@article {276, title = {Molecular profiling of prostatic acinar morphogenesis identifies PDCD4 and KLF6 as tissue architecture-specific prognostic markers in prostate cancer.}, journal = {Am J Pathol}, volume = {182}, year = {2013}, month = {2013 Feb}, pages = {363-74}, abstract = {

Histopathological classification of human prostate cancer (PCA) relies on the morphological assessment of tissue specimens but has limited prognostic value. To address this deficiency, we performed comparative transcriptome analysis of human prostatic acini generated in a three-dimensional basement membrane that recapitulates the differentiated morphological characteristics and gene expression profile of a human prostate glandular epithelial tissue. We then applied an acinar morphogenesis-specific gene profile to two independent cohorts of patients with PCA (total n = 79) and found that those with tumors expressing this profile, which we designated acini-like tumors, had a significantly lower risk of postoperative relapse compared with those tumors with a lower correlation (hazard ratio, 0.078; log-rank test P = 0.009). Multivariate analyses showed superior prognostic prediction performance using this classification system compared with clinical criteria and Gleason scores. We prioritized the genes in this profile and identified programmed cell death protein 4 (PDCD4) and Kruppel-like factor 6 (KLF6) as critical regulators and surrogate markers of prostatic tissue architectures, which form a gene signature that robustly predicts clinical prognosis with a remarkable accuracy in several large series of PCA tumors (total n = 161; concordance index, 0.913 to 0.951). Thus, by exploiting the genomic program associated with prostate glandular differentiation, we identified acini-like PCA and related molecular markers that significantly enhance prognostic prediction of human PCA.

}, keywords = {Acinar Cells, Aged, Apoptosis Regulatory Proteins, Cell Differentiation, Epithelial Cells, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Humans, Kruppel-Like Transcription Factors, Male, Middle Aged, Morphogenesis, Organ Specificity, Prognosis, Prostate, Prostatic Neoplasms, Proto-Oncogene Proteins, Recurrence, RNA-Binding Proteins, Tumor Markers, Biological}, issn = {1525-2191}, doi = {10.1016/j.ajpath.2012.10.024}, author = {Li, Chi-Rong and Su, Jimmy J-M and Wang, Wei-Yu and Lee, Michael T-L and Wang, Ting-Yun and Jiang, Kuan-Ying and Li, Chein-Feng and Hsu, Jong-Ming and Chen, Chi-Kuan and Chen, Marcelo and Jiang, Shih-Sheng and Weaver, Valerie M and Tsai, Kelvin K-C} } @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 {356, title = {SWI/SNF chromatin remodeling enzyme ATPases promote cell proliferation in normal mammary epithelial cells.}, journal = {J Cell Physiol}, volume = {223}, year = {2010}, month = {2010 Jun}, pages = {667-78}, abstract = {

The ATPase subunits of the SWI/SNF chromatin remodeling enzymes, Brahma (BRM) and Brahma-related gene 1 (BRG1), can induce cell cycle arrest in BRM and BRG1 deficient tumor cell lines, and mice heterozygous for Brg1 are pre-disposed to breast tumors, implicating loss of BRG1 as a mechanism for unregulated cell proliferation. To test the hypothesis that loss of BRG1 can contribute to breast cancer, we utilized RNA interference to reduce the amounts of BRM or BRG1 protein in the nonmalignant mammary epithelial cell line, MCF-10A. When grown in reconstituted basement membrane (rBM), these cells develop into acini that resemble the lobes of normal breast tissue. Contrary to expectations, knockdown of either BRM or BRG1 resulted in an inhibition of cell proliferation in monolayer cultures. This inhibition was strikingly enhanced in three-dimensional rBM culture, although some BRM-depleted cells were later able to resume proliferation. Cells did not arrest in any specific stage of the cell cycle; instead, the cell cycle length increased by approximately 50\%. Thus, SWI/SNF ATPases promote cell cycle progression in nonmalignant mammary epithelial cells.

}, keywords = {Adenosine Triphosphatases, Basement Membrane, Cell Cycle, Cell Line, Cell Proliferation, Chromatin Assembly and Disassembly, DNA Helicases, Doxycycline, Epithelial Cells, Female, Gene Knockdown Techniques, Humans, Mammary Glands, Human, Nuclear Proteins, Protein Subunits, RNA, Small Interfering, RNA, Small Nucleolar, Transcription Factors, Up-Regulation}, issn = {1097-4652}, doi = {10.1002/jcp.22072}, author = {Cohet, Nathalie and Stewart, Kathleen M and Mudhasani, Rajini and Asirvatham, Ananthi J and Mallappa, Chandrashekara and Imbalzano, Karen M and Weaver, Valerie M and Imbalzano, Anthony N and Nickerson, Jeffrey A} } @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 {396, title = {Biomechanical regulation of cell orientation and fate.}, journal = {Oncogene}, volume = {27}, year = {2008}, month = {2008 Nov 24}, pages = {6981-93}, abstract = {

Biomechanical regulation of tumor phenotypes have been noted for several decades, yet the function of mechanics in the co-evolution of the tumor epithelium and altered cancer extracellular matrix has not been appreciated until fairly recently. In this review, we examine the dynamic interaction between the developing epithelia and the extracellular matrix, and discuss how similar interactions are exploited by the genetically modified epithelium during tumor progression. We emphasize the process of mechanoreciprocity, which is a phenomenon observed during epithelial transformation, in which tension generated within the extracellular microenvironment induce and cooperate with opposing reactive forces within transformed epithelium to drive tumor progression and metastasis. We highlight the importance of matrix remodeling, and present a new, emerging paradigm that underscores the importance of tissue morphology as a key regulator of epithelial cell invasion and metastasis.

}, keywords = {Animals, Biochemical Processes, Bioreactors, Cell Culture Techniques, Cell Differentiation, Cell Movement, Cell Polarity, Cell Transformation, Neoplastic, Embryonic Development, Epithelial Cells, Humans, Mechanotransduction, Cellular, Models, Biological, Neoplasm Metastasis}, issn = {1476-5594}, doi = {10.1038/onc.2008.348}, author = {Lopez, J I and Mouw, J K and Weaver, V 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} } @article {521, title = {The tissue microenvironment as an epigenetic tumor modifier.}, journal = {Methods Mol Biol}, volume = {223}, year = {2003}, month = {2003}, pages = {315-47}, keywords = {Animals, Breast Neoplasms, Cell Adhesion, Cell Nucleus, Dimerization, Epithelial Cells, Genes, Tumor Suppressor, Humans, Keratinocytes, Models, Biological, Neoplasm Metastasis, Neoplasms, Neovascularization, Pathologic, Phenotype, Promoter Regions, Genetic, Signal Transduction, Time Factors}, issn = {1064-3745}, doi = {10.1385/1-59259-329-1:315}, author = {Unger, Meredith and Weaver, Valerie M} } @article {531, title = {beta4 integrin-dependent formation of polarized three-dimensional architecture confers resistance to apoptosis in normal and malignant mammary epithelium.}, journal = {Cancer Cell}, volume = {2}, year = {2002}, month = {2002 Sep}, pages = {205-16}, abstract = {

Tumor cells can evade chemotherapy by acquiring resistance to apoptosis. We investigated the molecular mechanism whereby malignant and nonmalignant mammary epithelial cells become insensitive to apoptosis. We show that regardless of growth status, formation of polarized, three-dimensional structures driven by basement membrane confers protection to apoptosis in both nonmalignant and malignant mammary epithelial cells. By contrast, irrespective of their malignant status, nonpolarized structures are sensitive to induction of apoptosis. Resistance to apoptosis requires ligation of beta4 integrins, which regulates tissue polarity, hemidesmosome formation, and NFkappaB activation. Expression of beta4 integrin that lacks the hemidesmosome targeting domain interferes with tissue polarity and NFkappaB activation and permits apoptosis. These results indicate that integrin-induced polarity may drive tumor cell resistance to apoptosis-inducing agents via effects on NFkappaB.

}, keywords = {Apoptosis, Basement Membrane, Breast Neoplasms, Cell Polarity, Epithelial Cells, Extracellular Matrix, Female, Gene Expression Regulation, Neoplastic, Humans, Integrin beta4, NF-kappa B, Tumor Cells, Cultured}, issn = {1535-6108}, author = {Weaver, Valerie M and Leli{\`e}vre, Sophie and Lakins, Johnathon N and Chrenek, Micah A and Jones, Jonathan C R and Giancotti, Filippo and Werb, Zena and Bissell, Mina J} } @article {541, title = {Tumour-stromal interactions. Integrins and cell adhesions as modulators of mammary cell survival and transformation.}, journal = {Breast Cancer Res}, volume = {3}, year = {2001}, month = {2001}, pages = {224-9}, abstract = {

Stromal-epithelial interactions modulate mammary epithelial cell (MEC) growth and apoptosis by influencing cell adhesion and tissue organization. Perturbations in the mammary stroma and cell adhesion characterize breast tumors and underlie the altered tissue organization, disrupted tissue homeostasis and enhanced survival phenotype of the disease. Apoptosis resistance likely arises during malignant transformation via genetic and epigenetic modification of cell adhesion pathways induced by a changing tissue microenvironment. Acquisition of adhesion-linked survival networks that enhance MEC viability in the absence of basement membrane interactions probably promote malignant transformation, and may render breast tumors sufficiently resistant to exogenous apoptotic stimuli to generate multidrug resistance.

}, keywords = {Apoptosis, Basement Membrane, Breast Neoplasms, Cell Adhesion Molecules, Cell Communication, Cell Differentiation, Cell Survival, Cell Transformation, Neoplastic, Drug Resistance, Multiple, Epithelial Cells, Female, Gene Expression Regulation, Neoplastic, Humans, Integrins, Stromal Cells}, issn = {1465-5411}, author = {Chrenek, M A and Wong, P and Weaver, V M} } @article {551, title = {Reciprocal interactions between beta1-integrin and epidermal growth factor receptor in three-dimensional basement membrane breast cultures: a different perspective in epithelial biology.}, journal = {Proc Natl Acad Sci U S A}, volume = {95}, year = {1998}, month = {1998 Dec 8}, pages = {14821-6}, abstract = {

Anchorage and growth factor independence are cardinal features of the transformed phenotype. Although it is logical that the two pathways must be coregulated in normal tissues to maintain homeostasis, this has not been demonstrated directly. We showed previously that down-modulation of beta1-integrin signaling reverted the malignant behavior of a human breast tumor cell line (T4-2) derived from phenotypically normal cells (HMT-3522) and led to growth arrest in a three-dimensional (3D) basement membrane assay in which the cells formed tissue-like acini (14). Here, we show that there is a bidirectional cross-modulation of beta1-integrin and epidermal growth factor receptor (EGFR) signaling via the mitogen-activated protein kinase (MAPK) pathway. The reciprocal modulation does not occur in monolayer (2D) cultures. Antibody-mediated inhibition of either of these receptors in the tumor cells, or inhibition of MAPK kinase, induced a concomitant down-regulation of both receptors, followed by growth-arrest and restoration of normal breast tissue morphogenesis. Cross-modulation and tissue morphogenesis were associated with attenuation of EGF-induced transient MAPK activation. To specifically test EGFR and beta1-integrin interdependency, EGFR was overexpressed in nonmalignant cells, leading to disruption of morphogenesis and a compensatory up-regulation of beta1-integrin expression, again only in 3D. Our results indicate that when breast cells are spatially organized as a result of contact with basement membrane, the signaling pathways become coupled and bidirectional. They further explain why breast cells fail to differentiate in monolayer cultures in which these events are mostly uncoupled. Moreover, in a subset of tumor cells in which these pathways are misregulated but functional, the cells could be \"normalized\" by manipulating either pathway.

}, keywords = {Antigens, CD29, Basement Membrane, Breast, Cell Line, Epithelial Cells, Female, Humans, Protein Binding, Protein Conformation, Receptor, Epidermal Growth Factor}, issn = {0027-8424}, author = {Wang, F and Weaver, V M and Petersen, O W and Larabell, C A and Dedhar, S and Briand, P and Lupu, R and Bissell, M J} } @article {546, title = {Structural cues from the tissue microenvironment are essential determinants of the human mammary epithelial cell phenotype.}, journal = {J Mammary Gland Biol Neoplasia}, volume = {3}, year = {1998}, month = {1998 Apr}, pages = {201-13}, abstract = {

Historically, the study of normal human breast function and breast disorders has been significantly impaired by limitations inherent to available model systems. Recent improvements in human breast epithelial cell lines and three-dimensional (3-D)3 culture systems have contributed to the development of in vitro model systems that recapitulate differentiated epithelial cell phenotypes with remarkable fidelity. Molecular characterization of these human breast cell models has demonstrated that normal breast epithelial cell behavior is determined in part by the precise interplay that exists between a cell and its surrounding microenvironment. Recent functional studies of integrins in a human model system provide evidence to support the idea that the structural stability afforded by integrin-mediated cell-extracellular matrix interactions is an important determinant of normal cellular behavior, and that alterations in tissue structure can give rise to tumorigenic progression.

}, keywords = {Breast, Breast Neoplasms, Cell Line, Epithelial Cells, Extracellular Matrix, Female, Humans, Integrins, Models, Biological}, issn = {1083-3021}, author = {Schmeichel, K L and Weaver, V M and Bissell, M J} }