Tyler Davis
Factors necessary to produce basoapical polarity in human glandular epithelium formed in
conventional and high-throughput three-dimensional culture: example of the breast
epithelium
It is crucial to have apical basal polarity in epithelia because of its ability to provide
control and protection for epithelial tissue. By having three-dimensional culture models that
reproduce epithelial tissue will help reveal the development of disease mechanisms. Apical basal
polarity (the differences in the shape, structure, and function of cells) establishment has already
been discovered; they now must research more on apical polarity in the three-dimensional
cultures because it has not been thoroughly investigated.
The apical polarity three-dimensional culture method was developed to help bring better
insight into high content screenings of agents that react with mammary tissue homeostasis, thus
resulting in steps towards understanding cancer and finding a cure.
Non-neoplastic human mammary HMT-3522 S1 cells and epithelial cells were cultured
at 37 degrees C in 5% CO2 and changed every two to three days. After that they began to make
the HTP (High Throughput) cultures. They plated 50,000 S1 cells per well of glass in four-well
chamber slides. After five minutes, 200 ul of H14 medium containing 4, 10, 20 and 40%
Matrigel were added to each well. After placing the coverslips at the bottom of a 12 well-plate,
cells were plated at a density of 89,000 cells and cultured in H14 medium supplemented with 1x
penicillin/streptomycin.
They discovered that the human mammary epithelial cell line-3522 S1 provides a
resilient model for studying the formation of basoapical polarity in glandular structures. By
testing three-dimensional culture systems revealed that apical basal polarity is more sensitive to
culture conditions than basal polarity. Using the new high-throughput culture method showed
that apical polarity-mediated signaling and collagen IV are both necessary for development of
apical polarity. By using that method it provided a new insight into the role of the basement
membrane and collagen IV in the development of the apical polarity. It also opened more insight
into high-content screenings of agents that act on mammary tissue homeostasis and cancer
development.
The analysis of the different methods of culture of human mammary epithelial cells
demonstrated that the development of apical polarity in tissue structures is more sensitive to
culture conditions. The molecular mechanism underlying the lack of apical polarity formation in
CBL (chicken basal lamina) cultures still remains to be understood. The function blocking
antibodies directed towards the integrin’s discredit the importance of the tissue context for the
response to ECM alterations. These experiments illustrate the impact of tissue architecture and
the organization of the signaling network. By having HTP cultures it should now be possible to
obtain large numbers of polarized tissue to perform measurements for large amounts of cell
material.