer to Drive Proliferation, Anoikis-Resistance, and Metastasis

The common currency of epithelial differentiation and homeostasis is calcium, stored primarily in the endoplasmic reticulum, rationed according to need, and replenished from the extracellular milieu via store-operated calcium entry (SOCE). This currency is disbursed by the IP3 receptor in response to diverse extracellular signals. The rate of release is governed by regulators of proliferation, autophagy, survival, and programmed cell death, the strength of the signal leading to different outcomes. Intracellular calcium acts chiefly through intermediates such as calmodulin that regulates growth factor receptors such as epidermal growth factor receptor (EGFR), actin polymerization, and adherens junction assembly and maintenance. Here we review this machinery and its role in differentiation, then consider how cancer cells subvert it to license proliferation, resist anoikis, and enable metastasis, either by modulating the level of intracellular calcium or its downstream targets or effectors such as EGFR, E-cadherin, IQGAP1, TMEM16A, CLCA2, and TRPA1. Implications are considered for the roles of E-cadherin and growth factor receptors in circulating tumor cells and metastasis. The discovery of novel, cell type-specific modulators and effectors of calcium signaling offers new possibilities for cancer chemotherapy.

Collective Migrations of Drosophila Embryonic Trunk and Caudal Mesoderm-Derived Muscle Precursor Cells

Mesoderm migration in the Drosophila embryo is a highly conserved, complex process that is required for the formation of specialized tissues and organs, including the somatic and visceral musculature. In this FlyBook chapter, we will compare and contrast the specification and migration of cells originating from the trunk and caudal mesoderm. Both cell types engage in collective migrations that enable cells to achieve new positions within developing embryos and form distinct tissues. To start, we will discuss specification and early morphogenetic movements of the presumptive mesoderm, then focus on the coordinate movements of the two subtypes trunk mesoderm and caudal visceral mesoderm, ending with a comparison of these processes including general insights gained through study.

Stearoyl-CoA Desaturase 1 as a Therapeutic Target for the Treatment of Cancer

A distinctive feature of cancer cells of various origins involves alterations of the composition of lipids, with significant enrichment in monounsaturated fatty acids. These molecules, in addition to being structural components of newly formed cell membranes of intensely proliferating cancer cells, support tumorigenic signaling. An increase in the expression of stearoyl-CoA desaturase 1 (SCD1), the enzyme that converts saturated fatty acids to ∆9-monounsaturated fatty acids, has been observed in a wide range of cancer cells, and this increase is correlated with cancer aggressiveness and poor outcomes for patients. Studies have demonstrated the involvement of SCD1 in the promotion of cancer cell proliferation, migration, metastasis, and tumor growth. Many studies have reported a role for this lipogenic factor in maintaining the characteristics of cancer stem cells (i.e., the population of cells that contributes to cancer progression and resistance to chemotherapy). Importantly, both the products of SCD1 activity and its direct impact on tumorigenic pathways have been demonstrated. Based on these findings, SCD1 appears to be a significant player in the development of malignant disease and may be a promising target for anticancer therapy. Numerous chemical compounds that exert inhibitory effects on SCD1 have been developed and preclinically tested. The present review summarizes our current knowledge of the ways in which SCD1 contributes to the progression of cancer and discusses opportunities and challenges of using SCD1 inhibitors for the treatment of cancer.

N-cadherin-mediated aggregate formation; cell detachment by Trypsin-EDTA loses N-cadherin and delays aggregate formation

Although cell aggregates/spheroids are useful tools in various fields of cell biology, the mechanism for aggregate formation is not fully resolved yet. Here I show the involvement of N-cadherin in the quick formation of packed aggregates in suspension culture. HEK293T cells detached from substratum by Trypsin alone quickly formed packed aggregates in suspension. This aggregate formation was inhibited by the down-regulation of N-cadherin. Meanwhile, aggregate formation of cells detached by Trypsin-EDTA was significantly delayed. N-cadherin was transiently lost by Trypsin-EDTA-treatment, and the re-expression of N-cadherin corresponded to delayed aggregate formation. Furthermore, packed phenotype was not observed in the absence of N-cadherin. These findings indicate that N-cadherin mediates quick formation of packed aggregates/spheroids in suspension culture.

A Novel Cadherin-like Protein Mediates Adherence to and Killing of Host Cells by the Parasite Trichomonas vaginalis

Trichomonas vaginalis, a prevalent sexually transmitted parasite, adheres to and induces cytolysis of human mucosal epithelial cells. We have characterized a hypothetical protein, TVAG_393390, with predicted tertiary structure similar to that of mammalian cadherin proteins involved in cell-cell adherence. TVAG_393390, renamed cadherin-like protein (CLP), contains a calcium-binding site at a position conserved in cadherins. CLP is surface localized, and its mRNA and protein levels are significantly upregulated upon parasite adherence to host cells. To test the roles of CLP and its calcium-binding dependency during host cell adherence, we first demonstrated that wild-type CLP (CLP) binds calcium with a high affinity, whereas the calcium-binding site mutant protein (CLP-mut) does not. CLP and CLP-mut constructs were then used to overexpress these proteins in T. vaginalis Parasites overexpressing CLP have ∼3.5-fold greater adherence to host cells than wild-type parasites, and this increased adherence is ablated by mutating the calcium-binding site. Additionally, competition with recombinant CLP decreased parasite binding to host cells. We also found that overexpression of CLP induced parasite aggregation which was further enhanced in the presence of calcium, whereas CLP-mut overexpression did not affect aggregation. Lastly, parasites overexpressing wild-type CLP induced killing of host cells ∼2.35-fold, whereas parasites overexpressing CLP-mut did not have this effect. These analyses describe the first parasitic CLP and demonstrate a role for this protein in mediating parasite-parasite and host-parasite interactions. T. vaginalis CLP may represent convergent evolution of a parasite protein that is functionally similar to the mammalian cell adhesion protein cadherin, which contributes to parasite pathogenesis.IMPORTANCE The adherence of pathogens to host cells is critical for colonization of the host and establishing infection. Here we identify a protein with no known function that is more abundant on the surface of parasites that are better at binding host cells. To interrogate a predicted function of this protein, we utilized bioinformatic protein prediction programs which allowed us to uncover the first cadherin-like protein (CLP) found in a parasite. Cadherin proteins are conserved metazoan proteins with central roles in cell-cell adhesion, development, and tissue structure maintenance. Functional characterization of this CLP from the unicellular parasite Trichomonas vaginalis demonstrated that the protein mediates both parasite-parasite and parasite-host adherence, which leads to an enhanced killing of host cells by T. vaginalis Our findings demonstrate the presence of CLPs in unicellular pathogens and identify a new host cell binding protein family in a human-infective parasite.

Getting a grip on adhesion: Cadherin switching and collagen signaling

Epithelial-mesenchymal transition (EMT) is a developmental biological process that is hijacked during tumor progression. Cadherin switching, which disrupts adherens junctions and alters cadherin-associated signaling pathways, is common during EMT. In many tumors, substantial extracellular matrix (ECM) is deposited. Collagen is the most abundant ECM constituent and it mediates specific signaling pathways by binding to integrins and discoidin domain receptors (DDRs). The interaction of the collagen receptors results in activation of signaling pathways that promote tumor progression including an induction of the cadherin switching. DDR inhibitors have demonstrated anticancer therapeutic efficacy preclinically by inhibiting the collagen signaling. Understanding how collagen signaling impacts cellular processes including EMT and cadherin switching is of great interest especially given the strong interest in stromal targeted therapies for desmoplastic cancers.

Neural differentiation of mouse induced pluripotent stem cells using cadherin gene-engineered PA6 feeder cells

Investigating neural differentiation of pluripotent stem cells, including induced pluripotent stem (iPS) cells, is of importance for studying early neural development and providing a potential source of cells for nerve regeneration. Stromal cell-derived inducing activity (SDIA) using PA6 stromal cells promotes neural differentiation of iPS cells. Thus, we hypothesized that cadherin gene-engineered PA6 feeder cells will enhance the performance of SDIA by facilitating cell-cell interactions. Consequently, we created cadherin gene-engineered PA6 cells. Efficiency of neural differentiation from mouse iPS cells on PA6 feeder cells overexpressing E-cadherin gene (46%) or N-cadherin gene (27%) was significantly higher compared with parental PA6 feeder cells (19%). In addition, efficiency of motor neuron differentiation from mouse iPS cells on cadherin-gene engineered feeder cells (E-cadherin, 7.4%; N-cadherin, 11%) was significantly higher compared with parental PA6 feeder cells (4.1%). Altogether, these results indicate that cadherin gene-engineered feeder cells are a potent tool for promoting neural differentiation of pluripotent stem cells.

Estradiol and the Development of the Cerebral Cortex: An Unexpected Role?

The cerebral cortex undergoes rapid folding in an "inside-outside" manner during embryonic development resulting in the establishment of six discrete cortical layers. This unique cytoarchitecture occurs via the coordinated processes of neurogenesis and cell migration. In addition, these processes are fine-tuned by a number of extracellular cues, which exert their effects by regulating intracellular signaling pathways. Interestingly, multiple brain regions have been shown to develop in a sexually dimorphic manner. In many cases, estrogens have been demonstrated to play an integral role in mediating these sexual dimorphisms in both males and females. Indeed, 17β-estradiol, the main biologically active estrogen, plays a critical organizational role during early brain development and has been shown to be pivotal in the sexually dimorphic development and regulation of the neural circuitry underlying sex-typical and socio-aggressive behaviors in males and females. However, whether and how estrogens, and 17β-estradiol in particular, regulate the development of the cerebral cortex is less well understood. In this review, we outline the evidence that estrogens are not only present but are engaged and regulate molecular machinery required for the fine-tuning of processes central to the cortex. We discuss how estrogens are thought to regulate the function of key molecular players and signaling pathways involved in corticogenesis, and where possible, highlight if these processes are sexually dimorphic. Collectively, we hope this review highlights the need to consider how estrogens may influence the development of brain regions directly involved in the sex-typical and socio-aggressive behaviors as well as development of sexually dimorphic regions such as the cerebral cortex.

Membrane-tethered syntaxin-4 locally abrogates E-cadherin function and activates Smad signals, contributing to asymmetric mammary epithelial morphogenesis

Spatial and temporal epithelial-mesenchymal transition (EMT) is a critical event for the generation of asymmetric epithelial architectures. We found that only restricted cell populations in the morphogenic mammary epithelia extrude syntaxin-4, a plasmalemmal t-SNARE protein, and that epithelial cell clusters with artificial heterogenic presentation of extracellular syntaxin-4 undergo asymmetric morphogenesis. A previous study revealed that inducible expression of cell surface syntaxin-4 causes EMT-like cell behaviors in the clonal mammary epithelial cells, where laminin-mediated signals were abolished so that cells readily succumb to initiate EMT. The present study added new mechanistic insight into syntaxin-4-driven EMT-like cell behaviors. Extracellular syntaxin-4 directly perturbs E-cadherin-mediated epithelial cell-cell adhesion and activates Smad signals. We found that the epithelial cells activated Smad2/3 upon induction of expression of extracellular syntaxin-4, leading to the upregulation of certain transcriptional targets of these TGF-β signaling mediators. Intriguingly, however, mRNA expression of canonical EMT initiators, such as Snail and Slug, was unchanged. In addition, E-cadherin protein was steeply decreased, yet its transcriptional expression remained constant for a couple of days. We found that extracellular syntaxin-4 directly bound to E-cadherin and sequestered β-catenin from cell-cell contact sites, perturbing intercellular adhesive property. The functional ablation of E-cadherin by syntaxin-4 was further validated by L cells with stably expressing E-cadherin, in which cells shows intercellular adhesive property solely by E-cadherin. These results underline the role of local exportation of syntaxin-4 for onset of complex epithelial morphogenesis.

EZH2 inhibition promotes epithelial-to-mesenchymal transition in ovarian cancer cells

Cancer cells acquire essential characteristics for metastatic dissemination through the process of epithelial-to-mesenchymal transition (EMT), which is regulated by gene expression and chromatin remodeling changes. The enhancer of zeste homolog 2 (EZH2), the catalytic subunit of the polycomb repressive complex 2 (PRC2), catalyzes trimethylation of lysine 27 of histone H3 (H3K27me3) to repress gene transcription. Here we report the functional roles of EZH2-catalyzed H3K27me3 during EMT in ovarian cancer (OC) cells. TGF-β-induced EMT in SKOV3 OC cells was associated with decreased levels of EZH2 and H3K27me3 (P<0.05). These effects were delayed (~72 h relative to EMT initiation) and coincided with increased (>15-fold) expression of EMT-associated transcription factors ZEB2 and SNAI2. EZH2 knockdown (using siRNA) or enzymatic inhibition (by GSK126) induced EMT-like changes in OC cells. The EMT regulator ZEB2 was upregulated in cells treated with either approach. Furthermore, TGF-β enhanced expression of ZEB2 in EZH2 siRNA- or GSK126-treated cells (P<0.01), suggesting that H3K27me3 plays a role in TGF-β-stimulated ZEB2 induction. Chromatin immunoprecipitation assays confirmed that TGF-β treatment decreased binding of EZH2 and H3K27me3 to the ZEB2 promoter (P<0.05). In all, these results demonstrate that EZH2, by repressing ZEB2, is required for the maintenance of an epithelial phenotype in OC cells.

Loss of E-Cadherin-Dependent Cell-Cell Adhesion and the Development and Progression of Cancer

Classical cadherins are the key molecules that control cell-cell adhesion. Notwithstanding this function, it is also clear that classical cadherins are more than just the "glue" that keeps the cells together. Cadherins are essential regulators of tissue homeostasis that govern multiple facets of cellular function and development, by transducing adhesive signals to a complex network of signaling effectors and transcriptional programs. In cancer, cadherins are often inactivated or functionally inhibited, resulting in disease development and/or progression. This review focuses on E-cadherin and its causal role in the development and progression of breast and gastric cancer. We provide a summary of the biochemical consequences and consider the conceptual impact of early (mutational) E-cadherin loss in cancer. We advocate that carcinomas driven by E-cadherin loss should be considered "actin-diseases," caused by the specific disruption of the E-cadherin-actin connection and a subsequent dependence on sustained actomyosin contraction for tumor progression. Based on the available data from mouse and human studies we discuss opportunities for targeted clinical intervention.

Historical review of the discovery of cadherin, in memory of Tokindo Okada

The cadherin family of cell-cell adhesion molecules plays a pivotal role in animal tissue formation. Discovery of this molecular family can be traced back to some unexpected observations of strange cell behavior that were made around 1970 in the Kyoto University laboratory of Tokindo Okada, and then in the Department of Embryology at the Carnegie Institution of Washington (currently the Carnegie Institution for Science). This article looks back on these discoveries, and recalls how these observations led to the identification of important cell-cell adhesion molecules known as cadherins.

DcR3 combined with hematological traits serves as a valuable biomarker for the diagnosis of cancer metastasis

Decoy receptor 3 (DcR3) is abnormally up-regulated in many cancer cells. It may help cancer cells to escape from immune surveillance and establish metastatic lesions. However, whether DcR3 can be used as a biomarker for the diagnosis of cancer metastasis is unclear. In this study, sera from healthy controls and patients with different cancers were collected, and tested for their DcR3 levels by ELISA. Significantly elevated DcR3 levels were observed in the sera of patients with gastric cancer (2.04 ± 1.01, P = 0.0061), lymphoma (1.62 ± 0.75, P = 0.041), and breast cancer (1.53 ± 0.51, P = 0.023). DcR3 was found to be a suitable biomarker for identifying gastric cancer patients. Importantly, DcR3 was positively associated with platelet distribution width (PDW) (P = 2.45 × 10⁻⁶, R = 0.63) in metastatic cancers but negatively associated with hemoglobin (HGB) (P = 0.002, R = −0.59) and hematocrit (HCT) (P = 0.001, R = −0.62) in non-metastatic cancers. Combined with PDW, HGB and HCT, serum DcR3 could be used to predict the occurrence of cancer metastasis. These findings indicate that DcR3 could be used as a biomarker for the diagnosis of gastric cancer, and for cancer metastasis in combination with hematological traits.

Lobular Carcinoma In Situ

Lobular carcinoma in situ (LCIS) is a risk factor and a nonobligate precursor of breast carcinoma. The relative risk of invasive carcinoma after classic LCIS diagnosis is approximately 9 to 10 times that of the general population. Classic LCIS diagnosed on core biopsy with concordant imaging and pathologic findings does not mandate surgical excision, and margin status is not reported. The identification of variant LCIS in a needle core biopsy specimen mandates surgical excision, regardless of radiologic-pathologic concordance. The presence of variant LCIS close to the surgical margin of a resection specimen is reported, and reexcision should be considered.

DcR3 promotes hepatoma cell migration by downregulating E-cadherin expression

Decoy receptor 3 (DcR3), a decoy molecule belonging to the tumor necrosis factor receptor superfamily (TNFRSF), is a soluble receptor that can neutralize the biological effects of three other TNFSF members, namely, Fas ligand (FasL/TNFSF6/CD95L), LIGHT (TNFSF14) and TNF-like molecule 1A (TL1A/TNFSF15). DcR3 expression is increased in tumor cells. As such, DcR3 has been considered a potential biomarker to predict cancer invasion and progression of inflammation. However, the molecular mechanisms of DcR3 in tumor progression and metastasis remain poorly described. In the present study, DcR3 induced cytoskeleton remodeling, inhibited E-cadherin expression, and promoted cancer cell migration. Immunofluorescence and flow cytometry demonstrated that DcR3 expression was increased in hepatoma cells, whereas E-cadherin expression was significantly downregulated. Immunohistochemistry revealed that DcR3 and E-cadherin exhibited an opposite expression pattern between normal and cancerous liver tissues. Moreover, DcR3 treatment promoted IκBα degradation and p65 nuclear translocation. Therefore, the present study uncovered the mechanism underlying the function of DcR3 in cancer cell migration and provides evidence that DcR3 may be a potential target for cancer therapy.

Linking E-cadherin mechanotransduction to cell metabolism through force-mediated activation of AMPK

The response of cells to mechanical force is a major determinant of cell behaviour and is an energetically costly event. How cells derive energy to resist mechanical force is unknown. Here, we show that application of force to E-cadherin stimulates liver kinase B1 (LKB1) to activate AMP-activated protein kinase (AMPK), a master regulator of energy homeostasis. LKB1 recruits AMPK to the E-cadherin mechanotransduction complex, thereby stimulating actomyosin contractility, glucose uptake and ATP production. The increase in ATP provides energy to reinforce the adhesion complex and actin cytoskeleton so that the cell can resist physiological forces. Together, these findings reveal a paradigm for how mechanotransduction and metabolism are linked and provide a framework for understanding how diseases involving contractile and metabolic disturbances arise.

Suppression of the grainyhead transcription factor 2 gene (GRHL2) inhibits the proliferation, migration, invasion and mediates cell cycle arrest of ovarian cancer cells

Previously, we have identified the Grainyhead transcription factor 2 gene (GRHL2) as notably hypomethylated in high-grade (HG) serous epithelial ovarian tumors, compared with normal ovarian tissues. GRHL2 is known for its functions in normal tissue development and wound healing. In the context of cancer, the role of GRHL2 is still ambiguous as both tumorigenic and tumor suppressive functions have been reported for this gene, although a role of GRHL2 in maintaining the epithelial status of cancer cells has been suggested. In this study, we report that GRHL2 is strongly overexpressed in both low malignant potential (LMP) and HG serous epithelial ovarian tumors, which probably correlates with its hypomethylated status. Suppression of the GRHL2 expression led to a sharp decrease in cell proliferation, migration and invasion and induced G1 cell cycle arrest in epithelial ovarian cancer (EOC) cells displaying either epithelial (A2780s) or mesenchymal (SKOV3) phenotypes. However, no phenotypic alterations were observed in these EOC cell lines following GRHL2 silencing. Gene expression profiling and consecutive canonical pathway and network analyses confirmed these data, as in both these EOC cell lines, GRHL2 ablation was associated with the downregulation of various genes and pathways implicated in cell growth and proliferation, cell cycle control and cellular metabolism. Taken together, our data are indicative for a strong oncogenic potential of the GRHL2 gene in EOC progression and support recent findings on the role of GRHL2 as one of the major phenotypic stability factors (PSFs) that stabilize the highly aggressive/metastatic hybrid epithelial/mesenchymal (E/M) phenotype of cancer cells.

Gamma secretase inhibitor impairs epithelial-to-mesenchymal transition induced by TGF-β in ovarian tumor cell lines

Ovarian cancer is characterized by being highly metastatic, a feature that represents the main cause of failure of the treatment. This study investigated the effects of γ-secretase inhibition on the TGF-β-induced epithelial-mesenchymal transition (EMT) process in ovarian cancer cell lines. SKOV3 cells incubated in the presence of TGF-β showed morphological and biochemical changes related to EMT, which were blocked by co-stimulation with TGF-β and the γ-secretase inhibitor DAPT. In SKOV3 and IGROV1 cells, the co-stimulation blocked the cadherin switch and the increase in the transcription factors Snail, Slug, Twist and Zeb1 induced by TGF-β. DAPT impaired the translocation of phospho-β-catenin to the inner cell compartment observed in TGF-β-treated cells, but was not able to block the induction at protein level induced by TGF-β. Moreover, the inhibitor blocked the increased cell migration and invasiveness ability of both cell lines induced by TGF-β. Notch target genes (Hes1 and Hey1) were induced by TGF-β, decreased by DAPT treatment and remained low in the presence of both stimuli. However, DAPT alone caused no effects on most of the parameters analyzed. These results demonstrate that the γ-secretase inhibitor used in this study exerted a blockade on TGF-β-induced EMT in ovarian cancer cells.

Nanodiamonds as Raman probes for specifically targeted bioimaging: visualization and mechanism study of the biorecognition between nanodiamonds-EGF and EGFR

Targeting ligand EGF induced cell morphology change and potential cell migration risks visualized with Raman mapping using NDs as probes.

The Extracellular C-loop Domain Plays an Important Role in the Cell Adhesion Function of Aquaporin 0

PURPOSE

Although aquaporin 0 (AQP0) is a member of the AQP family, it has limited water permeability compared with other members. AQP0 may also have cell adhesion-related functions, but the evidence is still limited. Here, we studied the relationship of AQP0 to cell adhesion and determined the region required for cell adhesion.

METHODS

L-cell fibroblasts stably expressing AQP0 or AQP1 (L-AQP0 or L-AQP1) were established. One group of cells was stained with CellTracker Red and cultured into a confluent monolayer, whereas the other group was loaded with CellTracker Blue and seeded over the monolayer. To study cell adhesion, the percentages of lower and upper layer cells were measured using flow cytometry. To determine the region of AQP0 required for adhesion, activity was done by pull-down assay using glutathione S-transferase fusion proteins. To study the water permeability, Xenopus laevis oocyte expressing AQP0 wild-type or AQP0 mutated in C-loop was transferred to a hypotonic solution and photographed, and the diameter was measured to calculate the volume.

RESULTS

More cells adhered to the lower cells in the L-AQP0 homotypic pair than other pairs such as L-AQP1 homotypic or L-AQP0/L-AQP1 heterotypic pairs. Pull-down assays revealed that AQP0 could bind to itself via the C-loop extracellular domain. Furthermore, we determined that ¹⁰⁹Pro and ¹¹⁰Pro in the C-loop were important for cell adhesion. However, mutation of the C-loop in AQP0 did not affect its water permeability.

CONCLUSIONS

AQP0 is known to bind lipids in the opposing membrane. Our data suggest that this cell-to-cell adhesion occurs not only in the AQP0/liquids but also via AQP0/AQP0 interaction through the C-loop domain. Mutations in the C-loop amino acids did not affect the water permeability of AQP0 but did affect its cell adhesion function. These independent dual functions of AQP0 are important for lens transparency.

The number of polyploid giant cancer cells and epithelial-mesenchymal transition-related proteins are associated with invasion and metastasis in human breast cancer

Background

Previously, we reported that polyploid giant cancer cells (PGCCs) induced by cobalt chloride (CoCl₂) could have generated daughter cells with strong invasiveness and migration capabilities via asymmetric divisions. This study compared the expression of epithelial-mesenchymal transition (EMT)-related proteins, including E-cadherin, N-cadherin, and vimentin, between PGCCs and their daughter cells, and control breast cancer cell lines MCF-7 and MDA-MB-231. The clinicopathological significance of EMT-related protein expression in human breast cancer was analyzed.

Methods

Western blot was used to compare the expression levels of E-cadherin, N-cadherin, and vimentin in breast cancer lines MCF-7 and MDA-MB-231, between PGCCs with budding daughter cells and control breast cancer cells. Furthermore, 167 paraffin-embedded breast tumor tissue samples were analyzed, including samples obtained from 52 patients with primary breast cancer with lymph node metastasis (group I) and their corresponding lymph node metastatic tumors (group II), 52 patients with primary breast cancer without metastasis (group III), and 11 patients with benign breast lesions (group IV). The number of PGCCs was compared among these four groups.

Results

The number of PGCCs increased with the malignant grade of breast tumor. Group IIhad the highest number of PGCCs and the differences among group I, II, III and IV had statistically significance (P =0.000). In addition, the expression of E-cadherin (P = 0.000), N-cadherin (P = 0.000), and vimentin (P = 0.000) was significantly different among the four groups. Group II exhibited the highest expression levels of N-cadherin and vimentin and the lowest expression levels of E-cadherin.

Conclusions

These data suggest that the number of PGCCs and the EMT-related proteins E-cadherin, N-cadherin, and vimentin may be valuable biomarkers to assess metastasis in patients with breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0277-8) contains supplementary material, which is available to authorized users.

Protocadherins and hypothalamic development: do they play an unappreciated role?

Normal brain development requires coordinated cell movements at precise times. It has long been established that cell-cell adhesion proteins of the cadherin superfamily are involved in the adhesion and sorting of cells during tissue morphogenesis. In the present review, we focus on protocadherins, which form the largest subfamily of the cadherin superfamily and mediate homophilic cell-cell adhesion in the developing brain. These molecules are highly expressed during neural development and the exact roles that they play are still emerging. Although, historically, protocadherins were considered to provide mechanical and chemical connections between adjacent cells, recent research suggests that they may also serve as molecular identity markers of neurones to help guide cell recognition and sorting, cell migration, outgrowth of neuronal processes, and synapse formation. This phenomenon of single cell diversity stems, in part, from the vast variation in protein structure, genomic organisation and molecular function of the protocadherins. Although expression profiles and genetic manipulations have provided evidence for the role of protocadherins in the developing brain, we have only begun to construct a complete understanding of protocadherin function. We examine our current understanding of how protocadherins influence brain development and discuss the possible roles for this large superfamily within the hypothalamus. We conclude that further research into these underappreciated but vitally important genes will shed insight into hypothalamic development and perhaps the underlying aetiology of neuroendocrine disorders.

PI3K/AKT pathway regulates E-cadherin and Desmoglein 2 in aggressive prostate cancer

Reduced expression of both classical and desmosomal cadherins has been associated with different types of carcinomas, including prostate cancer. This study aims to provide a comprehensive view of the role and regulation of cell-cell adhesion in prostate cancer aggressiveness by examining the functional implications of both E-cadherin and Desmoglein 2 (DSG2). E-cadherin expression was first examined using immunofluorescence in 50 normal prostate tissues and in a cohort of 414 prostate cancer patients. Correlation and survival analyses were performed to assess its clinical significance. In primary prostate cancer patients, reduced expression of both E-cadherin and DSG2 is significantly associated with an earlier biochemical recurrence. Transgenic DU145 E-cadherin knockdown and constitutively active AKT overexpression lines were generated. Functional implications of such genetic alterations were analyzed in vitro and in vivo, the latter by using tumorigenesis as well as extravasation and metastatic tumor formation assays. We observed that loss of E-cadherin leads to impaired primary and metastatic tumor formation in vivo, suggesting a tumor promoter role for E-cadherin in addition to its known role as a tumor suppressor. Activation of AKT leads to a significant reduction in E-cadherin expression and nuclear localization of Snail, suggesting a role for the PI3K/AKT signaling pathway in the transient repression of E-cadherin. This reduced expression may be regulated by separate mechanisms as neither the loss of E-cadherin nor activation of AKT significantly affected DSG2 expression. In conclusion, these findings illustrate the critical role of cell-cell adhesion in the progression to aggressive prostate cancer, through regulation by the PI3K pathway.