Human placenta contains an epithelial scatter protein.

Scatter factor (SF) is a protein produced by cultured fibroblasts which causes epithelia to "scatter" into isolated cells. We found significant scatter activity in vivo in second trimester (but not term) human amniotic fluid and in human placenta. Placental SF was purified 500,000-fold and identified as a protein with Mr 78 kd. Factor scattered Madin-Darby canine kidney and human squamous carcinoma cells at 15 pM. Amino acid sequences from tryptic peptides did not match any known protein. Human placental fibroblasts produced high titers of scatter activity. SF may be involved in development and may enhance carcinoma invasion.