THE C-ETS1 PROTOONCOGENE IS EXPRESSED IN HUMAN TROPHOBLAST DURING THEFIRST-TRIMESTER OF PREGNANCY

Expression of the c-Ets1 protooncogene which codes for a transcription factor is associated with neovascularization and invasive processes. In order to determine c-Ets1 expression at the mRNA level, during the process of implantation during the first trimester of human pregnancy, samples of trophoblast were retrieved at the time of legal abortion a nd processed for in situ hybridization. We found that c-Ets1 mRNAs are transcribed in the endothelial cells of villous trophoblast and in th e extravillous trophoblastic cells invading the uterine vessels. Howev er, no transcript was found in maternal endothelial cells. We conclude that c-Ets1 plays a role in angiogenesis occurring in the development of the villous tree and is involved during the invasive process of th e endometrium and maternal vessels by trophoblastic cells; this latter physiological event is crucial for a normal development of the fetus, its failure leading to pathological cases. We suggest that the role o f the c-Ets1 protoncogene is related to the regulation of metalloprote inase genes transcription, a gene family which is known to be a target for Ets protein. (C) 1997 Elsevier Science Ireland Ltd.