@article {731, title = {Tumor mechanics and metabolic dysfunction.}, journal = {Free Radic Biol Med}, volume = {79}, year = {2015}, month = {2015 Feb}, pages = {269-80}, abstract = {

Desmosplasia is a characteristic of most solid tumors and leads to fibrosis through abnormal extracellular matrix (ECM) deposition, remodeling, and posttranslational modifications. The resulting stiff tumor stroma not only compromises vascular integrity to induce hypoxia and impede drug delivery, but also promotes aggressiveness by potentiating the activity of key growth, invasion, and survival pathways. Intriguingly, many of the protumorigenic signaling pathways that are mechanically activated by ECM stiffness also promote glucose uptake and aerobic glycolysis, and an altered metabolism is a recognized hallmark of cancer. Indeed, emerging evidence suggests that metabolic alterations and an abnormal ECM may cooperatively drive cancer cell aggression and treatment resistance. Accordingly, improved methods to monitor tissue mechanics and metabolism promise to improve diagnostics and treatments to ameliorate ECM stiffening and elevated mechanosignaling may improve patient outcome. Here we discuss the interplay between ECM mechanics and metabolism in tumor biology and suggest that monitoring these processes and targeting their regulatory pathways may improve diagnostics, therapy, and the prevention of malignant transformation.

}, issn = {1873-4596}, doi = {10.1016/j.freeradbiomed.2014.11.020}, author = {Tung, Jason C and Barnes, J Matthew and Desai, Shraddha R and Sistrunk, Christopher and Conklin, Matthew W and Schedin, Pepper and Eliceiri, Kevin W and Keely, Patricia J and Seewaldt, Victoria L and Weaver, Valerie M} } @article {266, title = {MT1-MMP-dependent control of skeletal stem cell commitment via a β1-integrin/YAP/TAZ signaling axis.}, journal = {Dev Cell}, volume = {25}, year = {2013}, month = {2013 May 28}, pages = {402-16}, abstract = {

In vitro, topographical and biophysical cues arising from the extracellular matrix (ECM) direct skeletal stem cell (SSC) commitment and differentiation. However, the mechanisms by which the SSC-ECM interface is regulated and the outcome of such interactions on stem cell fate in vivo remain unknown. Here we demonstrate that conditional deletion of the membrane-anchored metalloproteinase MT1-MMP (Mmp14) in mesenchymal progenitors, but not in committed osteoblasts, redirects SSC fate decisions from osteogenesis to adipo- and chondrogenesis. By effecting ECM remodeling, MT1-MMP regulates stem cell shape, thereby activating a β1-integrin/RhoGTPase signaling cascade and triggering the nuclear localization of the transcriptional coactivators YAP and TAZ, which serve to control SSC lineage commitment. These data identify a critical MT1-MMP/integrin/YAP/TAZ axis operative in the stem cell niche that oversees SSC fate determination.

}, keywords = {Adaptor Proteins, Signal Transducing, Adipogenesis, Animals, Antigens, CD29, Bone Marrow Cells, Cell Lineage, Cell Nucleus, Cell Shape, Cells, Cultured, Chondrogenesis, Extracellular Matrix, Gene Knock-In Techniques, Humans, Matrix Metalloproteinase 14, Mesenchymal Stromal Cells, Mice, Mice, Inbred C57BL, Mice, Transgenic, Osteogenesis, Phenotype, Phosphoproteins, Proteolysis, Signal Transduction, Stem Cell Niche, Transcription Factors, Transcriptional Activation}, issn = {1878-1551}, doi = {10.1016/j.devcel.2013.04.011}, author = {Tang, Yi and Rowe, R Grant and Botvinick, Elliot L and Kurup, Abhishek and Putnam, Andrew J and Seiki, Motoharu and Weaver, Valerie M and Keller, Evan T and Goldstein, Steven and Dai, Jinlu and Begun, Dana and Saunders, Thomas and Weiss, Stephen J} } @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 {301, title = {In situ force mapping of mammary gland transformation.}, journal = {Integr Biol (Camb)}, volume = {3}, year = {2011}, month = {2011 Sep}, pages = {910-21}, abstract = {

Tumor progression is characterized by an incremental stiffening of the tissue. The importance of tissue rigidity to cancer is appreciated, yet the contribution of specific tissue elements to tumor stiffening and their physiological significance remains unclear. We performed high-resolution atomic force microscopy indentation in live and snap-frozen fluorescently labeled mammary tissues to explore the origin of the tissue stiffening associated with mammary tumor development in PyMT mice. The tumor epithelium, the tumor-associated vasculature and the extracellular matrix all contributed to mammary gland stiffening as it transitioned from normal to invasive carcinoma. Consistent with the concept that extracellular matrix stiffness modifies cell tension, we found that isolated transformed mammary epithelial cells were intrinsically stiffer than their normal counterparts but that the malignant epithelium in situ was far stiffer than isolated breast tumor cells. Moreover, using an in situ vitrification approach, we determined that the extracellular matrix adjacent to the epithelium progressively stiffened as tissue evolved from normal through benign to an invasive state. Importantly, we also noted that there was significant mechanical heterogeneity within the transformed tissue both in the epithelium and the tumor-associated neovasculature. The vascular bed within the tumor core was substantially stiffer than the large patent vessels at the invasive front that are surrounded by the stiffest extracellular matrix. These findings clarify the contribution of individual mammary gland tissue elements to the altered biomechanical landscape of cancerous tissues and emphasize the importance of studying cancer cell evolution under conditions that preserve native interactions.

}, keywords = {Animals, Bioengineering, Biomechanical Phenomena, Biophysical Phenomena, Cell Transformation, Neoplastic, Extracellular Matrix, Female, Mammary Glands, Animal, Mammary Neoplasms, Experimental, Mammary Tumor Virus, Mouse, Mice, Mice, Transgenic, Microscopy, Atomic Force, Neoplasm Invasiveness, Retroviridae Infections, Tensile Strength, Tumor Virus Infections, Vitrification}, issn = {1757-9708}, doi = {10.1039/c1ib00043h}, author = {Lopez, Jose I and Kang, Inkyung and You, Weon-Kyoo and McDonald, Donald M and Weaver, Valerie M} } @article {371, title = {Filamin A-beta1 integrin complex tunes epithelial cell response to matrix tension.}, journal = {Mol Biol Cell}, volume = {20}, year = {2009}, month = {2009 Jul}, pages = {3224-38}, abstract = {

The physical properties of the extracellular matrix (ECM) regulate the behavior of several cell types; yet, mechanisms by which cells recognize and respond to changes in these properties are not clear. For example, breast epithelial cells undergo ductal morphogenesis only when cultured in a compliant collagen matrix, but not when the tension of the matrix is increased by loading collagen gels or by increasing collagen density. We report that the actin-binding protein filamin A (FLNa) is necessary for cells to contract collagen gels, and pull on collagen fibrils, which leads to collagen remodeling and morphogenesis in compliant, low-density gels. In stiffer, high-density gels, cells are not able to contract and remodel the matrix, and morphogenesis does not occur. However, increased FLNa-beta1 integrin interactions rescue gel contraction and remodeling in high-density gels, resulting in branching morphogenesis. These results suggest morphogenesis can be \"tuned\" by the balance between cell-generated contractility and opposing matrix stiffness. Our findings support a role for FLNa-beta1 integrin as a mechanosensitive complex that bidirectionally senses the tension of the matrix and, in turn, regulates cellular contractility and response to this matrix tension.

}, keywords = {Animals, Antigens, CD29, Biomechanical Phenomena, Cell Line, Tumor, Collagen, Contractile Proteins, Epithelial Cells, Extracellular Matrix, Filamins, Gels, Humans, Mice, Microfilament Proteins, Morphogenesis, Myosin Light Chains, Phosphorylation, Protein Binding}, issn = {1939-4586}, doi = {10.1091/mbc.E08-12-1186}, author = {Gehler, Scott and Baldassarre, Massimiliano and Lad, Yatish and Leight, Jennifer L and Wozniak, Michele A and Riching, Kristin M and Eliceiri, Kevin W and Weaver, Valerie M and Calderwood, David A and Keely, Patricia J} } @article {366, title = {Matrix crosslinking forces tumor progression by enhancing integrin signaling.}, journal = {Cell}, volume = {139}, year = {2009}, month = {2009 Nov 25}, pages = {891-906}, abstract = {

Tumors are characterized by extracellular matrix (ECM) remodeling and stiffening. The importance of ECM remodeling to cancer is appreciated; the relevance of stiffening is less clear. We found that breast tumorigenesis is accompanied by collagen crosslinking, ECM stiffening, and increased focal adhesions. Induction of collagen crosslinking stiffened the ECM, promoted focal adhesions, enhanced PI3 kinase (PI3K) activity, and induced the invasion of an oncogene-initiated epithelium. Inhibition of integrin signaling repressed the invasion of a premalignant epithelium into a stiffened, crosslinked ECM and forced integrin clustering promoted focal adhesions, enhanced PI3K signaling, and induced the invasion of a premalignant epithelium. Consistently, reduction of lysyl oxidase-mediated collagen crosslinking prevented MMTV-Neu-induced fibrosis, decreased focal adhesions and PI3K activity, impeded malignancy, and lowered tumor incidence. These data show how collagen crosslinking can modulate tissue fibrosis and stiffness to force focal adhesions, growth factor signaling and breast malignancy.

}, keywords = {Aging, Animals, Breast Neoplasms, Collagen, Epidermal Growth Factor, Extracellular Matrix, Female, Fibrosis, Genes, ras, Humans, Integrins, Mammary Glands, Human, Mice, Mice, Inbred BALB C, Protein-Lysine 6-Oxidase, Signal Transduction}, issn = {1097-4172}, doi = {10.1016/j.cell.2009.10.027}, author = {Levental, Kandice R and Yu, Hongmei and Kass, Laura and Lakins, Johnathon N and Egeblad, Mikala and Erler, Janine T and Fong, Sheri F T and Csiszar, Katalin and Giaccia, Amato and Weninger, Wolfgang and Yamauchi, Mitsuo and Gasser, David L and Weaver, Valerie M} } @article {391, title = {Mechanics, malignancy, and metastasis: the force journey of a tumor cell.}, journal = {Cancer Metastasis Rev}, volume = {28}, year = {2009}, month = {2009 Jun}, pages = {113-27}, abstract = {

A cell undergoes many genetic and epigenetic changes as it transitions to malignancy. Malignant transformation is also accompanied by a progressive loss of tissue homeostasis and perturbations in tissue architecture that ultimately culminates in tumor cell invasion into the parenchyma and metastasis to distant organ sites. Increasingly, cancer biologists have begun to recognize that a critical component of this transformation journey involves marked alterations in the mechanical phenotype of the cell and its surrounding microenvironment. These mechanical differences include modifications in cell and tissue structure, adaptive force-induced changes in the environment, altered processing of micromechanical cues encoded in the extracellular matrix (ECM), and cell-directed remodeling of the extracellular stroma. Here, we review critical steps in this \"force journey,\" including mechanical contributions to tissue dysplasia, invasion of the ECM, and metastasis. We discuss the biophysical basis of this force journey and present recent advances in the measurement of cellular mechanical properties in vitro and in vivo. We end by describing examples of molecular mechanisms through which tumor cells sense, process and respond to mechanical forces in their environment. While our understanding of the mechanical components of tumor growth, survival and motility remains in its infancy, considerable work has already yielded valuable insight into the molecular basis of force-dependent tumor pathophysiology, which offers new directions in cancer chemotherapeutics.

}, keywords = {Animals, Biophysics, Cell Transformation, Neoplastic, Epigenesis, Genetic, Extracellular Matrix, Focal Adhesion Protein-Tyrosine Kinases, Humans, Lasers, Microscopy, Atomic Force, Models, Biological, Neoplasm Invasiveness, Neoplasm Metastasis, Neoplasms, rho-Associated Kinases, Stress, Mechanical}, issn = {1573-7233}, doi = {10.1007/s10555-008-9173-4}, author = {Kumar, Sanjay and Weaver, Valerie M} } @article {416, title = {alpha6beta4 integrin activates Rac-dependent p21-activated kinase 1 to drive NF-kappaB-dependent resistance to apoptosis in 3D mammary acini.}, journal = {J Cell Sci}, volume = {120}, year = {2007}, month = {2007 Oct 15}, pages = {3700-12}, abstract = {

Malignant transformation and multidrug resistance are linked to resistance to apoptosis, yet the molecular mechanisms that mediate tumor survival remain poorly understood. Because the stroma can influence tumor behavior by regulating the tissue phenotype, we explored the role of extracellular matrix signaling and tissue organization in epithelial survival. We report that elevated (alpha6)beta4 integrin-dependent Rac-Pak1 signaling supports resistance to apoptosis in mammary acini by permitting stress-dependent activation of the p65 subunit of NF-kappaB through Pak1. We found that inhibiting Pak1 through expression of N17Rac or PID compromises NF-kappaB activation and renders mammary acini sensitive to death, but that resistance to apoptosis could be restored to these structures by overexpressing wild-type NF-kappaB p65. We also observed that acini expressing elevated levels of Pak1 can activate p65 and survive death treatments, even in the absence of activated Rac, yet will die if activation of NF-kappaB is simultaneously inhibited through expression of IkappaBalphaM. Thus, mammary tissues can resist apoptotic stimuli by activating NF-kappaB through alpha6beta4 integrin-dependent Rac-Pak1 signaling. Our data emphasize the importance of the extracellular matrix stroma in tissue survival and suggest that alpha6beta4 integrin-dependent Rac stimulation of Pak1 could be an important mechanism mediating apoptosis-resistance in some breast tumors.

}, keywords = {Apoptosis, Enzyme Activation, Humans, Integrin alpha6beta4, Mammary Glands, Human, p21-Activated Kinases, Proto-Oncogene Proteins c-akt, rac GTP-Binding Proteins, Transcription Factor RelA}, issn = {0021-9533}, doi = {10.1242/jcs.03484}, author = {Friedland, Julie C and Lakins, Johnathon N and Kazanietz, Marcelo G and Chernoff, Jonathan and Boettiger, David and Weaver, Valerie M} } @article {431, title = {Mammary epithelial cell: influence of extracellular matrix composition and organization during development and tumorigenesis.}, journal = {Int J Biochem Cell Biol}, volume = {39}, year = {2007}, month = {2007}, pages = {1987-94}, abstract = {

Stromal-epithelial interactions regulate mammary gland development and are critical for the maintenance of tissue homeostasis. The extracellular matrix, which is a proteinaceous component of the stroma, regulates mammary epithelial growth, survival, migration and differentiation through a repertoire of transmembrane receptors, of which integrins are the best characterized. Integrins modulate cell fate by reciprocally transducing biochemical and biophysical cues between the cell and the extracellular matrix, facilitating processes such as embryonic branching morphogenesis and lactation in the mammary gland. During breast development and cancer progression, the extracellular matrix is dynamically altered such that its composition, turnover, processing and orientation change dramatically. These modifications influence mammary epithelial cell shape, and modulate growth factor and hormonal responses to regulate processes including branching morphogenesis and alveolar differentiation. Malignant transformation of the breast is also associated with significant matrix remodeling and a progressive stiffening of the stroma that can enhance mammary epithelial cell growth, perturb breast tissue organization, and promote cell invasion and survival. In this review, we discuss the role of stromal-epithelial interactions in normal and malignant mammary epithelial cell behavior. We specifically focus on how dynamic modulation of the biochemical and biophysical properties of the extracellular matrix elicit a dialogue with the mammary epithelium through transmembrane integrin receptors to influence tissue morphogenesis, homeostasis and malignant transformation.

}, keywords = {Animals, Cell Lineage, Cell Transformation, Neoplastic, Epithelial Cells, Extracellular Matrix, Female, Humans, Mammary Glands, Human, Neoplasms}, issn = {1357-2725}, doi = {10.1016/j.biocel.2007.06.025}, author = {Kass, Laura and Erler, Janine T and Dembo, Micah and Weaver, Valerie M} }