Abstract: | Multicellular tumor spheroids (MCTS) are avascular spherical tumors grown systematically out of single cells in vitro. The coculture of MCTS of the human bladder carcinoma cell line J 82 with confluent human endothelial cell layers serves as a model to study cell-cell interactions as an important feature in hematogenous tumor spread. Basic information is obtained by phase contrast microscopy and histochemistry. More detailed information is given by the application of scanning and transmission electron microscopy. Immunohistochemistry helps to differentiate endothelial cells from tumor cells (factor VIII-related antigen). The application of this coculture model and of the various methods of evaluation enables us to study cell-to-cell contact phenomena systematically. |