ABSTRACT
The coordination of cell growth and differentiation as well as of tissue homeostasis and synchronization of tissue functions requires the transfer of information between cells. Most investigations on intercellular communication have been performed with cells in monolayer cultures. A possible participation of intercellular communication in tumor invasion discussed under two aspects. These are: advantages resulting from homologous gap-junction coupling between tumor cells, and advantages resulting from heterologous gap-junction coupling between host and tumor cells. Cells that are interconnected by gap junctions in a monolayer culture change their degree of coupling when cultured as multicell spheroids. Cells that are interconnected by gap junctions, when grown as a two-dimensional monolayer, are also coupled when cultivated as a three-dimensional multicell spheroid. Heterologous cultures of embryonic chick heart cells with permanently growing mammalian tumor cells were obtained by seeding tumor cells to subconfluent heart monolayer cultures.
