IMMUNOLOCALIZATION OF BASIC FIBROBLAST GROWTH-FACTOR (BFGF) IN GROWING AND GROWTH-INHIBITED PLACENTAL CELLS - A POSSIBLE ROLE FOR BFGF IN PLACENTAL CELL-DEVELOPMENT

The distribution of basic (b) fibroblast growth factor (FGF) in growing and growth-arrested human placental tumour cells, as well as normal placental villous trophoblasts, was studied by immunofluorescence microscopy with antibodies to the amino terminus of bFGF. Placenta (JAR, JEG-3), breast (MCF-7, T-47D), cervix (HeLa) and uterine (HEC-1 A) tumour cells showed the same two patterns after immunofluorescent staining with antibodies to bFGF: (i) a perinuclearpattern and (ii) an intense homogeneous staining ofthe nucleus and cytoplasm. The homogeneous bFGF staining pattern was associatedpredominantly with actively dividing cells, observed at different stages of mitosis and cytokinesis. Placental (YEG-3) cell division was inhibited with methotrexate (MTX), a chemotherapeutic agent used in the treatment of placental tumours. MTX-treated fEG-3 cells as well as 'normal' non proliferatioe placental (syncytiotrophoblast) cells from term placentae, showed perinuclear staining with antibodies to bFGF and immunofluorescence microscopy. The nuclear localization of bFGF in dividing but not non-dividing placental cells, suggests a role for bFGF in cytotrophoblast proliferation in vivo. © 1991.