Immunoexpression of the hepatocyte growth factor (HGF), HGF-receptor (c-met) and STAT3 on placental tissues from malformed fetuses

To characterize the possible relationship between the expression of the HGF/HGF-R system with transcription factor STAT3, responsible for morphogenetic response of HGF stimulation, and the embryonic development alterations, we investigated, by immunohistochemistry, the expression of HGF, c-met and STAT3 in 9 placentas from malformed fetuses and 9 control placentas from non-malformed fetuses. The major and distinct patterns of expression characterizing the placentas from malformed fetuses were a higher percentage mean of stromal cells stained for HGF, c-met and STAT3 antibodies (60%, 66% and 54%, respectively on fibroblast cells and 44%, 57% and 42%, respectively on myofibroblast cells) and a lower percentage mean of cytotrophoblast cells stained for the same antibodies (2%, 2% and 1%, respectively), than in control placentas. In fact, in this latter group, the stromal fibroblast cells were stained in a percentage mean of 27%, 22% and 7%, respectively; the stromal myofibroblast cells in a percentage mean of 5%, 6% and 2%, respectively and the cytotrophoblast cells in a percentage mean of 25%, 34% and 18%, respectively. The expression of each antibody on stromal cells in both groups suggests an alternative role of the HGF/HGF-R system activating the via STAT3 transdution and operating on placental tissues, overall in organogenesis alteration conditions. This immunohistochemical approach could be used in the diagnostic practice of pathologists on chorionic villi biopsy when genetic alterations are absent and ultrasound aspects are doubtful for malformations.