  Cells in tissues can organize into a broad spectrum of structures according
to their function. Drastic changes of organization, such as
epithelial-mesenchymal transitions or the formation of spheroidal aggregates,
are often associated either to tissue morphogenesis or to cancer progression.
Here, we study the organization of cell colonies by means of simulations of
self-propelled particles with generic cell-like interactions. The interplay
between cell softness, cell-cell adhesion, and contact inhibition of locomotion
(CIL) yields structures and collective dynamics observed in several existing
tissue phenotypes. These include regular distributions of cells, dynamic cell
clusters, gel-like networks, collectively migrating monolayers, and 3D
aggregates. We give analytical predictions for transitions between noncohesive,
cohesive, and 3D cell arrangements. We explicitly show how CIL yields an
effective repulsion that promotes cell dispersal, thereby hindering the
formation of cohesive tissues. Yet, in continuous monolayers, CIL leads to
collective cell motion, ensures tensile intercellular stresses, and opposes
cell extrusion. Thus, our work highlights the prominent role of CIL in
determining the emergent structures and dynamics of cell colonies.
