One of the earliest manifestations of malignant progression is loss of tissue organization. This proposal continues to examine the hypothesis that architectural integrity is crucial for maintenance of normal breast function as well as for suppression of neoplasia. We have postulated that elucidation of a """"""""signaling integration plan"""""""" that establishes and maintains polarity and structure within the acini and ducts of breast tissue will uncover prognostic and therapeutically-relevant markers of intermediary steps in malignancy. As such, we postulated and provided evidence that myoepithelial cells (MEPs) provide crucial structural and functional cues to luminal epithelial cells (LEPs) partly via production of, and signaling through, laminin-111 (Ln-1). We further postulated, and now provide additional evidence, that in traditional cell culture conditions, purified LEPs almost immediately develop a hybrid LEP/MEP phenotype acquiring aspects of MEP gene expression and in particular developing the tumor suppressor functions normally conferred in vivo by MEPs and an ability to make acini, which normally requires the presence of MEPs. Consequently, in order to make relevant models for the study of human LEP-MEP interactions we must identify the conditions that instruct these cell types to retain their original functions. Accordingly, we have developed new and versatile microenvironmental arrays (MEArrays) to probe how MEPs and LEPs become, and remain, determined. We now propose to expand our findings in 3 specific aims. We will specifically: 1- identify pathways that allow retention of MEP- and LEP- specific functions in culture using designer MEArrays and designer media. We then could probe the importance of desmosomal proteins and other regulatory molecules in addition to Ln-1 produced by MEPs, in how MEPs and LEPs interact to retain polarity, architecture and function. 2- complete the identification of Ln-1 signaling cascade components for mammary specific functions using inhibitory peptides, blocking antibodies, mutant cells and shRNA ablation in high throughput assays using Cellomics and other devices and designer 3D microenvironments. 3- identify and characterize central players and connections in the 'signaling integration plan'for structural integrity of acini using bioinformatics analysis of gene expression arrays, genome-wide methylation profiles and other changes in chromatin structure, identification of miRNAs affecting cellular architecture, and by positioning the new genes we identified using a unique 3D screen, on our integration map. Collectively these experiments address the importance of MEP/LEP interactions in maintenance of polar acinar structures in breast tissue, and could also provide a proof of principle for other tissues. Since loss of appropriate balance and/or integration of these signals leads to malignancy, our results will both advance fundamental knowledge and yield novel markers for early diagnosis and therapeutic strategies to limit and/or reverse breast tumor progression.

Public Health Relevance

This proposal seeks to define the influences of cellular microenvironments on human breast cells, with particular attention to the effects of myoepithelial and luminal epithelial cells on one another. Building on our studies characterizing the role of the microenvironment in normal human breast morphogenesis, we have repeatedly shown that changes in the microenvironment can cause malignant human breast tumor cells to re-acquire critical attributes of normal cells, and we have specifically demonstrated that myoepithelial cells play a central role in preventing human breast cells from becoming malignant. This proposal continues our research into this important field of inquiry;our results will further common understanding of the complex interactions which serve to contain and even reverse human breast tumors.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Method to Extend Research in Time (MERIT) Award (R37)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-ONC-M (02))
Program Officer
Mohla, Suresh
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Lawrence Berkeley National Laboratory
Organized Research Units
United States
Zip Code
Di Modugno, Francesca; Spada, Sheila; Palermo, Belinda et al. (2018) hMENA isoforms impact NSCLC patient outcome through fibronectin/?1 integrin axis. Oncogene 37:5605-5617
Fiore, Ana Paula Zen Petisco; Spencer, Virginia A; Mori, Hidetoshi et al. (2017) Laminin-111 and the Level of Nuclear Actin Regulate Epithelial Quiescence via Exportin-6. Cell Rep 19:2102-2115
Hines, William C; Kuhn, Irene; Thi, Kate et al. (2016) 184AA3: a xenograft model of ER+ breast adenocarcinoma. Breast Cancer Res Treat 155:37-52
Matsubara, Masahiro; Bissell, Mina J (2016) Inhibitors of Rho kinase (ROCK) signaling revert the malignant phenotype of breast cancer cells in 3D context. Oncotarget 7:31602-22
Mroue, Rana; Inman, Jamie; Mott, Joni et al. (2015) Asymmetric expression of connexins between luminal epithelial- and myoepithelial- cells is essential for contractile function of the mammary gland. Dev Biol 399:15-26
Hines, William C; Yaswen, Paul; Bissell, Mina J (2015) Modelling breast cancer requires identification and correction of a critical cell lineage-dependent transduction bias. Nat Commun 6:6927
Gomes, Angélica Maciel; Bhat, Ramray; Correia, Ana Luísa et al. (2015) Mammary Branching Morphogenesis Requires Reciprocal Signaling by Heparanase and MMP-14. J Cell Biochem 116:1668-79
Lee, Somin Eunice; Chen, Qian; Bhat, Ramray et al. (2015) Reversible Aptamer-Au Plasmon Rulers for Secreted Single Molecules. Nano Lett 15:4564-70
Diamond, Marc I; Cai, Shirong; Boudreau, Aaron et al. (2015) Subcellular localization and Ser-137 phosphorylation regulate tumor-suppressive activity of profilin-1. J Biol Chem 290:9075-86
Schwarz, Richard I (2015) Collagen I and the fibroblast: high protein expression requires a new paradigm of post-transcriptional, feedback regulation. Biochem Biophys Rep 3:38-44

Showing the most recent 10 out of 62 publications