Factors necessary to produce basoapical polarity in human glandular epithelium formed in conventional and high-throughput three-dimensional culture: example of the breast epithelium

Cedric Plachot,Lesley S Chaboub,Hibret A Adissu,Lei Wang,Albert Urazaev,Sophie A Lelièvre,Jennifer Sturgis,Elikplimi K Asem

doi:10.1186/1741-7007-7-77

Cedric Plachot, Lesley S Chaboub + Show 6 more

Open Access

https://doi.org/10.1186/1741-7007-7-77

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Abstract

BackgroundBasoapical polarity in epithelia is critical for proper tissue function, and control of proliferation and survival. Cell culture models that recapitulate epithelial tissue architecture are invaluable to unravel developmental and disease mechanisms. Although factors important for the establishment of basal polarity have been identified, requirements for the formation of apical polarity in three-dimensional tissue structures have not been thoroughly investigated.ResultsWe demonstrate that the human mammary epithelial cell line-3522 S1, provides a resilient model for studying the formation of basoapical polarity in glandular structures. Testing three-dimensional culture systems that differ in composition and origin of substrata reveals that apical polarity is more sensitive to culture conditions than basal polarity. Using a new high-throughput culture method that produces basoapical polarity in glandular structures without a gel coat, we show that basal polarity-mediated signaling and collagen IV are both necessary for the development of apical polarity.ConclusionThese results provide new insights into the role of the basement membrane, and especially collagen IV, in the development of the apical pole, a critical element of the architecture of glandular epithelia. Also, the high-throughput culture method developed in this study should open new avenues for high-content screening of agents that act on mammary tissue homeostasis and thus, on architectural changes involved in cancer development.

Highlights

Basoapical polarity in epithelia is critical for proper tissue function, and control of proliferation and survival
A mammary acinus/alveolus is made of an internal and continuous layer of luminal epithelial cells that exert secretory functions and an external and discontinuous layer of myoepithelial cells. Both myoepithelial and luminal epithelial cells make contact with basement membrane (BM) components via integrin dimers, while only luminal cells show the presence of apical tight junctions
The human mammary epithelial cell line, HMT-3522 S1 [13], has been extensively used to study mammary acinar differentiation in 3D culture [1]. They form basoapically polarized acini with tiny lumens when cultured in defined H14 medium [14] (Table 1) in the presence of BM components laminin 111 and collagen IV-rich gel [15], the MatrigelTM used either in solution in the medium with the cells resting on a gel coat (3DMatrigelTM drip culture or 'on-top' assay [16]) or as a thick gel in which cells are totally embedded [1,16] (Additional Methods; Additional Movie 1 see Additional files 1 and 2)

Summary

Introduction

Basoapical polarity in epithelia is critical for proper tissue function, and control of proliferation and survival. Three-dimensional culture permits the study of epithelial cell arrangement into tissue structures, and the investigation of pathways critical for the establishment and maintenance of structural and functional aspects of tissue differentiation. In glandular and tubular epithelial structures, in which epithelial cells are organized as one layer surrounding a lumen, the establishment of apical polarity characterized by the formation of cell-cell adherens and tight junctions accompanies lumen formation [2]. This organization provides a proper functional barrier to regulate vectorial secretion and intake of molecules. The basal cellular pole is characterized by transmembrane integrin dimers that connect cells to specific extracellular matrix (ECM) molecules of the BM [3]

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