摘要
Most cell culture systems grow and spread as contact-inhibited monolayers on flat culture dishes, but the embryonic stem cell (ES C) is one of the cell phenotypes that prefer to self-organize as tightly packed three-dimensional (3D) colonies. ES C also readily form 3D cell aggregates, called embryoid bodies (EB) that partially mimic the spatial and temporal processes of the developing embryo. Here, the rationale for ES C aggregation, rather than "spreading" on gelatin-coated or mouse embryonic fibroblast (MEF)-coated dishes, is examined through the quantification of the expression levels of adhesion molecules on ES C and the calculation of the adhesive forces on ES C. Modeling each ES C as a dodecahedron, the adhesive force for each ES C-ES C binding was found to be 9.1 × 10 5 pN, whereas, the adhesive force for ES C-MEF binding was found to be an order of magnitude smaller at 7.9 × 10 4 pN. We also show that E-cadherin is the dominating molecule in the ES C-ES C adhesion and blocking E-cadherin leads to a significant reduction in colony formation. Here, we mathematically describe the preference for ES C to self-assemble into ES C-ES C aggregates and 3D colonies, rather than to bind and spread on gelatin or MEF-coated dishes, and have shown that these interactions are predominantly due to E-cadherin expression on ESC. © 2011 Landes Bioscience.