@article {671, title = {The cancer glycocalyx mechanically primes integrin-mediated growth and survival.}, journal = {Nature}, volume = {511}, year = {2014}, month = {2014 Jul 17}, pages = {319-25}, abstract = {

Malignancy is associated with altered expression of glycans and glycoproteins that contribute to the cellular glycocalyx. We constructed a glycoprotein expression signature, which revealed that metastatic tumours upregulate expression of bulky glycoproteins. A computational model predicted that these glycoproteins would influence transmembrane receptor spatial organization and function. We tested this prediction by investigating whether bulky glycoproteins in the glycocalyx promote a tumour phenotype in human cells by increasing integrin adhesion and signalling. Our data revealed that a bulky glycocalyx facilitates integrin clustering by funnelling active integrins into adhesions and altering integrin state by applying tension to matrix-bound integrins, independent of actomyosin contractility. Expression of large tumour-associated glycoproteins in non-transformed mammary cells promoted focal adhesion assembly and facilitated integrin-dependent growth factor signalling to support cell growth and survival. Clinical studies revealed that large glycoproteins are abundantly expressed on circulating tumour cells from patients with advanced disease. Thus, a bulky glycocalyx is a feature of tumour cells that could foster metastasis by mechanically enhancing cell-surface receptor function.

}, keywords = {Animals, Breast, Cell Line, Tumor, Cell Proliferation, Cell Survival, Fibroblasts, Glycocalyx, Glycoproteins, Humans, Immobilized Proteins, Integrins, Mice, Molecular Targeted Therapy, Mucin-1, Neoplasm Metastasis, Neoplasms, Neoplastic Cells, Circulating, Protein Binding, Receptors, Cell Surface}, issn = {1476-4687}, doi = {10.1038/nature13535}, author = {Paszek, Matthew J and DuFort, Christopher C and Rossier, Olivier and Bainer, Russell and Mouw, Janna K and Godula, Kamil and Hudak, Jason E and Lakins, Jonathon N and Wijekoon, Amanda C and Cassereau, Luke and Rubashkin, Matthew G and Magbanua, Mark J and Thorn, Kurt S and Davidson, Michael W and Rugo, Hope S and Park, John W and Hammer, Daniel A and Giannone, Gr{\'e}gory and Bertozzi, Carolyn R and Weaver, Valerie M} } @article {641, title = {Force engages vinculin and promotes tumor progression by enhancing PI3K activation of phosphatidylinositol (3,4,5)-triphosphate.}, journal = {Cancer Res}, volume = {74}, year = {2014}, month = {2014 Sep 1}, pages = {4597-611}, abstract = {

Extracellular matrix (ECM) stiffness induces focal adhesion assembly to drive malignant transformation and tumor metastasis. Nevertheless, how force alters focal adhesions to promote tumor progression remains unclear. Here, we explored the role of the focal adhesion protein vinculin, a force-activated mechanotransducer, in mammary epithelial tissue transformation and invasion. We found that ECM stiffness stabilizes the assembly of a vinculin-talin-actin scaffolding complex that facilitates PI3K-mediated phosphatidylinositol (3,4,5)-triphosphate phosphorylation. Using defined two- and three-dimensional matrices, a mouse model of mammary tumorigenesis with vinculin mutants, and a novel super resolution imaging approach, we established that ECM stiffness, per se, promotes the malignant progression of a mammary epithelium by activating and stabilizing vinculin and enhancing Akt signaling at focal adhesions. Our studies also revealed that vinculin strongly colocalizes with activated Akt at the invasive border of human breast tumors, where the ECM is stiffest, and we detected elevated mechanosignaling. Thus, ECM stiffness could induce tumor progression by promoting the assembly of signaling scaffolds, a conclusion underscored by the significant association we observed between highly expressed focal adhesion plaque proteins and malignant transformation across multiple types of solid cancer. See all articles in this Cancer Research section, "Physics in Cancer Research."

}, issn = {1538-7445}, doi = {10.1158/0008-5472.CAN-13-3698}, author = {Rubashkin, Matthew G and Cassereau, Luke and Bainer, Russell and DuFort, Christopher C and Yui, Yoshihiro and Ou, Guanqing and Paszek, Matthew J and Davidson, Michael W and Chen, Yunn-Yi and Weaver, Valerie M} } @article {271, title = {A physical sciences network characterization of non-tumorigenic and metastatic cells.}, journal = {Sci Rep}, volume = {3}, year = {2013}, month = {2013}, pages = {1449}, abstract = {

To investigate the transition from non-cancerous to metastatic from a physical sciences perspective, the Physical Sciences-Oncology Centers (PS-OC) Network performed molecular and biophysical comparative studies of the non-tumorigenic MCF-10A and metastatic MDA-MB-231 breast epithelial cell lines, commonly used as models of cancer metastasis. Experiments were performed in 20 laboratories from 12 PS-OCs. Each laboratory was supplied with identical aliquots and common reagents and culture protocols. Analyses of these measurements revealed dramatic differences in their mechanics, migration, adhesion, oxygen response, and proteomic profiles. Model-based multi-omics approaches identified key differences between these cells\&$\#$39; regulatory networks involved in morphology and survival. These results provide a multifaceted description of cellular parameters of two widely used cell lines and demonstrate the value of the PS-OC Network approach for integration of diverse experimental observations to elucidate the phenotypes associated with cancer metastasis.

}, keywords = {Cell Line, Tumor, Cell Movement, Cell Size, Cell Survival, Computer Simulation, Gene Expression Regulation, Neoplastic, Humans, Models, Biological, Neoplasm Metastasis, Neoplasm Proteins, Tumor Markers, Biological}, issn = {2045-2322}, doi = {10.1038/srep01449}, author = {Agus, David B and Alexander, Jenolyn F and Arap, Wadih and Ashili, Shashanka and Aslan, Joseph E and Austin, Robert H and Backman, Vadim and Bethel, Kelly J and Bonneau, Richard and Chen, Wei-Chiang and Chen-Tanyolac, Chira and Choi, Nathan C and Curley, Steven A and Dallas, Matthew and Damania, Dhwanil and Davies, Paul C W and Decuzzi, Paolo and Dickinson, Laura and Estevez-Salmeron, Luis and Estrella, Veronica and Ferrari, Mauro and Fischbach, Claudia and Foo, Jasmine and Fraley, Stephanie I and Frantz, Christian and Fuhrmann, Alexander and Gascard, Philippe and Gatenby, Robert A and Geng, Yue and Gerecht, Sharon and Gillies, Robert J and Godin, Biana and Grady, William M and Greenfield, Alex and Hemphill, Courtney and Hempstead, Barbara L and Hielscher, Abigail and Hillis, W Daniel and Holland, Eric C and Ibrahim-Hashim, Arig and Jacks, Tyler and Johnson, Roger H and Joo, Ahyoung and Katz, Jonathan E and Kelbauskas, Laimonas and Kesselman, Carl and King, Michael R and Konstantopoulos, Konstantinos and Kraning-Rush, Casey M and Kuhn, Peter and Kung, Kevin and Kwee, Brian and Lakins, Johnathon N and Lambert, Guillaume and Liao, David and Licht, Jonathan D and Liphardt, Jan T and Liu, Liyu and Lloyd, Mark C and Lyubimova, Anna and Mallick, Parag and Marko, John and McCarty, Owen J T and Meldrum, Deirdre R and Michor, Franziska and Mumenthaler, Shannon M and Nandakumar, Vivek and O{\textquoteright}Halloran, Thomas V and Oh, Steve and Pasqualini, Renata and Paszek, Matthew J and Philips, Kevin G and Poultney, Christopher S and Rana, Kuldeepsinh and Reinhart-King, Cynthia A and Ros, Robert and Semenza, Gregg L and Senechal, Patti and Shuler, Michael L and Srinivasan, Srimeenakshi and Staunton, Jack R and Stypula, Yolanda and Subramanian, Hariharan and Tlsty, Thea D and Tormoen, Garth W and Tseng, Yiider and van Oudenaarden, Alexander and Verbridge, Scott S and Wan, Jenny C and Weaver, Valerie M and Widom, Jonathan and Will, Christine and Wirtz, Denis and Wojtkowiak, Jonathan and Wu, Pei-Hsun} } @article {231, title = {Scanning angle interference microscopy reveals cell dynamics at the nanoscale.}, journal = {Nat Methods}, volume = {9}, year = {2012}, month = {2012 Aug}, pages = {825-7}, abstract = {

Emerging questions in cell biology necessitate nanoscale imaging in live cells. Here we present scanning angle interference microscopy, which is capable of localizing fluorescent objects with nanoscale precision along the optical axis in motile cellular structures. We use this approach to resolve nanotopographical features of the cell membrane and cytoskeleton as well as the temporal evolution, three-dimensional architecture and nanoscale dynamics of focal adhesion complexes.

}, keywords = {Cell Membrane, Cells, Cultured, Cytoskeleton, Epithelial Cells, Fibronectins, Focal Adhesions, Humans, Microscopy, Interference, Nanotechnology}, issn = {1548-7105}, doi = {10.1038/nmeth.2077}, author = {Paszek, Matthew J and DuFort, Christopher C and Rubashkin, Matthew G and Davidson, Michael W and Thorn, Kurt S and Liphardt, Jan T and Weaver, Valerie M} } @article {316, title = {Balancing forces: architectural control of mechanotransduction.}, journal = {Nat Rev Mol Cell Biol}, volume = {12}, year = {2011}, month = {2011 May}, pages = {308-19}, abstract = {

All cells exist within the context of a three-dimensional microenvironment in which they are exposed to mechanical and physical cues. These cues can be disrupted through perturbations to mechanotransduction, from the nanoscale-level to the tissue-level, which compromises tensional homeostasis to promote pathologies such as cardiovascular disease and cancer. The mechanisms of such perturbations suggest that a complex interplay exists between the extracellular microenvironment and cellular function. Furthermore, sustained disruptions in tensional homeostasis can be caused by alterations in the extracellular matrix, allowing it to serve as a mechanically based memory-storage device that can perpetuate a disease or restore normal tissue behaviour.

}, keywords = {Animals, Cell Adhesion, Extracellular Matrix, Homeostasis, Humans, Intercellular Junctions, Mechanotransduction, Cellular, Models, Biological, Stress, Mechanical}, issn = {1471-0080}, doi = {10.1038/nrm3112}, author = {DuFort, Christopher C and Paszek, Matthew J and Weaver, Valerie M} } @article {361, title = {Integrin clustering is driven by mechanical resistance from the glycocalyx and the substrate.}, journal = {PLoS Comput Biol}, volume = {5}, year = {2009}, month = {2009 Dec}, pages = {e1000604}, abstract = {

Integrins have emerged as key sensory molecules that translate chemical and physical cues from the extracellular matrix (ECM) into biochemical signals that regulate cell behavior. Integrins function by clustering into adhesion plaques, but the molecular mechanisms that drive integrin clustering in response to interaction with the ECM remain unclear. To explore how deformations in the cell-ECM interface influence integrin clustering, we developed a spatial-temporal simulation that integrates the micro-mechanics of the cell, glycocalyx, and ECM with a simple chemical model of integrin activation and ligand interaction. Due to mechanical coupling, we find that integrin-ligand interactions are highly cooperative, and this cooperativity is sufficient to drive integrin clustering even in the absence of cytoskeletal crosslinking or homotypic integrin-integrin interactions. The glycocalyx largely mediates this cooperativity and hence may be a key regulator of integrin function. Remarkably, integrin clustering in the model is naturally responsive to the chemical and physical properties of the ECM, including ligand density, matrix rigidity, and the chemical affinity of ligand for receptor. Consistent with experimental observations, we find that integrin clustering is robust on rigid substrates with high ligand density, but is impaired on substrates that are highly compliant or have low ligand density. We thus demonstrate how integrins themselves could function as sensory molecules that begin sensing matrix properties even before large multi-molecular adhesion complexes are assembled.

}, keywords = {Algorithms, Computer Simulation, Extracellular Matrix, Glycocalyx, Integrins, Ligands, Protein Binding, Stress, Physiological, Substrate Specificity}, issn = {1553-7358}, doi = {10.1371/journal.pcbi.1000604}, author = {Paszek, Matthew J and Boettiger, David and Weaver, Valerie M and Hammer, Daniel A} } @article {421, title = {Tensional homeostasis and the malignant phenotype.}, journal = {Cancer Cell}, volume = {8}, year = {2005}, month = {2005 Sep}, pages = {241-54}, abstract = {

Tumors are stiffer than normal tissue, and tumors have altered integrins. Because integrins are mechanotransducers that regulate cell fate, we asked whether tissue stiffness could promote malignant behavior by modulating integrins. We found that tumors are rigid because they have a stiff stroma and elevated Rho-dependent cytoskeletal tension that drives focal adhesions, disrupts adherens junctions, perturbs tissue polarity, enhances growth, and hinders lumen formation. Matrix stiffness perturbs epithelial morphogenesis by clustering integrins to enhance ERK activation and increase ROCK-generated contractility and focal adhesions. Contractile, EGF-transformed epithelia with elevated ERK and Rho activity could be phenotypically reverted to tissues lacking focal adhesions if Rho-generated contractility or ERK activity was decreased. Thus, ERK and Rho constitute part of an integrated mechanoregulatory circuit linking matrix stiffness to cytoskeletal tension through integrins to regulate tissue phenotype.

}, keywords = {3T3 Cells, Animals, Cell Line, Tumor, Cell Shape, Cytoskeleton, Homeostasis, Mice, Neoplasms, Phenotype, Stress, Mechanical, Stromal Cells}, issn = {1535-6108}, doi = {10.1016/j.ccr.2005.08.010}, author = {Paszek, Matthew J and Zahir, Nastaran and Johnson, Kandice R and Lakins, Johnathon N and Rozenberg, Gabriela I and Gefen, Amit and Reinhart-King, Cynthia A and Margulies, Susan S and Dembo, Micah and Boettiger, David and Hammer, Daniel A and Weaver, Valerie M} } @article {506, title = {The tension mounts: mechanics meets morphogenesis and malignancy.}, journal = {J Mammary Gland Biol Neoplasia}, volume = {9}, year = {2004}, month = {2004 Oct}, pages = {325-42}, abstract = {

The tissue microenvironment regulates mammary gland development and tissue homeostasis through soluble, insoluble and cellular cues that operate within the three dimensional architecture of the gland. Disruption of these critical cues and loss of tissue architecture characterize breast tumors. The developing and lactating mammary gland are also subject to a plethora of tensional forces that shape the morphology of the gland and orchestrate its functionally differentiated state. Moreover, malignant transformation of the breast is associated with dramatic changes in gland tension that include elevated compression forces, high tensional resistance stresses and increased extracellular matrix stiffness. Chronically increased mammary gland tension may influence tumor growth, perturb tissue morphogenesis, facilitate tumor invasion, and alter tumor survival and treatment responsiveness. Because mammary tissue differentiation is compromised by high mechanical force and transformed cells exhibit altered mechanoresponsiveness, malignant transformation of the breast may be functionally linked to perturbed tensional-homeostasis. Accordingly, it will be important to define the role of tensional force in mammary gland development and tumorigenesis. Additionally, it will be critical to identify the key molecular elements regulating tensional-homeostasis of the mammary gland and thereafter to characterize their associated mechanotransduction pathways.

}, keywords = {Animals, Biomechanical Phenomena, Cell Transformation, Neoplastic, Homeostasis, Humans, Morphogenesis, Neoplasms}, issn = {1083-3021}, doi = {10.1007/s10911-004-1404-x}, author = {Paszek, Matthew J and Weaver, Valerie M} }