Studies on coexistence and intercellular communication. Scanning electron microscopy for early stages of co-culturing of normal mesothelial cells and mouse ascites tumor cells in vitro.

Mouse ascites tumor cells (MAT-cells) were co-cultured with mesothelial cells of the mouse. During early stages of coexistence (30-60 min) the mesothelial cells show fingerlike protrusions formed mostly at their flanks pointing towards MAT-cells in the neighbourhood. Obviously there is a directional response of the mesothelial cells to the existence of MAT-cells. The mesothelial cells are the most active partner at the beginning of coexistence. Later on MAT-cells also develop fingerlike protrusions which grow towards the mesothelial cells. A network of fingerlike protrusions is formed in the region between MAT-cells and mesothelial cells when they come near to each other. The advantages of the system serving as a model for investigations on intercellular communication are discussed.