Cadherin-mediated adhesions serve as key mechanical and signaling hubs in epithelial tissues, linking the actin cytoskeleton of adjacent cells. Their disruption is a hallmark of cancer progression. The “cadhesome” network comprises over 170 proteins involved in cadherin-mediated adhesion and force transmission, yet its complexity hampers functional understanding. We developed a high-throughput platform combining gene silencing, imaging, and AI-based analysis to profile the role of each cadhesome component in monolayer formation and mechanical integrity. Using EpH4 epithelial cells, we analyzed phenotypes under vehicle and nocodazole-challenge conditions. Machine learning enabled classification of monolayer disruption, junctional organization, and contractile state. Beyond confirming known mechanotransduction hubs centered on E-cadherin, EGFR, and RAC1, our approach systematically uncovered candidate regulators of monolayer contractile state and stress adaptation, identified condition-specific roles of poorly characterized proteins, and organized them into annotated mechanobiological subnetworks that serve as a basis for hypothesis generation. Presented as a prioritized discovery resource, this work establishes a scalable strategy to decode mechano-molecular networks and provides a blueprint for hypothesis-driven investigation of epithelial mechanics with potential translational relevance.
Incomplete reporting of microscopy methods undermines transparency, reproducibility, and data reuse. Despite recent initiatives, comprehensive, broadly endorsed, and accessible reporting guidelines are still lacking. Here, we present a bare minimal microscopy reporting requirements checklist that integrates human- and machine-readable input to provide clear, actionable guidance for researchers, reviewers, and publishers and to advance community standards in microscopy.
The persistence of cell migration is a fundamental property of motile behavior, enabling cells to maintain directionality while adapting to fluctuations and external cues. This feature underlies essential processes such as development, immune responses, and cancer invasion. Classical mathematical models have offered key insights into directed migration, yet they often neglect temporal correlations arising from cellular mechanisms that stabilize polarity and protrusion dynamics. Here, we introduce an agent-based model based on stochastic differential equations that integrates fractional Brownian motion to explicitly incorporate translational autocorrelation in cell trajectories. We simulate migration as a function of angular reorientation and the strength of correlated noise. In this framework, temporal correlation stabilizes trajectory features inherited from initial conditions, whereas angular reorientation introduces variability that enables transitions between erratic and directed motion. Our simulations show that, unlike models driven by white noise, positive correlation markedly enhances persistence even under strong angular reorientation. Moreover, the combination of [Formula: see text] and [Formula: see text] gives rise to emergent behaviors, particularly in the presence of taxis, where persistence and responsiveness are jointly tuned. These results identify correlated noise as a proxy for intrinsic cellular memory and provide a versatile computational framework to interpret the diversity and complexity of migratory behaviors.
Vasculogenic mimicry (VM) refers to the ability of non-endothelial cells to form fluid-conducting, vessel-like structures independently of endothelial cells. In cancer, VM is associated with tumor aggressiveness and poor prognosis, although similar structures may also be formed by non-cancerous cells. Here, we systematically screened more than 23 human and murine cell lines, including diverse cancer types, fibroblasts, and primary-tumor-derived cells, identifying cell types capable or incapable of VM formation. Using confocal microscopy and 3D reconstruction, we define in vitro VM as the formation of lumen-containing tubular structures by non-endothelial cells, distinguishing this phenomenon from simple cellular clustering or alignment. Importantly, cell types capable of confirmed VM in vitro corresponded closely with previous findings in mouse xenograft models. We further provide a practical protocol for screening VM capacity and demonstrate that cell density, glucose concentration, serum availability, and matrix stiffness are critical environmental determinants of VM formation.
β-Catenin embodies a fundamental paradox of multicellular life. The same molecular system that enabled the emergence of animal multicellularity by coupling cell-cell adhesion to gene regulation also creates a vulnerability that can drive cancer when misregulated. As a central regulator of cell physiology, β-catenin integrates cell-cell adhesion, mechanotransduction, and gene expression to coordinate tissue architecture with transcriptional programs controlling proliferation, differentiation, and homeostasis. Phylogenomic analyses indicate that bona fide β-catenins form a metazoan-specific monophyletic clade derived from an ancestral armadillo-repeat scaffold. This conserved superhelical structure generates a single interaction groove that mediates mutually exclusive binding to E-cadherin, adenomatous polyposis coli (APC), and T-cell factor/lymphoid enhancer factor (TCF/LEF) transcription factors. Although this architecture enabled early metazoans to coordinate adhesion, signaling, and morphogenesis, it also introduced an intrinsic regulatory vulnerability. Mutations that disrupt β-catenin degradation stabilize the protein, uncoupling Wnt signaling from its normal regulatory constraints and driving persistent proliferative transcriptional programs. In parallel, emerging structural and biophysical studies reveal conformational plasticity and mechanosensitive properties that enable dynamic partitioning between adhesive and signaling pools. Disruption of these regulatory layers promotes tumor progression, metastasis, immune evasion, and therapy resistance, positioning β-catenin as both a central oncogenic node and a challenging therapeutic target. In this review, we integrate evolutionary, structural, and mechanobiological perspectives to illustrate how β-catenin exemplifies the double-edged nature of biological innovation, an ancient protein that enabled multicellular organization yet whose dysregulation underlies fundamental mechanisms of human cancer.
Cancer vasculogenic mimicry (VM) is the formation of vasculature structures in the absence of endothelial cells. We previously established an in vitro model that facilitates the formation of a lumen-containing and fluid-conducting tubular structures after 4 days of cancer cell growth on Matrigel. Herein, we mechanistically characterize this model in breast and ovarian cancer cell lines demonstrating distinct phases of VM formation and the dependence of specific extracellular matrix proteins. We report that VM occurs in four distinct stages. Firstly, alignment, migration then clustering delineate the area of the future tubular structure. Secondly, contraction of aligned structures followed by loss of attachment of some cells and cellular blebbing. Thirdly, a phase of mass proliferation followed by the raising of specific areas of the cancer cell mass above the Matrigel (bridge). Finally, the formation of a cell monolayer closes the tubular structure, forms a glycoprotein-rich luminal lining, then elevates the structure. Only later stages of VM require AKT and FAK signaling, as confirmed by chemical inhibition and phosphorylation analysis. We demonstrate that the lining of the tubular lumen is rich in laminin. Furthermore, the presence of Laminin 111 (but not collagen I) is sufficient in the extracellular matrix (Matrigel) for VM to occur and we confirm that integrin β1, but not integrin β3, is required and this protein changes location during the formation process. RNASeq analysis suggests that VM formation principally occurs through post-transcriptional regulation. As VM is associated with poor patient survival VM, an understanding of the mechanism of VM may bring to light novel biomarkers and anticancer targets.
Cadherin-mediated adhesions are crucial mechanical and signaling hubs that connect cells within a tissue and probe the mechanics of the surrounding environment. They constitute a physical link between the actin cytoskeleton of neighboring cells, providing the mechanical coordination needed for morphogenetic processes, tissue homeostasis, collective migration, and regeneration. Disruptions in adhesion mechanisms are closely linked to the breakdown of epithelial structure and the emergence of disease-related traits characteristic of cancer progression. The cadhesome network comprises over 170 structural and regulatory proteins involved in cadherin-mediated adhesion. While this network is essential for coordinating tissue responses to mechanical stress, its complexity has historically limited our understanding of how individual components contribute to force transmission and tissue homeostasis. Recent technological advances offer tools to investigate large molecular networks in cellular function and pathology (functional omics). Leveraging these advances, we developed an experimental and analytical platform combining high-throughput gene silencing, imaging, and artificial intelligence (AI) to systematically profile each role of each protein in tissue formation, mechanical stability, and response to induced tension. Using EpH4 cells as an epithelial tissue model, we performed systematic silencing in triplicate, capturing a range of tissue phenotypes under baseline and tension-inducing conditions. Machine learning methods were used to analyze complex imaging data, quantify tissue ruptures, characterize junctional organization, and measure tension states of the tissue. By incorporating machine learning algorithms, we automated image feature extraction, clustering, and classification, enabling an unprecedented quantitative evaluation of tissue mechanics at scale. Our machine learning models allowed us to identify significant patterns, including protein-specific responses to tension and their roles in tissue-level mechanical integrity. Finally, we constructed a protein interaction network detailing the roles of each protein, their physical interactions, and known links to cancer. The network analysis revealed three prominent mechanotransductive and signaling subnetworks centered around E-cadherin, EGFR, and RAC1. Our study provides a foundational framework for investigating mechanosensing proteins and it offers a scalable blueprint for discovering potential therapeutic targets in diseases like cancer, where tissue mechanics play a crucial role. ### Competing Interest Statement The authors have declared no competing interest.
Abstract Introduction: Vasculogenic mimicry (VM) is a clinical phenomenon by which cancer cells can form vessel-like structures in an endothelial-free (CD31-) fashion. VM presence in tumors correlates to poor patient prognosis. In our laboratory we have established an in vitro model where cancer cells from either cell lines or primary culture form lumen-lined and fluid-conducting tubular structures when grown on laminin-rich Matrigel over a four-day period. Given the duration of formation and the complexity of these structures, we hypothesize that VM in vitro is a multistep process, where each stage requires spatio-temporal organization of adhesive proteins, stemness and EMT (suggesting the need for epithelial to mesenchymal transition) signaling. Methods: Using our in vitro models, we analyzed by siRNA, immunostaining and live cell imaging with Airyscan the distinct phases and the corresponding spatio-temporal organization of selected proteins. Results: We show that VM in vitro has three distinct phases that are characterized by (1) alignment and migration, (2) contraction, proliferation and bridge formation, and (3) tubular structure closure and lumen formation. These steps require spatio-temporal distribution of ZEB1 and E-cadherin (suggesting gain and loss of epithelial to mesenchymal transition), the presence of Integrin β1 and laminin 111, and the distinct localization of Laminin and CD44. Conclusion: A better characterization of VM may lead to the identification of a clinically useful marker to predict poor patient prognosis and shed light on a druggable pathway to treat this subgroup of aggressive cancer. Citation Format: Gareth I. Owen, Nicolle Santander, Gabriel Mingo, Pamela Gonzalez, Valentina George, Nicole Babbitt, Alejandra Espinioza, Isidora Vega, Cristobal Canales, Carolina Ibañez, Roger Gejman, Juan Carlos Roa, Francisco Nualart, Andrea Ravasio, Cristina Bertocchi. Vasculogenic mimicry: A three-step progress to form lumen-containing and fluid-conducting tubular structures in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5401.
Force transmission through adherens junctions (AJs) is crucial for multicellular organization, wound healing and tissue regeneration. Recent studies shed light on the molecular mechanisms of mechanotransduction at the AJs. However, the canonical model fails to explain force transmission when essential proteins of the mechanotransduction module are mutated or missing. Here, we demonstrate that, in absence of α-catenin, β-catenin can directly and functionally interact with vinculin in its open conformation, bearing physiological forces. Furthermore, we found that β-catenin can prevent vinculin autoinhibition in the presence of α-catenin by occupying vinculin´s head-tail interaction site, thus preserving force transmission capability. Taken together, our findings suggest a multi-step force transmission process at AJs, where α-catenin and β-catenin can alternatively and cooperatively interact with vinculin. This can explain the graded responses needed to maintain tissue mechanical homeostasis and, importantly, unveils a force-bearing mechanism involving β-catenin and extended vinculin that can potentially explain the underlying process enabling collective invasion of metastatic cells lacking α-catenin.
Images document scientific discoveries and are prevalent in modern biomedical research. Microscopy imaging in particular is currently undergoing rapid technological advancements. However, for scientists wishing to publish obtained images and image-analysis results, there are currently no unified guidelines for best practices. Consequently, microscopy images and image data in publications may be unclear or difficult to interpret. Here, we present community-developed checklists for preparing light microscopy images and describing image analyses for publications. These checklists offer authors, readers and publishers key recommendations for image formatting and annotation, color selection, data availability and reporting image-analysis workflows. The goal of our guidelines is to increase the clarity and reproducibility of image figures and thereby to heighten the quality and explanatory power of microscopy data. Community-developed checklists offer best-practice guidance for biologists preparing light microscopy images and describing image analyses for publications.
Recent key technological developments, such as super-resolution microscopy and microfabrication, enabled investigation of biological processes, including macroautophagy/autophagy, with unprecedented spatiotemporal resolution and control over experimental conditions. Such disruptive innovations deepened our capability to provide mechanistic understandings of the autophagic process and its causes. This addendum aims to expand the guidelines on autophagy in three key directions: optical methods enabling visualization of autophagic machinery beyond the diffraction-limited resolution; bioengineering enabling accurate designs and control over experimental conditions; and theoretical advances in mechanobiology connecting autophagy and mechanical processes of the cell.
Quantitative descriptions of multi-cellular structures from optical microscopy imaging are prime to understand the variety of three-dimensional (3D) shapes in living organisms. Experimental models of vertebrates, invertebrates and plants, such as zebrafish, killifish, Drosophila or Marchantia, mainly comprise multilayer tissues, and even if microscopes can reach the needed depth, their geometry hinders the selection and subsequent analysis of the optical volumes of interest. Computational tools to “peel” tissues by removing specific layers and reducing 3D volume into planar images, can critically improve visualization and analysis. We developed VolumePeeler, a versatile FIJI plugin for virtual 3D “peeling” of image stacks. The plugin implements spherical and spline surface projections. We applied VolumePeeler to perform peeling in 3D images of spherical embryos, as well as non-spherical tissue layers. The produced images improve the 3D volume visualization and enable analysis and quantification of geometrically challenging microscopy datasets. ImageJ/FIJI software, source code, examples, and tutorials are openly available in https://cimt.uchile.cl/mcerda
With 270 million infections annually and nearly half a million death a year, shigellosis is a severe intestinal infection caused by bacteria of the Shigella family. Appearance and spread of drug-resistant strains renewed global concerns for public health and finding novel targets for treatment is fast becoming a priority. To this end, invasins are a potentially good candidate. Also called Ipa(s), which is the short for Invasion Plasmid Antigen, invasins play a key role in mediating bacterial invasion and infection of the host cell. Importantly, they have been reported to hijack inbuilt mechanical capability of the host cells such as cell adhesion and active processes mediated by the actin cytoskeleton to enable bacterial ingress into the host cells. IpaA is an invasin of particular interest as it presents three motifs that mimic vinculin binding sites and thus it allows IpaA to interact with vinculin, which is one of the most critical regulators of cellular and tissue mechanics. Using a mechanobiology point-of-view, we aim to provide an overview of Shigella´s infection mechanism, to highlight recently discovered molecular mechanisms of IpaA/vinculin interaction and to finally discuss their consequences for epithelial cell and tissue mechanical homeostasis that may result in the symptomatic outcomes seen in severe shigellosis.
The implementation of in vitro approaches using undifferentiated embryonic cells from annual killifish to complement existing in vivo developmental studies has been hindered by a lack of efficient isolation techniques. Here, we present a protocol to isolate annual killifish blastoderm cells, at the epiboly and early dispersion phase, from embryos. We describe steps for hair removal, embryo cleaning, dechorionation, and cell purification. This protocol may also be used to develop strategies to isolate cells from embryos presenting similar challenges.
Introduction: Deciphering the biological and physical requirements for the outset of multicellularity is limited to few experimental models. The early embryonic development of annual killifish represents an almost unique opportunity to investigate de novo cellular aggregation in a vertebrate model. As an adaptation to seasonal drought, annual killifish employs a unique developmental pattern in which embryogenesis occurs only after undifferentiated embryonic cells have completed epiboly and dispersed in low density on the egg surface. Therefore, the first stage of embryogenesis requires the congregation of embryonic cells at one pole of the egg to form a single aggregate that later gives rise to the embryo proper. This unique process presents an opportunity to dissect the self-organizing principles involved in early organization of embryonic stem cells. Indeed, the physical and biological processes required to form the aggregate of embryonic cells are currently unknown.Methods: Here, we developed an in silico, agent-based biophysical model that allows testing how cell-specific and environmental properties could determine the aggregation dynamics of early Killifish embryogenesis. In a forward engineering approach, we then proceeded to test two hypotheses for cell aggregation (cell-autonomous and a simple taxis model) as a proof of concept of modeling feasibility. In a first approach (cell autonomous system), we considered how intrinsic biophysical properties of the cells such as motility, polarity, density, and the interplay between cell adhesion and contact inhibition of locomotion drive cell aggregation into self-organized clusters. Second, we included guidance of cell migration through a simple taxis mechanism to resemble the activity of an organizing center found in several developmental models.Results: Our numerical simulations showed that random migration combined with low cell-cell adhesion is sufficient to maintain cells in dispersion and that aggregation can indeed arise spontaneously under a limited set of conditions, but, without environmental guidance, the dynamics and resulting structures do not recapitulate in vivo observations.Discussion: Thus, an environmental guidance cue seems to be required for correct execution of early aggregation in early killifish development. However, the nature of this cue (e.g., chemical or mechanical) can only be determined experimentally. Our model provides a predictive tool that could be used to better characterize the process and, importantly, to design informed experimental strategies.
Cells are exposed and respond to various mechanical forces and physical cues stemming from their environment. This interaction has been seen to differentially regulate various cellular processes for maintenance of homeostasis, of which autophagy represents one of the major players. In addition, autophagy has been suggested to regulate mechanical functions of the cells including their interaction with the environment. In this minireview, we summarize the state of the art of the fascinating interplay between autophagy and the mechanotransduction machinery associated with cell adhesions, that we name ¨Mechanoautophagy¨.
Palmitic acid (PA) is significantly increased in the hypothalamus of mice, when fed chronically with a high-fat diet (HFD). PA impairs insulin signaling in hypothalamic neurons, by a mechanism dependent on autophagy, a process of lysosomal-mediated degradation of cytoplasmic material. In addition, previous work shows a crosstalk between autophagy and the primary cilium (hereafter cilium), an antenna-like structure on the cell surface that acts as a signaling platform for the cell. Ciliopathies, human diseases characterized by cilia dysfunction, manifest, type 2 diabetes, among other features, suggesting a role of the cilium in insulin signaling. Cilium depletion in hypothalamic pro-opiomelanocortin (POMC) neurons triggers obesity and insulin resistance in mice, the same phenotype as mice deficient in autophagy in POMC neurons. Here we investigated the effect of chronic consumption of HFD on cilia; and our results indicate that chronic feeding with HFD reduces the percentage of cilia in hypothalamic POMC neurons. This effect may be due to an increased amount of PA, as treatment with this saturated fatty acid in vitro reduces the percentage of ciliated cells and cilia length in hypothalamic neurons. Importantly, the same effect of cilia depletion was obtained following chemical and genetic inhibition of autophagy, indicating autophagy is required for ciliogenesis. We further demonstrate a role for the cilium in insulin sensitivity, as cilium loss in hypothalamic neuronal cells disrupts insulin signaling and insulin-dependent glucose uptake, an effect that correlates with the ciliary localization of the insulin receptor (IR). Consistently, increased percentage of ciliated hypothalamic neuronal cells promotes insulin signaling, even when cells are exposed to PA. Altogether, our results indicate that, in hypothalamic neurons, impairment of autophagy, either by PA exposure, chemical or genetic manipulation, cause cilia loss that impairs insulin sensitivity.
Introduction: Vasculogenic mimicry (VM) describes a process by which cancer cells establish an alternative perfusion pathway in an endothelial cell-free manner. Despite the strong correlation with reduced patient survival, the mechanisms by which a tumor can create this self-generated irrigation system are still not fully understood. The process of VM in vitro can occur in laminin-111-containing Matrigel and requires the PI3K pathway. However, the membrane protein component and signaling pathways involved in this process are unknown. Methods: In an established in vitro model of VM of ovarian and breast cancer cells (HEY and MDA-MB-231, respectively) on Matrigel coating, we utilized gene silencing and blocking antibodies to elucidate the signaling pathways involved in this process. RNASeq was used to identify novel transcripts and siRNA was utilized to verify the requirement of candidate RNA/protein in tubular formation. Results: siRNA and antibody blocking of integrin β1, but not β3, prevented VM formation in vitro. Individual silencing of cortactin, TKS5, MMP-2, MMP-9 and MMP-14 affected tubular formation. RNAseq analysis suggested that VM has minimal dependence on de novo transcriptional activity yet reported a strong upregulation of small Integral Membrane Protein 11 (SMIM11A). This result was verified by qPCR and siRNA silencing of SMIM11A prevented VM formation. Discussion: Laminin 111 may interact with integrin β1, and the consequent activation of the PI3K pathway could potentially remodel cytoskeletal proteins and promote the activity of MMPs. We report for the first time a biological role for SMIM11a. This gene is regulated at the RNA level and is required for the formation of tubular structure in vitro. As VM is strongly associated with poor patient survival, understanding the formation of this alternative irrigation system may deliver new druggable targets. Citation Format: Gabriel Mingo, Javiera Pradenas, Nicole Babbitt, Pamela González, Cristina Bertocchi, Gareth Owen. SMIM11A, a novel protein involved in the mechanism of vasculogenic mimicry formation in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3841.