Analysis of collective invasion of carcinoma cells in a 3D organotypic model.

Cancer cell invasion and dissemination from primary tumors are complex multistep mechanisms which remain poorly understood. It is now clear that cancer cells can adapt their mode of invasion to the signalling provided by the surrounding stroma. Single and collective cancer cell invasion are the two invasion features most currently observed and described by pathologists. Here we describe a three-dimensional organotypic assay that allows the study of squamous cell carcinoma cell collective invasion induced by the carcinoma associated fibroblasts. This model preserves the relationship between epithelial and mesenchymal cells, which are observed in vivo, and allows to decipher the molecular and cellular mechanisms involving the tumor and its stromal microenvironment. This three-dimensional model of invasion provides an invaluable tool to gain major insights in the understanding of tumor cell dissemination.