EXPRESSION OF VAV PROTOONCOGENE BY NONHEMATOPOIETIC TROPHOBLAST CELLSAT THE HUMAN UTEROPLACENTAL INTERFACE

Vav is a signal transducing molecule containing SH2 and SH3 domains an d a guanine nucleotide releasing factor-like domain. Its expression is thought to be highly specific for hematopoietic cells. Here we descri be the expression of vav transcripts in human nonhematopoietic trophob lasts. By Northern blotting, expression of 2.8-kb vav mRNA was detecte d in human decidual, placental, and chorionic villous tissues and in a choriocarcinoma cell line BeWo. By in situ hybridization, vav mRNA wa s found to be expressed in the cytotrophoblast shell and columns and i n the extravillous trophoblasts in the maternal decidua from the first through third trimesters. Vav mRNA was also detected in villous syncy tiotrophoblasts du ring the second and third, but not the first, trime sters. When 1 mu M oligodeoxynucleotide antisense to the vav mRNA was added to the medium, growth of BeWo cells was significantly inhibited. These results suggest that vav plays an important role for successful implantation and placental development by regulating development of t rophoblasts.