title: Fetal antigen 2 (FA2) in human fetal osteoblasts, cultured osteoblasts and osteogenic osteosarcoma cells.
abstract: Immunohistochemical staining techniques used on an 11-week-old fetus showed that fetal antigen 2 (FA2) was present intracellularly in endochondral and perichondral osteoblasts, and the immunoreaction was extended into the adjacent bone matrix. Osteoclasts and chondroblasts were found to be FA2 negative. A granular perinuclear intracytoplasmic FA2 immunoreaction was found in cultured osteoblasts and osteogenic osteosarcoma cells, and immunoelectron-microscopical examination revealed a granular immunoreaction product in the rough endoplasmic reticulum. These findings indicate that FA2 is synthesized by osteoblasts and osteogenic osteosarcoma cells. A reaction of immunological identity was found between FA2 purified from second trimester amniotic fluid and serum-free supernatants of cultured osteogenic osteosarcoma cells. This shows that an antigen recognized by the anti FA2 antibody is secreted by these malignant cells. Thus, FA2 may represent a marker for altered bone metabolism, and have a potential in the classification of osteogenic osteosarcoma/chondrosarcoma.
authors.affiliation: Department of Human Anatomy, Odense University, Denmark.
authors.forename: D
authors.initials: D
authors.lastname: Tornehave
authors.forename: B
authors.initials: B
authors.lastname: Teisner
authors.forename: H B
authors.initials: HB
authors.lastname: Rasmussen
authors.forename: J
authors.initials: J
authors.lastname: Chemnitz
authors.forename: M
authors.initials: M
authors.lastname: Kassem
mesh_terms: D001842:Bone and Bones / Q000737:chemistry* / Q000166:cytology / Q000196:embryology; D002478:Cells, Cultured; D024042:Collagen Type I; D005326:Fetal Proteins; D005333:Fetus; D006801:Humans; D016253:Microscopy, Immunoelectron; D009363:Neoplasm Proteins / Q000032:analysis*; D010006:Osteoblasts / Q000737:chemistry*; D012516:Osteosarcoma / Q000737:chemistry*; D010446:Peptide Fragments; D011347:Procollagen; D014407:Tumor Cells, Cultured
chemical_list: D024042:Collagen Type I; D005326:Fetal Proteins; D009363:Neoplasm Proteins; D010446:Peptide Fragments; D011347:Procollagen; C047202:procollagen Type I N-terminal peptide