The tree-like architecture of the mammary gland is generated by branching morphogenesis, a reiterative process of branch site initiation and tubule invasion from a pre-existing epithelial structure. Branching is controlled by the interplay between positive and negative regulators, defects in either of which can give rise to aberrancies ranging from hyperplasia to malignant growth. Our long term goal is to delineate how these positive and negative signals are integrated spatially within the tissue to determine which cells branch, and thereby define the branching pattern. We have developed a lithography-based three-dimensional organotypic culture model that recapitulates the architecture of mammary epithelial ducts, enables micrometer-resolution control of tissue geometry and microenvironment, and provides quantitative data in a physiologically relevant context. The engineered ducts execute a complete series of morphogenetic events that can be predicted computationally. Using this culture model, we have shown that the position of branching is determined in part by the concentration profile of transforming growth factor (TGF)-21, an autocrine inhibitory morphogen. Furthermore, we have found that cells located in positions that branch up- regulate the expression of mesenchymal markers during morphogenesis. Based on these preliminary and published data, we propose: 1- To investigate the features of the TGF21 concentration profile perceived and transduced by mammary epithelial ducts. 2- To determine the mesenchymal markers differentially expressed during morphogenesis, and whether these are necessary and/or sufficient to define position of branching. We will further test whether the pattern of mesenchymal gene expression is regulated by the TGF21 inhibitory profile. 3- To begin to dissect how branching is regulated by the physical properties of the microenvironment, by determining whether the extracellular matrix alters branching pattern, TGF21 inhibitory concentration profile, or neo-expression of mesenchymal markers. These studies will provide insight into the local cues and gene expression changes that govern position of branching. PROJECT

Public Health Relevance

Cells integrate information from stimulatory and inhibitory signals during branching morphogenesis to develop into the tree-like structure of the mammary gland;disruption or misregulation of these signals can lead to neoplastic growths and eventual development of frank tumors. Here we present studies aimed at understanding how mammary epithelial cells perceive inhibitory signals and translate them into patterned differences in gene expression during branching morphogenesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM083997-05
Application #
8260558
Study Section
Special Emphasis Panel (ZRG1-ICI-D (01))
Program Officer
Hoodbhoy, Tanya
Project Start
2008-05-01
Project End
2014-04-30
Budget Start
2012-05-01
Budget End
2014-04-30
Support Year
5
Fiscal Year
2012
Total Cost
$281,362
Indirect Cost
$95,143
Name
Princeton University
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
002484665
City
Princeton
State
NJ
Country
United States
Zip Code
08544
Pang, Mei-Fong; Siedlik, Michael J; Han, Siyang et al. (2016) Tissue Stiffness and Hypoxia Modulate the Integrin-Linked Kinase ILK to Control Breast Cancer Stem-like Cells. Cancer Res 76:5277-87
Tzou, Daniel; W Spurlin 3rd, James; Pavlovich, Amira L et al. (2016) Morphogenesis and morphometric scaling of lung airway development follows phylogeny in chicken, quail, and duck embryos. Evodevo 7:12
Varner, Victor D; Nelson, Celeste M (2016) Computational models of airway branching morphogenesis. Semin Cell Dev Biol :
Piotrowski-Daspit, Alexandra S; Tien, Joe; Nelson, Celeste M (2016) Interstitial fluid pressure regulates collective invasion in engineered human breast tumors via Snail, vimentin, and E-cadherin. Integr Biol (Camb) 8:319-31
Siedlik, Michael J; Varner, Victor D; Nelson, Celeste M (2016) Pushing, pulling, and squeezing our way to understanding mechanotransduction. Methods 94:4-12
Nelson, Celeste M (2016) On Buckling Morphogenesis. J Biomech Eng 138:021005
Kim, Hye Young; Pang, Mei-Fong; Varner, Victor D et al. (2015) Localized Smooth Muscle Differentiation Is Essential for Epithelial Bifurcation during Branching Morphogenesis of the Mammalian Lung. Dev Cell 34:719-26
Siedlik, Michael J; Nelson, Celeste M (2015) Regulation of tissue morphodynamics: an important role for actomyosin contractility. Curr Opin Genet Dev 32:80-5
Paluch, Ewa K; Nelson, Celeste M; Biais, Nicolas et al. (2015) Mechanotransduction: use the force(s). BMC Biol 13:47
Varner, Victor D; Gleghorn, Jason P; Miller, Erin et al. (2015) Mechanically patterning the embryonic airway epithelium. Proc Natl Acad Sci U S A 112:9230-5

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