Figure 2

Three-dimensional culture method versus rotary culture. The methods shown utilize isolated purified human breast luminal and myoepithelial cells from reduction mammoplasty. In the three-dimensional culture method, coculture of purified luminal and myoepithelial cells in collagen I gel results in the formation of two different types of structures. The majority are (a) a single layer of cells that form acinar structures in which the secretion of laminin-1 by surrounding myoepithelial cells signals to luminal cells to polarize correctly, and the minority are (b) double layer acinar structures that are more reflective of the acinus in vivo. Gudjonsson and coworkers [15] showed that myoepithelial cells were able to induce correct luminal polarity via the synthesis of the basement membrane (BM) component laminin-1. In contrast, in the (c) rotary culture method, purified luminal and myoepithelial cells are grown in suspension. Acinar structures form, albeit at a smaller size compared with the three-dimensional method. Runswick and coworkers [5] showed that blocking desmosome adhesion via blocking peptides inhibited acinar formation.