Tissue Models to Study Tumor-Stroma Interactions

The above summarized findings of this laboratory on tumor-stroma interactions, together with a growing number of other reports contribute to the accumulating evidence that the stromal part of epithelial tumors plays a more active role in epithelial tumor development and progression than until recently recognized. The transplantation assay developed by us represents in in vivo system particularly suited to highlight early tumor-stroma interactions and to discriminate tumor stage-dependent characteristics in this interplay. Furthermore, by the unique assembly and geometry of this model the essential role of tumor-stroma interactions for tumor invasion has been documented unimbigously for the first time. Thus, the significance of extracellular matrix composition, stromal protease activity and growth factor interactions for modulating the tumor phenotype has been evidenced in different experimental settings. In addition to the transplantation assay comparable culture systems in vitro provide relevant models to study the mechanistic details of the complex interplay between tumor and stroma cells. These investigations will not only increase our knowledge on the important role of stromal cells in tumor biology, but may yield additional targets for novel therapeutic strategies aiming at genetically normal cells according to the principle of antiangiogenic therapy.