Communication between the epithelial and stromal tissue layers, separated by basement membrane, is known to provide the information necessary for development, differentiation, and homeostasis. These interactions are altered in benign or malignant diseases, in particular when the basement membrane barrier is disrupted allowing a greater proximity between the two cell layers that triggers tissue remodeling. Epithelial–stromal interactions (ESI) have been examined in vitro by various approaches that can be broadly divided into interactions arising from secreted diffusible factors and interactions through direct cell–cell contact. Here we describe a method for the study of direct ESI through CD147, an adhesion molecule present on the epithelial cell surface and which is known to interact with stromal cells, such as fibroblasts and endothelial cells, and signal them to increase production of matrix metalloproteinases. This method can be extended to other adhesion molecules involved in ESI.
