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Background: CDH1 and CTNNA1 remain as the main genes for hereditary gastric cancer. However, they only explain a small fraction of gastric cancer cases with suspected inherited basis. In this study, we aimed to identify new hereditary genes for early-onset gastric cancer patients (EOGC; < 50 years old). Methods: After germline exome sequencing in 20 EOGC patients and replication of relevant findings by gene-panel sequencing in an independent cohort of 152 patients, CTNND1 stood out as an interesting candidate gene, since its protein product (p120ctn) directly interacts with E-cadherin. We proceeded with functional characterization by generating two knockout CTNND1 cellular models by gene editing and introducing the detected genetic variants using a lentiviral delivery system. We assessed β-catenin and E-cadherin levels, cell detachment, as well as E-cadherin localization and cell-to-cell interaction by spheroid modeling. Results: Three CTNND1 germline variants [c.28_29delinsCT, p.(Ala10Leu); c.1105C > T, p.(Pro369Ser); c.1537A > G, p.(Asn513Asp)] were identified in our EOGC cohorts. Cells encoding CTNND1 variants displayed altered E-cadherin levels and intercellular interactions. In addition, the p.(Pro369Ser) variant, located in a key region in the E-cadherin/p120ctn binding domain, showed E-cadherin mislocalization. Conclusions: Defects in CTNND1 could be involved in germline predisposition to gastric cancer by altering E-cadherin and, consequently, cell-to-cell interactions. In the present study, CTNND1 germline variants explained 2% (3/172) of the cases, although further studies in larger external cohorts are needed. [ABSTRACT FROM AUTHOR]

Human-specific genes are potential drivers of brain evolution. Among them, SRGAP2C has contributed to the emergence of features characterizing human cortical synapses, including their extended period of maturation. SRGAP2C inhibits its ancestral copy, the postsynaptic protein SRGAP2A, but the synaptic molecular pathways differentially regulated in humans by SRGAP2 proteins remain largely unknown. Here, we identify CTNND2, a protein implicated in severe intellectual disability (ID) in Cri-du-Chat syndrome, as a major partner of SRGAP2. We demonstrate that CTNND2 slows synaptic maturation and promotes neuronal integrity. During postnatal development, CTNND2 moderates neuronal excitation and excitability. In adults, it supports synapse maintenance. While CTNND2 deficiency is deleterious and results in synaptic loss of SYNGAP1, another major ID-associated protein, the human-specific protein SRGAP2C, enhances CTNND2 synaptic accumulation in human neurons. Our findings suggest that CTNND2 regulation by SRGAP2C contributes to synaptic neoteny in humans and link human-specific and ID genes at the synapse., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: This study aims to explore the effects of miR-223-3p and miR-155-5p on epithelial-mesenchymal transition (EMT) and migration in oral squamous cell carcinoma (OSCC)., Methodology: EMT markers (E-cadherin, N-cadherin, P120 catenin (P120ctn), and vimentin) expression was determined by qRT-PCR and western blot analysis in SCC-9 cells which overexpress miR-155-5p and/or not express miR-223-3p. Scratch assays and Transwell migration assays were conducted to evaluate cell migration ability., Results: When miR-223-3p was inhibited in OSCC cells, P120ctn and E-cadherin mRNA levels were dramatically downregulated (P<0.05), while N-cadherin levels were significantly upregulated, and the migration ability of OSCC cells increased. The overexpression of miR-155-5p in OSCC cells upregulated miR-223-3p significantly (34-fold) compared to the control group. It also led to significant downregulation of the mRNA of P120ctn and E-cadherin and significant upregulation of the mRNA of N-cadherin and Vimentin (P<0.05). Meanwhile, the migratory ability of OSCC cells significantly increased. When miR-155-5p was overexpressed while miR-223-3p was inhibited, the highest expression of E-cadherin and P120ctn mRNA and the lowest expression of N-cadherin(P<0.05) was observed. Simultaneously, tumor cell migration was significantly facilitated., Conclusion: miR-223-3p inhibits the migration of OSCC cells, while miR-155-5p can elevate the miR-223-3p mRNA expression. The simultaneous miR-155-5p overexpression and miR-223-3p inhibition can activate pEMT, increasing OSCC migration in vitro. This provides a novel approach and potential target for the effective treatment of OSCC.

CTNND2 encodes δ-catenin, a component of an adherens junction complex, and plays an important role in neuronal structure and function. To date, only heterozygous loss-of-function CTNND2 variants have been associated with mild neurodevelopmental delay and behavioral anomalies, a condition, which we named Rauch-Azzarello syndrome. Here, we report three siblings of a consanguineous family of Syrian descent with a homozygous deletion encompassing the last 19 exons of CTNND2 predicted to disrupt the transcript. All presented with severe neurodevelopmental delay with absent speech, profound motor delay, stereotypic behavior, microcephaly, short stature, muscular hypotonia with lower limb hypertonia, and variable eye anomalies. The parents and the fourth sibling were heterozygous carriers of the deletion and exhibited mild neurodevelopmental impairment resembling that of the previously described heterozygous individuals. The present study unveils a severe manifestation of CTNND2-associated Rauch-Azzarello syndrome attributed to biallelic loss-of-function aberrations, clinically distinct from the already described mild presentation of heterozygous individuals. Furthermore, we demonstrate novel clinical features in homozygous individuals that have not been reported in heterozygous cases to date., (© 2024 The Authors. Clinical Genetics published by John Wiley & Sons Ltd.)

Prostate cancer (PCa) is the second leading cause of death in males. It has been reported that δ-catenin expression is upregulated during the late stage of prostate cancer. Palmitoylation promotes protein transport to the cytomembrane and regulates protein localization and function. However, the effect of δ-catenin palmitoylation on the regulation of cancer remains unknown. In this study, we utilized prostate cancer cells overexpressing mutant δ-catenin (J6A cells) to induce a depalmitoylation phenotype and investigate its effect on prostate cancer. Our results indicated that depalmitoylation of δ-catenin not only reduced its membrane expression but also promoted its degradation in the cytoplasm, resulting in a decrease in the effect of EGFR and E-cadherin signaling. Consequently, depalmitoylation of δ-catenin reduced the proliferation and metastasis of prostate cancer cells. Our findings provide novel insights into potential therapeutic strategies for controlling the progression of prostate cancer through palmitoylation-based targeting of δ-catenin., Competing Interests: Declaration of competing interest No conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

The epicardium is integral to cardiac development and facilitates endogenous heart regeneration and repair. While miR-194-3p is associated with cellular migration and invasion, its impact on epicardial cells remains uncharted. In this work we use gain-of-function and loss-of-function methodologies to investigate the function of miR-194-3p in cardiac development. We culture embryonic epicardial cells in vitro and subject them to transforming growth factor β (TGF-β) treatment to induce epithelial-mesenchymal transition (EMT) and monitor miR-194-3p expression. In addition, the effects of miR-194-3p mimics and inhibitors on epicardial cell development and changes in EMT are investigated. To validate the binding targets of miR-194-3p and its ability to recover the target gene-phenotype, we produce a mutant vector p120-catenin -3'UTR-MUT. In epicardial cells, TGF-β-induced EMT results in a notable overexpression of miR-194-3p. The administration of miR-194-3p mimics promotes EMT, which is correlated with elevated levels of mesenchymal markers. Conversely, miR-194-3p inhibitor attenuates EMT. Further investigations reveal a negative correlation between miR-194-3p and p120-catenin, which influences β-catenin level in the cell adhesion pathway. The suppression of EMT caused by the miR-194-3p inhibitor is balanced by silencing of p120-catenin . In conclusion, miR-194-3p directly targets p120-catenin and modulates its expression, which in turn alters β-catenin expression, critically influencing the EMT process in the embryonic epicardial cells via the cell adhesion mechanism.

Background: Circβ-catenin, our first reported circRNA, has been reported to mediate tumorigenesis in various cancers. However, its biological functions and underlying mechanisms in colorectal cancer (CRC) remain unknown., Methods: The qRT-PCR examination was used to detect the expression of circβ-catenin, miR-197-3p, and CTNND1 in cells and human tissues. Western blot was conducted to detect the protein expression levels. The biological function of circβ-catenin was verified by MTT, colony formation, wound healing, and transwell assays. The in vivo effects of circβ-catenin were verified by nude mice xenograft and metastasis models. The regulatory network of circβ-catenin/miR-197-3p/CTNND1 was confirmed via dual-luciferase reporter and RIP assays., Results: In the present study, circβ-catenin was found to promote CRC cell proliferation and metastasis in vitro and in vivo. Mechanistically, circβ-catenin served as miRNA decoy to directly bind to miR-197-3p, then antagonized the repression of the target gene CTNND1, and eventually promoted the malignant phenotype of CRC. More interestingly, the inverted repeated Alu pairs termed AluJb1/2 and AluY facilitated the biogenesis of circβ-catenin, which could be partially reversed by EIF4A3 binding to Alu element AluJb2., Conclusions: Our findings illustrated a novel mechanism of circβ-catenin in modulating CRC tumorigenesis and metastasis, which provides a potential therapeutic target for CRC patients., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

A prototype of cross-membrane signal transduction is that extracellular binding of cell surface receptors to their ligands induces intracellular signalling cascades. However, much less is known about the process in the opposite direction, called inside-out signalling. Recent studies show that it plays a more important role in regulating the functions of many cell surface receptors than we used to think. In particular, in cadherin-mediated cell adhesion, recent experiments indicate that intracellular binding of the scaffold protein p120-catenin (p120ctn) can promote extracellular clustering of cadherin and alter its adhesive function. The underlying mechanism, however, is not well understood. To explore possible mechanisms, we designed a new multiscale simulation procedure. Using all-atom molecular dynamics simulations, we found that the conformational dynamics of the cadherin extracellular region can be altered by the intracellular binding of p120ctn. More intriguingly, by integrating all-atom simulation results into coarse-grained random sampling, we showed that the altered conformational dynamics of cadherin caused by the binding of p120ctn can increase the probability of lateral interactions between cadherins on the cell surface. These results suggest that p120ctn could allosterically regulate the cis-dimerization of cadherin through two mechanisms. First, p120ctn controls the extracellular conformational dynamics of cadherin. Second, p120ctn oligomerization can further promote cadherin clustering. Therefore, our study provides a mechanistic foundation for the inside-out signalling in cadherin-mediated cell adhesion, while the computational framework can be generally applied to other cross-membrane signal transduction systems., (© Crown copyright (2023).)

Ethnopharmacological Relevance: Jinfu'an Decoction (JFAD) is a traditional Chinese decoction used in lung cancer treatment to improve patient quality of life and survival. Previous research has established that JFAD has a significant therapeutic effect on non-small cell lung cancer (NSCLC), although the underlying molecular mechanisms have not been largely underexplored., Aim of the Study: We used network pharmacology to identify the putative active ingredients of JFAD and conducted experimental studies to determine the potential molecular mechanism of JFAD in NSCLC treatment., Materials and Methods: The herbal components in JFAD-containing serum were identified by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS), and targets associated with the anti-lung cancer metastasis effects of JFAD were retrieved from various databases. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to perform Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Next, the protein-protein interactions network and the "JFAD-Chemical Component-Target-KEGG Pathway" network were constructed. The network pharmacology findings were confirmed by in vitro and in vivo experiments. In vitro experiments were conducted to assess cell viability by CCK8 assay, cell cycle analysis by propidium iodide (PI) assay, and migration and invasion ability of cells by the transwell assay. In vivo experiments were performed to assess the efficacy of JFAD on the tumor by observing the growth of transplanted tumor models in nude mice and evaluated by in vivo bioluminescence imaging. Moreover, we assessed the effect of JFAD on the PI3K/Akt signaling pathway and proteins of Lumican, p120ctn, and specific RhoGTP enzyme family members (RhoA, Rac1, and RhoC) by Western Blot and immunohistochemistry., Results: 32 herbal components were identified in the JFAD-containing serum, which potentially acted on 229 targets related to lung cancer metastasis. Network pharmacology results suggested that JFAD may treat lung cancer metastasis by targeting the PI3K/Akt pathway via regulating multiple core targets. Our experiments showed that JFAD suppressed the proliferation of A549 cells in vitro, induced cell cycle arrest, and reduced the migration and invasion ability of A549 cells. Our in vivo study revealed that JFAD inhibited tumor growth in a nude mouse model. Additionally, we found that JFAD could downregulate the expression of the PI3K/Akt pathway and affect the expression of Lumican, p120ctn, and specific RhoGTPase family members., Conclusions: In conclusion, through network pharmacology, we have unveiled the underlying mechanisms that link the various components, targets, and pathways influenced by JFAD in the context of lung cancer metastasis. Our experimental results suggest that the oncostatic effects of JFAD may be achieved by upregulating the expression of Lumican/p120ctn and downregulating the levels of specific RhoGTPase family members, which in turn block the PI3K/Akt signaling pathway., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Cadherin-17 (CDH17), a marker of differentiation in intestinal cells, binds and activates α2β1 integrin to promote cell adhesion and proliferation in colorectal cancer (CRC) metastasis. Furthermore, CDH17 associates with p120- and β-catenin in a manner yet to be fully elucidated. In this report, we explored the molecular mediators involved in this association, their contribution to CRC dissemination and potential therapeutic implications., Methods: Proteomic and confocal analyses were employed to identify and validate CDH17 interactors. Functional characterization involved the study of proliferation, migration, and invasion in cell lines representative of various phenotypes. Immunohistochemistry was conducted on CRC tissue microarrays (TMA). In vivo animal experiments were carried out for metastatic studies., Results: We found that desmocollin-1 (DSC1), a desmosomal cadherin, interacts with CDH17 via its extracellular domain. DSC1 depletion led to increased or decreased invasion in CRC cells displaying epithelial or mesenchymal phenotype, respectively, in a process mediated by the association with p120-catenin. Down-regulation of DSC1 resulted in an increased expression of p120-catenin isoform 1 in epithelial cells or a shift in cellular location in mesenchymal cells. Opposite results were observed after forced expression of CDH17. DSC1 is highly expressed in budding cells at the leading edge of the tumor and associates with poor prognosis in the stem-like, mesenchymal CRC subtypes, while correlates with a more favorable prognosis in the less-aggressive subtypes. In vivo experiments demonstrated that DSC1 silencing reduced tumor growth, liver homing, and metastasis in CRC mesenchymal cells. Furthermore, a synthetic peptide derived from CDH17, containing the NLV motif, effectively inhibited invasion and liver homing in vivo, opening up new possibilities for the development of novel therapies focused on desmosomal cadherins., Conclusions: These findings shed light on the multifaceted roles of CDH17, DSC1, and p120-catenin in CRC metastasis, offering insights into potential therapeutic interventions for targeting desmosomal cadherins in poorly-differentiated carcinomas., (© 2024. The Author(s).)

Objective: The advancement of neuroimaging and genetic research has revealed the presence of morphological abnormalities and numerous risk genes, along with their associations. We aimed to estimate magnetic resonance imaging-derived cortical thickness across multiple brain regions., Methods: The cortical thickness of 129 schizophrenia patients, 42 of their unaffected siblings, and 112 healthy controls was measured and the candidate genes were sequenced. Comparisons were made of cortical thickness (including 68 regions of the Desikan-Killiany Atlas) and genetic variants (in 108 risk genes for schizophrenia) among the three groups, and correlation analyses were performed regarding cortical thickness, clinical symptoms, cognitive tests (such as the N-back task and the logical memory test), and genetic variants., Results: Schizophrenia patients had significantly thinner bilateral frontal, temporal, and parietal gyri than healthy controls and unaffected siblings. Association analyses in target genes showed that four single nucleotide variants (SNVs) were significantly associated with schizophrenia, including thioredoxin-related transmembrane protein 2-catenin, cadherin-associated protein, delta 1 (SNV20673) (positive false discovery rate [PFDR] = 0.008) and centromere protein M (rs35542507, rs41277477, rs73165153) (PFDR = 0.030). Additionally, cortical thickness in the right pars triangularis was lower in carriers of the SNV20673 variant than in non-carriers (PFDR = 0.048). Finally, a positive correlation was found between right pars triangularis cortical thickness and logical memory in schizophrenia patients (r = 0.199, p = 0.032)., Conclusions: This study identified regional morphological abnormalities in schizophrenia, including the right homologue of Broca's area, which was associated with a risk variant that affected delta-1 catenin and logical memory. These findings suggest a potential association between candidate gene loci, cortical thickness, and schizophrenia., Competing Interests: The authors report no conflicts of interest.