HOW TUMORS ABUSE THEIR HOST - THE TRANSCR IPTION FACTOR C-ETS1 AND THE REGULATION OF TUMOR ANGIOGENESIS AND INVASION

During their progression, epithelial tumors induce a stromal reaction essential for their development and for metastasis. In situ hybridizat ion studies have revealed that the protooncogene c-ets 1 is expressed in endothelial cells at the beginning tumor angiogenesis, and in strom al fibroblasts surrounding invasive tumors. C-ets 1 encodes a transcri ption factor that may activate the transcription of genes encoding col lagenase 1, stromelysin 1 and urokinase plasminogen activator, proteas es involved in extracellular matrix degradation. A working hypothesis is that c-Ets 1 takes part in regulating invasive processes by control ing the transcription of these genes. Experimental evidences that may confirm this hypothesis will be discussed.