[Does oncogene c-ets 1 participate in the regulation of tumor angiogenesis?].

The formation of new blood vessels is an essential process in embryonic development and wound healing, for tumor growth and metastasis. In situ hybridization studies have revealed that the protooncogene c-est1 is expressed in endothelial cells at the beginning of blood vessel formation, in normal and pathological conditions. c-ets1 encodes a transcription factor, a protein which binds specifically to DNA and which regulates the transcription of genes containing these specific binding sequences in their promotors. Thus, in vitro experiments suggest that c-ets1 may activate the transcription of genes encoding collagenase 1, stromelysine 1 and urokinase plasminogen activator, proteases involved in extracellular matrix degradation. A working hypothesis is that c-ets1 takes part in regulating angiogenesis by controlling the transcription of these genes whose activity is necessary for the migration of endothelial cells from pre-existing capillaries. This hypothesis is discussed with respect to current experimental evidence and to the complexity of the regulatory network controlling gene transcription and extracellular matrix degradation.