Fig. 2.

An illustration of the different levels through which ECM controls gene expression and tissue function. As cells transition from a 2D monolayer to a 3D environment, they undergo changes in cell shape that influence the expression of certain genes. Exposure to ECM engages specific cell surface receptors and initiates the transduction of biochemical and mechanical signals through the cell to the nucleus, where they further influence gene expression. As the duration of exposure time to ECM increases, cells undergo morphogenic events involving the formation of acinar structures and once again exhibit changes in their gene expression profile. Thus, tissue structure influences gene expression and, therefore, dictates tissue function. (Modified, with permission, from Bissell et al., 1999, 2005; Roskelley et al., 1995.) (See Color Insert.)