Publications
83 results found
Cortes E, Lachowski D, Robinson B, et al., 2019, Tamoxifen mechanically reprograms the tumor microenvironment via HIF-1A and reduces cancer cell survival, EMBO Reports, Vol: 20, ISSN: 1469-221X
The tumor microenvironment is fundamental to cancer progression, and the influence of its mechanical properties is increasingly being appreciated. Tamoxifen has been used for many years to treat estrogen-positive breast cancer. Here we report that tamoxifen regulates the level and activity of collagen cross-linking and degradative enzymes, and hence the organization of the extracellular matrix, via a mechanism involving both the G protein-coupled estrogen receptor (GPER) and hypoxia-inducible factor-1 alpha (HIF-1A). We show that tamoxifen reduces HIF-1A levels by suppressing myosin-dependent contractility and matrix stiffness mechanosensing. Tamoxifen also downregulates hypoxia-regulated genes and increases vascularization in PDAC tissues. Our findings implicate the GPER/HIF-1A axis as a master regulator of peri-tumoral stromal remodeling and the fibrovascular tumor microenvironment and offer a paradigm shift for tamoxifen from a well-established drug in breast cancer hormonal therapy to an alternative candidate for stromal targeting strategies in PDAC and possibly other cancers.
Cortes E, Lachowski D, Rice A, et al., 2018, Tamoxifen mechanically deactivates hepatic stellate cells via the G protein-coupled estrogen receptor, Oncogene, Vol: 38, Pages: 2910-2922, ISSN: 0950-9232
Tamoxifen has been used for many years to target estrogen receptor signalling in breast cancer cells. Tamoxifen is also an agonist of the G protein-coupled estrogen receptor (GPER), a GPCR ubiquitously expressed in tissues that mediates the acute response to estrogens. Here we report that tamoxifen promotes mechanical quiescence in hepatic stellate cells (HSCs), stromal fibroblast-like cells whose activation triggers and perpetuates liver fibrosis in hepatocellular carcinomas. This mechanical deactivation is mediated by the GPER/RhoA/myosin axis and induces YAP deactivation. We report that tamoxifen decreases the levels of hypoxia-inducible factor-1 alpha (HIF-1α) and the synthesis of extracellular matrix proteins through a mechanical mechanism that involves actomyosin-dependent contractility and mechanosensing of tissue stiffness. Our results implicate GPER-mediated estrogen signalling in the mechanosensory-driven activation of HSCs and put forward estrogenic signalling as an option for mechanical reprogramming of myofibroblast-like cells in the tumour microenvironment. Tamoxifen, with half a century of safe clinical use, might lead this strategy of drug repositioning.
Vella A, Eko EM, Hernandez ADR, 2018, The emergence of solid stress as a potent biomechanical marker of tumour progression, EMERGING TOPICS IN LIFE SCIENCES, Vol: 2, Pages: 739-749, ISSN: 2397-8554
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- Citations: 3
Yeldag G, Rice A, Del Rio Hernandez A, 2018, Chemoresistance and the self-maintaining tumor microenvironment, Cancers, Vol: 10, ISSN: 2072-6694
The progression of cancer is associated with alterations in the tumor microenvironment, including changes in extracellular matrix (ECM) composition, matrix rigidity, hypervascularization, hypoxia, and paracrine factors. One key malignant phenotype of cancer cells is their ability to resist chemotherapeutics, and elements of the ECM can promote chemoresistance in cancer cells through a variety of signaling pathways, inducing changes in gene expression and protein activity that allow resistance. Furthermore, the ECM is maintained as an environment that facilitates chemoresistance, since its constitution modulates the phenotype of cancer-associated cells, which themselves affect the microenvironment. In this review, we discuss how the properties of the tumor microenvironment promote chemoresistance in cancer cells, and the interplay between these external stimuli. We focus on both the response of cancer cells to the external environment, as well as the maintenance of the external environment, and how a chemoresistant phenotype emerges from the complex signaling network present.
Samandari M, Julia MG, Rice A, et al., 2018, Liquid biopsies for management of pancreatic cancer, TRANSLATIONAL RESEARCH, Vol: 201, Pages: 98-127, ISSN: 1931-5244
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- Citations: 42
Cameron W, Elijah M, Del Rio Hernandez A, 2018, Role of extracellular matrix in development and cancer progression, International Journal of Molecular Sciences, Vol: 19, ISSN: 1422-0067
The immense diversity of extracellular matrix (ECM) proteins confers distinct biochemical and biophysical properties that influence cell phenotype. The ECM is highly dynamic as it is constantly deposited, remodelled, and degraded during development until maturity to maintain tissue homeostasis. The ECM’s composition and organization are spatiotemporally regulated to control cell behaviour and differentiation, but dysregulation of ECM dynamics leads to the development of diseases such as cancer. The chemical cues presented by the ECM have been appreciated as key drivers for both development and cancer progression. However, the mechanical forces present due to the ECM have been largely ignored but recently recognized to play critical roles in disease progression and malignant cell behaviour. Here, we review the ways in which biophysical forces of the microenvironment influence biochemical regulation and cell phenotype during key stages of human development and cancer progression.
Haining AWM, Rahikainen R, Cortes E, et al., 2018, Mechanotransduction in talin through the interaction of the R8 domain with DLC1, PLoS Biology, Vol: 16, Pages: 1-20, ISSN: 1544-9173
The mechanical unfolding of proteins is a cellular mechanism for force transduction with potentially broad implications in cell fate. Despite this, the mechanism by which protein unfolding elicits differential downstream signalling pathways remains poorly understood. Here, we used protein engineering, atomic force microscopy, and biophysical tools to delineate how protein unfolding controls cell mechanics. Deleted in liver cancer 1 (DLC1) is a negative regulator of Ras homolog family member A (RhoA) and cell contractility that regulates cell behaviour when localised to focal adhesions bound to folded talin. Using a talin mutant resistant to force-induced unfolding of R8 domain, we show that talin unfolding determines DLC1 downstream signalling and, consequently, cell mechanics. We propose that this new mechanism of mechanotransduction may have implications for a wide variety of associated cellular processes.
Elsharkawy S, Al-Jawad M, Pantano MF, et al., 2018, Protein disorder-order interplay to guide the growth of hierarchical mineralized structures, Nature Communications, Vol: 9, ISSN: 2041-1723
Del Rio Hernandez AE, Matellan C, 2018, Cost-effective rapid prototyping and assembly of poly(methyl methacrylate)microfluidic devices., Scientific Reports, Vol: 8, ISSN: 2045-2322
The difficulty in translating conventional microfluidics from laboratory prototypes to commercial products has shifted research efforts towards thermoplastic materials for their higher translational potential and amenability to industrial manufacturing. Here, we present an accessible method to fabricate and assemble polymethyl methacrylate (PMMA) microfluidic devices in a “mask-less” and cost-effective manner that can be applied to manufacture a wide range of designs due to its versatility. Laser micromachining offers high flexibility in channel dimensions and morphology by controlling the laser properties, while our two-step surface treatment based on exposure to acetone vapour and low-temperature annealing enables improvement of the surface quality without deformation of the device. Finally, we demonstrate a capillarity-driven adhesive delivery bonding method that can produce an effective seal between PMMA devices and a variety of substrates, including glass, silicon and LiNbO3. We illustrate the potential of this technique with two microfluidic devices, an H-filter and a droplet generator. The technique proposed here offers a low entry barrier for the rapid prototyping of thermoplastic microfluidics, enabling iterative design for laboratories without access to conventional microfabrication equipment.
Mykuliak V, Haining A, von Essen M, et al., 2018, Mechanical unfolding reveals stable 3-helix intermediates in talin and α-catenin, PLoS Computational Biology, Vol: 14, ISSN: 1553-734X
Mechanical stability is a key feature in the regulation of structural scaffolding proteins and their functions. Despite the abundance of α-helical structures among the human proteome and their undisputed importance in health and disease, the fundamental principles of their behavior under mechanical load are poorly understood. Talin and α-catenin are two key molecules in focal adhesions and adherens junctions, respectively. In this study, we used a combination of atomistic steered molecular dynamics (SMD) simulations, polyprotein engineering, and single-molecule atomic force microscopy (smAFM) to investigate unfolding of these proteins. SMD simulations revealed that talin rod α-helix bundles as well as α-catenin α-helix domains unfold through stable 3-helix intermediates. While the 5-helix bundles were found to be mechanically stable, a second stable conformation corresponding to the 3-helix state was revealed. Mechanically weaker 4-helix bundles easily unfolded into a stable 3-helix conformation. The results of smAFM experiments were in agreement with the findings of the computational simulations. The disulfide clamp mutants, designed to protect the stable state, support the 3-helix intermediate model in both experimental and computational setups. As a result, multiple discrete unfolding intermediate states in the talin and α-catenin unfolding pathway were discovered. Better understanding of the mechanical unfolding mechanism of α-helix proteins is a key step towards comprehensive models describing the mechanoregulation of proteins.
von Erlach T, Bertazzo S, Wozniak MA, et al., 2018, Cell-geometry-dependent changes in plasma membrane order direct stem cell signalling and fate, Nature Materials, Vol: 17, Pages: 237-242, ISSN: 1476-1122
Cell size and shape affect cellular processes such as cell survival, growth and differentiation1,2,3,4, thus establishing cell geometry as a fundamental regulator of cell physiology. The contributions of the cytoskeleton, specifically actomyosin tension, to these effects have been described, but the exact biophysical mechanisms that translate changes in cell geometry to changes in cell behaviour remain mostly unresolved. Using a variety of innovative materials techniques, we demonstrate that the nanostructure and lipid assembly within the cell plasma membrane are regulated by cell geometry in a ligand-independent manner. These biophysical changes trigger signalling events involving the serine/threonine kinase Akt/protein kinase B (PKB) that direct cell-geometry-dependent mesenchymal stem cell differentiation. Our study defines a central regulatory role by plasma membrane ordered lipid raft microdomains in modulating stem cell differentiation with potential translational applications.
Lachowski D, Cortes E, Robinson B, et al., 2018, FAK controls the mechanical activation of YAP, a transcriptional regulator required for durotaxis, FASEB JOURNAL, Vol: 32, Pages: 1099-1107, ISSN: 0892-6638
Lachowski D, Cortes E, Robinson B, et al., 2017, The role of mechanosensor molecules in HSCs durotaxis, 68th Annual Meeting of the American-Association-for-the-Study-of-Liver-Diseases (AASLD) / Liver Meeting, Publisher: WILEY, Pages: 215A-215A, ISSN: 0270-9139
Inostroza-Brito KE, Collin EC, Majkowska A, et al., 2017, Cross-linking of a biopolymer-peptide co-assembling system, Acta Biomaterialia, Vol: 58, Pages: 80-89, ISSN: 1742-7061
The ability to guide molecular self-assembly at the nanoscale into complex macroscopic structures could enable the development of functional synthetic materials that exhibit properties of natural tissues such as hierarchy, adaptability, and self-healing. However, the stability and structural integrity of these kinds of materials remains a challenge for many practical applications. We have recently developed a dynamic biopolymer-peptide co-assembly system with the capacity to grow and undergo morphogenesis into complex shapes. Here we explored the potential of different synthetic (succinimidyl carboxymethyl ester, poly (ethylene glycol) ether tetrasuccinimidyl glutarate and glutaraldehyde) and natural (genipin) cross-linking agents to stabilize membranes made from these biopolymer-peptide co-assemblies. We investigated the cross-linking efficiency, resistance to enzymatic degradation, and mechanical properties of the different cross-linked membranes. We also compared their biocompatibility by assessing the metabolic activity and morphology of adipose-derived stem cells (ADSC) cultured on the different membranes. While all cross-linkers successfully stabilized the system under physiological conditions, membranes cross-linked with genipin exhibited better resistance in physiological environments, improved stability under enzymatic degradation, and a higher degree of in vitro cytocompatibility compared to the other cross-linking agents. The results demonstrated that genipin is an attractive candidate to provide functional structural stability to complex self-assembling structures for potential tissue engineering or in vitro model applications.
Mazza G, Al-Akkad W, Telese A, et al., 2017, Rapid production of human liver scaffolds for functional tissue engineering by high shear stress oscillation-decellularization, Scientific Reports, Vol: 7, Pages: 1-14, ISSN: 2045-2322
The development of human liver scaffolds retaining their 3-dimensional structure and extra-cellular matrix (ECM) composition is essential for the advancement of liver tissue engineering. We report the design and validation of a new methodology for the rapid and accurate production of human acellular liver tissue cubes (ALTCs) using normal liver tissue unsuitable for transplantation. The application of high shear stress is a key methodological determinant accelerating the process of tissue decellularization while maintaining ECM protein composition, 3D-architecture and physico-chemical properties of the native tissue. ALTCs were engineered with human parenchymal and non-parenchymal liver cell lines (HepG2 and LX2 cells, respectively), human umbilical vein endothelial cells (HUVEC), as well as primary human hepatocytes and hepatic stellate cells. Both parenchymal and non-parenchymal liver cells grown in ALTCs exhibited markedly different gene expression when compared to standard 2D cell cultures. Remarkably, HUVEC cells naturally migrated in the ECM scaffold and spontaneously repopulated the lining of decellularized vessels. The metabolic function and protein synthesis of engineered liver scaffolds with human primary hepatocytes reseeded under dynamic conditions were maintained. These results provide a solid basis for the establishment of effective protocols aimed at recreating human liver tissue in vitro.
Rice AJ, Cortes E, Lachowski D, et al., 2017, Matrix stiffness induces epithelial-mesenchymal transition and promotes chemoresistance in pancreatic cancer cells, Oncogenesis, Vol: 6, Pages: e352-e352, ISSN: 2157-9024
Increased matrix rigidity associated with the fibrotic reaction is documented to stimulate intracellular signalling pathways that promote cancer cell survival and tumour growth. Pancreatic cancer is one of the stiffest of all human solid carcinomas and is characterised by a remarkable desmoplastic reaction. Here we use mouse models, genetically engineered to recapitulate human pancreatic cancer, and several pancreatic cancer cell lines as a model to investigate the effect of matrix stiffness in epithelial-mesenchymal transition (EMT) and resistance to chemotherapeutics. We found that recapitulation of the fibrotic rigidities found in pancreatic cancer tissues promote elements of EMT, including increases in vimentin expression, decreases in E-cadherin expression, nuclear localisation of β-catenin, YAP and TAZ and changes in cell shape towards a mesenchymal phenotype. We also report that stiffness induces chemoresistance to paclitaxel, but not to gemcitabine, both commonly used therapeutics, suggesting that environmental rigidity underlies an aspect of chemoresistance.
Lachowski D, Cortes E, Pink D, et al., 2017, Substrate rigidity controls activation and durotaxis in pancreatic stellate cells, Scientific Reports, Vol: 7, ISSN: 2045-2322
Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive malignancy characterised by the presence of extensive desmoplasia, thought to be responsible for the poor response of patients to systemic therapies. Pancreatic stellate cells (PSCs) are key mediators in the production of this fibrotic stroma, upon activation transitioning to a myofibroblast-like, high matrix secreting phenotype. Given their importance in disease progression, characterisation of PSC activation has been extensive, however one aspect that has been overlooked is the mechano-sensing properties of the cell. Here, through the use of a physiomimetic system that recapitulates the mechanical microenvironment found within healthy and fibrotic pancreas, we demonstrate that matrix stiffness regulates activation and mechanotaxis in PSCs. We show the ability of PSCs to undergo phenotypic transition solely as a result of changes in extracellular matrix stiffness, whilst observing the ability of PSCs to durotactically respond to stiffness variations within their local environment. Our findings implicate the mechanical microenvironment as a potent contributor to PDAC progression and survival via induction of PSC activation and fibrosis, suggesting that direct mechanical reprogramming of PSCs may be a viable alternative in the treatment of this lethal disease.
Mohri Z, Hernandez ADR, Krams R, 2017, The emerging role of YAP/TAZ in mechanotransduction, JOURNAL OF THORACIC DISEASE, Vol: 9, Pages: E507-E509, ISSN: 2072-1439
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- Citations: 37
Weinberg PD, Hernandez ADR, Brown R, 2017, Engineering solutions for cancer, CONVERGENT SCIENCE PHYSICAL ONCOLOGY, Vol: 3, ISSN: 2057-1739
Chronopoulos A, Lieberthal TJ, del Río Hernández AE, 2017, Exosomes as a platform for ‘liquid biopsy’ in pancreatic cancer, Convergent Science Physical Oncology, Vol: 3, Pages: 013005-013005
Chronopoulos A, Lieberthal TJ, del Río Hernández AE, 2017, Pancreatic cancer: a mechanobiology approach, Convergent Science Physical Oncology, Vol: 3, Pages: 013001-013001
Rice A, Julian L, Olson M, et al., 2016, Traction force microscopy with elastic pillars for quantification of forces during cell apoptosis Abstracts, CONVERGENT SCIENCE PHYSICAL ONCOLOGY, Vol: 2, ISSN: 2057-1739
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- Citations: 3
Attwood S, Cortes E, Haining, et al., 2016, Adhesive ligand tether length affects the size and length of focal adhesions and influences cell spreading and attachment, Scientific Reports, Vol: 6, ISSN: 2045-2322
Cells are known to respond to physical cues from their microenvironment such as matrix rigidity.Discrete adhesive ligands within flexible strands of fibronectin connect cell surface integrins to thebroader extracellular matrix and are thought to mediate mechanosensing through the cytoskeletonintegrin-ECMlinkage. We set out to determine if adhesive ligand tether length is another physical cuethat cells can sense. Substrates were covalently modified with adhesive arginylglycylaspartic acid (RGD)ligands coupled with short (9.5nm), medium (38.2nm) and long (318nm) length inert polyethyleneglycol tethers. The size and length of focal adhesions of human foreskin fibroblasts gradually decreasedfrom short to long tethers. Furthermore, we found cell adhesion varies in a linker length dependentmanner with a remarkable 75% reduction in the density of cells on the surface and a 50% reduction incell area between the shortest and longest linkers. We also report the interplay between RGD ligandconcentration and tether length in determining cellular spread area. Our findings show that withoutvarying substrate rigidity or ligand density, tether length alone can modulate cellular behaviour.
Lachowski D, Cortes E, Robinson B, et al., 2016, SAT-402 - Elucidating the Biomechanical Response of Human Hepatic Stellate Cells on Substrates Mimicking Healthy and Fibrotic Matrix Rigidity, EASL International Liver Congress, Publisher: Elsevier, Pages: S706-S706, ISSN: 0168-8278
Chronopoulos A, Robinson B, Sarper M, et al., 2016, ATRA mechanically reprograms pancreatic stellate cells to suppress matrix remodelling and inhibit cancer cell invasion, Nature Communications, Vol: 7, Pages: 1-12, ISSN: 2041-1723
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a dismal survival rate. Persistent activation of pancreatic stellate cells (PSCs) can perturb the biomechanical homoeostasis of the tumour microenvironment to favour cancer cell invasion. Here we report that ATRA, an active metabolite of vitamin A, restores mechanical quiescence in PSCs via a mechanism involving a retinoic acid receptor beta (RAR-β)-dependent downregulation of actomyosin (MLC-2) contractility. We show that ATRA reduces the ability of PSCs to generate high traction forces and adapt to extracellular mechanical cues (mechanosensing), as well as suppresses force-mediated extracellular matrix remodelling to inhibit local cancer cell invasion in 3D organotypic models. Our findings implicate a RAR-β/MLC-2 pathway in peritumoural stromal remodelling and mechanosensory-driven activation of PSCs, and further suggest that mechanical reprogramming of PSCs with retinoic acid derivatives might be a viable alternative to stromal ablation strategies for the treatment of PDAC.
Robinson B, Rice A, Cortes E, et al., 2016, Assessment of extracellular matrix remodeling using 3D Matrigel/collagen matrices and second harmonic generation microscopy, Jove-Journal of Visualized Experiments, ISSN: 1940-087X
Sarper M, Lieberthal T, Del Rio Hernandez AE, 2016, Elucidating the Effect of Extracellular Matrix Remodeling by Stromal Cells on Pancreatic Cancer Cell Invasion in 3D Organotypic Systems, Jove-Journal of Visualized Experiments, ISSN: 1940-087X
Haining AW, von Essen M, Attwood SJ, et al., 2016, All subdomains of the talin rod are mechanically vulnerable and may contribute to cellular mechanosensing, ACS Nano, Vol: 10, Pages: 6648-6658, ISSN: 1936-0851
Although the relevance of mechanotransduction in cell signaling is currently appreciated, the mechanisms that drive this process remain largely unknown. Mechanical unfolding of proteins may trigger distinct downstream signals in cells, providing a mechanism for cellular mechanotransduction. Force-induced unfolding of talin, a prominent focal adhesion protein, has been demonstrated previously for a small portion of its rod domain. Here, using single-molecule atomic force microscopy (smAFM), we show that the entire talin rod can be unfolded by mechanical extension, over a physiological range of forces between 10 and 40 pN. We also demonstrate, through a combination of smAFM and steered molecular dynamics, that the different bundles within the talin rod exhibit a distinct hierarchy of mechanical stability. These results provide a mechanism by which different force conditions within the cell control a graduated unfolding of the talin rod. Mechanical unfolding of the rod subdomains, and the subsequent effect on talin’s binding interactions, would allow for a finely tuned cellular response to internally or externally applied forces.
Kis Z, Rodin T, Zafar A, et al., 2016, Development of a synthetic gene network to module gene expression by mechanical forces, Scientific Reports, Vol: 6, ISSN: 2045-2322
The majority of (mammalian) cells in our body are sensitive to mechanical forces, but little work hasbeen done to develop assays to monitor mechanosensor activity. Furthermore, it is currently impossibleto use mechanosensor activity to drive gene expression. To address these needs, we developed thefrst mammalian mechanosensitive synthetic gene network to monitor endothelial cell shear stresslevels and directly modulate expression of an atheroprotective transcription factor by shear stress. Thetechnique is highly modular, easily scalable and allows graded control of gene expression by mechanicalstimuli in hard-to-transfect mammalian cells. We call this new approach mechanosyngenetics. To insertthe gene network into a high proportion of cells, a hybrid transfection procedure was developed thatinvolves electroporation, plasmids replication in mammalian cells, mammalian antibiotic selection,a second electroporation and gene network activation. This procedure takes 1 week and yielded over60% of cells with a functional gene network. To test gene network functionality, we developed a fowsetup that exposes cells to linearly increasing shear stress along the length of the fow channel foor.Activation of the gene network varied logarithmically as a function of shear stress magnitude.
Sarper M, Cortes E, Lieberthal T, et al., 2016, ATRA modulates mechanical activation of TGF-β by pancreatic stellate cells, Scientific Reports, Vol: 6, ISSN: 2045-2322
The hallmark of pancreatic ductal adenocarcinoma (PDAC) is abundant desmoplasia, which is orchestrated by pancreatic stellate cells (PSCs) and accounts for the majority of the stroma surrounding the tumour. Healthy PSCs are quiescent, but upon activation during disease progression, they adopt a myofibroblast-contractile phenotype and secrete and concomitantly reorganise the stiff extracellular matrix (ECM). Transforming growth factor β (TGF-β) is a potent activator of PSCs, and its activation requires spatiotemporal organisation of cellular and extracellular cues to liberate it from an inactive complex with latent TGF-β binding protein (LTBP). Here we study the mechanical activation of TGF-β by PSCs in vitro by investigating LTBP-1 organisation with fibrillar fibronectin and show that all trans-retinoic acid (ATRA), which induces PSC quiescence, down-regulates the ability of PSCs to mechanically organise LTBP-1 and activate TGF-β through a mechanism involving myosin II dependent contractility. Therefore, ATRA inhibits the ability of PSCs to mechanically release active TGF-β, which might otherwise act in an autocrine manner to sustain PSCs in an active state and a tumour-favouring stiff microenvironment.
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