MATRIX/CELL-CELL/CYTOSKELETAL TENSION

MIGRATION/INVASION

ANOIKIS-RESISTANCE

EMT

“DYNAMIC RECIPROCITY”

Mina Bissell

1. Changes in tensional forces (cell-cell and/or cell-matrixcan affect EMT-related cell behavior

Fig. 3 Endogenous mechanical stress patterns EMT. a In monolayersof epithelial cells, stress is concentrated at the free edges andcorners of the tissues. b Under these conditions, MRTF-A accumulatesin the nuclei of cells located at the free edges andcorners of the tissue, but is sequestered in the cytoplasm of cellslocated in the center of the tissue. c When treated with TGFβ, cellslocated in high stress regions undergo EMT

Regulation of Epithelial-Mesenchymal Transitionby Transmission of Mechanical Stressthrough Epithelial TissuesNikolce Gjorevski & Eline Boghaert & Celeste M. Nelson

Cancer MicroenvironmentDOI 10.1007/s12307-011-0076-5

Regulation of Epithelial-Mesenchymal Transitionby Transmission of Mechanical Stressthrough Epithelial TissuesNikolce Gjorevski & Eline Boghaert & Celeste M. Nelson

Cancer MicroenvironmentDOI 10.1007/s12307-011-0076-5

Fig. 2 Regulation of MRTF-Aby mechanical stress. a Increasedmechanical stress causes increasedactin polymerization,thereby decreasing the cytoplasmicpool of G-actin and increasingthe nuclear localization ofMRTF-A by triggering its dissociationfrom G-actin. b Underconditions of low mechanicalstress a larger cytoplasmic poolof G-actin sequesters MRTF-A in the cytoplasm

Fig. 3 Integrin-mediated signaling pathways regulate normal epithelial polarity and differentiation. Adhesion of α6β4 integrin to the basal lamina (B. Lamina) results in activation of FAK, and subsequent signaling to Rac to promote cell proliferation and survival via p21 and NFkB. Signaling through Rac to promote basal secretion of laminin-5 (LN-5) helps establish cell polarity. Adhesion to the basal lamina prevents apoptosis via PAK activation of Bcl2 and Bad. Loss of adhesion to the basal lamina results in apoptosis, necessary for luminal clearing. In the case of tumorigenesis, tumor cells degrade the basal lamina, and invade into the stromal matrix. Tumor cells can secrete their own autocrine LN-5 and prevent apoptosis. Moreover, α2β1 integrin adhesion to collagen promotes cell proliferation and survival via activation of FAK, pERK, and PI-3-K pathways. Activated pFAK antagonizes p53 to prevent apoptosis

Mechanisms by Which the Extracellular Matrix and Integrin Signaling Act to Regulate the Switch Between Tumor Suppression and Tumor PromotionPatricia J. Keely

Journal of Mammary Gland Biology and Neoplasia

Matrix density-induced mechanoregulation of breast cell phenotype, signaling, and gene expression through a FAK-ERK linkagePaolo P. Provenzano,1,2,3,4* David R. Inman,1,4 Kevin W. Eliceiri,2,3 and Patricia J. Keely1,2,3,4*

Oncogene. 2009 December 10; 28(49): 4326–4343.

Mechanical tugging force regulates the size of cell–cell junctionsZhijun Liua,1, John L. Tanb,1, Daniel M. Cohena,1, Michael T. Yanga, Nathan J. Sniadeckia,Sami Alom Ruiza, Celeste M. Nelson, and Christopher S. Chen

9944–9949 PNAS June 1, 2010 vol. 107 ∣ ∣ ∣ ∣

CAN THESE FACTORS AFFECT EMT VIA CYTOSKELETON:

A.CORTACTIN (WEED)

B. MYOSIN ISOFORMS (WYSOLMERSKI)

C. FAK (SCHALLER)

D. ANKYRIN-G (FRISCH)

2. EMT can affect cell-matrix and cell-cell tension, with importantcellular responses

Figure 3. Deflection images of alveolar epithelial cells measured by atomicforce microscopy. A549 cells were grown on chamber slides and treated withTGF-β1 (5 ng/ml) for 48 h. Cells were then fixed using a mixture ofparaformaldehyde and glutaraldehyde. Images were acquired using acantilever with 2.8 N/m spring constant in PBS buffer at room temperature.(A-D)Visualization of the cell ultrastructure revealed numerous distinctfilamentous structures (arrows) in those cells treated with TGF-β1 on glass(B) or on collagen I (D), representative of F-actin stress fibers. In contrast,untreated cells (A,C) exhibited indistinct filament arrangements. Imagesshown are representative data of 3 independent experiments. Bars 10 μm.

Approaches for investigating intercellular forces and mechanosensing through cell surface adhesion proteins. (a) In traction force microscopy,fluorescent particles embedded in soft gels serve as fiduciary markers to quantify the traction force exerted by attached cells. Bead displacementmaps are converted to local traction forces, which are represented in heat maps (b), which indicate cell traction force distributions. Here, two cells arein contact, and the cell boundary is indicated in (a) and (b) (from [27]). (c) Micro-arrays of elastomeric pillars are used to determine cell tractions fromthe cell-induced deflections of the pillars. Figures c and d show two adhering cells on the array. (d) Between cell doublets constrained to a bowtiepattern on the array, increases in the net force at the cell–cell contact correlated with an increase in the size of the intercellular junction, indicated by bcatenin(green) (from [29]). (e) In magnetic twisting cytometry (MTC), cadherin-modified beads are attached to the cell surfaces. (f) The magnetizedbeads are subject to an orthogonal, oscillating magnetic field, H, which induces a torque, T, on the bead. The amplitude of the resulting beaddisplacement, D, reflects the stiffness of the bead-cell-cytoskeletal linkage.Current Opinion in Cell Biology 2011, 23:523–530 www.sciencedirect.com

Transcriptional crosstalk between TGF-β and stem cell pathways in tumor cell invasion

Jonas Fuxe,1,* Theresa Vincent2 and Antonio Garcia de Herreros

Cell Cycle 9:12, 2363-2374; June 15, 2010

Invasion genes (?)Anoikis-resistance genes (?)

Targets of miR-200c mediate suppression of cell motility and anoikis resistanceErin N Howe, Dawn R Cochrane and Jennifer K Richer

Howe et al. Breast Cancer Research 2011, 13:R45 http://breast-cancer-research.com/content/13/2/R45

They guessed MoesinWas important from microarray.

Turned out to be right.

But a functional screen would be morepowerful!

Cancer Metastasis Rev. 2009 Jun;28(1-2):15-33. EMT, the cytoskeleton, and cancer cell invasion. Yilmaz M, Christofori G.

Cancer Cell 19, 372–386, March 15, 2011

TwistPDGRinvadopodiainvasion

Other stuff

HOW DOES EMT TRANSLATE INTO INCREASED MIGRATION/INVASION?

--HOW DOES EMT ALTER CELL-CELL OR CELL-MATRIX ADHESIONS AND THETENSION THEY PRODUCE? (LEGLEITER, WYSOLMERSKI, SCHALLER)

--DO SPECIFIC EMT-REGULATORY GENES(RUPPERT—KLF4, GLI, TGF-B; FRISCH—ZEB1, GRHL2; CTBP, TGF-B; IVANOV—ZEB1)

AFFECT CELL STRUCTURES(WYSOLMERSKI, LEGLEITER—CYTOSKELETON; SCHALLER—FOCAL ADHESIONS; WEED—INVADOPODIA,LAMELLIPODIA; FRISCH-CELL JUNCTIONS)

OR MAYBE EVEN OUR FAVORITE PROTEINS WITHIN THESE STRUCTURES:(WEED—SRC, ABL, CORTACTIN; WYSOLMERSKI—MYOSIN; SCHALLER—FAK; FRISCH--ANKYRIN)

WE CAN FIND OUT THROUGH COLLABORATIONS

…AND PUBLISH SOME INTERESTING PAPERS

(THE FIRST STEP TOWARD FUNDING)

Nature Reviews Molecular Cell Biology 12, 308-319 (May 2011) | doi:10.1038/nrm3112

Balancing forces: architectural control of mechanotransduction

Christopher C. DuFort1, Matthew J. Paszek1 & Valerie M. Weaver

J Mammary Gland Biol Neoplasia. 2011 Sep;16(3):205-19. Epub 2011 Aug 7.Mechanisms by which the extracellular matrix and integrin signaling act to regulate the switch between tumor suppression and tumor promotion.Keely PJ.

Growth control by intracellular tension and extracellular stiffness.

Assoian RK, Klein EA.

Trends Cell Biol. 2008 Jul;18(7):347-52. Epub 2008 May 29. Review.

Tensional homeostasis and the malignant phenotype.

Paszek MJ, Zahir N, Johnson KR, Lakins JN, Rozenberg GI, Gefen A, Reinhart-King CA, Margulies SS, Dembo M, Boettiger D, Hammer DA, Weaver VM.

Cancer Cell. 2005 Sep;8(3):241-54.

Mechanotransduction at cadherin-mediated adhesions Deborah E Leckband1, Quint le Duc2, Ning Wang3 and Johan de Rooij Current Opinion in Cell Biology 2011, 23:523–530

Cancer Metastasis Rev. 2009 Jun;28(1-2):15-33.EMT, the cytoskeleton, and cancer cell invasion.Yilmaz M, Christofori G.